Recyclable nano copper oxide catalyzed synthesis of quinoline-2,3-dicarboxylates under ligand free conditions

An efficient protocol was developed for the recyclable nano CuO powder catalyzed synthesis of quinoline derivatives from acetylenedicarboxylates and 2-aminocarbonyl compounds using acetonitrile as solvent at 40 °C in air. A variety of quinoline derivatives were synthesized in good yields with good chemoselectivity in the presence of a catalytic amount of CuO nano powder under ligand/additive free conditions. The catalyst is air-stable, inexpensive and recyclable up to four cycles.