Fe₃O₄@SiO₂-Alanine/Imidazole-CuI Nanocomposite: An Efficient and Recoverable Catalyst for Multicomponent Synthesis of 2-Aryl Quinazolines and 2,4,5-Triaryl Oxazoles

Magnetic catalysts are prized for their stability and the ease with which they can be recovered and reused, thanks to their magnetic properties. In this paper, Fe₃O₄@SiO₂ nanocomposite was modified with alanine-imidazole constructed as a magnetic ligand, and copper (I) iodide was successfully supported on its surface to fabricate a novel magnetically recoverable copper catalyst [Fe₃O₄@SiO₂-Alanine/Imidazole-CuI]. The as-constructed Fe₃O₄@SiO₂-Alanine/Imidazole-CuI nanocomposite showed high catalytic activity for the synthesis of 2-aryl quinazoline and 2,4,5-triaryl oxazole derivatives through one-pot multicomponent reaction in glycerol as the green solvent. Among the features of this catalytic system, the following can be mentioned: the synthesis of products with high yields in less than 1 h, the broad scope of this catalytic system for different substrates, good tolerance of various functional groups, performing the reaction in the green solvent, simple separation of the Fe₃O₄@SiO₂-Alanine/Imidazole-CuI catalyst and high recyclability of the catalyst. The Fe₃O₄@SiO₂-Alanine/Imidazole-CuI catalyst can be reused eight consecutive times without reducing its catalytic efficiency.