Seminar Pr Kazushi Mashima
Pr Kazushi Mashima
Osaka University, Japan
Activation of dioxygen and carbon dioxide by cerium complexes
We found that in situ generated cerium(IV) carboxylate generated by mixing the precursor Ce(OtBu)4 with the corresponding carboxylic acids served as efficient photocatalysts for the direct formation of carboxyl radicals from carboxylic acids under blue light-emitting diodes (blue LEDs) irradiation and air, resulting in catalytic decarboxylative oxygenation of aliphatic carboxylic acids to give C−O bond-forming products such as aldehydes and ketones. In addition, we also found that tetranuclear complexes including cerium atom work as the catalyst for oxidation reaction and alternative copolymerization of carbon dioxide and epoxides.
Références
(1) Mixed-Metal Ce-Zr-Mn Clusters as Photo-Catalysts for Decarboxylative Functionalization of Carboxylic Acids S. Tamaki, T. Kusamoto, K. Mashima, and H. Tsurugi, Angew. Chem. Int. Ed., accepted (2025).
(2) Renaissance of Homogeneous Cerium Catalysts with Unique Ce(IV/III) Couple: Redox-Mediated Organic Transformations Involving Homolysis of Ce(IV)-Ligand Covalent Bonds, H. Tsurugi, K. Mashima, J. Am. Chem. Soc., 143, 7879-7890 (2021).
(3) Aerobic Oxygenation of α-Methylene Ketones under Visible-light Catalysed by a CeNi3 Complex with a Macrocyclic Tris(salen)-Ligand, H. Nagae, K. Sakamoto, S. Fujiwara, T. Schindler, Y. Kon, K. Sato, J. Okuda, K. Mashima, Chem. Commun., 7, 11169-11172 (2021).
(4) Cerium(IV) Carboxylate Photocatalyst for Catalytic Radical Formation from Carboxylic Acids: Decarboxylative Oxygenation of Aliphatic Carboxylic Acids and Lactonization of Aromatic Carboxylic Acids, S. Shirase, S. Tamaki, K. Shinohara, K. Hirosawa, H. Tsurugi, T. Satoh, K. Mashima, J. Am. Chem. Soc., 142, 5668-5675 (2020).
(5) Alternating Copolymerization of CO2 and Cyclohexene Oxide Catalyzed by Cobalt–Lanthanide Mixed Multinuclear Complexes, H. Asaba, T. Iwasaki, M. Hatazawa, J. Deng, H. Nagae, K. Mashima, K. Nozaki, Inorg. Chem., 59, 7928-7933 (2020).
(6) Lanthanide Complexes Supported by a Trizinc-crown Ether as Catalysts for Alternating Copolymerization of Epoxide and CO2: Telomerization Controlled by Carboxylate Anions, H. Nagae, R. Aoki, S. Akutagawa, J. Kleemann, R. Tagawa, T. Schindler, G. Choi, T. P. Spaniol, H. Tsurugi, J. Okuda, K. Mashima, Angew. Chem. Int. Ed., 57, 2492-2496 (2018).
(7) Oxidation of Alcohols to Carbonyl Compounds Catalyzed by Oxo-bridged Dinuclear Cerium Complexes with Pentadentate Schiff-base Ligands under Dioxygen Atmosphere. Satoru Shirase, Koichi Shinohara, Hayato Tsurugi, and Kazushi Mashima, ACS Catal., 8, 6939-6947 (2018).
(8) Cerium Complex—catalyzed Oxidation of Arylmethanols under Atmospheric Pressure of Dioxygen and Its Mechanism through a Dinuclear Peroxo Ce2( -O2) Complex. Mitali Paul, Satoru Shirase, Yuma Morimoto, Laurent Mathey, Murugesapandian Balasubramanian, Shinji Tanaka, Shinobu Itoh, Hayato Tsurugi, and Kazushi Mashima, Chem. Eur. J., 22, 4008-4014 (2016)
(9) Cerium(IV) Hexanuclear Clusters from Cerium(III) Precursors: Molecular Models for Oxidative Growth of Ceria Nanoparticles. Laurent Mathey, Mitali Paul, Christophe Copéret, Hayato Tsurugi, and Kazushi Mashima, Chem. Eur. J., 21, 13454-13461 (2015).