Copper-Catalyzed Direct Synthesis of 1,2,4-Oxadiazoles from Amides and Organic Nitriles by Oxidative N-O Bond Formation.

Herein, we report the first Cu-catalyzed one-step method for the synthesis of 1,2,4-oxadiazoles from stable, less toxic, and readily available amides and organic nitriles by a rare oxidative N-O bond formation using O2 as sole oxidant. This method has a broad substrate scope and a good tolerance for diverse functional groups. Moreover, the synthetic utility of this method is highlighted by the synthesis of biologically active 3,5-disubstituted derivatives. [ABSTRACT FROM AUTHOR]