Synthesis of Nano Magnetite Fe3O4 Based Vanadic Acid: A Highly Efficient and Recyclable Novel Nano-catalyst for the Synthesis of 4,4’-(arylmethylene)-bis(3-methyl-1-phenyl-1H-pyrazol-5-ols)

Nano magnetic Fe3O4 based vanadic acid [MNPs@VO(OH)2] (average diameter 20–26 nm) has been synthesized by grafting VOCl3 on the Fe3O4 surface nanoparticles as a retrievable supporter to produce novel heterogeneous reusable solid acid with dual ability (Bronsted and Lewis acid) followed by stirring in the air. The resultant material was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) analysis and energy-dispersive X-ray spectroscopy (EDX). Significantly, the as-prepared [MNPs@VO(OH)2] exhibits a high catalytic activity in the synthesis of 4,4’-(arylmethylene)bis(3-methyl-1-phenyl-1H-pyrazol-5-ols). Additionally, the newly synthesized heterogeneous solid acid catalyst can be reused for several times without apparent loss of its catalytic activity. This work is licensed under a Creative Commons Attribution 4.0 International License

Novel nano molten salt tetra-2,3-pyridiniumporphyrazinato-oxo-vanadium tricyanomethanide as a vanadium surface-free phthalocyanine catalyst: Application to Strecker synthesis of α-aminonitrile derivatives

Efficient and recyclable novel nano tetra-2,3-pyridiniumporphyrazinato-oxo-vanadium tricyanomethanide, {[VO(TPPA)][C(CN)3]4}, as a vanadium surface-free phthalocyanine-based molten salt catalyst was successfully designed, produced and used for the Strecker synthesis of α-aminonitrile derivatives through a one-pot three-component reaction between aromatic aldehydes, trimethylsilyl cyanide and aniline derivatives under neat conditions at 50 °C. This catalyst was well characterized using Fourier transform infrared, UV–visible, X-ray photoelectron and energy-dispersive X-ray spectroscopies, X-ray diffraction, scanning and high-resolution transmission electron microscopies, inductively coupled plasma mass spectrometry and thermogravimetric analysis. The catalyst can be simply recovered and reused several times without significant loss of catalytic activity.We thank Bu‐Ali Sina University, Nahavand University, the Iran National Science Foundation (INSF, grant no. 95820271), the National Elites Foundation, the University of Alicante (VIGROB‐173) and the Spanish Ministerio de Economíay Competitividad (CTQ2015‐66624‐P) for financial support to our research groups

Synthesis and application of chitosan supported vanadium oxo in the synthesis of 1,4-dihydropyridines and 2,4,6-triarylpyridines via anomeric based oxidation

Chitosan, as a biopolymer, exhibits a strong affinity for complexation with suitable metal ions. Thus, it has received increased attention for the preparation of stable bioorganic–inorganic hybrid heterogeneous catalysts. Herein, a novel chitosan based vanadium oxo (ChVO) catalyst was prepared and fully characterized by several techniques such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), derivative thermal gravimetric (DTG), differential thermal analysis (DTA), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma mass spectrometry (ICP-MS). The synthesized catalyst has been successfully used as a reusable catalyst in the synthesis of dihydropyridines and triarylpyridines.We thank Bu-Ali Sina University, Nahavand University, the Iran National Science Foundation (INSF) (Grant No: 95831207) and the National Elites Foundation for financial support of our research group