Five-component domino synthesis of tetrahydropyridines using hexagonal PbCrxFe12−xO19 as efficient magnetic nanocatalyst

Abstract

Abstract: Hexagonal PbCrxFe12−xO19 nanostructures were prepared through a sol–gel autocombustion (SGAC) method using malonic acid as fuel. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) analysis, and vibrating-sample magnetometry were used as tools to study the structure, morphology, and composition of the nanostructures. The optimal product was further evaluated as a reusable magnetic catalyst in a five-component reaction for synthesis of highly functionalized tetrahydropyridines (HF-THP). All reactions completed in short time and all products were obtained in good yield in presence of the magnetic nanocatalyst. Besides, it was found that PbCrxFe12−xO19 could be recovered five times, without any noticeable loss in catalytic activity.