Facile synthesis of magnetic Fe₃O₄@Chitosan nanocomposite as environmentally green catalyst in multicomponent Knoevenagel-Michael domino reaction

Magnetic Fe₃O₄ has interesting characteristics such as large surface area, low toxicity, ferromagnetic, and biocompatible. The presence of magnetic properties in Fe₃O₄ provides an advantage in its application as a heterogeneous catalyst. This study highlights the synthesis of Fe₃O₄ modified chitosan composite and evaluates the catalytic ability in multicomponent Knoevenagel-Michael domino reaction. The synthesis and characterization of pristine Fe₃O₄ and Fe₃O₄@Chi samples were investigated. The XRD analysis combined with refinement technique indicates that the pristine Fe₃O₄ crystallized in a cubic structure with Fd-3mz symmetry and the presence of chitosan in Fe₃O₄ sample did not change its structure. The FTIR analysis also demonstrated the binding of chitosan to the Fe₃O₄ nanoparticles. TEM image reveals the presence of chitosan in the composite sample formed a core-shell interaction and covered the surface of Fe₃O₄ nanoparticles. The evaluation of Fe₃O₄@Chi catalytic ability in multicomponent Knoevenagel-Michael domino reaction demonstrated reliable catalyst performance with a yield of 92.3% at optimum conditions. Fe₃O₄@Chi could be classified as a green catalyst because it can be used repeatedly with high yield and easy separation.