A binuclear copper (II) complex [Cu2(dien)2(ox)(ClO4)] (dien = diethylenetriamine and ox = oxalate) was readily synthesized and obtained in the perchlorate salt form. The structure of the compound has been determined using X‐ray crystallography, UV–Vis spectroscopy, and infrared techniques. This new catalyst has effectively facilitated the production of 1,2,3‐triazole derivatives by “Click reaction” in an aqueous environment and propargylamine derivatives by “A3‐coupling reaction” under solvent‐free conditions, resulting in yields ranging from good to excellent. Additionally, subsequent investigations have revealed that this catalytic system can be recovered and reused for up to five cycles in both cycloaddition and coupling reactions.