Acid-Base Magnetic Silica Heterogeneous Catalyst for Green Aldol and Aza-Michael Reactions

摘要

In this paper,a bifunctional ligand containing two mutually acidic and basic sites was successfully immobilized on magnetic nanoparticles.The prepared nanocatalyst was analyzed by various techniques such as Fourier transform infrared spectroscopy(FT-IR),field emission scanning electron microscope(FESEM),vibrating sample magnetometer(VSM),thermal analysis(TGA),and X-ray diffraction(XRD).This novel easy-prepared catalyst gave excellent efficiency in Aldol and aza-Michael reactions in green and mild reaction conditions.The applicability of the introduced catalytic system was also studied successfully in the large-scale synthesis of derivatives of dihydroquinolines.This procedure possesses many advantages such as simple work-up,high yield,and short reaction times.