Nano copper(i) oxide–zinc oxide catalyzed coupling of aldehydes or ketones, secondary amines, and terminal alkynes in solvent-free conditions

Abstract

A simple, efficient, and environmentally benign method has been described for the synthesis of propargylamines through a one-pot three-component coupling reaction of terminal alkynes, aldehydes or ketones, and secondary amines in excellent isolated yields, under solvent-free conditions, using a catalytic amount of nano Cu₂O–ZnO as the recyclable, and heterogeneous catalyst. The catalyst can be reused in further catalytic reactions, and it was found that its activity remained largely unchanged for ten successive runs. The catalyst was characterized by using powder X-ray diffraction (XRD), a transmission electron microscopy (TEM), a scanning electron microscopy (SEM), BET surface area measurement and FT-IR spectroscopy.