Hybrid Catalyst for Light-Driven Green Molecular Transformations

ChemPlusChem, 2017, 82, 18.



分子システム国際コースのTian Huiさん(D3)の論文が、Dalton Trans.に掲載され、また表紙に採用されました。B12触媒とIr光増感剤の組み合わせにより、1万回を超える触媒回転数を示す可視光駆動型のB12触媒システムの開発に成功しました。また本反応システムは、自然エネルギーである太陽光によっても効率良く進行することを見出しました。本論文は、韓国の梨花女子大学のYoungmin You准教授との国際共同研究の成果です。

A visible light induced three-component catalytic system with the cobalamin derivative (B12) as a catalyst, the cyclometalated iridium(III) complex 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.

Photocatalytic Function of B12 Complex with Cyclometalated Iridium(III) Complex as Photosensitizer under Visible Light Irradiation

Hui Tian, Hisashi Shimakoshi, Sinheui Kim, Gyurim Park, Youngmin You, Yoshio Hisaeda

Dalton Trans., 2018, 47, 675-683.



Enhanced photocatalytic activity of a B12-based catalyst co-photosensitized by TiO2 and Ru(II) towards dechlorination

Ying Sun, Wei Zhang, Tian-Ti Ma, Yu Zhang, Hisashi Shimakoshi, Yoshio Hisaeda and Xi-Ming Song

RSC Advances, 2018, 8, 662-670.

A novel hybrid photocatalyst denoted as B12–TiO2–Ru(II) was prepared by co-immobilizing a B12 derivative and trisbipyridine ruthenium (Ru(bpy)32+) on the surface of a mesoporous anatase TiO2 microspheres. By using the hybrid photocatalyst, DDT was completely didechlorinated 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. This is the first report on a B12-based photocatalyst co-sensitized by two photosensitizers with wide spectral response.


本研究は、Chemical CommunicationsのFront Coverに採択され高い評価を受けました。

The first synthesis of meso-dicycloalkylporphycenes: ring strain effects on structural and optical properties of isomeric porphyrins

Toshikazu Ono , Daiki Koga, Kenji Yoza and Yoshio Hisaeda

Chem. Commun., 2017, 53, 12258-12261

Two novel meso-dicycloalkylporphycenes, namely meso-dicyclopentyl- (Cy5Pc) and meso-dicyclohexylporphycenes (Cy6Pc) are synthesized for the first time in porphycene chemistry. We use intermolecular oxidative coupling of 5,6-dicycloalkydipyrroethenes mediated by hypervalent iodine(III) reagents. The solution fluorescence maxima of Cy5Pc are more than 400 times as intense as that of Cy6Pc. The results suggested that photoluminescence switching is achieved through the ring strain perturbation of the meso-substituted cycloalkyl groups on the porphycene cavity.



本研究は、Chemical CommunicationsのBack Coverに掲載されました。

A vitamin B12 derivative catalyzed electrochemical trifluoromethylation and perfluoroalkylation of arenes and heteroarenes in organic media

Md. Jakir Hossain, Toshikazu Ono, Kosuke Wakiya and Yoshio Hisaeda

Chem. Commun., 2017, 53, 10878-10881

The electrochemical trifluoromethylation and perfluoroalkylation of aromatic compounds mediated by a vitamin B12 derivative as a novel catalyst has been developed. The Co(I) species of a vitamin B12 derivative, prepared by controlled-potential electrolysis at –0.8 V vs. Ag/AgCl in methanol, reacted with RfI (Rf = CF3,  n-C3F7,  n-C4F9,  n-C8F17, and n-C10F21) to form a Co–Rf complex. This complex released an Rf radical under visible light irradiation, which then reacted directly with non-activated (hetero)arenes to form the desired fluoroalkylated molecules through direct C–H functionalization. To our knowledge, this is the first report of a naturally-derived vitamin B12 catalyzed trifluoromethylation and perfluoroalkylation of aromatic compounds as a cobalt-mediated catalyst.


ビタミンB12錯体による電解反応に関する総説が、Current Opinion in Electrochemistryに掲載されました。

Electrochemistry and catalytic properties of vitamin B12derivatives in nonaqueous media

 H. Shimakoshi, Y. Hisaeda, Current Opinion in Electrochemistry, 2018, 8, 24. 



分子システム国際コースのTian Huiさん(D2)の論文が、Chemical Communicationsに掲載されました。B12-TiO2ハイブリッド触媒による、C-F結合の切断を伴うアルケン還元反応を世界で初めて見出しました。本論文は、九州大学先導物質化学研究所の吉澤教授、塩田准教授との共同研究の成果です。

Photocatalytic synstheses of gem-difluoroolefins were performed using the B12-TiO2 hybrid catalyst during C=C bond reduction of a-trifluoromethyl styrenes with C-F bond cleavage at room temperature under nitrogen.  The gem-difluoroolefins were used as synthetic precursors for fluorinated cyclopropanes.

Photocatalytic alkene reduction by B12-TiO2 hybrid catalyst coupled with C-F bond cleavage for gem-difluoroolefin synthesis


Hui Tian, Hisashi Shimakoshi, Kenji Imamura, Yoshihito Shiota, Kazunari Yoshizawa, Yoshio Hisaeda

Chemical Communications, 2017, 53, 9478-9481.








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). The hybrid catalyst showed an enhanced photocatalytic activity in the presence of Ru(bpy)32+ for 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) dechlorination with 100% conversion.

Significant enhancement of visible light photocatalytic activity of the hybrid B12-PIL/rGO in the presence of Ru(bpy)32+ for DDT dehalogenation


Ying Sun, Wei Zhang, Jian Tong, Yu Zhang, Shuyao Wu, Daliang Liu,

Hisashi Shimakoshi, Yoshio Hisaeda and Xi-Ming Song


RSC Advances, 2017, 7, 19197-19204.




本論文は、Chemistry Lettersに掲載されました。

A simple naphthalene diimide derivative (1) gave inclusion crystals with toluene, 4-fluorotoluene, and p-xylene effectively by the aid of cooperative intermolecular interactions, such as CT interactions and inclusion phenomena. The crystals showed intense guest-dependent solid-state emission based on ground state charge–transfer complexes between electron-deficient naphthalene diimide and electron-rich aromatic guests.


Inclusion Crystal Growth and Optical Properties of Organic Charge–Transfer Complexes Built from Small Aromatic Guest Molecules and Naphthalenediimide Derivatives

Toshikazu Ono*, Yoshifumi Tsukiyama, Ai Taema, and Yoshio Hisaeda*

Chem. Lett., 2017, in press.

DOI: http://dx.doi.org/10.1246/cl.170122




本論文は、Journal of Organometallic Chemistry の8th International Symposium on Bioorganometallic Chemistry特集号に掲載されました。


We report a new electroorganic reaction catalyzed by the B12 model complex with cobalt hydride species as reactive intermediate.  Conjugated alkenes showed a good reactivity during electrolysis to form reduced products.  We revealed that the cobalt-hydrogen 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 and ethylbenzene via styrene as reductive coupling and hydrogenated products, respectively.


Cathodic reductive couplings and hydrogenations of alkenes and alkynes catalyzed by the B12 model complex

Hisashi Shimakoshi,* Zhongli Luo, Kazuya Tomita, Yoshio Hisaeda*

Journal of Organometallic Chemistry, 2017, in press.

DOI: http://dx.doi.org/10.1016/j.jorganchem.2017.02.002



1 / 612345...最後 »