Fe3O4@chitosan nanoparticles: a valuable heterogeneous nanocatalyst for the synthesis of 2,4,5-trisubstituted imidazoles

Chitosan-coated Fe3O4 nanoparticles (Fe3O4@CS) were prepared simply through in situ co-precipitation of Fe2+ and Fe3+ ions via NH4OH in an aqueous solution of chitosan and their catalytic activity was investigated in the synthesis of 2,4,5-trisubstituted imidazoles by a one-pot condensation of benzil derivatives, aryl aldehydes and ammonium acetate in EtOH. This novel method offers several advantages compared to those reported in the previous literature, including avoiding the use of harmful catalysts, easy and quick isolation of the products, excellent yields, mild and clean conditions, and simplicity of the methodology. High catalytic activity and ease of recovery using an external magnetic field are additional eco-friendly attributes of this catalytic system.