Recyclable Cu/C3N4 composite catalyzed AHA/A3 coupling reactions for the synthesis of propargylamines.

Abstract

The heterogeneous Cu/C3N4 catalyst was found to be efficient for the synthesis of propargylamines using a three-component coupling reaction of alkynes, CH2Cl2 and amines (AHA) without additional base. Moreover, the catalyst also showed highly catalytic activity in the synthesis of C1-alkynylated tetrahydroisoquinolines (THIQs) via an A3 reaction of alkynes, aldehydes and THIQ. The Cu/C3N4-catalyzed multicomponent reactions exhibited good functional group tolerance in most examples. Furthermore, the easily prepared Cu/C3N4 catalyst could be recovered and reused conveniently over 5 times without losing catalytic activities.