Ultrasound-Assisted Preparation of Copper(I) Oxide Nanocubes: High Catalytic Activity in the Synthesis of Quinazolines

摘要

A facile and green ultrasound-assisted synthesis of Cu2O nanocubes at room temperature is presented. The Cu2O nanocubes were characterized using XRD, SEM, TEM, energy-dispersive X-ray spectroscopy, UV/Vis spectroscopy, differential scanning calorimetry with thermogravimetric analysis, and FTIR spectroscopy. The Cu2O nanocubes were employed as a heterogeneous nanocatalyst and were found to be highly active in the preparation of quinazolines by the tandem cyclization of 2-bromobenzaldehydes with amidines under ligand-free conditions. Various quinazolines could be prepared in excellent yields within a very short reaction time. Furthermore, the Cu2O nanocatalyst could be recycled and reused up to four times without any significant loss of catalytic activity.