Synthesis of chitosan-based heterogeneous catalyst and its performance in nitroarenes reduction reactions

Design and synthesis of heterogeneous catalysts to reduce nitroarenes are an important and essential technique in green chemistry. In this research, C/B/Ni heterogeneous catalyst was prepared through functionalization of the chitosan and immobilization of nickel cations on the surface of the chitosan. The ammine groups of the chitosan reacted with aldehyde groups of 2-(4-chlorophenyl thio) benzaldehyde via Schiff base condensation and NS donor groups which can bind to metal, placed on the surface of the chitosan. In the end, NS donor groups coordinated to Ni2+ cations. After characterization of the prepared catalyst with various physicochemical technique, its performance was considered in reduction of nitroarenes to aminoarenes. The prepared catalyst depicted a very good efficiency in reduction of nitroarenes in aqueous media, room temperature, and relatively short time. Moreover, recovered catalyst was utilized in catalytic cycles and its efficiency is reportable after three consecutive cycles without negligible reduce.