| 1. |
Keita Shichijo, Hisashi Shimakoshi, Green Molecular Transformation in Dual Catalysis: Photoredox Activation of Vitamin B12 Using Heterogeneous Photocatalyst, ChemPlusChem, 2024.03, This concept focuses on dual-catalysis using metal complexes and heterogeneous photocatalysts. Vitamin B12 derivatives are sophisticated metal complexes that facilitate enzymatic reactions in the biological systems. The B12 enzymes inspired reactions catalytically proceed in dual-catalyst systems of B12 derivatives and heterogeneous photocatalysts, such as titanium oxide (TiO2) and metal-organic frameworks (MOFs), under light irradiation. The cobalt ions in vitamin B12 derivatives are effectively reduced by photoexcited photocatalysts, producing low-valent Co(I) species. The photoinduced nucleophilic Co(I) species react with an alkyl halide to form an organometallic complex with a Co-C bond. The Co-C bond dissociates during photolysis to generate alkyl radicals. Based on this mechanism, dual-catalysis effectively promotes various light-driven organic syntheses and light-driven dehalogenation reactions of toxic alkyl halides. The concepts of the dual-catalyst system and recent progress in this field are discussed in this concept.. |
| 2. |
Baihui Zheng, Junsheng Zhi, Nan Wang, Dandan Zhang, Hisashi Shimakoshi, Yifei Li, Qun Liua, Ling Pan, Radical-triggered base-free 1,3-C → C migrations: chemodivergent synthesis of cyclic imines from N-allyl enamines, Organic Chemistry Frontiers, 10.1039/d3qo01849k, 11, 2, 500-507, 2023.12, Functional group migrations are one of the most powerful strategies in the construction of complex molecules. [1,3]-Migrations, especially 1,3-C → C migrations are more challenging for the difficulty in the formation of highly strained four-membered ring intermediates. In the limited reports, narrow substrate tolerance, basic additives or high temperature are unavoidable. Herein, visible-light-mediated novel 1,3-C → C migrations of N-allyl enamines under base-free conditions are researched. Radical-triggered 1,3-C → C acyl and cyano migrations were achieved, initiated by a reductive radical-polar crossover (RPC) process. A variety of biologically active cyclic imines were synthesized in good-to-excellent yields under very mild reaction conditions. DFT calculations support our proposal that the radical cyclization of N-allyl enamines facilitates the reductive RPC process, which triggers the formation of strained four-membered ring intermediates for 1,3-migrations. Thus, a tandem radical cyclization/RPC/1,3-C → C migration process has been developed under base-free conditions. Furthermore, from the same N-allyl enamines, different cyclic imines, i.e., (3-azabicyclo[3.1.0]hex-2-enes), could be achieved in high selectivity mediated by the acridine photosensitizer and Co(ii) additive.. |
| 3. |
Kaito Sasaki, Keita Shichijo, Mamoru Fujitsuka, Hisashi Shimakoshi, Visible Light-Driven Borylation of Aryl Halides by B12 Derivative Based on Dual Photoredox Strategy, Journal of Porphyrins and Phthalocyanines, 10.1142/S108842462350081, 27, 7, 1270-1277, 2023.03, Reductive dehalogenation of an aryl halide (Ar-X) subsequent coupling with bis(pinacolato)diboron (B2pin2) to form an arylboronate (Ar-Bpin) by the photo-excited B12 complex of the CoI oxidation state with an iridium photosensitizer (PS), [Ir(dtbbpy)(ppy)2]PF6, under anaerobic conditions was reported. The robust B12 complex and iridium PS provided the highest turnover numbers of over 3,800 for the borylation reaction at room temperature. The CoI state of the B12 complex was formed via the reductive quenching pathway of [Ir(dtbbpy)(ppy)2]PF6 by visible light irradiation in the presence of N, N-diisopropylethylamine (i-Pr2NEt) as a sacrificial reductant which was confirmed by a photoluminescence lifetime analysis. A sub-pico second time-resolved spectroscopic analysis showed that the electron transfer from the excited CoI state of the B12 complex (*CoI) to the Ar-X occurred in the order of the rate constants for electron transfer (k”eT), Ar-I > Ar-Br > Ar-Cl. Based on the mechanistic studies, dual excitation of PS and the B12 complex is involved in the catalytic reaction and single electron transfer (SET) from *CoI to Ar-X could provide the aryl radical by fragmentation of the Ar-X radical anion. The aryl radical should react with the radical trapping reagent, B2pin2, to form the Ar-Bpin product. . |
| 4. |
K. Shichijo, Y. Kametani, Y. Shiota, K. Yoshizawa, M. Fujitsuka, H. Shimakoshi, Effect of Macrocycles on the Photochemical and Electrochemical Properties of Cobalt-Dehydrocorrin Complex: Formation and Investigation of Co(I) Species., Inorg. Chem., 62, 11785-11795, 2023.09, Co(II)-Pyrocobester (P-Co(II)), a dehydrocorrin complex, was semisynthesized from vitamin B12 (cyanocobalamin), and its photochemical and electrochemical properties were investigated and compared to those of the cobseter (C-Co(II)), the cobalt corrin complex. The UV-vis absorptions of P-Co(II) in CH2Cl2, ascribed to the π-π* transition, were red-shifted compared to those of C-Co(II) due to the π-expansion of the macrocycle in the pyrocobester. The reversible redox couple of P-Co(II) was observed at E1/2 = –0.30 V vs. Ag/AgCl in CH3CN, which was assigned to the Co(II)/Co(I) redox couple by UV-vis, ESR and molecular orbital analysis. This redox couple was positively shifted by 0.28 V compared to that of C-Co(II). This is caused by the high electronegativity of the dehydrocorrin macrocycle, which was estimated by DFT calculations for the free base ligands. The reactivity of the Co(I)-pyrocobester (P-Co(I)) was evaluated by the reaction with methyl iodide in CV and UV-vis to form a photo-sensitive Co(III)-CH3 complex (P Co(III)-CH3). The properties of the excited state of P-Co(I), *Co(I), were also investigated by femtosecond transient absorption (TA) spectroscopy. The lifetime of *Co(I) was estimated to be 29 ps from the kinetic trace at 587 nm. The lifetime of *Co(I) became shorter in the presence of Ar-X, such as iodobenzonitrile (1a), bromobenzonitrile (1b), and chlorobenzonitrile (1c), and the rate constants of electron transfer (ET) between the *Co(I) and Ar-X were determined to be 2.9 × 1011 M–1s–1, 4.9 × 1010 M–1s–1, and 1.0 × 1010 M–1s–1 for 1a, 1b, and 1c, respectively. . |
| 5. |
Keita Shichijo, Hisashi Shimakoshi, Visible light-driven photocatalytic benzoyl azides formation from
benzotrichlorides using rhodium ion modified TiO2, Journal of Photochemistry and Photobiology, 14, 100170-100178, 2023.01, Visible light-driven benzoyl azides formation catalyzed by a rhodium ion modified TiO2 (Rh3+/TiO2) is reported.
The Rh3+/TiO2 was prepared as a visible light responsive photocatalyst by a simple procedure from TiO2 and
RhCl3･3H2O. The Rh3+/TiO2 exhibited a broaden visible light absorption from 400 nm to 600 nm. Benzoyl azide
formation from a benzotrichloride and a trimethylsilyl azide (TMS-N3) was performed catalyzed by the Rh3+/
TiO2 under visible light irradiation (λ ≥ 420 nm) in air at room temperature. In this reaction, the benzotrichloride
was effectively reduced by the single electron transfer (SET) from the Rh3+/TiO2, and the benzoyl azide
was produced in 71% yield via the reaction between the benzoyl chloride and TMS-N3. In addition, several
benzotrichloride derivatives were applied to this reaction and the corresponding benzoyl azide derivatives were
formed in up to 71% yield. A kinetic analysis was also performed on these reactions, and it was suggested that the
SET is the rate determining step in this reaction.. |
| 6. |
Tomoki Imoto, Hikaru Matsumoto, Seiya Nonaka, Keita Shichijo, Masanori Nagao, Hisashi Shimakoshi, Yu Hoshino, Yoshiko Miura, 4-Amino-TEMPO-Immobilized Polymer Monolith:
Preparations, and Recycling Performance of Catalyst for
Alcohol Oxidation, Polymers, 10.3390/polym14235123, 14, 5123-5133, 2022.12, Continuous flow reactors with immobilized catalysts are in great demand in various
industries, to achieve easy separation, regeneration, and recycling of catalysts from products.
Oxidation of alcohols with 4-amino-TEMPO-immobilized monolith catalyst was investigated in
batch and continuous flow systems. The polymer monoliths were prepared by polymerizationinduced
phase separation using styrene derivatives, and 4-amino-TEMPO was immobilized on the
polymer monolith with a flow reaction. The prepared 4-amino-TEMPO-immobilized monoliths
showed high permeability, due to their high porosity. In batch oxidation, the reaction rate of 4-
amino-TEMPO-immobilized monolith varied with stirring. In flow oxidation, the eluent permeated
without clogging, and efficient flow oxidation was possible with residence times of 2–8 min. In the
recycling test of the flow oxidation reaction, the catalyst could be used at least six times without
catalyst deactivation.. |
| 7. |
J. Cheng, Y. Shiota, M. Yamasaki, K. Izukawa, Y. Tachi, K. Yoshizawa, H. Shimakoshi, Mechanistic Study for the Reaction of B12 Complexes with m-Chloroperbenzoic Acid in Catalytic
Alkane Oxidations
, Inorg. Chem., 61, 9710-9724, 2022.09, The oxidation of alkanes with m-chloroperbenzoic acid (mCPBA) catalyzed by the B12 derivative, heptamethyl cobyrinate, was investigated under several conditions. During the oxidation of cyclohexane, heptamethyl cobyrinate works as a catalyst to form cyclohexanol and cyclohexanone at a 0.67 alcohol to ketone ratio (A/K) under aerobic conditions in 1hr. The reaction rate shows a first-order dependence on the [catalyst] and [mCPBA] while independent of [cyclohexane]; Vobs = k2[catalyst][mCPBA]. The kinetic deuterium isotope effect (KIE) was determined to be 1.86, suggesting that substrate hydrogen atom abstraction (HAA) is not dominantly involved in the rate-determining step. By the reaction of mCPBA and heptamethyl cobyrinate at low temperature, the corresponding cobalt (III) acylperoxido complex was formed which was identified by UV-vis, IR, ESR, and ESI-MS. A theoretical study suggested the homolysis of the O-O bond in the acylperoxido complex to form Co(III)-oxyl (Co-O•) and the m-chlorobenzoyloxyl radical. Radical trapping experiments using N-tert-butyl-α-phenylnitrone (PBN) and CCl3Br, product analysis of various alkane oxidations, and computer analysis of the free energy for radical abstraction from cyclohexane by Co(III)-oxyl suggested that both Co(III)-oxyl and m-chlorobenzoyloxyl radical could act as hydrogen-atom transfer (HAT) reactants for the cyclohexane oxidation.. |
| 8. |
J. Cheng, H. Matsumoto, K. Shichijo, Y. Miura, H. Shimakoshi, Effect of Catalyst Support in B12-Based Heterogeneous Catalysts for Catalytic Alkane Oxidations., Bull. Chem. Soc. Jpn., 95, 1250-1252, 2022.05, Heterogeneous catalysts composed of the vitamin B12 derivative with a polymer or mesoporous silica were synthesized and characterized. These two types of catalysts were used in alkane oxidation reactions with the mCPBA oxidant, and an improved catalytic efficiency was obtained by the polymer supported B12 catalyst with a monolith structure compared to that of the monomeric B12 catalyst. The catalytic effects were also evaluated in several alkane substrates and the polymer supported B12 catalyst showed a better performance in all reactions compared to the silica-supported B12 catalyst.. |
| 9. |
Keita Shichijo, Midori Watanabe, Yoshio Hisaeda, Hisashi Shimakoshi, Development of Visible Light-Driven Hybrid Catalysts Composed of Earth Abundant Metal Ions Modified TiO2 and B12 Complex, Bull. Chem. Soc. Jpn., 2022.05, The development of highly-functional visible light-driven hybrid catalysts (B12-Mn+/TiO2) prepared from B12 complexes (B12) derived from natural vitamin B12, earth-abundant metal ions (Mn+), and titanium oxide (TiO2) was reported. The metal ions, such as Cu2+, Ni2+, Fe2+, Zn2+, Mn2+, Al3+, and Mg2+, were modified on the surface of TiO2 (2.4×10-5 − 9.9×10-5 mol/g) to obtain the effective response to visible light, and the B12 complex was also loaded (6.2×10-6 − 1.1×10-5 mol/g) to produce a highly-functional hybrid catalyst. Amide formations from dichlorodiphenyltrichloroethane (DDT) catalyzed by the B12-Mn+/TiO2 proceeded in up to 89% yields in the presence of triethylamine (NEt3) under visible light irradiation (λ≧420 nm) in air at room temperature. These hybrid catalysts were able to be classified into two groups based on these reactivities, and it was found that the B12-Mg2+/TiO2 showed the most effective catalytic activities of all the prepared samples. The B12-Mg2+/TiO2 also catalyzed the syntheses of fine chemicals, such as N,N-diethyl-3-methylbenzeamide (DEET), and N,N-diethylcyanoformamide, from the corresponding trichloromethyl compounds (FG-CCl3) with about 80% yields.. |
| 10. |
Moniruzzaman, Mohammad; Yano, Yoshio; Ono, Toshikazu; Hisaeda, Yoshio; Shimakoshi, Hisashi, Aerobic Electrochemical Transformations of DDT to Oxygen-Incorporated Products Catalyzed by a B-12 Derivative, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 10.1246/bcsj.20210316, 94, 11, 2784-2791, 2021.11. |
| 11. |
Moniruzzaman, Mohammad; Yano, Yoshio; Ono, Toshikazu; Imamura, Kenji; Shiota, Yoshihito; Yoshizawa, Kazunari; Hisaeda, Yoshio; Shimakoshi, Hisashi, Electrochemical Synthesis of Cyanoformamides from Trichloroacetonitrile and Secondary Amines Mediated by the B-12 Derivative, JOURNAL OF ORGANIC CHEMISTRY, 10.1021/acs.joc.1c00837, 86, 22, 16134-16143, 2021.11. |
| 12. |
Hisashi Shimakoshi, Yoshio Hisaeda, Bioinspired Electrolysis for Green Molecular Transformations of Organic Halides Catalyzed by B12 Complex, The Chemical Record, 2021.05, Naturally-occurring B12-dependent enzymes catalyze various molecular transformations that are of particular interest from the viewpoint of biological chemistry as well as synthetic organic chemistry. Inspired by the unique property of the B12-dependent enzymes, various catalytic reactions have been developed using its model complex. Among the B12 model complexes, heptamethyl cobyrinate, synthesized from natural vitamin B12, is highly soluble in various organic solvents and a redox active cobalt complex with an excellent catalysis in electroorganic synthesis. The electrochemical dechlorination of pollutant organic chlorides, such as DDT, was effectively catalyzed by the B12 complex. Modification of the electrode surface by the sol-gel method to immobilize the B12 complex was also developed. The B12 modified electrodes were effective for the dehalogenation of organic halides with high turnover numbers based on the immobilized B12 complex. Electrolysis of an organic halide catalyzed by the B12 complex provided dechlorinated products under anaerobic conditions, while the electrolysis under aerobic conditions afforded oxygen incorporated products, such as an ester and amide along with dechlorination. Benzotrichloride was transformed into ethylbenzoate or N,N-diethylbenzamide in the presence of ethanol or diethylamine, respectively. This amide formation was further expanded to a unique paired electrolysis. Electrochemical reductions of an alkene and alkyne were also catalyzed by the B12 complex. A cobalt-hydrogen complex should be formed as a bioinspired intermediate. Using the B12 complex, light-assisted electrosynthesis was also developed to save the applied energy.. |
| 13. |
Mohammad Moniruzzaman, Yoshio Yano, Toshikazu Ono, Yoshio Hisaeda, Hisashi Shimakoshi, Electrochemical approach to trifluoroacetamide synthesis from 1,1,1-trichloro-2,2,2-trifluoroethane (CFC-113a) catalyzed by B12 complex, Journal of Porphyrins and Phthalocyanines, https://doi.org/10.1142/S1088424621500292, 2021.01, One-pot synthetic approach to produce trifluoroacetamide has been developed using an electrochemical method with the B12 complex as a catalyst under mild conditions, in air, at room temperature. Thirty examples of trifluoroacetamide were synthesized from 1,1,1-trichloro-2,2,2-trifluoroethane (CFC-113a) in moderate to good yields. This user-friendly strategy is compatible with a broad range of trifluoroacetamide syntheses.. |
| 14. |
Zhongli Luo, Kenji Imamura, Yoshihito Shiota, Kazunari Yoshizawa, Yoshio Hisaeda, Hisashi Shimakoshi, One-Pot Synthesis of Tertiary Amides from Organic Trichlorides through Oxygen Atom Incorporation from Air by Convergent Paired Electrolysis, J. Org. Chem., https://doi.org/10.1021/acs.joc.1c00161, 86, 5983-5990, 2021.04, A convergent paired electrolysis catalyzed by a B12 complex for the
one-pot synthesis of a tertiary amide from organic trichlorides (R-CCl3) has been
developed. Various readily available organic trichlorides, such as benzotrichloride
and its derivatives, chloroform, dichlorodiphenyltrichloroethane (DDT), trichloro-2,2,2-trifluoroethane (CFC-113a), and trichloroacetonitrile (CNCCl3), were converted to amides in the presence of tertiary amines through oxygen incorporation from air at room temperature. The amide formation mechanism in the paired electrolysis, which was mediated by a cobalt complex, was proposed.. |
| 15. |
Shimakoshi, Hisashi; Shichijo, Keita; Tominaga, Shiori; Hisaeda, Yoshio; Fujitsuka, Mamoru; Majima, Tetsuro, Catalytic Dehalogenation of Aryl Halides via Excited State Electron Transfer from the Co(I) State of B-12 Complex, CHEMISTRY LETTERS, 10.1246/cl.200241, 49, 7, 820-822, 2020.07, Catalytic Dehalogenation of Aryl Halides via Excited State Electron Transfer from the Co(I) State of B12 Complex. |
| 16. |
Anai, Yuki; Shichijo, Keita; Fujitsuka, Mamoru; Hisaeda, Yoshio; Shimakoshi, Hisashi, Synthesis of a B-12-BODIPY dyad for B(12-)inspired photochemical transformations of a trichloromethylated organic compound, CHEMICAL COMMUNICATIONS, 10.1039/d0cc04274a, 56, 80, 11945-11948, 2020.10, The B12 complex-BODIPY dyad was synthesized by peripheral modification of the cobalamin derivative. The photophysical properties of the dyad were investigated by UV-vis, PL, and transient absorption spectroscopies. The visible light-driven dechlorination reaction of the trichlorinated organic compound, DDT, was reported. The dyad showed an efficient catalysis for the dechlorination under N2 with turnover numbers of over 220 for the reaction. The one-pot syntheses of an ester and amide from DDT and benzotrichloride were also achieved using the dyad in air.. |
| 17. |
Taro Koide, Zihan Zhou, Ning Xu, Yoshio Yano, Toshikazu Ono, Zhongli Luo, Hisashi Shimakoshi, Yoshio Hisaeda, Electrochemical properties and catalytic reactivity of cobalt complexes with redox-active meso -substituted porphycene ligands, Journal of Porphyrins and Phthalocyanines, 10.1142/S1088424619500780, 24, 1-3, 90-97, 2020.01, The cobalt complexes of meso-aryl substituted porphycenes were synthesized and characterized. The reduction potentials of the complexes were shifted to the positive side depending on the strength of the electron-withdrawing properties of the meso-substituents, while the optical properties, such as the absorption spectra of these complexes, were similar. This suggests that the energy levels of the molecular orbitals of the complexes were changed by the meso-substituents while the gaps of the orbitals were not significantly changed. The one-electron reduction of the complex did not afford the Co(I) species, but the ligand-reduced radical anion, which was characterized by electrospectrochemistry. The generated ligand-reduced species reacted with alkyl halides to form the Co(III)-alkyl complex. As a result, the reduction potential of the electrolytic reaction could be directly controlled by the substituents of the porphycene. The catalytic reaction with trichloromethylbenzene was also performed and it was found that the ratio of the obtained products was changed by the reduction potentials of the catalyst, i.e. the cobalt porphycenes.. |
| 18. |
Keita Shichijo, Mamoru Fujitsuka, Yoshio Hisaeda, Hisashi Shimakoshi, Visible light-driven photocatalytic duet reaction catalyzed by the B-12-rhodium-titanium oxide hybrid catalyst, JOURNAL OF ORGANOMETALLIC CHEMISTRY, 10.1016/j.jorganchem.2019.121058, 907, 121058, 2020.02. |
| 19. |
Li Chen, Yohei Kametani, Kenji Imamura, Tsukasa Abe, Yoshihito Shiota, Kazunari Yoshizawa, Yoshio Hisaeda, Hisashi Shimakoshi, Visible light-driven cross-coupling reactions of alkyl halides with phenylacetylene derivatives for C(sp3)-C(sp) bond formation catalyzed by a B12 complex, Chemical Communications, 10.1039/c9cc06185a, 55, 87, 13070-13073, 2019.01, Visible light-driven cross-coupling reactions of alkyl halides with phenylacetylene and its derivatives catalyzed by the cobalamin derivative (B12) with the [Ir(dtbbpy)(ppy)2]PF6 photocatalyst at room temperature are reported. The robust B12 catalyst and Ir photocatalyst provided high turnover numbers of over 33 000 for the reactions.. |
| 20. |
Hisashi Shimakoshi, Noriyuki Houfuku, Li Chen, Yoshio Hisaeda, Redox active ionic liquid as efficient mediator and solvent for visible light-driven B
12
catalytic reactions, Green Energy and Environment, 10.1016/j.gee.2019.03.001, 4, 2, 116-120, 2019.04, The redox active ionic liquid, 1-ethyl-4-(methoxycarbonyl)pyridinium bis(trifluoromethanesulfonyl)amide (RIL), was synthesized from its iodide form by an anion exchange reaction of Li(NTf
2
) with viscos liquid (η = 122 cP at 25 °C) and characterized by NMR, IR, and elemental analysis. The compound showed reversible redox couples at −0.65 V and −1.48 V vs. Ag/AgCl and worked as an electron mediator in the B
12
complex/[Ru(bpy)
3
]Cl
2
photosensitizer catalytic system under visible light irradiation. The catalytic efficiency in the RIL was higher than those in DMF, MeOH, and the redox inactive ionic liquid, 1-butyl-3-methyl imidazolium bis(trifluoromethylsulfonyl)amide.. |
| 21. |
Koichi Hashimoto, Taro Koide, Toru Okawara, Hisashi Shimakoshi, Yuta Hori, Yoshihito Shiota, Kazunari Yoshizawa, Yoshio Hisaeda, Redox behaviour of the β-dihydroporphycene cobalt complex
study on the effect of hydrogenation of the ligand, Dalton Transactions, 10.1039/c8dt03743d, 48, 3, 872-881, 2019.01, The dihydrogenated porphycene cobalt(ii) complex was synthesized and electrochemical experiments were carried out. The one-electron reduction of the complex proceeded at the central metal to afford the Co(i) species; in contrast, for the non-hydrogenated porphycene cobalt(ii) complex, the one-electron reduction gave the ligand reduced radical anion species. The reactivity of the one-electron reduced species with alkyl halides showed clear differences between the complexes. Hydrogenation of the β-position of the porphycene makes it possible to generate a central cobalt reduced species possessing a higher reactivity than the ligand reduced radical anion species.. |
| 22. |
Li Chen, Yoshio Hisaeda, Hisashi Shimakoshi, Visible Light-Driven, Room Temperature Heck-Type Reaction of Alkyl Halides with Styrene Derivatives Catalyzed by B
12
Complex, Advanced Synthesis and Catalysis, 10.1002/adsc.201801707, 2019.01, A visible light driven Heck-type coupling reaction of alkyl halides with styrene and its derivatives catalyzed by the cobalamin derivative (B
12
) with the [Ru(bpy)
3
]Cl
2
photosensitizer at room temperature is reported. The catalytic efficiencies of the B
12
catalyst were compared to that of other cobalt complexes such as cobaloxime. Various control experiments supported a radical-based mechanism similar to those for typical B
12
model reactions. A unique coupling reaction combined with 1,2-migration of the functional group is also reported. Mild reaction conditions using an environmentally benign cobalt catalyst derived from the natural B
12
provided a practical protocol for the synthetic organic chemistry of the B
12
catalyzed reaction system. (Figure presented.).. |
| 23. |
Hui Tian, Hisashi Shimakoshi, Toshikazu Ono, Yoshio Hisaeda, Visible-Light-Driven, One-pot Amide Synthesis Catalyzed by the B12 Model Complex under Aerobic Conditions, ChemPlusChem, 10.1002/cplu.201800586, 2019.01, Invited for this month's cover is the group of Prof. Dr. Hisashi Shimakoshi at Kyushu University, Japan. The front cover shows “le mariage” of an iridium complex and a vitamin B12 derivative with two wedding rings in the background. This collaboration of two complexes is induced by visible light in the presence of air to achieve green molecular transformations. This protocol was applied to the synthesis of amides from a wide range of trichlorinated organic compounds. Read the full text of the article at 10.1002/cplu.201800522.. |
| 24. |
Ying Sun, Wei Zhang, Tian Yi Ma, Yu Zhang, Hisashi Shimakoshi, Yoshio Hisaeda, Xi Ming Song, Enhanced photocatalytic activity of a B12-based catalyst co-photosensitized by TiO2 and Ru(II) towards dechlorination, RSC Advances, 10.1039/c7ra13037f, 8, 2, 662-670, 2018.01, A novel hybrid photocatalyst denoted as B12-TiO2-Ru(ii) was prepared by co-immobilizing a B12 derivative and trisbipyridine ruthenium (Ru(bpy)3 2+) on the surface of a mesoporous anatase TiO2 microspheres and was characterized by DRS, XRD, SEM and BET et al. By using the hybrid photocatalyst, DDT was completely didechlorinated and a small part of tridechlorinated product was also detected in the presence of TEOA only after 30 min of visible light irradiation. Under simulated sunlight, the hybrid exhibited a significantly enhanced photocatalytic activity for dechlorination compared with B12-TiO2 under the same condition or itself under visible light irradiation due to the additivity in the contribution of UV and visible part of the sunlight to the electron transfer. In addition, this hybrid catalyst can be easily reused without loss of catalytic efficiency. This is the first report on a B12-based photocatalyst co-sensitized by two photosensitizers with wide spectral response.. |
| 25. |
Taro Koide, Isao Aritome, Tatsuya Saeki, Yoshitsugu Morita, Yoshihito Shiota, Kazunari Yoshizawa, Hisashi Shimakoshi, Yoshio Hisaeda, Cobalt-Carbon Bond Formation Reaction via Ligand Reduction of Porphycene-Cobalt(II) Complex and Its Noninnocent Reactivity, ACS Omega, 10.1021/acsomega.8b00239, 3, 4, 4027-4034, 2018.01, The interesting redox properties and reactivity of metalloporphycene have been studied for decades; however, the detailed experimental investigation on the reactivity and reaction mechanism under inert condition combined with theoretical calculations had not been performed so far. In this study, the novel reactivity of the reduced form of the cobalt porphycene with alkyl halides to form cobalt-carbon (Co-C) bonds was revealed. Under electrochemical reductive conditions, not the central cobalt, but the ligand was reduced and reacted with alkyl halides to afford the cobalt-alkyl complexes under N2 atmosphere in a glovebox. The reaction mechanism was clarified by the combination of experimental and theoretical studies that the porphycene ligand works as a noninnocent ligand and allows the SN2-type Co-C bond formation. This result provides us the possibility of the reaction triggered by the reduction of ligand with macrocyclic π-conjugated system, not by the reduction of metal.. |
| 26. |
Hisashi Shimakoshi, Yoshio Hisaeda, Bioinspired molecular transformations by biorelated metal complexes combined with electrolysis and photoredox systems, Yuki Gosei Kagaku Kyokaishi/Journal of Synthetic Organic Chemistry, 10.5059/yukigoseikyokaishi.76.894, 76, 9, 894-903, 2018.01, Naturally-occurring B 12(cobalamin)-dependent enzymes catalyze various molecular transformations that are of particular interest from the viewpoint of biological chemistry as well as synthetic organic chemistry. As bioorganometallic compounds are considered as intermediate for B 12-dependent reactions, those were utilized as catalysts for various molecular transformations. Using the unique property of the B 12 compound, various catalytic reactions have been developed using its model complex. Electroorganic syntheses mediated by the B 12 complex have been developed as green molecular transformations. The redox active B 12 complex shows a unique catalysis in organic synthesis such as the dechlorination of organic halides and the radical mediated isomerization reactions. The B 12 complex-photosensitizer composites have also become a green and efficient catalyst for molecular transformations. The B 12-dependent enzymes mimic reactions catalytically occurring using the B 12 complex-photosensitizer composites. In addition to the B 12 mimic reaction, novel bioinspired reactions were also developed, such as hydrogen production or alkene and alkyne reductions, and the cobalt-hydrogen complex was considered as a putative intermediate of the reactions.. |
| 27. |
Toshikazu Ono, Kosuke Wakiya, Md Jakir Hossain, Hisashi Shimakoshi, Yoshio Hisaeda, Synthesis of trifluoromethylated B12 derivative and photolysis of cobalt(III)-trifluoromethyl bond, Chemistry Letters, 10.1246/cl.180355, 47, 8, 979-981, 2018.01, A vitamin B12 derivative with a trifluoromethyl group as an axial ligand, heptamethyl trifluoromethylaquacobyrinate perchlorate, [[(CF3)(H2O)Cob(III)7C1ester]ClO4], is prepared and characterized by elemental analysis, 1H NMR, 19F NMR, ESI-MS, UV-vis absorption, and cyclic voltammetry. The Co-CF3 complex shows homolysis of the Co(III)-CF3 bond under visible light irradiation, which releases a CF3 radical that can be detected by a radical trapping experiment.. |
| 28. |
Hui Tian, Hisashi Shimakoshi, Toshikazu Ono, Yoshio Hisaeda, Visible Light-Driven, One-pot Amide Synthesis Catalyzed by the B12 Model Complex under Aerobic Conditions, ChemPlusChem, 10.1002/cplu.201800522, 2018.01, A visible light responsive catalytic system with the B12 complex as the catalyst and [Ir(dtbbpy)(ppy)2]PF6 as the photosensitizer was developed. It provides a convenient and efficient way to synthesize amides. Based on this method, trichlorinated organic compounds were converted into amides in the presence of an amine under aerobic conditions at room temperature in a one-pot procedure. Various trichlorinated organic compounds and an amine source, such as primary, secondary, and cyclic amines, have been evaluated for this transformation, providing the expected products in moderate to excellent yields. Notably, product formation depended on the reaction atmosphere where the amide was obtained under aerobic conditions while partially dechlorinated products were obtained under anaerobic conditions. As this protocol is free from hazardous reagents, extra additives, noble metals, and dangerous gas, the present method provides a novel and efficient approach for amide synthesis under mild and easily controlled conditions.. |
| 29. |
Hisashi Shimakoshi, Yoshio Hisaeda, Electrochemistry and catalytic properties of vitamin B12 derivatives in nonaqueous media, Current Opinion in Electrochemistry, https:// doi.org/ 10.1016/ j.coelec.2017.12.001, 8, 24-30, 2017.12, Electroorganic synthesis mediated by vitamin B12 derivatives has been developed in nonaqueous media. Especially, amphiphilic heptamethyl cobyrinate with a high solubility in various organic solvents was used in various kinds of electroorganic syntheses based on enzymatic function. Electrolysis of an organic halide catalyzed by the B12 model complex provided dechlorinated products under anaerobic conditions, while the electrolysis under aerobic conditions afforded oxidized products such as an ester and amide with dechlorination. Electrochemical reductions of an alkene and alkyne were also catalyzed by the B12 model complex at less negative applied potentials than those of the alkene and alkyne reductions. A bioinspired intermediate, expected as a cobalt-hydrogen complex, should be formed and catalyze the reaction.. |
| 30. |
Hui Tian, Hisashi Shimakoshi, Sinheui Kim, Gyurim Park, Youngmin You, Yoshio Hisaeda, Photocatalytic Function of B12 Complex with Cyclometalated Iridium(III) Complex as Photosensitizer under Visible Light Irradiation, Dalton Transaction, 10.1039/c7dt03742b, 47, 675-683, 2017.12, A visible light induced three-component catalytic system with the cobalamin derivative (B12) as a catalyst, the cyclometalated iridium(III) complex (Irdfppy, Irppy, Irpbt and [Ir{dF(CF3)ppy}2(dtbpy)]PF6 as a photosensitizer and triethanolamine as an electron source under N2 was developed. This catalytic system showed a much higher catalytic efficiency than the previous catalytic system using [Ru(bpy)3]Cl2 as the photosensitizer for the dechlorination reaction of 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT). Noteworthy is the fact that the remarkable high turnover number (over ten thousand) based on B12, which ranks at the top among the reported studies, was obtained when Irdfppy was used as a photosensitizer. This photocatalytic system was also successfully applied to the B12 enzyme-mimic reaction, i.e., the 1,2-migration of the phenyl group of 2-bromomethyl-2-phenylmalonate. The plausible reaction mechanism was proposed, which involved two quenching pathways, an oxidative quenching pathway and a reductive quenching pathway, to be responsible for the initial electron transfer of the excited-state photosensitizers during the DDT dechlorination reaction. Transient photoluminescence experiments revealed that oxidative quenching of the photosensitizer dominated over the reductive quenching pathway.. |
| 31. |
Keishiro Tahara, Ling Pan, Ryoko Yamaguchi, Hisashi Shimakoshi, Masaaki Abe, Yoshio Hisaeda, Impact of the corrin framework of vitamin B12 on the electrochemical carbon-skeleton rearrangement in comparison to an imine/oxime planar ligand; tuning selectivity in 1,2-migration of a functional group by controlling electrolysis potential, Journal of Inorganic Biochemistry, 10.1016/j.jinorgbio.2017.07.021, 175, 239-243, 2017.10, Among the coenzyme B12-dependent enzymes, methylmalonyl-CoA mutase (MMCM) catalyzes the carbon-skeleton rearrangement reaction between R-methylmalonyl-CoA and succinyl-CoA. Diethyl 2-bromomethyl-2-phenylmalonate, an alkyl bromide substrate having two different migrating groups (phenyl and carboxylic ester groups) on the β-carbon, was applied to the electrolysis mediated by a hydrophobic vitamin B12 model complex, heptamethyl cobyrinate perchlorate in this study. The electrolysis of the substrate at − 1.0 V vs. Ag-AgCl by light irradiation afforded the simple reduced product (diethyl 2-methyl-2-phenylmalonate) and the phenyl migrated product (diethyl 2-benzyl-2-phenylmalonate), as well as the electrolysis of the substrate at − 1.5 V vs. Ag-AgCl in the dark. The electrolysis of the substrate at − 2.0 V vs. Ag-AgCl afforded the carboxylic ester migrated product (diethyl phenylsuccinate) as the major product. The selectivity for the migrating group was successfully tuned by controlling the electrolysis potential. We clarified that the cathodic chemistry of the Co(III) alkylated heptamethyl cobyrinate is critical for the selectivity of the migrating group through mechanistic investigations and comparisons to the simple vitamin B12 model complex, an imine/oxime-type cobalt complex.. |
| 32. |
Hui Tian, Hisashi Shimakoshi, Kenji Imamura, Yoshihito Shiota, Kazunari Yoshizawa, and Yoshio Hisaeda, Photocatalytic alkene reduction by B12-TiO2 hybrid catalyst coupled with C-F bond cleavage for gem-difluoroolefin synthesis, Chemical Communication, 10.1039/c7cc04377e, 53, 9478-9481, 2017.07, Photocatalytic synstheses of gem-difluoroolefins were performed using the B12-TiO2 hybrid catalyst during C=C bond reduction of α-trifluoromethyl styrenes with C-F bond cleavage at room temperature under nitrogen. The gem-difluoroolefins were used as synthetic precursors for fluorinated cyclopropanes.. |
| 33. |
Ying Sun, Wei Zhang, Jian Tong, Yu Zhang, Shuyao Wu, Daliang Liu, Hisashi Shimakoshi, Yoshio Hisaeda, Xi Ming Song, Significant enhancement of visible light photocatalytic activity of the hybrid B12-PIL/rGO in the presence of Ru(bpy)3 2+ for DDT dehalogenation, RSC Advances, 10.1039/c7ra02062g, 7, 31, 19197-19204, 2017.01, A new B12-PIL/rGO hybrid was prepared successfully through immobilizing a B12 derivative on the surface of poly(ionic liquid) (PIL)-modified reduced graphene oxide (rGO) by electrostatic attraction and π-π stacking attraction among the different components. The hybrid catalyst showed an enhanced photocatalytic activity in the presence of Ru(bpy)3 2+ for 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) dechlorination with ∼100% conversion. Especially, the yield of didechlorinated products could reach 78% after 1 h of visible light irradiation, which should be attributed to a synergistic effect of B12, rGO and PIL in B12-PIL/rGO, including their respective catalytic performance, the excellent electron transport of rGO and the concentration of DDT and 1,1-bis(4-chlorophenyl)-2,2-dichloroethane (DDD) on the surface of B12-PIL/rGO. Furthermore, the hybrid catalyst was easily recycled for use without obvious loss of catalytic activity.. |
| 34. |
Hisashi Shimakoshi, Zhongli Luo, Kazuya Tomita, Yoshio Hisaeda, Cathodic reductive couplings and hydrogenations of alkenes and alkynes catalyzed by the B12 model complex, Journal of Organometallic Chemistry, 10.1016/j.jorganchem.2017.02.002, 2016.11, The reductive coupling and hydrogenation of alkenes were catalyzed by the B12 model complex, heptamethyl cobyrinate perchlorate (1), in the presence of acid during electrolysis at -0.7 V vs. Ag/AgCl in acetonitrile. Conjugated alkenes showed a good reactivity during electrolysis to form reduced products. The product distributions were dependent on the substituents at the CC bond of the alkenes. ESR spin-trapping experiments using 5,5-dimethylpyrroline N-oxide (DMPO) revealed that the cobalt-hydrogen complex (CoH complex) should be formed during the electrolysis and it functioned as an intermediate for the alkene reduction. The electrolysis was also applied to an alkyne, such as phenylacetylene, to form 2,3-diphenylbutane (racemic and meso) and ethylbenzene via styrene as reductive coupling and hydrogenated products, respectively.. |
| 35. |
Shimakoshi Hisashi, Yoshio Hisaeda, Hybrid Catalyst for Light-Driven Green Molecular Transformations, ChemPlusChem, 10.1002/cplu.201600303, 82, 18-29, 2016.10, This review is focused on the development of a hybrid catalyst composed of photosensitizers and a metal complex, especially B12 derivatives. The semiconductor-metal complex composites become an effective photocatalyst for molecular transformations due to the synergistic effect by both components. As a design of the B12 complex for the hybridization with TiO2, cobyrinic acid having seven carboxyric groups derived from naturally-occurring B12 was a simple and straightforward compound, which stably immobilized on the TiO2. By using the hybrid catalysts, light driven B12-dependent enzymes mimic reactions, such as the dechlorination of organic halide pollutants, and the radical mediated isomerization reactions catalytically proceeded. In addition to the enzyme mimic reaction, bioinspired reactions were also developed with the hybrid catalyst. The B12-TiO2 hybrid catalyst was used for the hydrogen evolution or alkenes reduction by UV light irradiation, and the cobalt-hydrogen complex (Co-H complex) was considered as a putative intermediate of the reactions. The multidisciplinary concept for the design of a hybrid catalyst is described in this review.. |
| 36. |
Shimakoshi Hisashi, Zhongli Luo, Yoshio Hisaeda, Electrolysis of Trichloromethylated Organic Compounds under Aerobic Condition Catalyzed by B12 Model Complex for Ester and Amide Formations, Dalton Trans., 10.1039/c6dt00556j, 45, 10173-10180, 2016.04, Electrolysis of benzotrichloride at -0.9 V vs. Ag/AgCl in the presence of B12 model complex, heptamethyl cobyrinate perchlorate (1), in ethanol under aerobic condition using undivided cell equipped with platinum mesh cathode and zinc plate anode produced ethylbenzoate in 56% yield with 92% selectivity. Corresponding esters were obtained when the electrolysis were carried out in various alcohols such as methanol, n-propanol, and i-propanol. Benzoyl chloride was detected by GC-MS during the electrolysis as an intermediate for ester formation. While electrolysis was carried out under anaerobic condition, dechlorinated products, 1,1,2,2-tetrachloro-1,2-diphenylethane and 1,2-dichlorostilibenes (E and Z forms) were obtained instead of ester. ESR spin-trapping experiments using 5,5,-dimethylpyrroline N-oxide (DMPO) revealed that corresponding oxygen-centered radical and carbon-centered radical were steadily generated during the electrolyses under aerobic and anaerobic conditions, respectively. Applications of the aerobic electrolysis to various organic halides such as substituted benzotrichlorides were shown. Furthermore, formation of amides with moderate yields by the aerobic electrolysis of benzotrichloride catalyzed by 1 in the presence of amines in acetonitrile were reported.. |
| 37. |
M. Giedyk, Hisashi Shimakoshi, K. Goliszewska, D. Gryko, Yoshio Hisaeda, Electrochemistry and catalytic properties of amphiphilic Vitamin B12 derivatives in nonaqueous media, Dalton Transactions, 10.1039/c6dt00355a, 45, 20, 8340-8346, 2016, The reduction pathway of cobalester (CN)Cble, an amphiphilic vitamin Bf12 derivative, was investigated in organic solvents under electrochemical conditions and compared with mono- and dicyanocobyrinates. The redox characteristics were determined using cyclic voltammetry and spectroelectrochemical methods. The presence of a nucleotide moiety in B12-derivative impedes the in situ formation of dicyano-species thus facilitating the (CN)Co(iii) to Co(i) reduction. The (CN)Cble shows stepwise reduction to Co(i) via (CN)Co(ii). The reduction of (CN)Co(ii)/Co(i) was found to depend on cyanide-solvent exchange equilibrium with weakly coordinating solvents and bulky peripheral chains promoting intact (CN)Co(ii) species existence. The studied complexes were also utilized as catalysts in bulk electrolysis of benzyl bromide affording bibenzyl in very good yield. The Royal Society of Chemistry.. |
| 38. |
Shimakoshi Hisashi, Yoshio Hisaeda, Oxygen-Controlled Catalysis by Vitamin B12-TiO2: Formation of Esters and Amides from Trichlorinated Organic Compounds by Photoirradiation, Angew. Chem. Int. Ed., 10.1002/anie.201507782, 54, 15439-15443, 2015.10. |
| 39. |
Shimakoshi Hisashi, Yoko Nagami, Yoshio Hisaeda, Crystal Structure Dependence for Reactivities of B12-TiO2 Hybrid Catalysts with Anatase and Rutile Forms, Rapid Communication in Photoscience/Korea Photoscience Society, 10.5857/RCP.2015.4.1.9, 4, 1, 9-11, 2015.05. |
| 40. |
Jing Xu, Hisashi Shimakoshi, Yoshio Hisaeda, Development of metal-organic framework (MOF)-B12 system as new bio-inspired heterogeneous catalyst, Journal of Organometallic Chemistry, 10.1016/j.jorganchem.2014.11.015, 782, 89-95, 2015.04, Abstract A novel bimetal complex {Zn4Ru2(bpdc)4·4C2NH8·9DMF}n (1) (H2bpdc = 4,4′-biphenyldicarboxylic acid) was synthesized by the solvothermal method. The results of the X-ray crystallographic analysis revealed that 1 crystallizes in the orthorhombic Pna21 space group, which has a 3D 2-fold interpenetrated hex framework, with open channel sizes along the [010] direction of ca. 1.4 nm × 1.4 nm. The photosensitizer [Ru(bpy)3]2+ was adsorbed into the 1 to form Ru@MOF by cation exchanging. A cobalamin derivative (B12), heptamethyl cobyrinate, was also effectively immobilized on Ru@MOF, and the resulting hybrid complex, B12-Ru@MOF, exhibited a high reactivity for the dechlorination reaction of 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) under an N2 atmosphere by visible light irradiation in the solid state. The catalysis of B12-Ru@MOF can still reach more than a ca. 80% conversion after third recyclings. Furthermore, the heterogeneous catalyst, B12-Ru@MOF, was useful for the cobalamin-dependent reaction, such as the 1,2-migration of the acetyl group.. |
| 41. |
Shimakoshi Hisashi, Hisaeda Yoshio, A polymerized ionic liquid-supported B12 catalyst with a ruthenium trisbipyridine photosensitizer for photocatalytic dechlorination in ionic liquids, Royal Society of Chemistry, 10.1039/c4dt01360c, 43, 13972-13978, 2014.08, A visible light-driven photocatalyst by immobilizing a B12 complex and a Ru(II) trisbipyridine photosensitizer in a polymerized ionic liquid (PIL) was developed. The synthesized copolymer was characterized by GPC, DLS, and its UV-vis absorption spectra and luminescence spectra. The Ru(II) trisbipyridine photosensitizer in the copolymer showed an enhanced emission compared to that of the monomer in the ionic liquid, 1-butyl-4-methylimidazolium bis(trifluoromethanesulfonly)amide ([C4mim][NTf2]). Formation of the Co(I) species of the B12 complex in the copolymer was confirmed by the UV-vis spectral change in [C4mim][NTf2] containing a sacrificial reductant (triethanolamine) during irradiation with visible light. The copolymer showed a high photocatalytic activity in various ionic liquids for the 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) dechlorination with ~99% conversion after a 2 h visible light irradiation. Furthermore, both the B12 catalyst and the photosensitizer in the polymer were easily recycled for use with the ionic liquid solvent without any loss of catalytic activity.. |
| 42. |
Shimakoshi Hisashi, Hisaeda Yoshio, B12-TiO2 Hybrid Catalyst for Light-Driven Hydrogen Production and Hydrogenation of C-C Multiple Bonds, ChemPlusChem, 10.1002/cplu.201402081, 79, 1250-1253, 2014.06, The B12-TiO2 hybrid catalyst mediated the H2O reduction to form hydrogen under UV light irradiation (1 turnover number per hour). The catalyst also mediated alkene reductions, such as styrene derivatives and alkylacrylates (maximum 100 turnover number per hour), under mild conditions; i.e., room temperature, ordinary pressure, and water or alcohol solvent.. |
| 43. |
Hitesh V. Motwani, Hisashi Shimakoshi, Bernard T. Golding, Margareta Törnqvist, Yoshio Hisaeda, Alkylcobyrinate from sucralose and mechanistic aspects of its CoC bond cleavage, Tetrahedron Letters, 10.1016/j.tetlet.2014.03.028, 55, 16, 2667-2670, 2014.04, Reaction of heptamethyl cob(I)yrinate with 1′,6′-dichloro- 1′,6′-dideoxy-β-d-fructofuranosyl-4-chloro-4-deoxy-α-d- galactopyranoside (sucralose) gave an alkylcobyrinate, heptamethyl-6′- [α-d-galactopyranoside- 1′-chloro-1′,6′-dideoxy-β- d-fructofuranosyl-4-chloro-4-deoxy]cobyrinate perchlorate, [(Suc)Cob(III)7C 1ester]ClO4. Cleavage behavior of CoC bond of the alkylcobyrinate was investigated under various conditions (hν, H+ and reduction) using UV-vis spectroscopy combined with the EPR spin-trapping technique, and by cyclic voltammetry.. |
| 44. |
Masatsugu Taneda, Akihiro Tanaka, Hisashi Shimakoshi, Atsushi Ikegami, Koichi Hashimoto, Masaaki Abe, Yoshio Hisaeda, Synthesis and characterizations of meso-disubstituted asymmetric porphycenes, Tetrahedron Letters, 10.1016/j.tetlet.2013.08.026, 54, 42, 5727-5729, 2013.10, A post-synthetic method has been developed to synthesize novel asymmetric porphycenes bearing two different substituents on the meso-positions. Nitration of 9-acetoxy-2,7,12,17-tetra-n-propylporphycene with AgNO3 in CH 3COOH/CH2Cl2 occurs regioselectively at the 19-position of the macrocycle to give 9-acetoxy-19-nitro-2,7,12,17-tetra-n- propylporphycene (3a) which was readily converted to 9-acetoxy-19-amino-2,7,12, 17-tetra-n-propylporphycene (4a) by the reduction with SnCl2 in pyridine.. |
| 45. |
Yoshio Hisaeda, 田原圭志朗, Hisashi Shimakoshi, Bioinspired Catalytic Reactions with Vitamin B12 Derivative and Photosensitizers, Pure and Applied Chemistry, 85, 1415-1426, 2013.08. |
| 46. |
M Fujitsuka, Shimakoshi Hisashi, H Tei, M Noda, S Tojo, Hisaeda Yoshio, T Majima, Photoinduced electron transfer in supramolecular donor-acceptor dyads of Zn corrphycene, Physical Chemistry Chemical Physics, 39, 5677-5683, 2013.02. |
| 47. |
Toru Okawara, Abe Masaaki, Shimakoshi Hisashi, Hisaeda Yoshio, A Pd(II)-hydroxyporphycene: Synthesis, characterization, and photoinduced proton-coupled electron transfer, Research on Chemical Intermediates, 39, 161-176, 2013.01. |
| 48. |
Hisashi Shimakoshi, K. Sasaki, Y. Iseki, Yoshio Hisaeda, Synthesis and Photosensitizing Properties of Porphycene with Imidazolium Tag, J. Por. Phthalocyanines, 16, 530-536, 2013.01. |
| 49. |
H. Shimakoshi, L. Li, M. Nishi, Y. Hisaeda, Photosensitizing Catalysis of B12 Complex without Additional Photosensitizer, Chem. Commun., 47, 10921, 2012.05. |
| 50. |
Toru Okawara, Abe Masaaki, Koichi Hashimoto, Shimakoshi Hisashi, Hisaeda Yoshio, Hydrogenation effects in metalloporphycenes: synthesis and redox behavior of Ni(II)-tetra(n-propyl)dihydroporphycene, Chem. Commun., 47, 10921, 2012.05. |
| 51. |
K. Tahara, H. Shimakoshi, A. Tanaka, Y. Hisaeda, Redox Behavior and Electrochemical Catalytic Function of B12-Hyperbranched Polymer, Bull. Chem. Soc. Jpn, 83, 1439-1446, 2011.12. |
| 52. |
K. Tahara, Y. Chen, L. Pan, T. Masuko, H. Shimakoshi, Y. Hisaeda, Electrochemical Catalytic Carbon-Skeleton Rearrangement mediated by Imine/oxime-type B12 Model Complex, Chem. Lett., 40, 177-179, 2011.05. |
| 53. |
H. Shimakoshi, M. Nishi, A. Tanaka, K. Chikama, Y. Hisaeda, Photocatalytic Function of Polymer-Supported B12 Complex with Ruthenium Trisbipyridine Photosensitizer, Chem. Commun., 47, 6548, 2011.05. |
| 54. |
Hisashi Shimakoshi, Makoto Abiru, Keita Kuroiwa, Nobuo Kimizuka, Midori Watanabe Yoshio Hisaeda, Preparation and Reactivity of B12-TiO2 Hybrid Catalyst Immobilized on Glass Plate, Bull. Chem. Soc. Jpn, 83, 170-172, 2011.04. |
| 55. |
Daisuke Maeda, Hisashi Shimakoshi, Mamoru Fujituska, Masaaki Abe, Tetsuro Majima, Yoshio Hisaeda, Synthesis of a Novel Sn(IV) Porphycene-Ferrocene Triad Linked by Axial Coordination and Solvent Polarity Effect in Photoinduced Charge Separation Process, Inorganic Chemistry, 49, 2872-2880, 2011.04. |
| 56. |
Hisashi Shimakoshi, Daisuke Maeda, Yoshio Hisaeda, Supramolecular Assemblies of Crown-substituted Dinickel and Dicobalt Complexes with Guest Cation Binding, Supramolecular Chemistry, 23, 1-2, 131-139, 2011.01. |
| 57. |
Mamoru Fujitsuka, Hisashi Shimakoshi, Yoshio Hisaeda, Tetsuro Majima, Reorganization Energy of Supramolecular Donor-Acceptor Dyad of Octaethyl porphyrin Isomers and Axial-Coordinated Acceptor: Experimental and Computational Study, J. Photochem. Photobiol. A: Chem, 217, 242-248, 2011.01. |
| 58. |
Redox behavior and Catalysis of B12 immobilized hyper-branched polymer were reported.. |
| 59. |
Keishiro Tahara, Hisashi Shimakoshi, Akihiro Tanaka, Yoshio Hisaeda, Synthesis, Characterization and Catalytic Function of B12-Hyperbranched Polymer, Dalton Transaction, 39, 3035-3042, 2010.04. |
| 60. |
M. Fujitsuka, H. Shimakoshi, S. Tojo, L. Cheng, D. Maeda, Y. Hisaeda, T. Majima, Electron Transfer in the Supramolecular Donor-Acceptor Dyad of Zinc Hemiporphycene, J. Phys. Chem. A, 114, 4156-4162, 2010.03. |
| 61. |
K. Tahara, H. Shimakoshi, A. Tanaka, Y. Hisaeda , Synthesis, Characterization and Catalytic Function of B12-Hyperbranched Polymer, Dalton Trans, 39, 3035-3042, 2010.03. |
| 62. |
Mamoru Fujitsuka, Hisashi shimakoshi, Sachiko Tojo, Lingli Cheng, Daisuke Maeda, Yoshio Hisaeda, Tetsuro Majima, Electron Transfer in the Supramolecular Donor-Acceptor Dyad of Zinc Hemiporphycene, J. Phys. Chem. A, 114, 4156-4162, 2010.03. |
| 63. |
S. Izumi, H. Shimakoshi, M. Abe, Y. Hisaeda, Photo-Induced Ring-Expansion Reactions Mediated by B12-TiO2 Hybrid Catalyst B12-Hyperbranched Polymer, Dalton Trans, 39, 3302-3307, 2010.02. |
| 64. |
H. Shimakoshi, M. Abiru, K. Kuroiwa, N. Kimizuka, M. Watanabe, Y. Hisaeda, Preparation and Reactivity of B12-TiO2 Hybrid Catalyst Immobilized on Glass Plate, Bull. Chem. Soc. Jpn, 83, 170-172, 2010.01. |
| 65. |
D. Maeda, H. Shimakoshi, M. Abe, M. Fujitsuka, T. Majima, Y. Hisaeda , Synthesis of a Novel Sn(IV) Porphycene-Ferrocene Triad Linked by Axial Coordination and Solvent Polarity Effect in Photoinduced Charge Separation Process, Inorg. Chem, 49, 2872-2880, 2010.01. |
| 66. |
Hisashi Shimakoshi, Masashi Nishi, Akihiro Tanaka, Katsumi, Chikama, Yoshio Hisaeda, Synthesis and Catalysis of B12-Core-Shell Hyperbranched Polymer, Chemistry Letters, 39, 22-23, 2010.01. |
| 67. |
H. Shimakoshi, M. Abiru, S. Izumi, Y. Hisaeda, Green Molecular Transformation by a B12-TiO2 Hybrid Catalyst as an Alternative to Tributyltin Hydride, Chem. Commun, 6427-6429 , 2009.12. |
| 68. |
L. Pan, H. Shimakoshi, T. Masuko, Y. Hisaeda, Vitamin B12 Model Complex Catalyzed Methyl Transfer Reaction to Alkylthiol under Electrochemical Conditions with Sacrificial Electrode, Dalton Trans, 9898-9905 , 2009.05. |
| 69. |
H. Shimakoshi, E. Sakumori, K. Kaneko, Y. Hisaeda, B12-TiO2 Hybrid Catalyst for Dehalogenation of Organic Halides, Chem. Lett, 38, 468-469 , 2009.05. |
| 70. |
H. Shimakoshi, K. Shibata, Y. Hisaeda , Molecular Recognition of Redox-Switchable Bis-crown Moieties Assembled on Dicobalt Complex., Inorg. Chem, 48, 1045-1052 , 2009.05. |
| 71. |
Emiko Sakumori, Kenji Kaneko, Yoshio Hisaeda, B12-TiO2 Hybrid Catalyst for Dehalogenation of Organic Halides, Chemistry Letters, Vol. 38, No. 5, 468-469, 2009, 2009.04. |
| 72. |
D. Maeda, H. Shimakoshi, M. Abe, Y. Hisaeda , Synthesis and Photochemical Properties of a New Molybdenum Porphycene Complex, Dalton Trans, 140-145 , 2009.03. |
| 73. |
Hisashi Shimakoshi, Tatsushi Baba, Yuseuke Iseki, Ayataka Endo, Chihaya Adachi, Midori Watanabe, Yoshio Hisaeda, Photosensitizing properties of the porphycene immobilized in sol-gel derived silica coating films, Tetrahedron Letters, 49, 6198-6201, 2008.07. |
| 74. |
Keishiro Tahara, Hisashi Shimakoshi, Akihiro Tanaka, Yohsio Hisaeda, Synthesis and characterization of vitamin B12-hyperbranched polymer, Tetrahedron Letters, 48, 5065-5068,2007, 2007.07. |
| 75. |
Hisashi Shimakoshi, T. Takemoto, Isao Aritome, Yoshio Hisaeda, Redox-Switchable Molecular Containers Consisting of Dicobalt Complexes, Inorganic Chemistry, 10.1021/ic051482o, 44, 25, 9134-9136, 2005, 44, 9134-9136, 2005.11. |
| 76. |
Hisashi Shimakoshi, Takayuki Kai, Isao Aritome, Yoshio Hisaeda, Syntheses of large-membered macrocycles having multipule hydrogen ｂｏｎｄmoieties, Tetrahedron Letters, 10.1016/S0040-4039(02)02022-1, 43, 46, 8261-8264, 43, 8261-8264, 2003.01. |
| 77. |
Hisahi Shimakoshi, Aki Nakazato, Mami Tokunaga, Kiyofumi Katagiri, Katsuhiko Ariga, Junichi Kikuchi, Yoshio Hisaeda, Hydrophobic vitamin B12 part 18. Preparation of a sol-gel modified electrode trapped with a vitamin B12 derivative and its photoelectrochemical reactivity, Dalton Transactions, 10.1039/b212863b, 11, 2308-2312, 2308-2312, 2003.01. |
| 78. |
Hisashi Shimakoshi, Takeshi Kaieda, Takashi Matsuo, Hideaki, Sato, Yoshio Hisaeda, Syntheses of new water-soluble dicobalt complexes having two cobalt-carbon bonds and their ability for DNA cleavage, Tetrahedron Letters, 10.1016/S0040-4039(03)01252-8, 44, 28, 5197-5199, 44, 5197-5199, 2003.01. |
| 79. |
Hisashi Shimakoshi, Tetsuo Inaoka, Yoshio Hisaeda, Solid-solid synthesis of a hydrophobic vitamin B12 having a benzo-18-crown-6 moiety at the C 10 position of the corrin ring, Terahedron Letters, 10.1016/S0040-4039(03)01587-9, 44, 34, 6421-6424, 44, 6421-6424, 2003.01. |
| 80. |
Hisashi Shimakoshi, Masaomi Koga, Yoshio Hisaeda, Synthesis, characterization, and redox behavior of new dicobalt complexes having monoanionic imine/oxime-type ligands, Bulletin of the Chemical Society of Japan, 10.1246/bcsj.75.1553, 75, 7, 1553-1558, 75, 7, 1553-1558, 2002.07. |
| 81. |
Isao Aritome, Hisashi Shimakoshi, Yoshio Hisaeda, 3,6,13,16-tetrabromo-2,7,12,17-tetrapropylporphycene, Acta Crystallographica Section C, 10.1107/S0108270102013483, 58, O563-O564, C58, o563-o564, 2002.01. |
| 82. |
Masahito Kodera, Yuko Taniike, M. Ito, Y. Tanahashi, Hisashi Shimakoshi, Koji Kano, Shun Hirota, Siichiro Iijima, Masaaki Ohba, Hisashi Okawa, Synthesis, characterization, and activation of thermally stable mu-1,2-peroxodiiron(III) complex, Inorganic Chemistry, 10.1021/ic0155434, 40, 19, 4821-+, 40, 19, 4821-4822, 2001.09. |
| 83. |
Hisashi Shimakoshi Aki Nakazato, Takashi Hayashi, Yoshimitsu Tachi, Yoshinori Naruta, Yoshio Hisaeda, Electroorganic syntheses of macrocycliclactonesmediated by vitamin B12 model complexes, Journal of Electroanalytical Chemistry, 10.1016/S0022-0728(01)00418-1, 507, 1-2, 170-176, 507, 170-176, 2001.07. |
| 84. |
Hisashi Shimakoshi, Wataru Ninomiya, Yoshio Hisaeda, Reductive coupling of benzyl bromide catalyzed by a novel dicobalt complex having two salen units, Dalton Transaction, 10.1039/b010022f, 13, 1971-1974, 13, 1971-1974, 2001.06. |
| 85. |
Hisashi Shimakoshi, Masaomi Koga, Takashi Hayashi, Yoshimitsu Tachi, Yoshinori Naruta, Yoshio Hisaeda, Formation and cleavage of a dicobalt complex bridged with a pentamethylene group, Chemistry Letters, 10.1246/cl.2001.346, 4, 346-347, 4, 346-347, 2001.04. |
| 86. |
Hisashi Shimakoshi, Akihiro Goto, Yoshimitsu Tachi, Yoshinori Naruta, Yoshio Hisaeda, Synthesis and redox behavior of dialkylated dicobalt complexes having two discrete salen units, Tetrahedron Letters, 10.1016/S0040-4039(01)00040-5, 42, 10, 1949-1951, 42, 1949-1951, 2001.03. |
| 87. |
Takashi Hayashi, Kenshi Okazaki, Naomi Urakawa, Hisashi Shimakoshi, J. L. Sessler, E. Vogel, Yoshio Hisaeda, Cobalt porphycene as catalysts. The oxidation of vinyl ethers via the formation and dissociation of cobalt-carbon bonds, Organometallics, 10.1021/om010141p, 20, 14, 3074-3078, 20, 3074, 2001.01. |
| 88. |
Katsuhiko Ariga, K. Tanaka, Kiyofumi Katagiri, Junichi Kikuchi, Hisashi Shimakoshi, Eiji Ohsima, Yoshio Hisaeda, Langmuir monolayer of organoalkoxysilane for vitamin B12-modified electrode, Physical chemistry Chemical Physics, 10.1039/b100974p, 3, 16, 3442-3446, 3, 3422, 2001.01. |
| 89. |
Yoshio Hisaed, Takahiro Masuko, Shigeru Nakashita, Hisashi Shimakoshi, Takashi Hayashi, HYbrid vesicle composed of artificial lipids and cobalt porphycenes, Annual reports HVEM LAB,Kyushu University, 24, 29-30, 2000.07. |
| 90. |
Takashi Hayashi, Keshi Okazaki, Hisashi Shimakoshi, Fumito Tani, Yoshinori Naruta, Yoshio Hisaeda, Synthesis and properties of alkylperoxocobalt(III) porphyrin and porphycene, Chemistry Letters, 2, 90-91, 2, 90-91, 2000.02. |
| 91. |
Masahito Kodera, Hisashi Shimakoshi, Yoshimitsu Tachi, Kou Katayama, Koji Kano, Efficient oxidation of various phenols catalyzed by di-mu-hydroxo-dicopper(II) complexes of a hexapyridine dinucleating ligand, Chemistry Letters, 5, 441-442, 1998.05. |
| 92. |
Masahito Kodera, Hisashi Shimakoshi, Koji Kano, First example of a rigid (mu-oxo-bis-mu-acetato)diiron(III) complex with 1,2-bis[2-di(2-pyridyl)methyl-6-pyridyl]ethane; itsefficient catalysis for functionalization of alkanes, Chemical Communications, 13, 1737-1738, 1996.11. |
| 93. |
Masahito Kodera, Hisashi Shimakoshi, Masa Nishimura, Hisashi Okawa, Seichiro IIjima, Koji Kano, Synthesis, characterization, and crystal structure of a (mu-oxo)bis(mu-acetato)diiron(III) complex with dinucleatig ligand,1,2-bis{2-(bis(2-pyridyl)methyl)-6-pyridyl}ethane. Thefirst example of a discrete (mu-oxo)bis(mu-acetato)diiron(III)complex with a dinucleatig ligand, INORGANIC CHEMISTRY, 10.1021/ic9600994, 35, 17, 4967-4973, 35, 4967-4973, 1996.08. |
| 94. |
Masayuki Takeuchi, Hisashi, Shinakoshi, Koji Kano, (Porphynato)iron-catalyzed addition reactions of thiols to alkenes via (s-alkyl)iron(II) complexes, Organometallics, 13,1208, 1994.01. |
| 95. |
Hisashi Shimakoshi, Mami Tokunaga, Keita Kuroiwa, Nobuo Hisaeda, Preparation and electrochemical behavior of hydrophobic vitamin B12 covalently immobilized onto platinum electrode, Chemical Communications, 50-51. |
