Visible light-promoted C3-H alkoxycarbonylation of quinoxalin-2(1H)-ones or coumarins with alkyloxalyl chlorides

Herein, we describe a green and efficient photoredox catalytic C3-H alkoxycarbonylation between quinoxalin-2(1H)-ones or coumarins and readily available alkyloxalyl chlorides under ambient conditions. A series of quinoxaline-3-carbonyl and coumarin-3-carbonyl compounds are prepared through the radical addition of in situ-generated alkoxycarbonyl radicals. Notably, this protocol features mild conditions, operational simplicity, and excellent functional group tolerance. More importantly, the carboxylated products can be readily derivatized into other important compounds that would be of great potential for the exploitation of pharmaceutically active compounds.