Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.orglett.3c00876

researchmap

Publishing type：Research paper (scientific journal)   Publisher：World Scientific Pub Co Pte Ltd  

Cyclo[8]pyrrole–phosphonate complexes were synthesized via the anion exchange method from cyclo[8]pyrrole sulfate. The molecular structures were determined by X-ray diffraction studies.

DOI： 10.1142/s1088424623500438

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：World Scientific Pub Co Pte Ltd  

Bicyclo[2.2.2]octadiene(BCOD)-fused 5,15-diazaporphyrins were synthesized via a metal-template aza-annulation of dipyrrin-metal complexes as a soluble precursor of tetrabenzodiazaporphyrin. 10-Azacorrole copper complex with a meso-imine bridge was serendipitously obtained via the same reaction using dimethylBCOD-fused dipyrrin-copper complex.

DOI： 10.1142/s1088424623500074

researchmap

Publishing type：Research paper (scientific journal)   Publisher：World Scientific Pub Co Pte Ltd  

DOI： 10.1142/s1088424622500869

researchmap

Publishing type：Research paper (scientific journal)   Publisher：World Scientific Pub Co Pte Ltd  

DOI： 10.1142/s1088424622500900

researchmap

Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry (RSC)  

Tropo(thio)ne-embedded homoHPHACs and their dications were synthesised by an electrophilic annulation of secoHPHAC and successive oxidation. 13C NMR spectra of the dications represented global 22π homoaromaticity via homoconjugation, while alkylation...

DOI： 10.1039/d1cc07152a

researchmap

Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.orglett.1c03882

researchmap

Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

DOI： 10.1021/acs.orglett.1c03669

researchmap

Publishing type：Research paper (scientific journal)  

Cyclo[9]pyrrole, a ring-expanded porphyrin without meso-bridges and having an odd number of pyrroles, was synthesized via the oxidative coupling of 2,2′:5′,2″-terpyrrole. X-ray crystallography showed a C2-like symmetry with a large root-mean-square deviation. The optical properties and electronic structures were analyzed using magnetic circular dichroism spectroscopy and time-dependent density functional theory calculations.

DOI： 10.1021/acs.orglett.1c00899

Scopus

PubMed

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)  

A hexapyrrolohexaazacoronene (HPHAC) with 12 less-bulky peripheral ethyl groups than its aryl-containing HPHAC counterpart was synthesized to investigate the innate character of HPHAC. X-ray diffraction analysis revealed that HPHAC had a planar structure and close packing because of CH-πinteractions between the alkyl groups and the HPHAC core. Compared to the previously reported HPHAC decorated with 12 peripheral aryl groups, this electron-rich π-system exhibited reversible multistep oxidations at low potentials and easily formed mono- and dicationic salts and charge-transfer (CT) complexes with 7,7,8,8-tetracyano-p-quinodimethane. These oxidized species exhibited clear changes in the bond-length alternation of the pyrrole units in the crystal state, indicating charge and spin delocalization. The distinct upfield shift of the central carbon signal of the dication in the 13C NMR spectrum affirms the global aromaticity from the viewpoint of a magnetic criterion. In the UV-vis/NIR spectra, broad absorption in the NIR region was observed only for HPHAC2+ and not the structurally similar cyclo[6]pyrrole. Magnetic circular dichroism measurements and time-dependent density functional theory calculations revealed that the broad absorption was assigned to the CT transition from the central benzene ring to the outer pyrrole rings.

DOI： 10.1021/acs.joc.0c03042

Scopus

researchmap

Authorship：Last author,　Corresponding author   Publishing type：Research paper (scientific journal)  

Radially π-extended hexapyrrolohexaazacoronene (HPHAC 2) was synthesized in two steps with 2,5-di-tert-butyl-acenaphtho[1,2-c]pyrrole and hexafluorobenzene. Like its parent HPHAC 1a, 2 exhibited reversible oxidation behavior. Crystal structures of not only the neutral and dicationic compounds but also the radical cation were all revealed. While analyzing its peculiar structure, the formation of a 1:1 complex with C60 was observed in solution by NMR and absorption analyses. The spectroscopic analyses of 2 and 1a were performed based on magnetic circular dichroism and theoretical calculations.

DOI： 10.1021/acs.joc.0c02825

Scopus

researchmap

Publishing type：Research paper (scientific journal)  

Here we report a highly stable 16π-electron antiaromatic system based on the ligand-oxidized Cu(ii)-tetrabenzocorrole. The antiaromaticity of the monocationic corrole complex was elucidated with the unique bond length alternation pattern of the crystal structure and the spectral diagnostic features. The NICS and GIMIC calculations clearly depicted its inner 15-membered-ring main pathway with a strong paratropic ring current. This journal is

DOI： 10.1039/d0cc06703b

Scopus

PubMed

researchmap

Publishing type：Research paper (scientific journal)  

Bicyclo[2.2.2]octadiene(BCOD)-fused dithiaamethyrin 4 was synthesized via a "3+3"condensation method. Thermal conversion of the BCOD moieties afforded tetrabenzodithiaamethyrin 5. The highly planar structures of 4 and 5 were confirmed by X-ray diffraction studies. The 1H NMR, absorption and MCD spectra, together with TD-DFT calculations revealed that both BCOD-fused and -extended dithiaamethyrins have a 24 antiaromatic character.

DOI： 10.1142/S1088424621500966

Scopus

researchmap

Authorship：Last author,　Corresponding author   Publishing type：Research paper (scientific journal)  

Introduction of functional groups on a -conjugated system is one of the most promissing methods to modulate their chemical and physical properties. Here, dinitrohexapyrrolohexaazacoronene (dinitroHPHAC) was synthesized, in which two nitro groups are introduced at the same pyrrole ring. The dinitroHPHAC possesses a large dipole moment (μ = 11.7 D at B3LYP/6-31G(d,p)) and showed solvatochromism with decreased HOMO-LUMO energy gap. Interestingly, the colour of the solid is black to the naked eye. The global aromaticity of the dication state is decreased compared with those of pristine HPHAC and mononitroHPHAC.

DOI： 10.1142/S108842462150098X

Scopus

researchmap

Authorship：Last author   Publishing type：Research paper (scientific journal)  

Symmetrical octaphenyltetrabenzoporphyrins 3 were synthesized via cyclotetramerization from bicyclo[2.2.2]octadiene (BCOD)-fused pyrrole, followed by a thermal conversion based on retro DielsAlder reaction. X-ray diffraction analysis revealed that the zinc complex 3b had C4h symmetry.

DOI： 10.1246/CL.210045

Scopus

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society (ACS)  

Performing bottom-up synthesis by using molecules adsorbed on a surface is an effective method to yield functional polycyclic aromatic hydrocarbons (PAHs) and nanocarbon materials. The intramolecular cyclodehydrogenation of hydrocarbons is a critical process in this synthesis; however, thus far, its elementary steps have not been elucidated thoroughly. In this study, we utilize the metal tip of a low-temperature noncontact atomic force microscope as a manipulable metal surface to locally activate dehydrogenation for PAH-forming cyclodehydrogenation. This method leads to the dissociation of a H atom of an intermediate to yield the cyclodehydrogenated product in a target-selective and reproducible manner. We demonstrate the metal-tip-catalyzed dehydrogenation for both benzenoid and nonbenzonoid PAHs, suggesting its universal applicability as a catalyst for nanographene synthesis.

DOI： 10.1021/acs.nanolett.0c03510

Scopus

PubMed

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：MDPI AG  

Hexapyrrolohexaazacoronene (HPHAC) is one of the N-containing polycyclic aromatic hydrocarbons in which six pyrroles are fused circularly around a benzene. Despite the recent development of HPHAC analogues, there is no report on direct introduction of functional groups into the HPHAC skeleton. This work reports the first example of nitration reaction of decaethylHPHAC. The structures of nitrodecaethylHPHAC including neutral and two oxidized species (radical cation and dication), intramolecular charge transfer (ICT) character, and global aromaticity of the dication are discussed.

DOI： 10.3390/molecules25112486

Scopus

PubMed

researchmap

Authorship：Lead author,　Corresponding author   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

A bicyclo[2.2.2]octadiene(BCOD)-fused bis(dipyrromethane) derivative was reacted with methylal in the presence of trifluoroacetic acid followed by oxidation with chloranil to give a doubly N-confused phlorin derivative, which did not undergo the retro-Diels–Alder reaction extruding an ethylene molecule on heating. In contrast, a 7-tert-butoxybicyclo[2.2.1]heptadiene(7-BuOBCHD)-fused bis(dipyrromethane) yielded benzene-ring-fused doubly N-confused porphyrins by following similar reaction sequences.

DOI： 10.1002/chem.202000339

Scopus

PubMed

researchmap

Other Link： https://onlinelibrary.wiley.com/doi/full-xml/10.1002/chem.202000339

Authorship：Last author   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

Treatment of 1,6-azaeneyne compounds with Ph3SnH resulted in the stereoselective formation of 5-(E)-alkylidene-2,3-cis-piperidine in moderate to good yields. Intermediate products including methylenepyrrolidine and stannomethylene pyrrolidine were also detected in the reaction mixture, suggesting that the reaction progressed via a highly cumulated radical cascade process involving sequential six radical processes, i.e. radical addition, 5-exo cyclization, substitution (1,4-tin migration), 3-exo cyclization, ring cleavage of cycloprolane, and hydrogen abstraction from Ph3SnH. The product distribution depended on the lower Ph3SnH concentration, resulting in higher piperidine yields. The E/Z selectivity of the exo-methylene unit was also sensitive to the reaction temperature. The vinylic triphenyltin group was converted into hydrogen and iodine. A kinetic analysis of the reaction indicated that the 1,4-tin migration and ring expansion progressed as irreversible reactions and that their reaction rates were large enough to progress the cascade reaction smoothly and to prevent side reactions such as hydrogen abstraction from Ph3SnH.

DOI： 10.1002/ejoc.202000034

Scopus

researchmap

Publishing type：Research paper (scientific journal)   Publisher：World Scientific Pub Co Pte Lt  

A ring-contracted carbaporphyrin, azulitriphyrin(2.1.1), was synthesized via intramolecular McMurry coupling reaction. Absorption, NMR spectra and NICS calculations of protonated azulitriphyrin(2.1.1) revealed its Hückel aromatic character as a 14[Formula: see text] porphyrinoid.

DOI： 10.1142/s108842461950130x

Scopus

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)  

Copyright © 2019 American Chemical Society. An antiaromatic cation of the expanded hexapyrrolohexaazacoronene (HPHAC) 1+ was synthesized by a Vilsmeier-type reaction of the partially unfused HPHAC 2. X-ray diffraction analysis revealed the formation of a seven-membered ring with a methyne linkage between the pyrrole moieties. Although 1+ is a monocation, upfield shifts of the peripheral ethyl protons were clearly observed in the 1H NMR spectra, indicating 24πantiaromaticity. Global antiaromaticity was also supported by nucleus-independent chemical shift and anisotropy of the induced current density calculations. Cation 1+ displayed two reversible oxidations and one irreversible reduction in the cyclic voltammetry measurements. Treatment of 1+ with NOSbF6 gave aromatic trication 13+ with 22π-electron conjugation.

DOI： 10.1021/jacs.9b09260

Scopus

PubMed

researchmap

Publishing type：Research paper (scientific journal)  

© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim A series of free-base and phosphorus(V) complexes of tetrabenzoporphyrin (TBP) and some phosphorus(V) porphyrins containing four or eight phenyl groups on the periphery have been synthesized and characterized by X-ray crystallography, electronic absorption, and magnetic circular dichroism (MCD) spectroscopy, together with quantum chemical calculations. All phosphorus TBP and meso-tetraphenyl porphyrin complexes adapted ruffled conformations due to the small P(V) ion, although the Zn(II)TBPs containing eight phenyl (Φ) groups at the so-called β and α positions showed planar and saddled structures in the solid state, due to, respectively, marginal or severe steric hindrance between the neighboring Φ groups. All P(V)TBPs showed the Soret and Q bands beyond 450 and 700 nm, respectively, which are some of the longest wavelengths exhibited by metallated TBPs reported to date. Of the eight Φ group-substituted P(V)TBPs, those substituted at α positions always showed absorption bands at longer wavelengths than those at β positions, which was reproduced by calculated absorption spectra. The Soret band positions of meso-tetraphenylated P(V) species without fused benzo-groups (ca. 430–440 nm) were also some of the longest among metalloporphyrins of this type.

DOI： 10.1002/ejoc.201900528

Scopus

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)  

© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Bis(bicyclic) molecules dimethanochrysene and diethanochrysene were prepared by Diels-Alder reaction of the naphthodiyne equivalent with cyclopentadiene and 1,3-cyclohexadiene, respectively. Reaction of dimethanochrysene and 7,9-diphenyl-8H-cyclopent[a]acenaphthylen-8-one resulted in the generation of a fluorescent hydrocarbon in unexpected multistep pericyclic reactions. Syn-oriented diethanochrysene-connected bisporphyrin tweezers was prepared from the reaction of chrysene-bridged syn-dipyrrole with tripyrranedicarbaldehyde. The structure of the receptor and its 1 : 1 complex with C60 or C70 was determined by X-ray diffraction analysis. The dihedral angles of the bicyclo[2.2.2]octadiene moieties were narrowed by complexation of the receptor with the fullerenes. The binding affinities of the tweezers with C60 and C70 were calculated to be 2.7(4)×104 and 8.01(7)×104 M−1, respectively by UV-vis and fluorescence spectroscopy.

DOI： 10.1002/cplu.201900046

Scopus

PubMed

researchmap

Authorship：Corresponding author   Publishing type：Research paper (scientific journal)  

© 2019 American Chemical Society. Synthesis of an azacoronene, in which both pyrrole and azulene moieties are circularly fused, was achieved just in three steps. This new azacoronene exhibited multistep reversible oxidations under electrochemical and chemical conditions. Formation of an aromatic 22π-electron conjugation and a tropylium cation (6π-electron conjugation) in the dicationic state was revealed by the single-crystal X-ray crystallographic analysis as well as the nucleus-independent chemical shift (NICS) and anisotropy of the induced current density (ACID) calculations.

DOI： 10.1021/acs.orglett.9b00515

Scopus

PubMed

researchmap

Publishing type：Research paper (scientific journal)  

© 2019 The Chemical Society of Japan. 1,3-Dihydrothieno[3,4-a]- and 1,3,8,10-tetrahydrodithieno-[3,4-a;3¤4¤-m]-HPHACs were prepared by the successive SNAr reactions of hexafluorobenzene with 1,3-dihydrothieno[3,4-c]-pyrrole and 3,4-dihexylpyrrole followed by Scholl oxidation. Oxidation of 1,3-dihydrothieno-fused HPHACs with excess amounts of iodine at room temperature quantitatively gave the corresponding dication bis(triiodide)s. Further dehydrogenative oxidation of the dicationic species with iodine giving a thieno-[3,4-a]HPHAC dication was achieved at a higher temperature by removing hydrogen iodide generated during the reaction. Neutral species of thieno[3,4-a]HPHAC could not be isolated.

DOI： 10.1246/bcsj.20190022

Scopus

researchmap

Publishing type：Research paper (scientific journal)  

DOI： 10.1246/bcsj.20190074

Scopus

researchmap

Publishing type：Research paper (scientific journal)  

© 2019 The Chemical Society of Japan Di(acenaphtho)-fused BODIPYs with four electron-withdrawing N,N-dimethylcarbamoyl groups were obtained by complexation of the corresponding dipyrrins, which were also proven to be a stable deep-red dye.

DOI： 10.1246/bcsj.20190021

Scopus

researchmap

Publishing type：Research paper (scientific journal)  

© 2019 The Chemical Society of Japan. A helicene compound called AIBTh, wherein two azulene units are fused with isobenzothiophene, has been prepared and characterized by spectroscopic and crystallographic methods. The enantiomers of AIBTh were resolved by HPLC, exhibiting stable optical activity. AIBTh showed two reversible oxidation and one irreversible reduction waves with a HOMO-LUMO gap of 2.07 eV. Upon one-electron oxidation of AIBTh, its air-stable cation radical was isolated and analyzed by EPR as well as X-ray crystallography. Based on the EPR spectrum, the crystal structure, and DFT calculation, it is suggested that favorable resonance structures including aromatic tropylium cation forms and wide delocalization of electronic spin are dominating in the electronic structure of the cation radical.

DOI： 10.1246/bcsj.20190219

Scopus

researchmap

Publishing type：Research paper (scientific journal)  

© 2019 The Japan Institute of Heterocyclic Chemistry. We have successfully synthesized 2,3-di(3-thienyl)benzo[b]porphyrin based on retro Diels-Alder reaction of bicyclo[2.2.2]octadiene(BCOD)-fused porphyrin and investigated its photoisomerization reaction.

DOI： 10.3987/COM-18-S(F)102

Scopus

researchmap

Publishing type：Research paper (scientific journal)  

© 2018 Elsevier Ltd New types of macrocyclic compounds, deltaarenes, are prepared. The compounds were readily synthesized in three steps from an arenedithiol and benzoquinone, and the yields of the macrocyclization reaction reached up to 40% under high dilution conditions. X-ray crystallographic analysis revealed that the macrocycle has a relatively rigid trimeric structure with a unique triangular hole, the size of which was approximately 11 Å along each side. NMR data suggests that the ring has a C3-symmetric structure. The X-ray analysis showed that the hole is large enough to capture one molecule of chlorobenzene. Use of a variety of dithiols allowed the synthesis of different types of deltaarene derivatives. MO calculations showed that the hole size depends on the dithiol unit. Deprotection of the twelve methoxyl groups was easily achieved by treatment with BBr3 and yielded the free-OH deltaarene derivative.

DOI： 10.1016/j.tet.2018.04.070

Scopus

researchmap

Publishing type：Research paper (scientific journal)  

Copyright © 2018 American Chemical Society. A core-expanded, pyrrole-fused azacoronene analogue containing two unusual N-doped heptagons was obtained from commercially available octafluoronaphthalene and 3,4-diethylpyrrole in two steps as a heteroatom-doped nonplanar nanographene. Full fusion with the formation of the tetraazadipleiadiene framework and the longitudinally twisted structure was unambiguously confirmed by single-crystal X-ray diffraction analysis. The edge-to-edge dihedral angle along the acene moiety was 63°. This electron-rich π-system showed four reversible oxidation peaks. Despite the nonplanar structure, the Hückel aromaticity owing to a peripheral π-conjugation in the dicationic state was concluded from the bond-length alternation and nucleus-independent chemical shift (NICS) and anisotropy of the induced current density (ACID) calculations.

DOI： 10.1021/jacs.8b06079

Scopus

PubMed

researchmap

Publishing type：Research paper (scientific journal)  

© 2018 American Chemical Society. The adsorption configurations of heptahelicene ([7]H) molecules on Cu(001) are investigated with noncontact atomic force microscopy (ncAFM) and scanning tunneling microscopy (STM). Because of the suppression of thermal diffusion at 5 K, racemic [7]H molecules exist as monomers, dimers, trimers, and tetramers on the surface. The terminal naphthaleno part of the molecule is attached horizontally to the substrate so that the two benzene ring centers are located at the hollow sites, whereas the other terminal is protruded toward a vacuum. A procedure for picking a [7]H molecule up from the surface (vertical manipulation) enables us to functionalize the tip apex to enhance the spatial resolution of ncAFM. The ncAFM images with the helicene tip clarify that whereas the tetramers are homochiral, the dimers and trimers are heterochiral. In contrast, homochiral dimers and trimers are unobservable probably because of the rapid formation of the stable homochiral tetramers. Thus, ncAFM imaging can identify the geometries and chiralities of the individual component molecules in a nondestructive manner, which would be an indispensable method to characterize complicated chiral aggregates at the single-molecule level.

DOI： 10.1021/acs.jpcc.8b00487

Scopus

researchmap

Publishing type：Research paper (scientific journal)  

© 2018 The Japan Institute of Heterocyclic Chemistry. A series of sapphyrins fused with bicyclo[2.2.2]octadiene were successfully synthesized via [3+1+1] porphyrinoid synthesis. The retro Diels-Alder thermal conversion afforded the corresponding di-, tri-, tetra-, and pentabenzosapphyrins.

DOI： 10.3987/COM-18-13910

Scopus

researchmap

Publishing type：Research paper (scientific journal)  

© 2018 The Pharmaceutical Society of Japan. Three 2-fluoroacetonylbenzoxazole ligands 1a–c and their new Zn(II) complexes 2a–c have been synthesized. In addition, syntheses of new metal [Mg(II), Ni(II), Cu(II), Pd(II), and Ag(I)] complexes from 1a have been also described. The molecular and crystal structures of six metal complexes 2b and 2d–h were determined by single-crystal X-ray diffraction analyses. Their antibacterial activities against six Gram-positive and six Gram-negative bacteria were evaluated by minimum inhibitory concentrations (MIC), which were compared with those of appropriate antibiotics and silver nitrate. The results indicate that some metal compounds have more antibacterial effects in comparison with free ligands and have preferred antibacterial activities that may have potential pharmaceutical applications. Noticeably, the Ag(I) complex 2h exhibited low MIC value of 0.7µM against Pseudomonas aeruginosa, which was even superior to the reference drug, Norfloxacin with that of 1.5µM. Against P. aeruginosa, 2h is bacteriostatic, exerts the cell surface damage observed by scanning electron microscopy (SEM) and is less likely to develop resistance. The new 2h has been found to display effective antimicrobial activity against a series of bacteria.

DOI： 10.1248/cpb.c18-00158

Scopus

PubMed

researchmap

Publishing type：Research paper (scientific journal)  

© 2018 The Royal Society of Chemistry. Benzene-fused bis(acenaphthoBODIPY)s prepared by retro-Diels-Alder reaction of bicyclo[2.2.2]octadiene-fused precursors showed strong absorption bands in the near-infrared region and very weak absorptions in the visible region.

DOI： 10.1039/c8ra01694a

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

In this study, a benzene-fused bis(thiaporphyrin) was synthesized by the retro-Diels-Alder reaction of a bicyclo[2.2.2]octadiene (BCOD)-fused bis(thiaporphyrin) precursor. This precursor was prepared by the double [3+ 1] porphyrin synthesis of the BCOD-fused dipyrrole with thiatripyrrane. The ultraviolet-visible (UV-vis) spectrum of benzene-fused bis( thiaporphyrin) in dichloromethane was extremely different from that of the corresponding benzene-fused bis(porphyrin). In contrast, extremely similar spectra were obtained in the presence of trifluoroacetic acid. The similar electronic structures in the protonated states were supported by X-ray analysis and time-dependent density-functional theory (TD-DFT) calculations.

DOI： 10.1246/bcsj.20170257

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

We report covalently interchain-linked graphene nanoribbons fabricated on Au(111) by a stepwise growth process via two-zone chemical vapor deposition. Prepolymer arrays were grown by surface-assisted polymerization of a precursor, 1,9-dibromodibenzo[g,p]chrysene at 250 degrees C. Further annealing at 450 degrees C converted the prepolymers into interchain-linked graphene nanoribbons via intramolecular and intermolecular dehydrogenation reactions.

DOI： 10.1246/cl.170614

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Chiral 2,3-trans-substituted piperidines were readily prepared in three steps from beta-amino-alpha-methylene esters, which were prepared by the Michael/Mannich domino reaction of chiral sulfinimines. Hydrogenation of the N-tosyl-2-aryl-1,2,5,6-tetrahydropyridine intermediates took place smoothly in the presence of a Pd/C catalyst to give trans-2,3-disubstituted piperidines in good yields and in a highly stereoselective manner. The total synthesis of optically active (25,3R)-(-)-epi-CP-99,994 was achieved in six-steps from an unsaturated piperidine. (C) 2017 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2017.06.054

Web of Science

researchmap

Publishing type：Research paper (scientific journal)  

Controlling the structural deformation of organic molecules can drive unique reactions that cannot be induced only by thermal, optical or electrochemical procedures. However, in conventional organic synthesis, including mechanochemical procedures, it is difficult to control skeletal rearrangement in polycyclic aromatic hydrocarbons (PAHs). Here, we demonstrate a reaction scheme for the skeletal rearrangement of PAHs on a metal surface using high-resolution noncontact atomic force microscopy. By a combination of organic synthesis and on-surface cyclodehydrogenation, we produce a well-designed PAH - diazuleno[1,2,3-cd:1′,2′,3′-fg]pyrene - adsorbed flatly onto Cu(001), in which two azuleno moieties are highly strained by their mutual proximity. This local strain drives the rearrangement of one of the azuleno moieties into a fulvaleno moiety, which has never been reported so far. Our proposed thermally driven, strain-induced synthesis on surfaces will pave the way for the production of a new class of nanocarbon materials that conventional synthetic techniques cannot attain.

DOI： 10.1038/ncomms16089

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The protonation behavior of bicyclo[2.2.2]octadiene (BCOD)-fused thiaporphyrin and thiabenzoporphyrin was examined by titration with trifluoroacetic acid. Neutral, monorotonated, and diprotonated species of thiaporphyrins were easily detected by UV-vis spectral measurement. The first (K-1) and second (K-2) equilibrium constants were found to be K-1 = 520 and K-2 approximate to 7.1 for BCOD-fused thiaporphyrin and K-1 = 1.4 x 10(4) and K-2 approximate to 1.4 for thiabenzoporphyrin. The difference between K-1 and K-2 values of thiaporphyrins is larger than that observed for porphyrins (N-4-porphyrins). The main contributing conjugation pathways for thiaporphyrins in both protonated species were investigated by NICS and AICD quantum calculations using their atomic geometries obtained by X-ray structural analysis. The 18 pi-conjugation pathways of the neutral, monoprotonated, and diprotonated species thiaporphyrins were found to contain 18, 19, and 20 atoms, respectively. Results of H-1 NMR studies also support the major contributing pathways. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2016.12.067

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Parikh-Doering oxidation of diethyl 9-hydroxy-2,6-dimethy1-4,8-dihydro-4,8-methanopyrrol[3,4-f]isoindole-1,7-dicarboxylate produced diethyl 9-oxo-2,6-dimethy1-4,8-dihydro-4,8-methanopyrrol[3,44] isoindole-1,7-dicarboxylate. This carbonyl derivative spontaneously underwent cheletropic extrusion of carbon monoxide, producing diethyl 2,6-dimethylpyrrol[3,4-f]isoindole-1,7-dicarboxylate, which showed 14 pi-electronic aromaticity on the whole five-six-five ring system. (C) 2017 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2017.01.015

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

A cyclophane composed of diethanoanthracene (DEA)-fused dipyrrole and tetrafluorobenzene was synthesized by one-pot aromatic nucleophilic substitution (SNAr). Reflecting the fixed angle of DEA-fused dipyrrole, X-ray single-crystal structure analysis of the cyclophane revealed its rice-ball-shaped structure.

DOI： 10.1246/cl.161026

Web of Science

researchmap

Publishing type：Research paper (scientific journal)  

© 2017 The Japan Institute of Heterocyclic Chemistry. 4-Trifluoroacetyl-3-phenylsydnone was first synthesized by trifluoromethylation of 4-formyl-3-phenylsydnone followed by oxidation of the corresponding trifluoromethyl alcohol. The structure of the product was determined by single-crystal X-ray analysis.

DOI： 10.3987/COM-17-13802

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The radical cascade reaction of allyltin with aza-1,6-enyne compounds was studied. Optically active aza-1,6-enynes underwent a radical cascade process in the presence of a high concentration of allyltributyltin to give stannolanes as the major isomer. Piperidines were also observed in small amounts when an allylic unit was introduced stereoselectively to the trans-position of the aryl group at the C2 position. The yield of the products dramatically decreased with concentrations of tin reagent. The E/Z selectivity at the exomethylene group in piperidine depended on the reaction temperature, and it almost doubled when the reaction was carried out at 30 degrees C. In this study, the reaction mechanism of the radical cascade is discussed. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2016.04.078

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

A novel one-pot conversion of mesoionic 4-trifluoroacetyl-1,3-oxazolium-5-olates into imidazo[1,5-a]pyrazin-8(7.H)-ones by the reaction with TosMIC is described. The structure of the product was determined by single-crystal X-ray analysis.

DOI： 10.3987/COM-16-13551

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

A series of porphyrins fused with acenaphthylene, phenanthroline, and benzofluoranthene polycyclic aromatic rings were prepared by means of a 3+1 porphyrin synthesis approach and subsequent retro-Diels-Alder reaction of bicyclo[2.2.2]octadiene-fused precursors. Analysis of the magnetic circular dichroism spectra and the results of time-dependent DFT calculations are used to identify the reasons for the trends observed in the wavelengths and relative intensities of the Q bands of the products. Michl's perimeter model is used as a conceptual framework to explain the changes in the relative energies of the frontier -molecular orbitals.

DOI： 10.1002/chem.201602213

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：SPRINGER  

The organozirconium complex with alpha-Keggin-type mono-aluminum-substituted silicotungstate, [(n-C4H9)(4)N](6)[alpha-SiW11Al(OH)(2)O38ZrCp2](2)center dot 2H(2)O (TBA-Si-Al-Zr) was synthesized by the reaction of Cp2Zr(OTf)(2)center dot THF (or Cp2ZrCl2) with [(n-C4H9)(4)N](4)K0.5H0.5[alpha-SiW11{Al(OH2)}O-39]center dot H2O in acetonitrile. This compound showed high catalytic activities for Meerwein-Ponndorf-Verley reduction of ketones with 2-propanol in both homogeneous and heterogeneous system.
[GRAPHICS]
.

DOI： 10.1007/s10562-016-1813-7

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/ange.201606246

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

In this study, hexagonal shape-persistent cyclophane with D-2h symmetry and rigid dihedral angles was obtained through the key SNAr reaction of perfluorobenzene moieties and dipyrroles. The X-ray analysis of the compound thus obtained revealed a hexagonal macrocyclic structure with D-2h symmetry due to the dihedral angles of 120 degrees and double 120 degrees for bicyclo[2.2.2]octadiene:fused dipyrrole and syn-diethanotetrahydroanthracene-fused dipyrrole, respectively. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2016.07.086

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Complexation of novel multiply N-confused expanded calix[n]phyrins with boron difluoride afforded a new class of cyclic BODIPY (boron-dipyrromethene) arrays. The structures of circularly arranged BODIPY subunits linked in an N-confused fashion give rise to such photophysical properties unique to the macrocycles as red-shifted emission wavelengths along with apparent large Stokes shifts, long emission lifetimes, and solid-state lasing. The DFT calculations support the size-dependent excited-state dynamics of the macrocycles.

DOI： 10.1002/anie.201606246

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Treatment of optically active 6-nitrohex-1-en-3-ols with Ag2O and iodine under basic conditions resulted in an oxidative intramolecular cyclization reaction to give isoxazoline-N-oxide along with bicyclo[3.1.0]hexane. The stereoselectivity and chemoselectivity of the reaction depended on the configuration of the stereogenic center adjacent to the alkenyl group. The structure was determined by X-ray crystallographic analyses as well as coupling constants from NMR data. Stereochemical preferences in the transition structure of the reaction are discussed.

DOI： 10.3987/COM-16-13497

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

A complex of Cyclo[8]pyrrole with polyoxometalate, POM-to-Rings, was synthesized by anion exchange from cyclo[8]pyrrole sulfate. X-ray crystallographic study revealed the double-decker structure. (C) 2016 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2016.06.021

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

An acenaphthylene-fused cyclo[10]pyrrole 1b was selectively synthesized via an oxidative coupling reaction of the corresponding 2,2'-bipyrrole with the appropriate dianion template, croconate anion. The structure of 1b as the isolated largest cyclo[n]pyrrole was elucidated by X-ray crystallographic analysis. The absorption spectrum exhibited a markedly red-shifted, intensified L band at 1982 nm, which was interpreted by application of Michl's perimeter and Gouterman's 4-orbital models, supported by magnetic circular dichroism (MCD) data and theoretical calculations.

DOI： 10.1021/jacs.6b04941

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Optically active bicyclic nitrocyclopropanes are readily prepared from primary chiral nitro compounds, prepared by the conjugate addition of propionaldehyde to a nitro alkene in the presence of proline-derived organocatalysts. The one-step cyclopropanation took place smoothly in a highly stereoselective manner regardless of the stereogenic center adjacent to the allylic unit. Although the allylation reaction catalyzed by BF3 center dot OEt2, provides a mixture of two possible diastereomers, subsequent oxidation of the alcoholic carbon after the formation of nitrocyclopropanes gave diastereomerically pure single products. As a result, separation of the diastereomers during the reaction sequence is unnecessary. Baeyer-Villiger oxidation of the bicyclic nitrocyclopropane ketones followed by enolization resulted in stereoselective formation of a novel cyclopenta[b]furan ring in good yield via ring expansion followed by transannular nudeophilic cyclization.

DOI： 10.1021/acs.joc.6b00566

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Scientific Research Publishing  

DOI： 10.4236/mrc.2016.54010

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Trialkyl phosphites were evaluated as phosphorus nucleophiles for addition to mesoionic 4-trifluoroacetyl-1,3-oxazolium-5-olates (1), thereby producing tetravalent phosphorus zwitterions (2) in good yields. The structure of 2 was determined to be a tetravalent phosphonium enolate via single crystal X-ray analysis.

DOI： 10.1039/c6cc01627h

Web of Science

researchmap

Language：Japanese   Publisher：The Surface Science Society of Japan  

DOI： 10.14886/sssj2008.36.0_289

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

Unsymmetrically substituted 8-methoxy-2-hydroxy-3,7-diarylthiodibenzofurans were readily prepared by the intramolecular oxidative condensation reaction of hydroquinone dimers in good yields.

DOI： 10.1080/10426507.2014.983598

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Iron salt-catalyzed Friedel-Crafts alkylation of chiral alpha-aryl alcohols with a trimethylsilyl group was found to proceed with retention of the configuration of the hydroxyl group as a leaving group. The memory of chirality of this system stems from the beta-silyl effect of the trimethylsilyl group on the carbocation intermediate.

DOI： 10.1021/acs.orglett.5b01582

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

4,8-Dihydropyrrol[3,4-f]isoindole was prepared from 4,7-dihydroisoindole based on the modified Barton-Zard reaction. Addition of phenylsulfenyl chloride followed by oxidation and dehydrochlorination gave phenylsulfonyldihydroisoindole, which underwent the smooth reaction with an isocyanoacetate under basic conditions to give 4,8-dihydropyrrol[3,4-f]isoindole-1,5- and 1,7-dicarboxylates in good yields. The pyrrolisoindole was successfully converted to the benzene-fused bisBODIPY, absorption maximum of which was 758 nm.

DOI： 10.3987/COM-14-S(K)91

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHINESE CHEMICAL SOC  

A kinetic study on radical cascade reactions of 1,6-enyne compounds was undertaken. The efficiency of the reaction depended on the presence of an ester group at the alkene unit, which clearly suggests that the addition of a tin radical was accelerated by the alpha,beta-unsaturated system. Stannolane formation progressed very quickly after a short induction period and completed within 12 min in the presence of Bu3SnH at 10(-2) M concentration at 110 degrees C. Product ratios between stannolane and exo-methylene compound depended on the concentration of Bu3SnH; a linear relationship was observed between the ratios of the two and the concentration of Bu3SnH. These results clearly indicate that the S(H)i process is irreversible. The slope of the graph allowed us to estimate the k(s) value, the S(H)i reaction rate at the tin atom, as 4.23 x 10(8) s(-1) at 303 K. The use of Bu2PhSnH for the reaction suggests that the S(H)i process partially progresses by the frontside attack of the vinyl radical, which generates a methylene radical that undergoes neophyl rearrangement to give methylene piperidine in a cis-selective manner.

DOI： 10.1039/c5qo00063g

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Electrophilic phenylsulfenylation of syn-7-tert-butoxy-2-phenylsulfonyl- bicyclo[2.2.1] hepta-2,5-diene with phenylsulfenyl chloride yielded a mixture of three simple adducts, two of which were derived by the endo face attack of the phenylsulfenyl cation. In the analogous reaction with the anti derivative, only one adduct with the exo phenylsulfanyl group at the nearer carbon was obtained. This product was derived by the attack of the phenylsulfenyl cation from the exo face followed by the endo attack of a chloride anion at the carbon opposite to the phenylsulfonyl group. The similar reaction of 7-tert-butoxybicyclo[2.2.1]hepta-2,5-diene itself underwent no Wager-Meerwein-type rearrangement or transannular reaction, and simple adducts were formed in good combined yield. The combined yield of the products reacted at the syn double bond was ca. 80%.

DOI： 10.1002/hc.21172

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WORLD SCI PUBL CO INC  

Synthesis of bona fide N-confused phlorin derivatives through simple chemical reduction of N-confused porphyrin precursors using sodium borohydride, p-toluenesulfonyl hydrazide, etc. is described. Spectroscopic, X-ray diffraction analyses and DFT-assisted calculations of these species support the nonaromatic phlorin electronic structure.

DOI： 10.1142/S1088424614500692

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Optically active seven-membered lactones, dimethyleneoxazepanones, were readily prepared in good yields from chiral beta-(N-propargylic)-amino-alpha-methylene carboxylic add tert-butyl esters in the presence of catalytic amounts of Ph3PAuCl and Cu(OTf)(2) A smooth 7-exo-dig cyclization was observed.

DOI： 10.1021/jo501254x

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WORLD SCI PUBL CO INC  

A series of O-chelated BODIPYs fused with aromatic rings such as benzene and acenaphthylene at beta,beta-positions was synthesized as a near-infrared dye. The photophysical properties were examined by UV-vis-NIR absorption and fluorescence measurement. Acenaphthylene-fused O-BODIPYs showed a intense absorption at 750-840 nm with the epsilon of 10(5) M-1.cm(-1). and a fluorescene emission at 770-850 nm with the high Phi value of 0.06-0.43.

DOI： 10.1142/S1088424614500503

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The syntheses and molecular structures of the two types of alpha-Dawson-type trialuminum-substituted polyoxometalates, [B-alpha-H3P2W15O59{Al(OH2)}(3)](6-) (1) and [B-alpha-H3P2W15O59{Al(OH)}(2){Al(OH2)}](2)(16-) (2), are described herein. The potassium and cesium salts of 1, K-6[B-alpha-H3P2W15O59{Al(OH2)}(3)]center dot 14H(2)O (K-1), and Cs-6[B-alpha-H3P2W15O59{Al(OH2)}(3)]center dot 13H(2)O (Cs-1) were formed by a stoichiometric reaction in water of trilacunary alpha-Dawson polyoxotungstate with aluminum nitrate under acidic conditions (pH similar to 3). The potassium/sodium and tetramethylammonium/sodium salts of 2, K14Na2[B-alpha-H3P2W15O59{Al(OH)}(2) {Al (OH2)}](2) center dot 30H(2)O (KNa-2) and [(CH3)(4)N](14)Na-2[B-alpha-H3P2W15O59{Al(OH)}(2){Al(OH2)}](2) center dot 39H(2)O (TMANa-2) were obtained under basic conditions (pH similar to 9). These compounds were characterized by X-ray structure analyses elemental analyses, thermogravimetric/differential thermal analyses, Fourier transform infrared, and solution P-31, Al-27, and W-183 NMR spectroscopy. The polyoxoanion 1 is a monomeric, alpha-Dawson-type structure, resulting in an overall C-3v symmetry, while the polyoxoanion 2 is a hydrogen-bonded dimeric structure, resulting in an overall S-3 symmetry in the solid state. The pH dependence of polyoxoanions 1 and 2 in aqueous solution was also investigated by P-31 NMR spectroscopy.

DOI： 10.1021/ic402650g

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Free-bases and a nickel(11) complex of phenothiazine-bridged cyclic porphyrin dimers bearing self-ssembling 4-pyridyl groups (M(2)PtzCPD(Py)(OCn); M = H-2 or Ni, OCn = OC6 or OC3) at opposite mesopositions have been prepared as host molecules for fullerenes. The freebase dimer (H(4)Ptz-CPDPy(OC6)) includes fullerenes with remarkably high association constants such as 3.9 +/- 0.7 x 10(6) M-1 for C-60 and 7.4 +/- 0.8 x 10(7) M-1 for C-70 in toluene. This C-60 affinity is the highest value ever among reported receptors composed of freebase porphyrins. The nickel dimer (Ni-2-Ptz-CPDPy(OC6)) also shows high affinities for C-60 (1.3 +/- 0.2 x 10(6) M-1) and C-70 (over 10(7) M-1). In the crystal structure of the inclusion complex of C-60 within H(4)PtzCPD(Py)(OC3()), the C-60 molecule is located just above the centers of the porphyrins. The two porphyrin planes are almost parallel to each other and the center-to-center distance (12.454 angstrom) is close to the optimal separation (similar to 12.5 angstrom) for C-60 inclusion. The cyclic porphyrin dimer forms a nanotube through its self-assembly induced by C-H center dot center dot center dot N hydrogen bonds between porphyrin beta-CH groups and pyridyl nitrogens as well as pi-pi interactions of the pyridyl groups. The C-60 molecules are linearly arranged in the inner channel of this nanotube.

DOI： 10.1021/jo500034f

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

1,3-Bisarylated-2,2'-biazulene 1 and 1,1'-bisarylated-2,2'-biazulene 1' were obtained by the Suzuki-Miyaura crosscoupling reaction of 1,1',3,3'-tetrahalo-2,2'-biazulene 2 with 4-tert-butylphenylboronic acid (3b). The other two halogen atoms were reductively removed by hydrogenation under the same reaction conditions. The major regioisomer 1 was obtained with a selectivity of up to 94% (15:1) and a combined yield of 1 and 1' of up to 77%.

DOI： 10.1246/cl.131142

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

4,4'-Disulfanyl-2,2',5,5'-tetrahydrobiaryl (5,5'-disulfanyl hydroquinone dimer) derivatives were readily synthesized from benzoquinone and thiols via an oxidative coupling reaction. The hydroquinone dimers showed strong fluorescence upon excitation at 330 nm, and it was observed that the presence of the sulfanyl groups at the C4 and C4' positions is important for achieving strong photoluminescence. The tetrapotassium salts of the hydroquinone dimers also showed good water solubility, but the fluorescence disappeared rapidly on dissolution in water. 2,2'- and 5,5'-protected biaryls were synthesized. The dipotassium salt of the 5,5'-dimethoxy-2,2'-dihydroxy derivative was observed to show good and stable fluorescence in water, while the dipotassium salt of the 2,2'-dirnethoxy-5,5'-dihydroxy derivative showed less water solubility. Introduction of propargyl groups was demonstrated to provide a convenient method for installing amino acids derivatives. This derivatization afforded potentially useful compounds for attaching the biologically active fragment to the fluorescent unit.

DOI： 10.1021/jo402522y

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The Hinsberg thiophene synthesis using 4,5,6,7-tetrahydro-4,7-ethanothiophene-5,6-dione and diethyl thiodiglycolate afforded a mixture of diethyl 4,8-dihydro-4,8-ethanobenzo[1,2-c;4,5-c']dithiophene-1,3-dicarboxylate and its dihydrate, although the yields were low. The latter dihydrate was converted to the former dithiophene in a good yield by the treatment with Ac2O and DMAP.

DOI： 10.3987/COM-13-S(S)53

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Cyclo[8]pyrrole with eight 9,10-dihydroanthracene wings was synthesized by oxidative coupling of the corresponding 2,2'-bipyrrole in good yield. The molecular structure was determined by single crystal X-ray analysis. The three-dimensionally structured cyclo[8]pyrrole possessed a cavity created by a pair of slip-stacked cyclo[8]pyrroles.

DOI： 10.3987/COM-13-S(S)42

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

A series of O-chelated BODIPYs fused with aromatic rings such as benzene and acenaphthylene at β,β-positions was synthesized as a near-infrared dye. The photophysical properties were examined by UV-vis-NIR absorption and fluorescence measurement. Acenaphthylene-fused O-BODIPYs showed a intense absorption at 750–840 nm with the ε of 105 M-1.cm-1. and a fluorescence emission at 770–850 nm with the high Φ value of 0.06–0.43.<br />
<br />
<br />
Read More: http://www.worldscientific.com/doi/abs/10.1142/S1088424614500503

DOI： 10.1142/S1088424614500503

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Bicyclo[2.2.2]octadiene-fused (BCOD-fused) bis(benzoborondipyrromethene)s (bisbenzoBODIPYs) bearing electron-withdrawing groups such as fluorine and cyano groups were prepared either by incorporating tetrafluoroisoindole moieties into BODIPY chromophores or by introducing cyano or ethoxycarbonyl groups at the 3,5-positions. The BCOD-fused bisbenzoBODIPYs were quantitatively converted to the corresponding benzene-fused bisbenzoBODIPYs by a retro-Diels-Alder reaction. The pi-fused bisbenzoBODIPYs were found to have intense absorption in the near-infrared region and not to have any strong absorption bands in the visible region. Moreover, the bisbenzoBODIPYs were stable under atmospheric conditions.

DOI： 10.1039/c3ob41996g

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Boron complexes of [14]triphyrins(2.1.1) were prepared from free-base [14]triphyrins(2.1.1) with phenylboron dichloride. The absorption spectrum of the meso-free β-alkyl-triphyrin boron complex in CH2Cl 2 showed a broad weak band at around 640 nm assigned to transition from B-phenyl to the triphyrin, while that of the meso-aryl benzotriphyrin boron complex showed only Soret and Q bands. © 2013 The Royal Society of Chemistry.

DOI： 10.1039/c3cc44788j

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

An acenaphthylene-fused cyclo[8]pyrrole was synthesized by using an oxidative coupling reaction of the corresponding 2,2-bipyrrole. Two conformational isomers 1a and 1b were isolated, and their molecular structures were elucidated by X-ray crystallographic studies. The less-polar and lower-symmetry 1b isomer can be converted into the 1a isomer through a thermal ring flip. Application of the perimeter model developed by Michl to magnetic circular dichroism spectroscopic data and theoretical calculations demonstrate that there is a marked redshift of the near-IR absorption maxima relative to cyclo[8]isoindole because there is a significant stabilization of the LUMO due to the differing effects of a fused ring expansion with acenaphthylene and benzene moieties on the frontier molecular orbitals.

DOI： 10.1002/chem.201301294

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

We have synthesized 13,13′-(3,5-bis(trifluoromethyl)phenyl)-6, 6′-bipentacene from a soluble bispentacenequinone precursor. Bispentacene takes orthogonal conformation in the solid state and exhibits four reversible redox potentials. In addition, a tetracyanobipentacenequinodimethane was obtained for the first time from the pure bispentacenequinone. © The Royal Society of Chemistry 2013.

DOI： 10.1039/c3ra41914b

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Treatment of mesoionic 1,3-oxazolium-5-olates with TosMIC in the presence of a base causes a novel ring transformation affording 2(1H)-pyrazinones in moderate yields. The origin of C-2 carbonyl oxygen in the product was elucidated to be molecular oxygen, based on O-18-labeling experiments.
[GRAPHICS]
.
(C) 2013 The Authors. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2013.06.018

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Bicyclic dihydrothiophenes are readily prepared by a radical cascade cyclization reaction triggered by the addition of a thiyl radical under thermal or photoirradiation conditions. The translocated radical attacks the sulfur atom in the initial radical donor unit in an S(H)i manner. Sufficient stereoselectivity is achieved when a large excess of disulfide is used for the reaction under photoirradiation conditions. The reaction in the absence of solvents provides vinylsulfides instead of dihydrothiophenes. Thus, the sulfur atom in the thiyl radical serves as a sulfur biradical synthetic equivalent.

DOI： 10.1021/jo400975t

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

9,10-Phenanthrenequinone (9,10-PQ) is one of the most abundant quinones among diesel exhaust particulates. Recent data have suggested that quinones induce apoptosis in immune, epithelial and tumor cells, leading to respirator illness; however, the mechanisms by which quinones induce apoptosis and the structure required for this remain unknown. We studied the antitumor activity of 9,10-PQ analogs against two human tumor cell lines, HCT-116 colon tumor cells and HL-60 promyelocytic leukemia cells. The loss of the cis-orthoquinone unit in 9,10-PQ abrogated its ability to induce apoptosis in the two tumor cell lines, and the LC50 values of these analogs were indicated over 10 mu M. An analog of 9,10-PQ in which the biaryl unit had been deleted displayed a reduced ability to induce tumor cell apoptosis, while the analogs 1,10-phenanthroline-5,6-dione (9) and pyrene-4,5-dione (10), which also had modified biaryl units, exhibited increased tumor cell apoptotic activity. The cis-orthoquinone unit in 9,10-PQ was identified as essential for its ability to induce apoptosis in tumor cells, and its biaryl unit is also considered to influence orthoquinone-mediated apoptotic activity. (C) 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.bmcl.2013.06.015

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Bicyclodihydrosiloles were readily prepared from optically active enyne compounds by a radical cascade reaction triggered by tris(trimethylsilyl)silane ((Me3Si)3SiH). The reaction was initiated by the addition of a silyl radical to an α,β-unsaturated ester, forming an α-carbonyl radical that underwent radical cyclization to a terminal alkyne unit. The resulting vinyl radical attacked the silicon atom in an SHi manner to give dihydrosilole. The reaction preferentially formed trans isomers of bicyclosiloles with an approximately 7:3 to 9:1 selectivity. © 2013 Miyazaki et al.

DOI： 10.3762/bjoc.9.149

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

DOI： 10.1002/anie.201302815

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Royal Society of Chemistry  

The non-luminous precursor, 2-(1-pyrenyl)-9,10-dihydro-9,10- ethanoanthracene-11,12-dione, was photochemically converted to highly-fluorescent 2-(1-pyrenyl)anthracene quantitatively in solution and in the PMMA film and the fluorescence quantum yield of the acene in benzonitrile was as high as 0.99. © The Royal Society of Chemistry 2013.

DOI： 10.1039/c3cc40827b

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

Highly fluorescent naphthacene derivatives and their photoconvertible precursors were synthesized for irreversibly photo-responsive fluorescent molecules. The fluorescence quantum yields (Φf) of the precursors were less than 0.02, and the precursors can be converted to the highly fluorescent naphthacene derivatives (Φf = 0.67-0.70) quantitatively by photo-irradiation. © 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2013.01.014

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

Optically active 4-aminopyrolidines were prepared by radical cyclization induced by addition of tin radical to N-(2-(methoxyimino)ethyl)--amino--methylene esters, which were readily prepared by Michael/aldol domino reaction to chiral sulfinimines.

DOI： 10.1080/10426507.2012.736893

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Time-resolved emission of aloesaponarin I was studied with the fluorescence up-conversion and time-correlated single-photon-counting techniques. The rates of the excited-state intramolecular proton transfer, of the solvent and molecular rearrangements, and of the decay from the excited proton-transferred species were determined and interpreted in the light of time-dependent density functional calculations. These results were discussed in conjunction with UV protection and singlet-oxygen quenching activity of aloe.

DOI： 10.1021/jp306870y

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Reductive treatment of bicyclic nitrocyclopropanes with zinc powder under acidic conditions resulted in the double cleavage of carbon-carbon bonds in the cyclopropane to give vinyl nitrile in good yields. The reductive cleavage of carbon-carbon bond depended on the reaction conditions and sufficient acidic treatment gave alkenyl nitriles in good yields, while weak acidic treatment afforded oxime derivative instead. (C) 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2013.01.094

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

A novel double Migita-Kosugi-Stille coupling reaction with dihydrostannolanes, which are readily available from a radical cascade reaction, was achieved with dihalobenzenes in the presence of a palladium catalyst. Use of unsymmetrical 1-bromo-2-iodobenzene derivatives accomplished the double coupling reaction which gave tetrahydrobenz[f]isoindoles in a regioselective manner. © 2013 American Chemical Society.

DOI： 10.1021/ol4003948

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Metalation of 6,13,20,21-tetrakis(4-methyl-phenyl)-22H-tribenzo[14]triphyrin(2.1.1) with PtCl2 gave a platinum(II) complex having a square-planar coordination structure with two pyrrolic nitrogen atoms and two chloride ions, with a saddle-shaped macrocycle. This platinum(II) complex was easily oxidized by air to an octahedral platinum(IV) complex coordinated by three pyrrolic nitrogen atoms as a tridentate monoanionic cyclic ligand and three chloride ions. When platinum(II) triphyrin was crystallized in air, an oxygen atom was incorporated between two alpha-carbon atoms of the pyrroles as an oxygen bridge to intercept the 14 pi aromatic system.

DOI： 10.1021/ic302624h

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

The synthesis and crystal structure of a zirconocene derivative with alpha-Keggin mono-aluminum-substituted polyoxotungstate, [alpha-PW11Al(OH)O39ZrCp2](2)(6-) (Cp = C5H5-) (1), which was obtained by the reaction of alpha-Keggin mono-aluminum-substituted polyoxotungstate with a biscyclopentadienylzirconium(IV) complex, is described herein. Analytically pure, homogeneous, yellow crystals of the tetra-n-butylammonium salt of polyoxoanion 1, [(n-C4H9)(4)N](6)[alpha-PW11Al(OH)O39ZrCp2](2) (TBA-1), were obtained from the ca. 1 : 1 reaction of [(n-C4H9)(4)N](4)[alpha-PW11{Al(OH2)}O-39] with Cp2Zr(OTf)(2)center dot THF (OTf = O3SCF3-) in acetonitrile solution under an argon atmosphere, followed by precipitation from water and crystallization from acetonitrile. TBA-1 was characterized based on X-ray structure analysis, elemental analysis, thermogravimetric/differential thermal analysis (TG/DTA), Fourier transform infrared (FTIR), and solution (P-31, Al-27, F-19, H-1, and C-13) nuclear magnetic resonance (NMR) spectroscopy. Single-crystal X-ray structure analysis revealed that the two {PW11AlO40} units are bridged by two "bent sandwich" Cp2Zr2+ fragments with C-2 symmetry. Each zirconium center was bound to a terminal oxygen atom of the aluminum and tungsten sites and an edge-sharing oxygen atom at the Al-O-W linkage. Further, the stability towards water was investigated by NMR (P-31, H-1, and C-13) and FTIR spectroscopy. The eta(5)-cyclopentadienylzirconium fragments were not eliminated from the surface of [alpha-PW11{Al(OH2)}O-39](4-) even after 24 h exposure to 50 equiv. of water.

DOI： 10.1039/c2dt32107f

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

P-n junction solar cells based on anthradithiophene (ADT) as a p-type semiconductor were fabricated by using the photoprecursor method in which an alpha-diketone-type precursor was spin-coated and then transformed to ADT in situ by photoirradiation. Combination with PC71BM as an n-layer material led to 1.54% photoconversion efficiency.

DOI： 10.1039/c3cc46178e

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

In this study, we have investigated the shape-dependence of TPA cross-section values of two-dimensionally extended benzoporphyrin arrays to determine the relationship between the directionality of pi-conjugation pathways and TPA properties.

DOI： 10.1039/c3cp50166c

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：World Scientific Publishing Co. Pte Ltd  

Magnetic circular dichroism (MCD) spectroscopy and TD-DFT calculations are used to analyze the electronic structure and optical properties of low-symmetry acenaphthoporphyrins with AAAB, ABAB and AABB structures. Evidence for dual fluorescence caused by tautomerism has been identified in the emission spectra of the AAAB and ABAB compounds. The sign sequences observed for the Q and B bands in the MCD spectra have been used to validate the results of the TD-DFT calculations. An anomalous +/- sign sequence is observed in the B band region with ascending energy similar to that reported previously for metal tetraphenyltetraacenaphthoporphyrin complexes. Copyright © 2013 World Scientific Publishing Company.

DOI： 10.1142/S1088424613500727

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Ethyl 12-oxo-4,11-dihydro-4,11-ethanonaphth[2,3-f]isoindole-1-carboxylate (2) was prepared from 7-tert-butoxynorbornadiene and quantitatively converted to ethyl naphth[2,3-f]isoindole-1-carboxylate (3) by the thermal or photochemical cheletropic reaction. Ethyl naphth[2,3-f] isoindole-1-carboxylate (3) existed in a 2H-form both in solution and as a solid, and gradually dimerized to give a dianthradiazafulvalene derivative under aerobic conditions.

DOI： 10.1039/c2ra22870j

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

DOI： 10.1002/anie.201209678

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Ethanonaphthoporphyrins with a halogen atom at the zeta position were prepared by the [3+1] porphyrin synthesis of halogen-substituted ethanobenz[f]isoindole with a tripyrrane derivative. The halogeno porphyrins were converted to the corresponding ethynyl and pinacolatoboronyl compounds by Sonogashira and borylation reactions, respectively. Suzuki, Sonogashira, and Glaser coupling reactions of these ethanonaphthoporphyrins gave bis-porphyrins connected with no atom, acetylene, and butadiyne, respectively. Retro Diels-Alder reaction of these bis-porphyrins brought about the conversion of bicyclo[2.2.2]octadiene (BCOD) to benzene moieties to give bis-naphthoporphyrins, quantitatively.

DOI： 10.3987/COM-12-S(N)50

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Bis(azulenylethynyl)thiophenes, terthiophenes, and dithienothiophenes have been synthesized by the Pd-catalyzed cross-coupling of the corresponding diiodothiophenes with 1- and 6-ethynylazulenes under Sonogashira-Hagihara conditions.

DOI： 10.3987/COM-12-S(N)63

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Peripherally pi-extended N-confused porphyrin rhenium complexes were synthesized by the rhenium-mediated reactions of N-confused porphyrins with 2-methyl azaarene and the structures were elucidated by X-ray crystallographic analyses. Extension of the pi-conjugation in the complexes was supported by the absorption spectra, electrochemical measurements and theoretical calculations.

DOI： 10.1039/c2sc20708g

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Bicyclo[2.2.2]octadiene (BCOD) fused azuliporphyrins were synthesized by 3+1 porphyrin synthesis of azulitripyrranes with diformylpyrroles. Subsequent retro-Diels-Alder reaction of the BCOD-fused azuliporphyrins afforded azulibenzo, azulidibenzo-, and azulitribenzoporphyrins 1-5. NMR and UV/Vis spectra, as well as nucleus-independent chemical shift (NICS) calculations revealed that 1-5 and their diprotonated dications exhibit relatively low porphyrinoid aromaticity, which was dependent on the position and number of fused benzene rings present.

DOI： 10.1002/chem.201201399

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Quinone dimers are readily prepared quantitatively from 2-sulfanyl-1,4-dimethoxybenzene by oxidative treatment. The oxidative coupling progressed in a highly regioselective manner. Removal of O-protection and subsequent oxidation gave 5,5'-bis(sulfanylquinone) dimer in good yields. Physical properties of the dimer derivatives are also investigated.

DOI： 10.1246/cl.2012.950

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

One-pot treatment of commercially available 1,3,3-tributoxy-2-cyanopropene with 2 equivalents of primary aromatic amines readily afforded 1,5-diaryl-1,5-diaza-3-cyanopenta-1,3-dienes. UV properties varied as steric size of the orthosubstituent in the N-aryl units increased. X-ray crystallographic analyses indicated preferable conformation of these compounds, and the twist angles between 1,5-diazapentadiene and aromatic units were measured. The relationship between the twisted angles and UV absorptions was rationalized by MO calculation, and the UV peak wavelengths are useful for the estimation of the twisted angles. A novel tetracoordinate diaryl-1,5-diazapentadiene was prepared. UV spectrum for its lithium complex in CHCl3 supported that the complex had a twisted conformation of the aryl units because the two etharial oxygen atoms coordinated to lithium cation.

DOI： 10.1246/cl.2012.984

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Cyclic nickel and free-base porphyrin dimers (Ni-2-CPDpy and H-4-CPDpy) include [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) both in solution and in the crystals. In the crystal packing of the inclusion complex of Ni-2-CPDpy and PCBM, a nanotubular structure is constructed through the self-assembly of the porphyrin moiety. The PCBM molecules are linearly arranged in the inner channel of the nanotube to give a supramolecular peapod. On the other hand, in the crystal of the inclusion complex of H-4-CPDpy and PCBM, a dimeric structure of the PCBM molecules is formed through pi-pi interaction between their phenyl groups.

DOI： 10.1246/bcsj.20120073

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Bisdimethylfluorenylamino-based push-pull dyes bearing one or two benzo[c]thiophene and its precursor bicyclo[2.2.2]octadiene (BCOD) fused thiophene as it bridge have been synthesized. The effect of fused-ring on thiophene bridge for the spectroscopic and electrochemical properties of these dyes has been investigated. Dye-sensitized solar cells fabricated with these dyes show moderate photovoltaic properties. (C) 2012 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2012.04.052

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：NATURAL PRODUCTS INC  

Four new eremophilane-type sesquiterpenes, culcitiolides A-D, were isolated from the stem of Senecio culcitioides Sch. Bip (Asteraceae). Their structures were established by detailed 2D NMR spectroscopic and single-crystal X-ray experiments. These compounds were assessed for inhibitory activity against nuclear factor kappa B (NF-kappa B). Culcitiolides C and D at 20 mu M showed 97 and 100% inhibition of NF-kappa B activity, respectively.

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

5,14-alpha-Diketopentacene, a structural isomer of 6,13-alpha-diketopentacene, was prepared from pentacene in three steps. In addition to the typical n-pi* absorption of the diketone moiety at around 468 nm and the anthracene-like absorption at 333, 349, and 367 nm, a broad absorption was observed at around 386 nm, which could be assigned to an intramolecular charge-transfer absorption from anthracene to the diketone moiety. 5,14-alpha-Diketopentacene could be converted into pentacene quantitatively by photoirradiation at 405 and 468 nm in toluene with quantum yields of 2.3 and 2.4%, respectively, and these values are higher than the quantum yield of 1.4% obtained for 6,13-alpha-diketopentacene irradiated at 468 nm. The quantum yields in acetonitrile were lowered to 0.33 and 0.28% with irradiation at 405 and 468 nm. The crystal structure of 5,14-alpha-diketopentacene showed a CH-pi interaction and pi-pi stacking between neighbouring anthracene and benzene moieties. The lower solubility of 5,14-alpha-diketopentacene compared with the 6,13-isomer could be explained by this crystal structure.

DOI： 10.1002/ejoc.201101736

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

6,13-Diiododibenzo[a,h]anthracene and 5,8-diiodopicene were synthesized by AuCl-catalyzed double cyclization. The highly selective reaction yielded a new class of pen-halogenated fused aromatics. (C) 2012 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2012.01.071

Web of Science

Scopus

researchmap

DOI： 10.1021/jp300771q

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Esters of 4,9-dihydro-2H-benz[2,3-f] isoindole-1-carboxylate and 4,11-dihydro-2H-naphth[2,3-f]isoindole-1-carboxylate were prepared by the modified Barton-Zard reaction of 2,3-bis(phenylsulfonyl)-1,2,3,4-tetrahydro-naphthalene and anthracene with isocyanoacetate esters, respectively. The bis(phenylsulfonyl) derivatives were, in turn, prepared by the pericyclic reactions of the corresponding sultines with trans-1,2-bis(phenylsulfonyl)ethylene. The pyrrole esters were converted to the corresponding mono-naphthoporphyrin and mono-anthraporphyrin in good overall yields.

DOI： 10.3987/COM-11-S(P)60

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Benzene-fused bis-(borondipyrromethene)s (bis-BODIPYs) were synthesized by retro-Diels-Alder reaction of the corresponding bicyclo[2.2.2]octadiene-fused (BCOD-fused) bis-BODIPYs, which were, in turn, prepared from 4,8-ethano-4,8-dihydropyrrolo[3,4-f]isoindole derivatives. The pi-fused bis-BODIPY chromophores were designed to show intensive absorption and strong fluorescence in the near-infrared region and not to have any strong absorption in the visible region. A 6,10-dibora-5a,6a,9a,10a-tetraaza-s-indaceno[2,3-b:6,5-b']difluorene derivative (syn-bis-benzoBODIPY) obtained by a thermal retro-Diels-Alder reaction of the corresponding BCOD-fused BODIPY dimer has strong absorption and emission bands at 775 and 781 nm, respectively. The absolute quantum yield is 0.36. The absorption is more than 5.0 times stronger than other absorptions observed in the visible region. In the case of 6,15-dibora-5a,6a,14a,15a-tetraaza-s-indaceno[2,3-b:6,7-b']difluorene derivatives (anti-bis-benzoBODIPY), the absorption and emission maxima exceed 840 nm.

DOI： 10.1039/c2ob25930c

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

o-Quinodimethane (o-QDM) generated from benzosultine was used to extend the pyrrole system for the preparation of octabromo-tetranaphtho[2,3]porphyrins via oxidative aromatization. The properties of these bromoporphyrins were presented and chemical transformation via Pd-catalyzed Suzuki reaction was also effectively achieved.

DOI： 10.1039/c2ob00041e

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Optically active ent-calystegine B4 was prepared in 13 steps from commercially available chiral L-dimethyl tartrate. The synthesis was achieved by the Michael addition and the aldol reaction of nitromethane to form cycloheptanone in a stereoselective manner. Reduction of the nitro group in the presence of Boc(2)O accomplished an efficient conversion to amino cycloheptanone, which readily afforded the desired ent-calystegine B4.

DOI： 10.1039/c2ob25386k

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Singly N-confused [26] and [28]hexaphyrins (4, 5) with planar and twisted structures, respectively, were prepared via the acid catalyzed [3 + 3] condensation of N-confused and regular tripyrrane precursors. Huckel aromaticity is observed for [26]hexaphyrin, while the [28]hexaphyrin and its mono-Pd(II) complex exhibit "nonaromaticity" in spite of their Mobius-type structures, judging from the spectroscopic features and theoretical calculations.

DOI： 10.1039/c2dt30306j

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Hole mobility was evaluated by top-contact bottom gate field effect transistor and time resolved microwave conductivity measurements in 2,6-dithienylanthracene and hexyl-substituted 2,6-dithienylanthracene films prepared by spin-coating of their alpha-diketone precursors followed by photoirradiation, revealing enough high potentials for semiconducting films with charge carrier mobilities of 0.8-0.9 cm(2) V-1 s(-1) in the photo-irradiated films.

DOI： 10.1039/c2cc35439j

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

The synthesis and molecular structure of a monomeric diplatinum(II) complex composed of mono-lacunary alpha-Keggin polyoxometalate is described. The polyoxometalate, Cs-3[alpha-PW11O39-{cis-Pt(NH3)(2)}(2)]center dot 8H(2)O (Cs-1), afforded by a stoichiometric reaction of mono-lacunary Keggin polyoxotungstate with cis-diamminedichloroplatinum(II) in water, followed by crystallization from water, was obtained as analytically pure, homogeneous, yellow crystals. The compound Cs-1 was characterized by elemental analysis, thermogravimetric/differential thermal analysis (TG/DTA), Fourier transform infrared (FTIR) and UV-visible spectroscopy, solution H-1 and P-31 nuclear magnetic resonance (NMR), and X-ray crystallography. The single-crystal X-ray structure analysis revealed that the two cis-platinum(II) moieties, [cis-Pt(NH3)(2)](2+), were coordinated each to two oxygen atoms in a mono-vacant site of [alpha-PW11O39](7-) with asymmetric configuration, resulting in an overall C-1 symmetry. Furthermore, hydrogen evolution from an EDTA center dot 2Na (ethylenediamine tetraacetic acid disodium salt) aqueous solution under visible-light irradiation (&gt;= 400 nm) was achieved by using polyoxoanion 1 and titanium dioxide.

DOI： 10.1039/c2dt30915g

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Optically active stannolanes and trigonal bipyramidal penta-coordinated tin complexes were readily prepared by radical cyclization of N-propargylated chiral aza-Morita-Baylis-Hillman adducts induced by Bu3SnH. A translocated radical through the cyclization attacked the Bu3Sn group in an S(H)2 manner.

DOI： 10.1039/c2cc31753b

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

DOI： 10.1002/anie.201203712

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

Cyclic nickel and free-base porphyrin dimers (Ni-2-CPDpy and H-4-CPDpy) include fullerene C-70 both in solution and in the crystals. Based on the C-13 NMR spectra in solution, the included C(70 molecu)le inside the cavity of Ni-2-CPDpy shows both end-on and side-on orientations, whereas the C-70 molecule within H-4-CPDPy has only a side-on orientation toward the porphyrin rings. X-ray crystallography revealed both "end-on" and "side-on" orientations of C-70 in the crystal structure of the inclusion complex of Ni-2-CPDPy and C-70. This is the first example of an X-ray crystallographic determination for an end-on orientation of C-70 cocrystallized with porphyrins. On the other hand, only a side-on orientation of C-70 was observed in the crystal structure of the complex of H-4-CPDPy and C-70. Further, a zigzag array of C-70 molecules through van der Waals contacts with each other is formed along the monoclinic b axis in the latter crystal.

DOI： 10.1246/bcsj.20110248

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WORLD SCI PUBL CO INC  

Facing zinc bisporphyrins connected with diethanoanthracene and diethanonaphthacene (syn-1 and syn-2) are prepared by double [3+1] porphyrin synthesis of tripyrranedicarbaldehyde with syn-5,11-dimethoxy-4,6,10,12-tetrahydro-4,12;6,10-diethanoanthracene[2,3-c;7,8-c']dipyrrole and syn-4,7,11,14-tetrahydro-4,14;7,11-diethanonaphthacene[2,3-c;8,9-c']dipyrrole. These bisporphyrins contain large clefts with different sizes capable for complexation with fullerenes such as C-60 and C-70. These designed syn-oriented bisporphyrins serve as effective and selective molecular tweezers for C-70. Binding affinity of the zinc bisporphyrins, namely, syn-1 and syn-2, towards C-60 and C-70 in solution is determined by employing UV-vis spectrophotometric technique. Values of binding constants (K) in toluene for the non-covalent complexes of syn-1 with C-60 and C-70 are estimated to be 3.1(4) x 10(4) and 5.0(2) x 10(5) M-1, respectively, and those of syn-2 with C-60 and C-70 are enumerated to be 2.1(4) x 10(4) and 1.70(13) x 10(5) M-1, respectively. Binding of C-60 and C-70 in the clefts of syn-1 and syn-2 is clearly demonstrated by the crystal structures of C-60/syn-1, C-70/syn-1, C-60/syn-2, and C-70/syn-2 complexes. In the crystal structures with C-70, the directions of the long axis of C-70 are found to be quite different: in the case of C-70/syn-1 complex the axis lies perpendicularly to the line connecting two zinc atoms; however, for the C-70/syn-2 complex, the axis occupies in-plane to the same line. Both the clefts of syn-1 and syn-2 are induced to fit the included fullerenes by domed out-of-plane distortion of porphyrin rings. Moreover, the bicyclo[2.2.2]octadiene moieties of syn-1 are widened by complexation with the fullerenes, while the same moieties of syn-2 are narrowed by the complexation. Therefore, syn-1 catches the fullerenes at the shallow part of the cleft. On the other hand, syn-2 catches the fullerenes at the bottom part of the cleft. NMR experiments of the complexes in THF-d(8) also support these orientations even in solution.

DOI： 10.1142/S1088424611003872

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WORLD SCI PUBL CO INC  

A series of benzoporphycenes and naphthoporphycenes and their zinc complexes were prepared from bicyclo[2.2.2]octadiene fused porphycenes by a retro-Diels-Alder reaction and their photophysical properties were studied. Free-base tetranaphthoporphycene was not soluble in common organic solvents, but zinc tetranaphthoporphycene was slightly soluble in pyridine and showed B- and Q-bands at 507 and 690 nm, respectively. Dinaphthoporphycene showed broad B- and Q-bands due to its lower symmetry. Tetrabenzo-, dibenzo-, and dinaphthoporphycenes showed fluorescence at 673, 654, and 670 nm with quantum yields of 0.32, 0.42, and 0.31, respectively, although their precursors were non-fluorescent. Zinc complexes of tetrabenzo-, dibenzo-, tetranaphtho-, dinaphthoporphycenes and their bicyclo[2.2.2]octadiene-fused precursors revealed moderate fluorescence with quantum yields of 0.15-0.37. The crystal structures of tetrabenzo-and dibenzoporphycenes showed herringbone structures, while the zinc tetrabenzoporphycene showed a hexagonal box-structure with six pyridine ligands inside.

DOI： 10.1142/S1088424611003823

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

Excited state dynamics of benzotriphyrin(2.1.1) is investigated by time-resolved fluorescence techniques. The fluorescence quantum yield is found to be 0.005, and the lifetime of the excited state of triphyrin(2.1.1) is found to be 140 ps. Fluorescence anisotropy clearly shows that intramolecular proton transfer does not occur within the excited state lifetime. The short lifetime of the excited state is due to fast internal conversion (IC) from the S(1) state, and to the nonplanarity of the macrocycle enhancing IC decay pathways. (C) 2011 Elsevier B. V. All rights reserved.

DOI： 10.1016/j.cplett.2011.07.075

Web of Science

Scopus

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：SOC SYNTHETIC ORGANIC CHEM JPN  

This paper focuses on the synthesis of new aromatic compounds by thermal, photochemical, or oxidative cleavage reaction of the corresponding precursors. The precursor-methods are useful for the derivatization of the non-soluble aromatic compounds. We have applied retro Diels-Alder reactions for the preparation of new pi-expanded porphyrinoid compounds such as [14] tribenzo-triphyrin (2.1.1), tetrabenzoporphycene, dodecasubstituted porphycene, tetraanthraporphyin, butadiyne-linked tetrabenzoporphyrin dimer, and so on. We have investigated the photocleavage synthesis of pentacenes from the corresponding alpha-diketone precursors. This photoreaction enabled us to prepare 1,4,8,11-tetrasubstituted pentacene. The synthesis of new pentacene derivatives with electron-withdrawing substituents at 6,13-positions by oxidative cleavage reaction will be also reported.

DOI： 10.5059/yukigoseikyokaishi.69.802

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WORLD SCI PUBL CO INC  

Bicyclo[2.2.2]octadiene(BCOD)-fused diazaporphyrin was synthesized by the reaction of BCOD-fused dipyrromethane with sodium nitrite in acetic acid/ethanol in the presence of copper(II) acetylacetonate. This soluble precursor was converted into the semiconducting thin film of (tetrabenzodiazaporphyrinato)copper(II) by heating after fabrication via spin-coating.

DOI： 10.1142/S1088424611003641

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

A pi-expanded BODIPY dye with an intramolecular boronate skeleton was synthesized by retro Diets-Alder reaction of the bicyclo[2.2.2]octadiene (BCOD)-fused BODIPY and the subsequent O-chelation. The photophysical and electrochemical properties were examined by UV-vis, fluorescence, CV measurements, and DFT calculation. This BODIPY exhibited the absorption and emission over a visible-NIR region at 600-850 nm. O-chelated BODIPY showed a bathocromic shift compared to F-BODIPYs. This dye showed a bright fluorescence emission at 733 nm with the high phi value of 0.58. (C) 2011 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2011.03.016

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

We have investigated the role of fused benzo rings on the electronic structures and intramolecular energy relaxation dynamics in a series of benzoporphyrins (Bpl, syn-Bp2, anti-Bp2, Bp3, and Bp4) by using time-resolved fluorescence measurements and theoretical calculations. Interestingly, even though anti- and syn-Bp2 have the same number of fused anti-Bp2 benzo rings, in the respective absorption spectra, shows an obvious splitting of B(x) (Q(x)) and B(y) (Q(y)) states, whereas syn-Bp2 exhibits degenerate B and Q bands. These features provide two dynamical models for the effect of the position of substituted benzo rings on the intramolecular energy relaxation dynamics. syn-Bp2 gives rise to similar intrarnolecular dynamics from the B state to the Q state in the case of ZnTPP having Do molecular symmetry. On the other hand, anti-Bp2 shows split B and Q bands in the order B(y) &gt; B(x) &gt; Q(x) &gt; Q(y), which leads a superimposition of the Q(x) (0,0) and Q(y) (1,0) bands. This overlap generates a strong coupling between these two states, which results in a direct internal conversion from B(x) (0,0) to Q(y) (0,0). This observation suggests that the anti-type fused position of benzo rings leads to a new mechanism in internal conversion from the B to the Q state. On the basis of this work, further insight was obtained into the effect of fused benzo rings on the photophysical properties of benzoporphyrins, providing a detailed understanding of the structure-property relationship in a series of benzoporphyrins.

DOI： 10.1021/jp200493p

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

5,12-Dicyanonaphthacene and 6,13-dicyanopentacene have been synthesized for the first time. The LUMO and HOMO levels are deepened as predicted and fabricated organic field-effect transistors (OFETs) showed ambipolar responses with carrier mobilities of 10(-3) cm(2)/V.s.

DOI： 10.1021/ol200145r

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

The synthesis of dodecasubstituted porphycenes has not been reported, to date. Herein, the preparation of tetramethyloctaethylporphycene by a McMurry-type coupling of 3,3', 4,4'-tetraethyl-5,5'-diformyl-2,2'-bipyrrole was attempted at first, but dodecasubstituted porphycene was not successfully obtained and only pyrrolocyclophene was obtained. The structure of the pyrrolocyclophene was determined by H-1 NMR spectroscopy, FAB MS, and X-ray crystal-structure analysis. The pyrrolocyclophene was not successfully oxidized to porphycene. Then, the McMurry-type coupling of bicyclo[2.2.2]octadiene (BCOD)-fused 5,5'diacyl-2,2'-bipyrroles was performed and tetra-meso-octa-beta-substituted (dodecasubstituted) porphycenes were successfully obtained for the first time. The structures were determined by H-1 NMR spectroscopy and X-ray crystal-structure analysis. The crystal structures and NMR spectra were compared carefully with octasubstituted porphycenes, and there was a good correlation between the position of the substituents, the N1-N2 and N1-N4 distances of the porphycene inner nitrogen atoms, and NMR chemical shifts of the inner NH protons, which expressed the strength of N-H center dot center dot center dot N hydrogen bonding between N1 and N2. These results suggested that the BCOD structure was relatively compact compared with common alkyl groups and that was why the dodecasubstituted porphycenes were available this time. UV/Vis absorption and fluorescence properties are also discussed.

DOI： 10.1002/chem.201002788

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

A new cytotoxic imidazole alkaloid, stellettazole D, containing norsesquiterpene and aminopropylimidazolium units, has been isolated from the marine sponge Jaspis duoaster. The structure of stellettazole D was assigned on the basis of NMR, mass spectrometry, and IR spectral data. Stellettazole D has moderate cytotoxicity against a limited number of tumor cells.

DOI： 10.1246/cl.2011.186

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The present paper reports the photophysical investigations of a designed bisporphyrin (1), and its supramolecular complexes with C-60 and C-70 in toluene medium. UV-vis studies reveal appreciable ground state interaction between fullerenes and 1. The stoichiometry of the fullerene complexes of 1 is found to be 1:1. Steady state fluorescence studies elicit quenching of fluorescence oil in the presence of fullerenes. The binding constants of the C-60/1 and C-70/1 complexes are estimated to be 3760 and 31,222.5 dm(3) mol(-1), respectively. Time resolved emission studies establish relatively long-lived charge separated state for the C-70/1 complex. Molecular mechanics calculations in vacuo evoke the stereoscopic structures of the fullerene/1 complexes and interpret the stability difference between C-60 and C-70 complexes of 1 in terms of heat of formation values. (C) 2010 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.saa.2010.09.019

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Novel bisimide-fused acenes were synthesized via bismuth triflate mediated double-cyclization reaction of acid chlorides and isocyanates. Their optical and electrical properties revealed significantly smaller HOMO-LUMO gaps compared with those of their parent acenes. Fabricated OFET based on tetracene bisimide showed n-type OFET outputs.

DOI： 10.1039/c1cc13980k

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Vibrational circular dichroism (VCD) spectra were measured on the chloroform solutions of a series of mixed-ligand diamagnetic Co(III) complexes, [Co(tfac)(n)(acac)(3-n)] (n = 0-3, tfac = 1,1,1-trifluoro-2,4-pentanedionato; acac = acetylacetonato). Distinct differences were observed in the VCD spectra among the geometrical isomers of the same ligand composition. Such differentiation was hardly possible by their infra-red spectra alone. The structural identification of these isomers was performed in conjunction with DFT calculations.

DOI： 10.1039/c0dt01342k

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

DOI： 10.1002/anie.201007510

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

The metal-free and meso-free [14]triphyrin(2.1.1) compound was successfully prepared based on the intramolecular McMurry coupling reaction of diformyl-tripyrrane in 16% yield, and was converted to the bowl-shaped Mn(I)(TriP)(CO)(3) and Re(I)(TriP)(CO)(3).

DOI： 10.1039/c0cc04286b

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

DOI： 10.1002/anie.201006784

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Free base and zinc porphyrins are linked with fullerene (C(60)) through beta,beta`-pyrrolic positions rather than meso-positions by Diels-Alder reaction of monoanthraporphyrins (H(2)P-mA and ZnP-mA) and C(60) to afford a pi-expanded free base porphyrin-fullerene dyad (H(2)P-C(60)) and its zinc porphyrin-fullerene dyad (ZnP-C(60)) in 86 and 51% yield, respectively The X-ray crystallographic analysis of ZnP-C(60) showed two comma-shaped swirls-like structure in a unit cell The intramolecular center-to-center and edge-to-edge distances between the porphyrin and fullerene moieties were 11 5 and 2 5 angstrom, respectively The porphyrins and fullerenes were packed in layer-by-layer structure and the porphyrins lied down in parallel The Intermolecular center-to-center distances between the neighboring fullerenes were 10 252, 10028, and 10 129 angstrom, which were less than typical van der Waals distance and the pi-pi interaction spread two-dimensionally The energy of the charge-separated (CS) state of ZnP-C(60) (1 11 eV) determined by differential-pulse voltammetry measurements in benzonitrile is significantly lower than those of zinc porphyrin-C(60) dyads linked at meso positions because of the low oxidation potential of the a-expanded ZnP moiety The CS energy of ZnP-C(60) in a nonpolar solvent such as toluene (1 40 V) is lower than the triplet excited state of C(60) ((3)C(60)*), enabling us to attain a longed lived triplet CS state (8 1 mu s) in toluene, detected by nanosecond laser flash photolysis experiments The distance between unpaired electrons in the triplet CS state was determined by the EPR spectrum to be 9 1 angstrom, which agreed with the distance between a zinc atom of the porphyrin and a carbon edge of C(60) in the crystal structure of ZnP-C(60) The rate constants of photoinduced electron transfer and back electron transfer of H(2)P-C(60) and ZnP-C(60), which were determined by femtosecond and nanosecond laser flash photolysis measurements, were analyzed in light of the Marcus theory of electron transfer

DOI： 10.1021/jp102966x

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Bicyclo[2.2.2]octadiene(BCOD)-fused trithiasapphyrin was prepared by 3+2 condensation of BCOD-fused thiatripyrrane with BCOD-fused bithiophene. The BCOD-fused trithiasapphyrin was successfully converted to pentabenzo[b,g,l,q,v]sapphyrin by the thermal retro-Diels-Alder reaction. In this case, trithiapentabenzo[b,g,l,q,v]- and trithiadibenzo[g,q]sapphyrins were selectively prepared by control of the temperature in the thermal retro-Diels-Alder reaction. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2010.06.086

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

A series of pi-expanded boron-dipyrromethenes (BODIPYs) fused with aromatic rings at beta,beta-positions, such as benzene, acenaphthylene, and benzofluoranthene were prepared by the reaction of BF(3)center dot OEt(2) with bicyclo[2.2.2]octadiene-fused dipyrromethene and the subsequent retro Diels-Alder reaction. These BODIPYs exhibited the absorptions and the fluorescence emissions over wide range of visible-near infrared region at 500-800 nm. BODIPYs composed of two fluorantho[8,9-f]isoindoles absorbed and emitted at red-region over 750 nm with absolute fluorescence quantum yield (Phi(f)) of ca. 0.3, although they are unstable under air in room light. BODIPY composed fluorantho[8,9-f]isoindole and acenaphtho [1,2-c]pyrrole was stable and showed a bright fluorescence emission at 695 nm with high Phi(f) of 0.70. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2010.06.045

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

15-Acetoxy- and 15-hydroxy-6,13-dihydro-6,13-ethanopentacenes sublimed over 300 degrees C and no pentacene was formed below the temperature. The precursors bearing chlorinated epithiomethano bridges suffered complicated decomposition to give oligomeric pentacene derivatives. The precursor bearing an epithio-oxomethano bridge underwent smooth and clean conversion to pentacene by heat or light. An organic field-effect transistor fabricated by the spin-coating method of the precursor followed by light irradiation at 120 degrees C showed a good FET performance of mu=2.5 x 10(-2) cm(2) V-1 s(-1) and on/off ratio=3.8 x 10(4). (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2010.06.051

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The intramolecular Pauson-Khand reaction of aza-Baylis-Hillman adducts, which were prepared through the thio-Michael/imino-aldol domino reaction of optically active sulfinimines, was examined and gave optically active cis- and trans-pyrrolidine-fused cyclopentenones in a stereoselective manner. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2010.02.115

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Tetrabenzoporphyrins fused with fluoranthenes were prepared by the retro Diels-Alder reaction of the precursors composed of a porphyrin and four fluoranthenes connected with bicyclo[2.2.2]octadiene (BCOD). These porphyrins exhibited the Soret (480-494 nm, epsilon = 243,000-277,000) and intense Q bands (739-760 nm, epsilon = 375,000-509,000). Free bases and Zn complexes of them fluoresce at 760 nm and 746 nm with small Storks shifts and high quantum yields of 30 and 10 %, respectively.

DOI： 10.3987/COM-09-S(S)98

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The syntheses of 1,4,8,11-tetraphenylpentacene and 1,4,8,11-tetra(2'-thienyl)pentacene are described via photodecarbonylation of the corresponding alpha-diketone precursors. (C) 2010 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2010.01.009

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

A cyclic free-base porphyrin dimer H-4-CPDPy (CPD = cyclic porphyrin dimer) linked by butadiyne moieties bearing 4-pyridyl groups self-assembles to form a novel porphyrin nanotube in the crystalline state. The cyclic molecules link together through non-classical C-H center dot center dot center dot N hydrogen bonds and pi-pi interactions of the pyridyl groups along the crystallographic a axis. H-4-CPDPy includes a C-60 molecule in its cavity in solution. In the crystal structure of the inclusion complex (C-60 subset of H-4-CPDPy), the dimer "bites" a C-60 molecule by tilting the porphyrin rings with respect to each other, and there are strong pi-pi interactions between the porphyrin rings and C-60. The included C-60 molecules form a zigzag chain along the crystallographic b axis through van der Waals contacts with each other. Femtosecond laser flash photolysis of C-60 subset of H-4-CPDPy in the solid state with photoexcitation at 420 nm shows the formation of a completely charge-separated state {H-4-CPDPy center dot+ + C-60(center dot-)}, which decays with a lifetime of 470 Ps to the ground state. The charge-carrier mobility of the single crystal of C-60 subset of H-4-CPDPy was determined by flash photolysis time-resolved microwave conductivity (FP-TRMC) measurements. C-60 subset of H-4-CPDPy has an anisotropic charge mobility (Sigma mu=0.16 and 0.13 cm(2)V(-1) s(-1)) along the zigzag chain of C-60 (which runs at 45 degrees and parallel to the crystallographic b axis). To construct a photoelectro-chemical cell, C-60 subset of H-4-CPDPy was deposited onto nanostructured SnO2 films on a transparent electrode. The solar cell exhibited photovoltaic activity with an incident photon to current conversion efficiency of 17%.

DOI： 10.1002/chem.201001815

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

Tetrameric porphyrin formation of 2-hydroxymethylpyrrole fused with porphyrins through a bicyclo[2.2.2]octadiene unit gave bicyclo[2.2.2]octadiene-fused porphyrin pentamers. Thermal conversion of the pentamers gave fully pi-conjugated cruciform porphyrin pentamers fused with benzene units in quantitative yields. UV/Vis spectra of fully pi-conjugated porphyrin pentamers showed one very strong Q absorption and were quite different from those of usual porphyrins. From TD-DFT calculations, the HOMO level is 0.49 eV higher than the HOMO-1 level. The LUMO and LUMO + 1 levels are very close and are lower by more than 0.27 eV than those of other unoccupied MOs. The strong Q absorption was interpreted as two mutually orthogonal single-electron transitions (683 nm: 86%, HOMO -&gt; LUMO; 680 nm: 86%, HOMO -&gt; LUMO + 1). The two-photon absorption (TPA) cross section value (sigma((2))) of the benzene-fused porphyrin pentamer was estimated to be 3900 GM at 1500 nm, which is strongly correlated with a cruciform molecular structure with multidirectional pi-conjugation pathways.

DOI： 10.1002/chem.200903196

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

A new alpha-diketoporphyrin and the corresponding Pd complex were prepared from the monoanthroporphyins and their photochemical properties were investigated by measurements of absorption and emission spectra, fluorescence lifetimes, laser flash photolysis, cyclic voltammetry, and theoretical calculations. Intramolecular electron transfer from the porphyrin singlet excited state to the diketone moiety was observed for the free base alpha-diketoporphyrin in benzonitrile, but this was not observed in toluene. Photoreactivity of the alpha-diketoporphyrins was also examined by irradiation at the Soret and Q bands. When the Soret band of the freebase alpha-diketoporphyrin was irradiated, cleavage of the diketone moiety occurred to afford the monoanthroporphyrin with the release of two CO molecules quantitatively in both benzonitrile and toluene. When the Q band of the freebase alpha-diketoporphyrin was irradiated, no photocleavage reaction occurred in toluene. In contrast to the freebase alpha-diketoporphyrin, the photocleavage reaction of the Pd complex occurred with irradiation at the Q band as well as the Soret band to afford the monoanthroporphyrin quantitatively in toluene. The photocleavage reaction proceeded much more effectively in toluene than in benzonitrile. The occurrence of rapid photoinduced electron transfer from the singlet excited state porphyrin to the diketone moiety, which was detected by femtosecond laser flash photolysis measurements, results in a significant decrease in the singlet excited state lifetime, prohibiting the photocleavage reaction in benzonitrile. Thus, the Pd alpha-diketoporphyrin can act as an excellent precursor for the corresponding acene in toluene. The photocleavage process provides a convenient and inexpensive method to make the thin film.

DOI： 10.1039/b923220f

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

(Figure Presented) Acid does the trick: A novel 1,10-phenanthroline- embedded sapphyrin analogue 1 (see scheme; R = COOEt, Ar = p-tolyl) bearing meso alkylidenyl double bonds has been synthesized. Interestingly, the protonated form of! ([1-3 H]3+) exhibits singlet biradicaloid character. © 2010 Wiley-VCH Verlag GmbH &amp; Co. KGaA, Weinheim.

DOI： 10.1002/anie.200907350

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

This article describes the preparation of (ethylenedithio)bicyclo[2.2.2]octadiene-fused porphyrins 13 and 14a,b as soluble precursors of 2,3-dihydrobenzo[1,4]dithiin-fused porphyrins and the retro Diels-Alder conversion of the precursors 13 and 14a,b.

DOI： 10.1080/10426501003773449

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

The synthesis of a novel spiro type gem-difluorocyclopropane building block, 1, 1,7,7-tetrafluoro-2,8-bis(hydroxymethyl)dispiro[2.2.2.2]decane(1), has been accomplished in optically pure form using chemo-enzymatic reaction protocol. Various types of diesters or dialkyl ether were prepared from diol (+)-1 or(-)-1 in optically active form and their helical twisting power(HTP) was evaluated by addition of 1.0 wt% to a non-chiral nematic liquid crystal host. Although their HTP values were not significant, all compounds showed liquid crystal property with SmC* phase when they were dissolved (20 wt%) in achiral nematic host liquid crystal. (C) 2009 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jfluchem.2009.06.007

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

meso-Chlorinated bicyclo[2.2.2]octadiene-fused porphyrins 2 (Cl(n)TBCODPs; n = 1-4) have been synthesized by chlorination of the free base TBCODP-H(2) (1-H(2)) using N-chlorosuccinimide (NCS). The chlorinated derivatives were easily separated by column chromatography on silica gel to give 2-H(2) in good yields. This method for the chlorination of porphyrin using NCS is mild, safe, and economic compared with the established procedure for the meso-chlorination of porphyrins. We also discovered the unexpected meso-chlorination of the porphyrin with dichlorodicyanobenzoquinone (DDQ) by single-electron transfer. Cl(n)TBCODPs 2 were converted into tetrabenzoporphyrins (Cl(n)TBPs) 3 in 100% yields by retro-Diels-Alder reaction. The derived compounds were characterized by NMR spectroscopy, UV/Vis spectrophotometry, cyclic voltammetry (CV), X-ray crystallography, and organic field-effect transistor (OFET) characteristics. The introduction of chlorine at the meso positions of the TBPs drastically changed their electronic and structural properties. The maxima of protonated Cl(4)TBP-H(2) (3d-H(2i) lambda(max) = 494, 649, and 707 nm) were redshifted by around 50-65 nm relative to those of protonated TBP-H(2) (lambda(max) = 431, 605, and 660 nm). The two Q-band maxima of the Cl(4)TBP dication are similar to those of a tetraacenaphthoporphyrin dication (lambda(max) = 525, 646, and 702 nm), which has one of the most redshifted Q-bands. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

DOI： 10.1002/ejoc.200900601

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Synthesis of [Ru(phenP)(3)](PF(6))(2), where phenP = phenanthrolinoporphyrin, has been achieved by the reaction of phenanthrolinoporphyrins with RuCl(3) for the first time. The phenP reacted with Ru(II) to form RuL(2)(phenP)(2+) complexes (L = 2,2&apos;-bipyridine or 1,10-phenanthroline), which were converted Into the dyads Ru-phenP(Zn) on treatment with zinc acetate.

DOI： 10.1021/ol901510e

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/ange.200900596

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：JAPAN SOCIETY APPLIED PHYSICS  

Organic thin-film transistors were successfully fabricated by the spin-coating method using a photo-precursor of pentacene, 6,13-dihydro-6,13-ethanopentacene-15,16-dione. After spin coating the soluble precursor, irradiation with visible light gave a pentacene film. A good mobility of 0.34 cm(2) V(-1) s(-1) and a high on/off ratio of 2.0 x 10(6) were achieved by treatment of the insulator surface with methyl silsesquioxane and by deposition of pentacene from the precursor with visible light irradiation (&gt;300 nm) and mild heat treatment (110-120 degrees C). In this case, small grains of pentacene crystals existed in the loosely ordered pentacene mesophase, in which pentacene molecules aligned vertically. Not only the grains of pentacene crystals but also the loosely packed pentacene phase played an important role in the field-effect transistor (FET) performance. (C) 2009 The Japan Society of Applied Physics

DOI： 10.1143/JJAP.48.051505

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Nitration of 4,7-ethanoisoindoles gave 1-nitro derivatives in moderate yields. Reduction of a nitro to amino group was successfully performed by sodium hydrosulfite in the case of ethyl 3-nitro-4,7-ethanoisoindole-1-carboxylate. The amino derivative was converted to benzylidenaminoisoindoles based on the retro Diels-Alder reaction. Their UV-vis spectra showed strong absorptions at 500-700 nm. (C) 2009 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2009.03.072

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

A novel transformation of N-acylprolines (1) to enol esters (2) was realized by utilizing chlorodifluoroacetic or trifluoroacetic anhydrides in the presence of inorganic bases, in which probable intermediates were mesoionic 1,3-oxazolium-5-olates. The structure of the enol ester (2a) was determined by single crystal X-ray analysis.

DOI： 10.3987/COM-08-S(D)50

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Various metalloporphyrins bearing a dihydroethanoisoindole unit were prepared by the inverse-type [3+1] porphyrin synthesis of a bicyclo[2.2.2]octadiene[BCOD]-connected dipyrrole with tetrahydrotripyrrin-dicarbaldehyde followed by metallation. Another [3+1] porphyrin synthesis of the pyrrole-connected porphyrins followed by the second metallation afforded BCOD-connected diporphyrins with different metals. Thermal conversion of the BCOD skeleton into benzene moiety gave pi-system-fused diporphyrin with the different metals in a highly pure form.

DOI： 10.3987/COM-08-S(F)55

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WORLD SCI PUBL CO INC  

Bicyclo[2.2.2]octadiene (BCOD)-fused porphyrins with no other substituents were prepared by [2 + 2] and [3 + 1] porphyrin syntheses front ethanodihydroisoindole derivatives in fairly good yields. Thermal retro-Diels-Alder reactions of BCOD-fused porphyrins gave the corresponding benzoporphyrins with no substituents in quantitative yields. Their UV-vis spectra and crystal structures were carefully examined in terms of pi-system expansion of the porphyrin ring current. In the cases of monobenzo- and adj-dibenzo-porphyrins, a single Soret band in their UV-vis spectra and no bond alteration in the benzene ring of their crystal structures were observed, while the split Soret bands and the obvious bond alteration in their benzene rings were recorded in the case of opp-dibenzoporphyrin.

DOI： 10.1142/S108842460900022X

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Getting in shape: Meso-pentafluorophenyl triply N-confused hexaphyrins have been synthesized in the free-base and oxidized forms and shown to have a triangular shape and efficient emission in the NIR region (see picture). The triangular shape is achieved by the presence of alternating confused and normal pyrrole rings. DFT calculations show that the triangular shape is more stable than a rectangular form. © 2009 Wiley-VCH Verlag GmbH &amp; Co. KGaA.

DOI： 10.1002/anie.200900596

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Pt(II) complex of meso-tetrakis(pentafluorophenyl) N-confused porphyrin (1-Pt) efficiently binds Cl-, Br-, and I- anions at the peripheral N-H, while deprotonation proceeds with F-, H2PO4-, and OH- in CH2Cl2 solution; neutral and anionic structures of 1-Pt were characterized by single crystal X-ray diffraction analysis.

DOI： 10.1039/b906018a

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

A novel one-step radical-ionic cyclopropanation was carried out to prepare aza- or oxabicyclo[3.1.0]hexane from β-nitroamides or β-nitroethers in a stereoselective manner (see scheme). The present procedure involves a higher-order domino process that includes one-electron oxidationradical cyclization-intramolecular SN2 reaction. © 2009 Wiley-VCH Verlag GmbH &amp; Co. KGaA.

DOI： 10.1002/chem.200901920

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The novel alkaloids cylindradines A and B were isolated from Axinella cylindratus, and their structures were elucidated by spectroscopic analyses. Stereochemistries of these compounds were determined by X-ray analysis. Cylindradines showed moderate inhibitory activity against the murine leukemia cell line P388.

DOI： 10.1021/ol802263j

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

A concise and stereoselective formation of azepines is achieved through the Conjugate addition of formamides to nitroalkenes and the subsequent intramolecular nitrile oxide cycloaddition (INOC) reaction. High cis-selectivity was observed. The one-pot modification of the two reactions provides direct preparation of azepines from nitroalkenes and formamides in moderate yields. The formyl group was readily removed by an acidic treatment without significant epimerization. (C) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2008.09.070

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/ange.200803670

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

One of 5-alkenyl-15-alkynyl-porphyrin and 5,15-dialkynyl-porphyrin was prepared selectively by 2+2 acid-catalyzed condensation of bicyclo[2.2.2]octadiene-fused dipyrrylmethane and TMS propynal in the presence of BF(3) OEt(2) only by the choice of the solvent. The alkenyl group was expected to be obtained by a protonation followed by intramolecular 1,2-hydride transfer from methine position of porphyrinogen. (C) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2008.05.115

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Linearly pi-expanded novel tetraanthroporphyrins with and without aromatic rings at the meso-positions were prepared quantitatively for the first time from the corresponding precursors by a retro-Diels-Alder reaction.

DOI： 10.1021/ol8008842

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The present paper highlights the photophysical aspects of the topologically new Ni(II)-diporphyrin (Ni-2-1)/fullerene host-guest ensembles. Both absorption and fluorescence studies reveal that Ni-2-1 undergoes efficient complexation with both C-60 and C-70 in toluene medium. In the fluorescence study, remarkable enhancement of the fluorescence intensity of Ni-2-1 was observed by the addition of C-60, while normal quenching of fluorescence occurred in case of C-70. From the fluorescence and UV-vis studies, the binding constants of Ni-2-1 with C-60 and C-70 were determined to be similar to 1.7 x 10(4) and similar to 2.7 x 10(4) dm(3) mol(-1), respectively. Ab initio theoretical calculations reveal that C-70/Ni-2-1 complex favor end-on orientation of C-70 rather than side-on approach. (C) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.saa.2007.12.004

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Candida antarctica lipase B (CAL-B) is one the most frequently used enzymes in organic synthesis for the preparation of optically active alcohols. However, it has not been used for the optical resolution of (+/-)-2,2'-binaphthol. We established an efficient linker-oriented design of 2,2'-binaphthol derivatives that is appropriate for optical resolution using CAL-B-catalyzed hydrolysis reaction. Methyl 4-(1-(6-bromo-2-methoxymethoxynaphthalen-1-yl)-6-bromonaphthalen-2-yloxy)butanoate was hydrolyzed by CAL-B to afford a corresponding acid with excellent enantioselectivity (E &gt; 200). Two types of optically active binaphthol derivatives, 1-(2-hydroxy-6-(naphthalen-1-yl)naphthalen-1-yl)-6-(naphthalen-1-yl)naphthalen-2-ol and 6-butyl-1-(6-butyl-2-hydroxynaphthalen-1-yl)naphthalen-2-ol, were prepared by this chemo-enzymatic reaction protocol and were used as chiral templates for symmetric reactions.

DOI： 10.1021/jo800351h

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

meso-Diphenylphosphanylporphyrins were successfully prepared via Pd-catalyzed C-P cross-coupling reaction of the corresponding meso-iodoporphyrins with diphenylphosphane. The meso-phosphanylporphyrins underwent regioselective metalation at the beta carbon to produce novel classes of porphyrin dimers linked by peripherally fused phosphametallacycles. A Pd-mononucler complex was structurally characterized by X-ray crystallography, which revealed a flat structure of the Pd-linked porphyrin pi systems. Both experimental and theoretical results demonstrate that the orbital interaction between the pyrrolic p pi orbitals and the metal d pi orbital affects optical and electrochemical properties of the metal-linked coplanar porphyrin dimers.

DOI： 10.1021/ja710542e

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

This paper describes the preparation of dimethylbicyclo[2.2.2]octadiene-fused porphyrins as extremely soluble precursors of tetrabenzoporphyrins and thermal conversion of the precursors to tetrabenzoporphyrins. (C) 2008 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2008.01.014

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Multistep thermal fragmentation of quadruply bicyclo[2.2.2]octadiene-fused porphyrins giving tetrabenzoporphyrins was examined in detail. After the first extrusion of an ethylene molecule from the porphyrin derivative, the opposite bicyclo[2.2.2]octadiene moiety preferentially underwent the second retro-Diels-Alder reaction to give an opp-dibenzoporphyrin derivative rather than an adj-dibenzoporphyrin derivative. These two benzoporphyrin derivatives then decomposed to give a tribenzoporphyrin derivative in similar rates. The temperature regions of these fragmentations could not be distinguished by thermogravimetric analysis. In contrast, the third and the fourth fragmentations obviously occurred stepwise. There was a temperature region where the tribenzoporphyrin derivative preferentially existed. In the case of the 21,23-dithiaporphyrin derivative, opp-21,23-dithiadibenzoporphyrin, possessing benzo moieties fused at the pyrrole parts of the core-modified porphyrin chromophore was predominantly formed during the fragmentation. In the case of the 21-thiaporphyrin derivative, an ethylene molecule was extruded selectively from the bicyclo[2.2.2]octadiene moiety adjacent to the thiophene part to give 21-thiabenzo[q]phyrin and then 21-thiabenzo[g,q]porphyrin derivatives. In these cases, the last ethylene extrusion also occurred very slowly. ((c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008).

DOI： 10.1002/ejoc.200700711

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

(Figure Presented) Are you N-fused? Doubly N-fused porphyrin (see picture; Br red, F green, N blue) exhibits exceptionally long-wavelength absorption for an 18π aromatic system (in excess of 1600 nm). The HOMO-LUMO energy gap of doubly N-fused porphyrin is extremely small for an [18]annulenic compound and results from endocyclic extension of the porphyrin π system. © 2008 Wiley-VCH Verlag GmbH &amp; Co. KGaA.

DOI： 10.1002/anie.200803670

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：American Chemical Society  

DOI： 10.1021/ja710542e

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-BLACKWELL  

The optical spectra of a series of core-modified tetrabenzoporphyrins were analyzed to determine the effects of core modification, ligand folding, and partial benzo substitution at the ligand periphery on the electronic structure by using magnetic circular dichroism (MCD) and NMR spectroscopy, X-ray crystallography, cyclic and differential pulse voltammetry, and TD-DFT calculations. Planar 21-carba-, 21-thia-, 21,23-dithia-, and 21-oxa-23thiatetrabenzo[b,g,l,q]porphyrins reported previously were studied together with the previously unreported 21-oxa- and 21-carba-23-thiatetrabenzo[b,g,l,q]porphyrins. The optical properties of these compounds are compared to those of tetrabenzo[b,g,l,q]-, 5,.10,15,20-tetraphenyl-, 5,10,15,20-tetraphenyltetrabenzo[b,g,l,q]-21-thia-, 5,10,15,20-tetraphenyltetrabenzodithia-, 5,10,15,20-tetraphenyldibenzo[g,q]21,23-dithia-, 5,10,15,20-tetraphenyldibenzo[b,t]-21,23-ditliia-, 5,10,15,20tetraphenyltribenzo[g,q]-1-21-thia-, and 5,10,15,20-tetraphenylbenzo[b]-21-thia- porphyrins. Michl&apos;s perimeter model and Gouterman&apos;s four-orbital model are used to conceptualize the results and to account for red shifts commonly observed in the spectral bands of nonplanar porphyrinoids.

DOI： 10.1002/chem.200701611

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Soluble precursors of 2,3-naphthalocyanine (Nc) and phthalocyanine (Pc) were prepared and were converted into insoluble semiconducting thin films of Pc and Nc by heating after fabrication via spin-coating.

DOI： 10.1039/b811674a

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Light from confusion: A set of doubly N-confused calix[6]phyrins bearing two coordination sites (NNNC,NNNC or NNNN,NNCC) were synthesized. Their bis-PtII complexes exhibit near-infrared emission around 1000 nm, which could make these compounds ideal for biological applications. (Graph Presented). © 2008 Wiley-VCH Verlag GmbH &amp; Co. KGaA.

DOI： 10.1002/anie.200801713

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The Diels-Alder reactions of tetrafluorobenzo[c]thiophene with electron-deficient olefins such p-benzoquinone and bis(phenylsulfonyl)ethylene gave adducts in moderate yields, while no product was obtained in the reaction with butyl vinyl ether. The Vilsmeier reaction gave tetrafluorobenzo[c]thiophene-1-carbaldehyde in good yield. The aldehyde was converted to tetrafluorothiabenzoporphyrin.

DOI： 10.3987/COM-07-S(U)46

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

The UV protection and singlet oxygen quenching of aloesaponarin I have been studied by means of laser spectroscopy. The excited-state intramolecular proton transfer that provides the UV protection takes place along only one of the molecule's two intramolecular hydrogen bonds, and this can be understood by considering the nodal pattern of the wave function. The functional groups participating in the excited-state intramolecular proton transfer also play important roles in the singlet oxygen quenching. Aloesaponarin I has a quenching rate constant larger than that of vitamin E and has a long duration of action due to its resistance to UV degradation and chemical attacks by singlet oxygen and free radicals.

DOI： 10.1021/jp075224j

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Optically active 5-substituted pyrrolidin-2-ones underwent conjugate addition to nitroalkenes to give the corresponding adducts in a diastereoselective manner. The presence of 18-crown-6 was crucial to achieve good stereoselective addition. Addition of 6-substituted piperidin-2-ones also gave the corresponding adduct in a stereoselective manner. The adduct was readily converted into a bicyclic lactam through intramolecular nitroaldol reaction, and the formal synthesis of indolizidine 167B was achieved. (c) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tet.2007.09.023

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

4,5,6,7-Tetrafluoroisoindole and their related compounds were prepared directly from the corresponding phthalonitriles by reduction of a hydride reagent such as DIBAL or catalytic hydrogenation in the presence of an acid. 4,5,6,7-Tetrafluoroisoindole was converted to fluorinated benzoporphyrins. (C) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2007.08.063

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

The synthesis of a novel chiral gem-difluorocyclopropane building block has been accomplished using chemo-enzymatic reaction protocol; the prochiral diol of 1,4-bis(2,2-difluoro-3-(hydroxymethyl)cyclopropyl)benzene (5) was converted to the corresponding chiral diacetate by Pseudomonas lipase (lipase SL-25, Meito)-catalyzed transesterification with vinyl acetate as acyl donor with &gt; 99% enantiomeric excess. Various types of diesters or dialkyl ether were prepared from the diol and their helical twisting power (HTP) was evaluated by addition of 1.0 wt% to a non-chiral nematic liquid crystal host; the HTP was significantly dependent on the structure of ester or ether moieties and diester of diol 5 with isopropylfumalic acid showed the largest HTP. (C) 2007 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.jfluchem.2007.05.004

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Porphyrin synthesis using 4,7-etheno-4,7-dihydro-2H-isoindole and tripyrranedicarbaldehyde gave a porphyrin derivative bearing no bicyclo[2.2.2]octatriene moiety as well as the targeted bicyclo[2.2.2 ]octatriene-fused porphyrin. (C) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2007.09.004

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：MARY ANN LIEBERT, INC  

Red ginseng root (Panax Ginseng CA Meyer) has been used clinically by many Asian people for thousands of years without any detrimental effects. One of the major components of Red ginseng root is ginsenoside Rb-1 (gRb1). Previously, we showed that intravenous infusion of gRb1 ameliorated ischemic brain damage through upregulation of an anti-apoptotic factor, BCI-X-L and that topical application of gRb1 to burn wound lesion facilitated wound healing through upregulation of vascular endothelial growth factor (VEGF). In the present study, we produced dihydroginsenoside Rb1 (dgRb1), a stable chemical derivative of gRb1, and showed that intravenous infusion of dgRb1 improved spinal cord injury (SCI) as well as ischemic brain damage. As we expected, the effective dose of dgRb1 was ten times lower than that of gRb1. Intravenous infusion of dgRb1 at this effective dose did not affect brain temperature, blood pressure or cerebral blood flow, suggesting that dgRb1 rescued damaged neurons without affecting systemic parameters. In subsequent in vitro studies that focused on dgRb1-induced expression of gene products responsible for neuronal death or survival, we showed that dgRb1 could upregulate the expression of not only BCI-XL, but also a potent angiogenic and neurotrophic factor, VEGF. We also showed that dgRb1-induced expression of bcl-X-L and VEGF mRNA was HRE (hypoxia response element) and STRE (signal transducers and activators of transcription 5 (Stat5) response element) dependent, respectively.

DOI： 10.1089/neu.2006.0182

Web of Science

Scopus

PubMed

researchmap

Language：German   Publishing type：Research paper (scientific journal)   Publisher：Wiley  

DOI： 10.1002/ange.200604371

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Nitration of biphenylene with bismuth subnitrate and thionyl chloride give a mixture of 2-nitrobiphenylene, 2-chloro-6-nitrobiphenylene, and 5-chloro-10-nitrobenzocyclooctene. Reactions of 2-nitrobiphenylene and 5-chloro-10-nitrobenzocyclooctene with ethyl isocyanoacetate in the presence of t-BuOK gave the corresponding pyrimidine N-oxide and pyrrole, respectively.

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

Optically active N-sulfinimines underwent stereoselective Michael/nucleophilic addition domino reaction triggered by magnesium thiolate to give alpha-phenylthiomethyl-beta-(N-sulfinylamino) esters in high diastereomeric excess. The adducts were readily converted into optically active alpha-methylene-beta-(N-sulfinylamino)esters so that this reaction provides a useful asymmetric aza-Baylis-Hillman-equivalent method.

DOI： 10.1021/jo062251h

Web of Science

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The stereoselective intramolecular nitrile oxide cycloaddition (INOC) reaction was achieved from N-formyl-beta-nitroamides, which were prepared through the Michael addition of allylic formamides to nitroalkenes, and cis-pyrroroisoxazoles and trans-piperidinoisoxazoles were obtained in a stereoselective manner. (c) 2007 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2007.01.025

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE BV  

The present Letter introduces a new type of metalloporphyrin dimer, 1, to examine its optical absorption and luminescence in complexation with C-60 and C-70 in toluene medium. Large binding constants (K) in the magnitude of similar to 3 x 10(4) and similar to 2 x 10(5) dm(3) Mol(-1) were obtained for the 1: 1 complexes of 1 with C-60 and C-70, respectively. Values of K suggest that 1 serves as an effective and selective tweezers to capture C-70 in preference to C-60. Molecular mechanics and semi-empirical PM3 calculations extend a good support in interpreting the stabilization energies and electronic structures for the C-60 and C-70 complexes of 1. (c) 2006 Elsevier B.V. All rights reserved.

DOI： 10.1016/j.cplett.2006.11.039

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Ring a ring of benzenes: An unsubstituted N-confused metalloporphyrin forms both C3- and C1-symmetric trimers in solution, whereas its monophenyl-substituted analogue forms exclusively C3-symmetric trimers (see picture) owing to significant stabilizing noncovalent interactions between the three phenyl groups, as evaluated both experimentally and theoretically. (Figure Presented). © 2007 Wiley-VCH Verlag GmbH &amp; Co. KGaA.

DOI： 10.1002/anie.200604371

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

Bicyclo[2.2.2]octadiene-connected pyrrolo-porphyrins have been prepared by an inverse-type [3+1] porphyrin synthesis of a bicyclo[2.2.2]octadiene-fused dipyrrole with a tripyrrane dicarbaldehyde. Another [3+1] porphyrin synthesis of pyrrole-connected porphyrins with the same or other tripyrrane dicarbalde- hydes gave bicyclo[2.2.2]octadiene-bridged diporphyrins, the central metals and/or peripheral substituents of which were different. Thermal decomposition of the, bicyclo[2.2.2]octadiene skeleton to a benzene moiety gave pi-system-fused porphyrin dimers in a highly pure form.

DOI： 10.1002/chem.200601644

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Mg complex of phthalocyanine fused with bicyclo[2.2.2]octadiene (BCOD) units is prepared by the reaction of BCOD-fused phthalonitrile with Mg(OPr)(2) in PrOH at 100 degrees C overnight in 42% yield. Subsequent heating the product at 250 degrees C results in clean formation naphthalocyanine via the retro Diels-Alder reaction. An attempt to the synthesis of BCOD-fused tetraazaporphyrin by the similar cyclization of the Diels-Alder adduct of dicyanoacetylene with 1,3-cyclohexadiene was unsuccessful.

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

The regioselectivity in the ruthenium-catalysed allylic alkylation of mono substituted allyl acetates with the malonate anion was highly controlled by Ru-3(CO)(12) with 2-(diphenylphosphino)benzoic acid, and the linear-type alkylated product was obtained.

DOI： 10.1039/b614015g

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Diels-Alder reaction of ethynyl p-tolyl sulfone with 1,3-dienes gave the corresponding tosyl-1,4-cyclohexadienes. The resulting adducts could be converted into 4,7-dihydro-2H-isoindole derivatives including bicyclo[2.2.2]ocatadiene(BCOD)-fused pyrrole as an isoindole equivalent.

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

A diketone precursor of air-stable bis-2-thienyl-2,6-anthracene was prepared and quantitatively converted to the target acene by photoirradiation of the n-pi* absorption both in solution and as a film, in air. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2006.08.013

Web of Science

Scopus

researchmap

Language：English   Publisher：Symposium on the chemistry of natural products  

DOI： 10.24496/intnaturalprod.2006.0__P-257_

CiNii Books

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Secondary acyclic formamide serves as an efficient nucleophile to nitroalkenes to give corresponding Michael adducts in good yields. The nitro group in the adducts was useful for further heterocyclic synthesis. (c) 2006 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2006.02.065

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Benzoporphyrins fused with acenaphthylene or fluoranthene (3) and (4) were prepared by the condensation of bicyclo[2.2.2]octadiene(BCOD)-fused tripyrrane (5) with appropriate pyrrole dialdehydes (13) or (14) and the subsequent retro Diels-Alder reaction. The absorptions of these new porphyrins were very intense at both Soret and Q bands, which might be useful as organic dyes for solar cells.

DOI： 10.3987/COM-05-S(T)23

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

5-Alkenyl-15-alkynylporphyrins have been obtained unexpectedly by [2 + 2] acid-catalyzed condensation of dipyrrylmethane and TMS propynal in addition to 5,15-dialkynylporphyrin, and the unsymmetrical porphyrin can be converted to a butadiyne-linked dimer by selective desilylation of the alkynyl TMS.

DOI： 10.1039/b513848e

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：SOC PORPHYRINS & PHTHALOCYANINES  

Soluble tetra(pyrazino)tetraazaporphyrin was synthesized by the reaction of bicyclo[2.2.2]octadiene-fused dicyanopyrazine. The retro Diels-Alder reaction of the soluble tetra(pyrazino)tetraazaporphyrin gave a tetra(quinoxalino)tetraazaporphyrin in quantitative yield. Copyright (c) 2006 Society of Porphyrins & Phthalocyanines.

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

A novel alpha-diketone precursor of pentacene, 6,13-dihydro-6,13-ethanopentacene-15,16-dione, was prepared and converted successfully to pentacene in 74% yield by photolysis of the precursor in toluene: Irradiation of the diketone solution in toluene with light of 460 nm under an Ar atmosphere caused the solution to change from yellow to fluorescent orange-pink within a few minutes, after which, purple precipitates appeared. After 35 min, the solution changed to colorless and the purple precipitates were filtered to give pentacene in 74% yield. By contrast, in the presence of oxygen, the color of the solution changed from yellow to pale yellow., and only 6,13-endoperoxide of pentacene was quantitatively obtained. The rate of the reaction upon photolysis was measured by observing the decay of n-pi* absorption of the precursor at 460 nm, and was found to be similar in both the presence and absence of oxygen. Therefore, the photoreaction of the alpha-diketone precursor seemed to occur via the singlet excited state. Because the T-T absorption of pentacene was observed upon photolysis of the precursor in the nanosecond transient absorption measurement under an Ar atmosphere, the excited triplet state of the pentacene generated singlet oxygen by sensitization, and it reacted with the ground-state pentacene to give the 6,13-endoperoxide. The alpha-diketone deposited on glass was also converted successfully to pentacene film by photoirradiation. In addition, diketone precursors of a mixture of 2,8- and 2,9-di-bromopentacene and 2,6-trianthrylene were also prepared and their photoconversion was performed.

DOI： 10.1002/chem.200500564

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：TAYLOR & FRANCIS LTD  

A new binuclear Cu(II) complex: [Cu-2(phen)(2)(4,4'-dpy)(3)(OH)(2)] center dot 2NO(3) center dot 5.5H(2)O (phen = 1,10-phenanthroline and 4,4'-dpy = 4,4'-dipyridine) 1 has been prepared and determined by single X-ray diffraction. The two Cu2+ ions are bridged by a 4,4'-dpy ligand. The intramolecular coupling between the two Cu-II (S = 1/2) ions was found to be weakly antiferromagnetic (J = - 0.38 cm(-1)).

DOI： 10.1080/00958970500157058

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The first total synthesis of bhimamycin B, a novel member of naphtho[2,3-c]furan quinone antibiotics, was achieved by oxidative skeletal rearrangement of 4-acetylnaphtho[1,2-b]furan-5-ol. (c) 2005 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2005.04.037

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：CHEMICAL SOC JAPAN  

A kinetic Study was performed for the free-radical scavenging actions of curcumin and half-curcumin, which has a half-structure of curcumin, in order to clarify the mechanism of free-radical-scavenging in curcumin. The second-order rate constants for radical-scavenging reactions of curcumin and half-curcumin were measured by a stopped-flow spectrophotometer in several organic solvents (methanol, ethanol, acetonitrile, chloroform, and benzene) and in aqueous Triton X-100 (5.0 wt %) micelle solutions at various pH. The difference in the rate constant and solvent dependence between curcumin and half-curcumin suggests that the enol structure with the intramolecular hydrogen-bond Of Curcumin strongly enhances the radical-scavenging activity. Furthermore, notable pH dependences were observed for the rate constants of curcumin and half-curcumin in micelle solutions, suggesting that the acid-base dissociation equilibrium of phenol-protons in curcumin and half-curcumin affects their radical-scavenging activities.

DOI： 10.1246/bcsj.78.615

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

6,13-Dihydro-6,1 3-ethanopentacene-15,16-dione gave pentacene efficiently both in solid and in solution by irradiation of light. (C) 2005 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2005.01.157

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Water-soluble bicycloporphyrin and benzoporphyrin having octacarboxyl groups are synthesized from the corresponding octaester porphyrin by simple hydrolyzing and heating procedures. These compounds are characterized by UV-vis, NMR and mass spectroscopies. The benzoporphyrin octacarboxylic acid exhibits extremely high planarity in spite of its poly-substitution. (C) 2004 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2004.11.024

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Enlargement of the pi-electronic network of meso-meso, beta-beta, beta-beta triply linked diporphyrin has been exploited by preparing a corresponding dibenzo-fused porphyrin dimer that exhibits a perturbed absorption spectrum and a large two-photon absorption cross section.

DOI： 10.1039/b505340d

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：WILEY-V C H VERLAG GMBH  

A retro-Diels-Alder reaction of a β-bicyclo[2.2.2]octadiene-fused precursor yields the doubly N-fused β-benzo[28]-hexaphyrin(1.1.1.1.1.1) shown, which undergoes oxidative rearrangement upon treatment with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) to yield a macrocycle that emits fluorescence in the visible/near-IR region. (Chemical Equation Presented) © 2005 Wiley-VCH Verlag GmbH &amp; Co. KGaA.

DOI： 10.1002/anie.200462815

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

X-Ray analyses of free base, zinc, and nickel complexes of 2,3; 7,8; 12,13; 17,18-tetrakis(6,13-dihydro-6,13-pentaceno)-21H,23H-porphine revealed that the porphyrin chromophores adopted a heavily-saddled conformation by interlocking of the biconcave porphyrins in the crystals containing halobenzenes as crystalline solvents, while the ring was almost at in the crystals obtained from benzene or from chlorobenzene and isopropanol.

DOI： 10.1039/b413082k

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

2,2'-Bi[-3(2H)-thioplienon]ylidene with two bicyclo[2.2.2]-octadiene moieties was quantitatively converted to thioindigo by the retro-Diels-Alder reaction. The thioindigo solid obtained from the precursor had the P2(1)/c structure which was different from the commercial thioindigo samples (P2(1)/n). (C) 2004 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2004.10.028

Web of Science

Scopus

researchmap

Language：English   Publisher：WILEY-BLACKWELL  

The X-ray crystallographic, optical spectroscopic, and electrochemical properties of a newly synthesized class of boron-diindomethene (BDI) dyes and their tetrahydrobicyclo precursors (bc-BDP) are presented. The BDI chromophore was designed to show intensive absorption and strong fluorescence in an applicationary advantageous spectral range. Its modular architecture permits fusion of a second subunit, for example, a receptor moiety to the dye&apos;s core to yield directly linked yet perpendicularly prearranged composite systems. The synthesis was developed to allow facile tuning of the chromophore platform and to thus adjust its redox properties. X-ray analysis revealed a pronounced planarity of the chromophore in the case of the BDIs, which led to a remarkable close packing in the crystal of the simplest derivative. On the other hand, deviation from planarity was found for the diester-substituted bc-BDP benzocrown that exhibits a "butterfly"-like conformation in the crystal. Both families of dyes show charge- or electron-transfer-type fluorescence-quenching characteristics in polar solvents when equipped with a strong donor in the meso-position of the core. These processes can be utilized for signaling purposes if an appropriate receptor is introduced. Further modification of the chromophore can invoke such a guest-responsive intramolecular quenching process, also for receptor groups of low electron density, for example, benzocrowns. In addition to the design of various prototype molecules, a promising fluoroionophore for Na(+) was obtained that absorbs and emits in the 650 nm region and shows a strong fluorescence enhancement upon analyte binding. Furthermore, investigation of the remarkable solvatokinetic fluorescence properties of the "butterfly" -like bc-BDP derivatives suggested that a second intrinsic nonradiative deactivation channel can play a role in the photophysics of boron-dipyrromethene dyes.

DOI： 10.1002/chem.200400173

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

A bicyclo[2.2.2]octadiene-fused tripyrrane was synthesized as a first versatile reagent for the preparation of pi-expanded heteroporphyrins. The reaction of the tripyrrane with 1,3-diformylindene and azulene-1,3-dicarbaldehyde afforded the corresponding heteroporphyrins. which were easily converted into tetrabenzocarbaporphyrin and tribenzoazuliporphyrin by retro Diels-Alder reaction. (C) 2004 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.tetlet.2004.05.041

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Successful synthesis of a series of highly conjugated porphyrin analogues, including thia-, dithia- and oxathia-tetrabenzoporphyrins, and their optical properties are reported.

DOI： 10.1039/b311879g

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Sapphyrins fused with mono-bicyclo[2.2.2]octadiene (BCOD) and di-BCOD units are prepared, which are converted into mono- and dibenzosappyrins by heating at 200 degreesC; soret bands are red shifted by 10-20 nm by introduction of fused benzene rings, but Q bands are not much affected in benzosapphyrins.

DOI： 10.3987/COM-03-S(P)16

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

The boron trifluoride-catalyzed Rothemund condensations of phenylpropargylaldehyde with 4,7-dihydro-4,7-ethano-2H-isoindole or 3, 4-diethylpyrrole in dichloromethane at low temperature give 5,10,15,20-tetrakis(phenylethynyl) porphyrins bearing bicyclo [2.2.2] octadiene and octaethyl substituents, respectively. The former undergoes a retro Diels Alder reaction to afford 5, 10,15,20-tetrakis(phenylethynyl) benzoporphyrin quantitatively. The different conformations of the porphyrin periphery were determined by X-ray diffraction and their redox and spectroscopic properties have been investigated.

DOI： 10.1039/b412688b

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Incorporation of acenaphtho[1,2-c]pyrrole units into the pi-conjugated systems is very effective to get the narrow HOMO-LUMO gap materials, and the absorption spectra of pi-conjugated polymers, porphyrins, and boron dipyrromethene dyes fused with acenaphthene rings are extensively red-shifted.

DOI： 10.3987/COM-03-S58

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：AMER CHEMICAL SOC  

On heating, syn-diporphyrin zinc complexes fused with bis(ethano)dimethoxyanthracene, the crystal structure of which showed a unique trimeric assembly, extruded one ethylene molecule at 240-310 °C to give a porphyrin-naphthoporphyrin diad, and the second retro-Diels-Alder reaction and concomitant decomposition of the methoxy groups occurred at 280-350 °C to give the anthraquinone-fused diporphyrin, while the first thermal conversion of the anti-diporphyrin zinc complex occurred in a much lower temperature range (180-230 °C). Copyright © 2003 American Chemical Society.

DOI： 10.1021/ja036203f

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Porphyrins fused with dihydroxylated bicyclo[2.2.2]octadiene at beta-positions were quantitatively converted to the corresponding tetrabenzoporphyrins either by treatment with NaH in DMF at 0degreesC or on boehmite at room temperature. (C) 2003 Published by Elsevier Science Ltd.

DOI： 10.1016/S0040-4039(03)01265-6

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

From X-ray analyses of 3,7,11-triphenylcyclonona[1,2-b;4,5-b';7,8-b"]tripyrrole-2,6,10-tricarboxylate (CNTP 1), the molecules existed as saddle forms in both crystals of 1.3ClPh and 1.1/2CHCl(3), In the former crystal, hydrogen bonds between pyrrolic hydrogen and ester carbonyl oxygen spread two-dimensionally, forming molecular sheets, between which the solvent molecules were included, while two independent molecules were bounded three-dimensionally by the hydrogen bonds in the latter. In CDCl3, CNTP was observed to adopt a crown form, while interconversion of the conformers was observed in C5D5N. (C) 2003 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0040-4020(02)01589-2

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Acid-catalyzed oligomerization of 2-(hydroxymethyl) pyrroles bearing C6F5, 2,6-Cl2C6H3, CF3 and CO2Et groups at beta-positions was examined. The reaction of ethyl pyrrole-3-carboxylates gave a mixture of oligomers and type I isomers of porphyrinogens and hexaphyrinogens were isolated when the other beta-substituents were sufficiently bulky, for example, mesityl, 2,6-Cl2C6H3 and C6F5 groups. On the other hand, the pyrroles having other electron-withdrawing groups afforded porphyrinogens as the only isolable products.

DOI： 10.1039/b307132d

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

reaction of nitropyridine derivatives with ethyl isocyanoacetate in the presence of 1,8-diazabicyclo[5.4.0]undecene proceeded tandem cyclization to give polycyclic pyrrolopyridines or imidazopyridines. On the other hand, N-protected 3-nitro- and 5-nitropyridones and N,N-diprotected 5-nitrouracil gave corresponding bicyclic pyrroles in good yields under the similar conditions.

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Bi- and tri-isothianaphtliene-alpha,omega-dicarbaidehydes were easily synthesized by using 4,7-dihydro-4,7-ethano-2-benzo[c]thiophene as a useful synthon of 1,3-unsubstituted isothianaphthene. The UV-vis absorptions of oligo-isothianaphthene derivatives exhibit a considerable bathochromic shift compared to the cases of other oligo-thiophene analogs, and their cyclic voltammetry shows narrowed HOMO-LUMO gaps of the isothianaphthene derivatives. This indicates high efficiency of pi-electron delocalization in the oligo-isothianaphthenes along the conjugated backbone. (C) 2002 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0040-4039(02)02054-3

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

Porphyrin dimers were prepared from beta,beta'-dipyrrole derivatives via the double pyrrolylmethylation followed by double [2+2] MacDonald porphyrin synthesis.

DOI： 10.1039/b108819j

Web of Science

Scopus

PubMed

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ROYAL SOC CHEMISTRY  

A soluble porphyrin dimer linked with bicyclo[2.2.2]octadiene was converted in to insoluble conjugated porphyrin dimer by heating at 200 degreesC, this provides a new strategy for the process control of conjugated porphyrins.

DOI： 10.1039/b108391k

Web of Science

Scopus

researchmap

Language：Japanese   Publisher：日本皮膚科学会-西部支部  

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

A new class of boron dipyrromethene (BDP) dyes fused with rigid bicyclo[2.2.2]octadiene units are prepared, which are converted into benzo BDP dyes via a retro Diels-Alder reaction; the absorption and fluorescence spectra of the new dyes are discussed. (C) 2001 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0040-4039(01)01299-0

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：ELSEVIER SCIENCE SA  

The electroreduction of beta -hydroxy gamma,delta -unsaturated sulfones did not lead to the formation of a double bond between the a and beta carbons, but a certain beta -hydroxy gamma,delta -unsaturated sulfone (3bA) in the absence of proton donors gave a cyclohexenol derivative. This compound was derived from fission of a carbon-carbon bond between alpha- and beta -positions followed by recombination of the two fragments in the tandem Michael and aldol reactions. (C) 2001 Elsevier Science B.V. All rights reserved.

DOI： 10.1016/S0022-0728(01)00367-9

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

The synthesis of polyenes by electrolysis of beta -acetoxy phenyl sulfones having some double bonds was studied in acetonitrile using a Hg pool cathode and a sacrificial ME anode. Most unsaturated beta -acetoxy phenyl sulfones were subject to the electroreductive elimination of both the acetoxy and the sulfonyl groups, but did not give the desired polyenes because of partial hydrogenation of double bonds. The electrolytic reduction of a beta -acetoxy phenyl sulfone having a trifluoromethyl group at the beta -position was subjected to such 1.2-elimination followed by reductive removal of all fluorine atoms to afford the corresponding unsaturated hydrocarbons, whereas beta -acetoxy phenyl sulfones having a fluorine atom at the alpha -position gave the desired fluoro-olefins in high yields. All saturated beta -acetoxy phenyl sulfones afforded the desired alkenes in high yields. (C) 2001 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0013-4686(01)00443-1

Web of Science

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

A meso-unsubstituted porphyrin having a formyl group was synthesized both from a mono(ethoxycarbonyl)porphyrin by reduction with LiAlH4, followed by oxidation with MnO2 and from a monocyanoporphyrin by reduction with DIBALH. The monoethoxycarbonyl and monocyanoporphyrins were prepared by the acid catalyzed mixed condensation of the corresponding 4-ethoxycarbonyl- and 4-cyano-2-(hydroxymethyl)pyrroles with 3-mesityl-4-methyl-2-(hydroxymethyl)pyrrole. A porphyrin with four formyl groups at the P-positions was prepared from ethyl 4-(dithiolan-2-yl)-3-methylpyrrole-2-carboxylate by the sequential treatment of LiAlH4, p-TsOH, and NBS. Cyclic voltammetry and UV-VIS spectroscopic analyses of these porphyrins revealed the highly electron-deficient property of the porphyrin chromophore.

Web of Science

Scopus

researchmap

meso-Unsubstituted porphyrin dimers linked with 1,3- and 1,4-phenylenes were prepared from the corresponding phenylenedipyrroles by double [3+1] MacDonald condensation in 16% and 27% yields, respectively. These dipyrroles were in turn prepared from tere- and iso-phthalaldehydes in respective yields of 23% and 41% via the 3-step reactions involving the modified Barton-Zard reaction.

DOI： 10.1055/s-2001-11428

Scopus

researchmap

Language：English   Publishing type：Research paper (scientific journal)   Publisher：PERGAMON-ELSEVIER SCIENCE LTD  

Benzoporphyrins with octamethoxycarbonyl groups 8a,b are obtained in near 100% yields by heating the corresponding tetra(bicyclo)porphyrins 7a,b at 200 degreesC without affecting the ester moiety. (C) 2000 Elsevier Science Ltd. All rights reserved.

DOI： 10.1016/S0040-4039(00)01875-X

Web of Science

Scopus

researchmap