Recyclable ZnO nano particles: Economical and green catalyst for the synthesis of A3 coupling of propargylamines under solvent free conditions

► ZnO NPs were prepared by simple economical and efficient CBD method. ► Recyclable ZnO NPs provides green synthesis of multicomponent A3 coupling reaction. ► ZnO NPs catalyst used for ten times without any significant loss. ► High catalytic activity was obtained in short reaction time.