Copper Acetate Catalyzed Regioselective Synthesis of Substituted 1,2,3-Triazoles: A Versatile Azide-Alkene Cycloaddition/Oxidation Approach

A copper acetate catalyzed oxidative cycloaddition reaction of benzyl and aryl azides with terminal and internal olefins that contain electron-withdrawing groups (COOR, CONH2, CN, CHO, COR) has been developed. The reaction employs air as the oxidant and does not require any base or additives to afford 1,4-disubstituted and 1,4,5-trisubstituted 1,2,3-triazoles in good to excellent yields with high regioselectivity.