Improved Conditions for the Visible-Light Driven Hydrocarboxylation by Rh(I) and Photoredox Dual Catalysts Based on the Mechanistic Analyses

• Main Authors: Kei Murata, Nobutsugu Numasawa, Katsuya Shimomaki, Jun Takaya, Nobuharu Iwasawa
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2019-05-01
• Series: Frontiers in Chemistry
• Subjects: carboxylation; CO2 fixation; photoredox catalyst; rhodium catalyst; visible light
• Online Access: https://www.frontiersin.org/article/10.3389/fchem.2019.00371/full
• ISSN: 2296-2646

The improved catalytic conditions and detailed reaction mechanism of the visible-light driven hydrocarboxylation of alkenes with CO2 by the Rh(I) and photoredox dual catalysts were investigated. The use of the benzimidazoline derivative, BI(OH)H, as a sacrificial electron donor was found to increase the yield of the hydrocarboxylated product by accelerating the reduction process. In addition, the incorporation of the cyclometalated Ir(III) complex as a second photosensitizer with [Ru(bpy)3]2+ photosensitizer also resulted in the promotion of the reduction process, supporting that the catalytic cycle includes two photochemical elementary processes: photoinduced electron and energy transfers.