Synthesis and Application of Novel Magnetic Supported Copper Nanocatalyst for the Preparation of Thiazoles

Abstract

Silica-decorated maghemite (γ-Fe2O3) nanoparticles have been prepared successfully through a simple co-precipitation method followed by coating with silica shell using tetraethoxysilane. Silica coating significantly enhanced the chemical and thermal stability of the iron oxide. 1,10‐Phenanthroline‐5,6‐diol (phendiol) was loaded onto the surface of silica-coated maghemite nanoparticles (γ-Fe2O3/SiO2 NPs) and reacted with Cu(NO3)2 · 3H2O to furnish the desired magnetic nanocatalyst (γ-Fe2O3@SiO2@Phen@Cu(II)). The catalyst was characterized by various physicochemical techniques such as Fourier transform-infrared spectroscopy, scanning electron microscopy, X-ray diffraction (XRD), energy‐dispersive X‐ray, vibrating sample magnetometry, thermo-gravimetric analysis, inductivity coupled plasma (ICP), transmission electron microscopy, and Ultraviolet-Visible spectroscopy (UV–Vis). Magnetic γ-Fe2O3@SiO2@Phen@Cu(II) was utilized as a catalyst for the synthesis of new thiazoles in ethanol as a solvent with excellent yield (88–97%) and short reaction time (5–15 min). The catalyst was easily separated from the reaction mixture using an external magnet and recycled for up to four cycles with no substantial loss of catalytic activities.