Visible-Light-Driven Thiolate-Catalyzed Carboxylation of C(sp2)–H Bonds in Azines with Carbon Dioxide

Abstract Catalytic carboxylation of C–H bonds with CO2 represents an efficient strategy to synthesize highly valuable carboxylic acids from simple substrates, featuring high atom, step, and redox economies. Recently, our group was successful in developing a visible-light-driven thiolate-catalyzed carboxylation of C(sp2)–H bonds in azines with CO2. This strategy provides facile access to a range of valuable N-heteroarene carboxylic acids from readily available azines. Furthermore, the synthetic potential of this approach has been demonstrated through the synthesis of bioactive molecules and the modification of commonly used nitrogen ligands. Mechanistic studies suggest that the formation of an electron donor–acceptor complex between the thiolate and azine is a crucial factor in the activation of the azine.