Aldehyde–alkyne–amine (A3) coupling catalyzed by a highly efficient dicopper complex

A dicopper(I) complex, Cu-2(I)(pip)(2) (pip = (2-picolyliminomethyl)pyrrole anion), was utilized to catalyze A(3) coupling reactions, which led to the formation of propargylamines. Aldehydes, alkynes and amines with a variety of structures have been tested. A low catalyst loading of 0.4 mol% was sufficient to give good to excellent yields. The low catalyst loading, broad scope of substrate and easy preparation make this dicopper complex a useful catalyst for A(3) coupling.