Magnetically Separable Iron Oxide Nanoparticles: An Efficient and Reusable Catalyst for Imino Diels–Alder Reaction

Abstract

Iron oxide nanoparticles were synthesized using Saururus chinensis (S. chinensis) leaf extract as a reducing and stabilizing agent via ultrasonication. The size, morphology, crystallinity, elemental composition, weight loss, surface chemical state, and magnetic properties of the synthesized nanoparticles were investigated. The synthesized nanoparticles were used as an efficient and recyclable catalyst for the synthesis of a variety of 2‐methyl‐4‐substituted‐1,2,3,4‐tetrahydroquinoline derivatives by the imino Diels–Alder reaction. After the reaction, the catalyst was recovered by an external magnetic field. The recovered catalyst was then reused in a subsequent reaction under identical conditions. The recycled iron oxide nanoparticles (IONPs) were reused five times without any significant loss of catalytic activity.