ZrO2/SO4 2-/Cu as a Multifunctional, Durable, Efficient, and Heterogeneous Recoverable Inorgano-Nanocatalyst for the Green Preparation of Quinolines

摘要

An efficient, simple and highly versatile method for the preparation of quinoline derivatives was developed via the Friedlander annulation reaction of 2-aminoarylketones with carbonyl compounds using copper-incorporated sulfated zirco- nium oxide (ZrO2/SO4 2-Cu) as a heterogeneous recyclable nanocatalyst. The catalyst was characterized by FTIR, TG-DTG, XRD, EDX, FE-SEM and TEM analyses. Surface acidity of the catalyst was measured by pyridine adsorption followed by FTIR spectroscopy. The catalyst contains various Lewis- and Bronsted acid sites, which along with the incorporated copper, provides high to excellent yields for all compounds in water as a green solvent at room temperature for short reaction times. The catalyst could be efficiently reused for several runs without any appreciable loss of activity. In addition, the scalability of the process was investigated in this work. Finally, a plausible reaction mechanism was suggested for this transformation.