Preparation and characterization of silica-supported magnetic nanocatalyst and application in the synthesis of 2-amino-4<i>H</i>-chromene-3-carbonitrile derivatives

Sucrose chelated Bismuth ferrite (BiFeO 3 ) nanoparticles as a novel heterogeneous catalyst was synthesized by an auto combustion route. Different calcination temperatures (150°C, 450°C, 550°C, 650°C, 750°C and 850°C) have been employed to obtain single phased BiFeO 3 nanoparticles. The perovskite structure formation and disappearance of organic phase (sucrose) was obtained by Fourier transform infrared spectroscopy (FT-IR). Phase determination and structural characterization was carried out by powder X-ray diffraction (XRD). The magnetic properties were analyzed by vibrating sample magnetometer (VSM) whereas surface area/pore volume was obtained by Brunauer-Emmett-Teller (BET). Transmission electron microscope (TEM) analyzed the particles size and morphology. Thermal stability was investigated by thermogravimetric analysis (TGA) and determination of constituent elements was carried out by X-ray Photo-Electron Spectroscopy (XPS). Raman spectroscopy confirmed the perovskite structure of the synthesized materials. The BiFeO 3 nanoparticles so obtained were employed as heterogeneous catalyst for the synthesis of polyhydroquinoline derivatives. All the polyhydroquinoline derivatives were characterized by Fourier transform infrared spectroscopy (FT-IR) and Nuclear magnetic resonance spectroscopy ( 1 H NMR). For the very first time ever we have used BiFeO 3 as a recyclable magnetic nanocatalyst in the one-pot four component cyclization reaction of benzaldehyde, ethylacetoacetate/methylacetoacetate, dimedone/cyclohexane-1,3-dione, and ammonium acetate for the synthesis of polyhydroquinoline derivatives without solvent under refluxing conditions to provide excellent yields of products. BiFeO 3 nanocatalyst (without any functionalization/surface coatings) shows easy magnetic separation, recyclability, reusability along with excellent yield of polyhydroquinoline derivatives in an economic and benign way.

Section: Resultsmentioning

confidence: 99%

Sucrose chelated auto combustion synthesis of BiFeO₃ nanoparticles: Magnetically recoverable catalyst for the one‐pot synthesis of polyhydroquinoline

Singh

Garg

Arora

et al. 2018

“…Similarly, in FT‐IR analysis, there was no change in peaks before and after recycling (Figure ). In addition, no special care has to be taken to handle or store the as‐prepared catalyst for further use during the recycling process …”

Section: Resultsmentioning

confidence: 99%

Dual functional novel catalytic Cu_1−xZr_xFe₂O₄ (x=0, 0.5, 1) nanoparticles for synthesis of polysubstituted pyridines and sunlight‐driven degradation of methylene blue

Singh

Rajput

Govil

et al. 2018

The effect of varied zirconium content on the structural, morphological, magnetic, optical, thermal and catalytic properties of nanoparticles of the ferrite Cu1 − xZrxFe2O4 (x = 0, 0.5, 1) was investigated. The mixed ferrite was synthesized by the auto‐combustion method using nitrates of respective metals and citric acid as a chelating agent. The as‐prepared nanoparticles showed dual benefits. They were employed as a heterogeneous catalyst for one‐pot synthesis of polysubstituted pyridine derivatives as well as for catalytic degradation of industrial waste dyes such as methylene blue (MB). The highlight of the research reported is the catalytic degradation of industrial waste (MB) with high efficiency in eluent of a wide range of pH (3–13). The proposed nanoparticles arguably offer certain great advantages that include: low cost, facile nature, anti‐leaching property, magnetic recoverability and recyclability. The characterization of the as‐synthesized nanoparticles was done using various techniques. The leaching study was carried out using inductively coupled plasma optical emission spectroscopy. The formation of organic products was confirmed using Fourier transform infrared and 1H NMR spectroscopies and examination of degradation products of MB dye was carried out using mass spectrometry and UV–visible spectroscopy.

“…In recent decade, SPIONs, as a main group of separation materials, has drawn significant attention to itself in chemistry and material science, due to its crucial applications in manufacturing catalysts for the synthesis of various biological active compounds. In addition, SPIONs has excellent properties such as magnetism and insolubility that enable the catalyst to be easily separated with an external magnetic field and reused frequently without considerable loss of catalytic activity …”

Section: Introductionmentioning

confidence: 99%

Surface modified SPIONs‐Cr(VI) ions‐immobilized organic‐inorganic hybrid as a magnetically recyclable nanocatalyst for rapid synthesis of polyhydroquinolines under solvent‐free conditions at room temperature

Maleki

Hamidi

Maleki

et al. 2018

Self Cite

In this work, a magnetic hybrid dichromate nanocomposite with triphenylphosphine surface modified superparamagnetic iron oxide nanoparticles (SPIONs) as a recyclable nanocatalyst was designed, prepared and characterized by Fourier transform infrared spectroscopy (FT-IR) spectra, X-ray diffraction (XRD) pattern analysis, vibrating sample magnetometer (VSM) curves, X-ray fluorescence (XRF) analysis, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images and dynamic light scattering (DLS) analysis. Then, it was used in a green and efficient procedure for one-pot multicomponent synthesis of polyhydroquinoline derivatives by the condensation of aldehydes, dimedone or 1,3-cyclohexadione, ethyl acetoacetate and ammonium acetate. This protocol includes some new and exceptional advantages such as short reaction times, low catalyst loading, high yields, solvent-free and room temperature conditions, easy separation and reusability of the catalyst.