Nano-ferrous ferric oxide (nano-Fe3O4): magnetite catalytic system for the one-pot four-component tandem imine/enamine formation-Knoevenagel–Michael-cyclocondensation reaction of dimedone, aldehydes, β-ketoesters and ammonium acetate under green media

Abstract

In this work, magnetite nano-Fe₃O₄ was applied as a green, efficient, heterogeneous and reusable catalytic system for the atomic economic preparation of hexahydroquinolines via the one-pot multi-component reaction of aryl aldehydes, dimedone (5,5-dimethylcyclohexane-1,3-dione), β-ketoesters and ammonium acetate at 50 °C under mild and solvent-free conditions. The catalyst was synthesized and characterized by several techniques including Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), vibrating sample magnetometry (VSM) and transmission electron microscopy (TEM). Also, optimization of the reaction conditions was investigated using the response surface method {Central Composite Design (CCD)}.