Brønsted Base-Switched Selective Mono- and Dithiolation of Benzamides via Copper Catalysis

A versatile protocol for the direct thiolation of an inert sp(2) C-H bond is presented via a catalytic amount of copper catalysis, by switching related Bronsted bases and regulating the reaction time, and the corresponding mono- and dithiolation products can be obtained selectively in moderate to good yields. The reaction exhibits a relatively broad substrate scope and a good functional group tolerance, even with different heterocyclic amides and alkyl thiols.