A bifunctional Yolk–Shell nanocatalyst with Lewis and organic functional base for the synthesis of spirooxindoles

Abstract

Guanidine supported on magnetic YSNPs MgFe2O4 nanoparticles was created and estimated as a recoverable nanocatalyst for the synthesis of spirooxindole compounds in excellent yields. This nanocatalyst has two active base sites one of which them is Lewis base on the core such as nanoreactor and the other is organic base on the shell. This novel nanocatalyst was prepared and characterized by using FT-IR spectra, X-ray diffraction (XRD), TPD analysis, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), thermo gravimetric analysis (TGA), Brunauer–Emmett–Teller (BET) and vibrating sample magnetometer (VSM). The catalyst can be recovered and recycled 6 times without marked loss of activity.