Solvent-Free Microwave Promoted [3+2] Cycloaddition of Alkyne-Azide in Uniform CuO Hollow Nanospheres

Abstract

CuO hollow nanospheres on acetylene black (CuO/AB) have been used for the catalytic [3 + 2] cycloaddition of azides with terminal alkynes without solvent, and within 1 min under microwave irradiation. The CuO/AB was readily separated by centrifugation, and could be reused five times under the present reaction conditions without any loss of catalytic activity.