Dendrimeric magnetic nanoparticle cores with Co-phthalocyanine tags and their application in the synthesis of tetrahydrobenzo[b]pyran derivatives

Abstract

A new and rational method for the synthesis of Fe₃O₄@SiO₂@SiO₂(CH)₃Cl based magnetic nanoparticles with amino cobalt phthalocyanine tags (ACoPc-MNPs) was described and these were evaluated as a reusable catalyst for the one-pot synthesis of tetrahydrobenzo[b]pyran derivatives. The described reaction proceeded in high to excellent yield, with a short reaction time, and under mild and green solvent-free conditions at room temperature. The ACoPc-MNP catalyst was characterized via Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET), X-ray fluorescence (XRF) analysis, energy-dispersive X-ray spectroscopy (EDX) and vibrating sample magnetometry (VSM). Moreover, the catalyst could be easily recovered by magnetic separation and recycled 4 times without significant loss of its catalytic activity. Moreover, by this synthetic method, some novel tetrahydrobenzo[b]pyran derivatives are prepared and characterized.