One-pot multicomponent reaction synthesis of spirooxindoles promoted by guanidine-functionalized magnetic Fe3O4 nanoparticles

Magnetic nanoparticles of Fe3O4-immobilized guanidine (MNPs-guanidine) have been characterized by powder X-ray diffraction (XRD), a vibrating sample magnetometer (VSM), scanning electronic microscopy (SEM), energy dispersive X-ray (EDS), X-ray photoelectron spectroscopy (XPS), DLS (dynamic light scattering), thermal gravimetric analysis (TGA) and FT-IR spectroscopy. A neat, atom-economical, environmentally benign one-pot multi-component synthetic route for the synthesis of spirooxindoles in good yields has been devised using guanidine-functionalized magnetic Fe3O4 nanoparticles. This method provides several advantages including mild reaction conditions, applicability to a wide range of substrates, reusability of the catalyst and little catalyst loading.