The identification of purine-derived ligands for a diversity of nucleotide-dependent enzymes has assisted in enlightenment in interest in the synthesis of purine derivatives in recent decades. The research work discloses the synthesis of CuO NPs coated with ionic liquid (triethylammonium chloride (HN 222 ) & aluminium chloride) as a novel and powerful nanocatalyst (CuO [HN 222 ][Al 2 Cl 7 ]) as well as the exploration of its activity in the synthesis of N-arylnucleobase and N-aryl heterocyclic derivatives by CÀ N cross-coupling reaction between adenine, imidazole, and benzimidazole compounds with aryl boronic acids in greener solvent at room temperature. This practical approach produced the products with good to excellent yields in acceptable reaction time (3 h). The nanocatalyst was characterized by Brunauer-Emmett-Teller (BET), Energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), Powder X-ray diffraction (P-XRD), and X-ray photoelectron spectroscopy (XPS). Additional eco-friendly aspects of this nanocatalyst include strong catalytic activity, ease of recovery of nanocatalyst from the reaction mixture via filtration, and recyclability upto five times without significant performance loss.