Heterogenization of homogeneous catalysis through supported single-atom catalysts (SACs) provided a feasible solution to recycling catalysts while keeping its efficiency in chemical synthesis. In this work, Cu SACs anchored on N-doped graphene (Cu SACs/NG) were prepared and first used for C−N coupling reactions. During the preparation, Cu−N−C structures, including Cu−N 4 moieties, were formed in a one-step pyrolysis method. Asprepared Cu SACs/NG exhibited excellent catalytic activity toward C−N coupling reactions with a broad scope of substrates and showed outstanding performance of recycling. Compared with Cu nanoparticles (Cu NPs/NG), the advantages of single-atom catalysts were validated via experimental and theoretical calculations. The enhanced performances were attributed to increasing the number of active sites and increasing the intrinsic activity of each active site. This work provides an alternative synthetic strategy for fabricating atomically dispersed SACs and represents a significant advance for coupling reactions.

A highly efficient visible light-induced regioselective and stereoselective oxysulfonylation of alkynes with arylsulfonate phenol esters has been developed. This photocatalyst-and metal-free method proceeds smoothly under very mild conditions and exhibits a broad substrate scope, providing (E)-β-phenoxy vinylsulfones in moderate to excellent yields. Mechanistic studies indicated the involvement of an electron donor− acceptor complex-mediated radical process.