First entry into nonmetal-centred porphycenes: synthesis of a phosphorus(V) complex of octaethylporphycene

Masaaki Abe, Hiroto Mukotaka, Taro Fujioka, Toru Okawara, Kei Umegaki, Toshikazu Ono, Yoshio Hisaeda

Dalton Trans. 2018, 47, 2487-2491. (Front Cover)


世界初のリンポルフィセンの合成と物性評価を報告しました。Dalton Transactionの表紙を飾りました!

A phosphorus(V) complex of porphycene [P(OEPc)(OMe)2]PF6 (OEPc = 2,3,6,7,12,13,16,17-octaethylporphycenato dianion) has been synthesized and structurally characterized as the first porphycene derivative incorporating nonmetal elements in the macrocyclic cavity. An extremely low energy level of the LUMO is observed, which is rationalized by the low-lying π* orbital of the porphycene ring coupled with the insertion of the highly-inductive pentavalent phosphorus centre. The compound is luminescent in bright red with a quantum yield of 22.7% in CH2Cl2 at 298 K.



ベータ位水素化ポルフィセンコバルト錯体の電気化学挙動と反応性についての論文がDalton Transactions に掲載されました。


雑誌の Inside cover に採用されました。

Koichi Hashimoto,Taro Koide, Toru Okawara, Hisashi Shimakoshi, Yuta Hori, Yoshihito Shiota, Kazunari Yoshizawa and Yoshio Hisaeda

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.

Dalton Transactions, Dalton Transactions, 2019, 48, 872-881.


Cobalt−Carbon Bond Formation Reaction via Ligand Reduction of Porphycene−Cobalt(II) Complex and Its Noninnocent Reactivity

Taro Koide, Isao Aritome, Tatsuya Saeki, Yoshitsugu Morita, Yoshihito Shiota, Kazunari Yoshizawa, Hisashi Shimakoshi, and Yoshio Hisaeda

ACS Omega, 2018, 3, 4027-4034.

DOI: 10.1021/acsomega.8b00239

コバルトポルフィセンの配位子還元体を経由したコバルトー炭素結合形成に関する論文がACS Omegaに掲載されました。


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.




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.