Synthesis of Symmetric 1,4-Diamino-2-Butynes via a Cu(I)-Catalyzed One-Pot A3-Coupling/Decarboxylative Coupling of a Propiolic Acid, an Aldehyde, and an Amine

A novel microwave-assisted approach for the one-pot Cu(I)-catalyzed A(3)-coupling/decarboxylative coupling (PA(2)-coupling) of a propiolic acid, an aldehyde, and an amine, resulting in the formation of diversely substituted 1,4-diamino-2-butynes, is described. It is noteworthy that this new multicomponent coupling provides an efficient access to introduce alkyl and aryl group at the 1,4-position of the 1,4-diamino-2-butynes.