Cobalt-Catalyzed Electrochemical Oxidative C-H/N-H Carbonylation with Hydrogen Evolution

Carbon monoxide is an abundant and costefficient Cl building block for the carbonylation industry. Transition-metal-catalyzed oxidative C-H/C(X)-H carbonylation with CO provides one of the most straightforward approaches to construct carbonyl compounds. However, the use of stoichiometric oxidants would bring several drawbacks such as high cost and undesired chemical waste. Especially, the explosion limit is a potential safety hazard in oxidative carbonylation using O-2 as the oxidant. To overcome these issues, an electrochemical strategy for oxidative C-H/N-H carbonylation has been designed by taking advantage of anodic oxidation to recycle a cobalt catalyst, and H-2 is generated at the cathode. The intra- and intermolecular carbonylation products can be achieved with good functional group tolerance in 31%-99% yields. A plausible reaction mechanism involving a Co-II/Com(III)/Co-I catalytic cycle is proposed by the studies of XANES and CV.