Recyclable Cu/C(3)N(4) composite catalyzed AHA/A(3) coupling reactions for the synthesis of propargylamines

The heterogeneous Cu/C(3)N(4) catalyst was found to be efficient for the synthesis of propargylamines using a three-component coupling reaction of alkynes, CH(2)Cl(2) and amines (AHA) without additional base. Moreover, the catalyst also showed highly catalytic activity in the synthesis of C1-alkynylated tetrahydroisoquinolines (THIQs) via an A(3) reaction of alkynes, aldehydes and THIQ. The Cu/C(3)N(4)-catalyzed multicomponent reactions exhibited good functional group tolerance in most examples. Furthermore, the easily prepared Cu/C(3)N(4) catalyst could be recovered and reused conveniently over 5 times without losing catalytic activities.