A copper complex containing decavanadate nanocluster, Na2[Cu(H2O)6]2{V10O28}·4H2O, was prepared by reaction of Cu(NO3)2·4H2O and NH4VO3 in an aqueous solution at pH = 4 and its structure was characterized using IR, CV and X-ray crystallography. It was found to be a highly efficient and effective catalyst for the azide alkyne cycloaddition and one-pot three-component (A3) coupling of aldehydes, amines, and alkynes to produce 1,2,3-triazoles and propargylamines respectively in high yields without any co-catalyst or activator.