Synthesis of a novel dendrimer core of oxo-vanadium phthalocyanine magnetic nano particles: as an efficient catalyst for the synthesis of 3,4-dihydropyrano[c]chromenes derivatives under green condition

Abstract

A new magnetically recoverable nanocatalyst was synthesized by covalent binding of an amino vanadium oxo phthalocyanine, on the surface of silica coated magnetite nano particles with 3-chloropropyl moieties. Full characterization of the prepared nano catalyst was performed with different physicochemical methods such as FT-IR spectra, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscope (AFM), and thermal gravimetric analysis (TGA), energy-dispersive X-ray spectroscopy (EDX), and vibrating sample magnetometry (VSM), Brunauer–Emmett–Teller (BET), X-ray fluorescence (XRF) and inductively coupled plasma (ICP). Finally, catalytic activity of the prepared Fe₃O₄@SiO₂@SiO₂(CH₂)₃@AVOPc was examined in the synthesis of 3,4-dihydropyrano[c]chromenes derivatives. The nano catalysts provided excellent catalytic activities to yield the desired products in short reaction time, mild and green conditions under solvent-free at room temperature. The catalysts could be easily separated from the reaction mixture by a magnet, and recycled eight consecutive cycles without any losing significant activities. Moreover, by this synthetic method, some novel 3,4-dihydropyrano[c]chromenes derivatives are prepared and characterized.