Carboxylation of Aromatic and Aliphatic Bromides and Triflates with CO2 by Dual Visible‐Light–Nickel Catalysis

Abstract We report the efficient carboxylation of bromides and triflates with K 2 CO 3 as the source of CO 2 in the presence of an organic photocatalyst in combination with a nickel complex under visible light irradiation at room temperature. The reaction is compatible with a variety of functional groups and has been successfully applied to the synthesis and derivatization of biologically active molecules. In particular, the carboxylation of unactivated cyclic alkyl bromides proceeded well with our protocol, thus extending the scope of this transformation. Spectroscopic and spectroelectrochemical investigations indicated the generation of a Ni 0 species as a catalytic reactive intermediate.