Tungstic acid-functionalized Fe₃O₄@TiO₂: preparation, characterization and its application for the synthesis of pyrano[2,3-c]pyrazole derivatives as a reusable magnetic nanocatalyst

Abstract

A new magnetic nanocatalyst based on the immobilization of tungstic acid onto 3-chloropropyl-grafted TiO 2 -coated Fe 3 O 4 nanoparticles (Fe 3 O 4 @TiO 2 @(CH 2 ) 3 OWO 3 H) was prepared, characterized, and applied for the synthesis of pyrano[2,3-c]pyrazole derivatives. The characterization was performed using FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive Xray spectroscopy (EDS), and vibrating sample magnetometry (VSM) analysis. Pyranopyrazoles were synthesized in the presence of this novel catalyst via a three-component reaction of 3-methyl-1-phenyl-2-pyrazolin-5-one, malononitrile, and aromatic aldehydes with high yields. It is a low cost, nontoxic and thermally stable catalyst, which shows a long life and can be reused for several catalytic cycles without deactivation or selectivity loss.

Advances in Pyranopyrazole Scaffolds’ Syntheses Using Sustainable Catalysts—A Review

“…FESEM study showed that the nanoparticles had a spherical morphology with size < 100 nm. The target molecules were prepared by a multicomponent reaction between malononitrile (3), 3-methyl-pyrazolone (8) and aldehydes (82) in the presence of Fe 3 O 4 @FSM-16-SO 3 H (30 mg) in a water-ethanol system in high yields (79-89%) for 80 min at reflux condition (Scheme 23). The recovered catalyst was reused five times with similar activity.…”

“…The recovered catalyst was reused five times with similar activity. A facile, three-component reaction of malononitrile (3), 3-methyl-pyrazolinone (8), and aromatic aldehydes (84) leading to pyranopyrazole derivatives (85) progressed well under a solvent-free condition in 120 min at 80 • C with the aid of a low catalytic amount (0.003 g) of Fe 3 O 4 @TiO 2 @(CH 2 ) 3 OWO 3 H via one-pot manner (Scheme 24) [82]. The prepared novel catalyst was assessed by several techniques, including SEM, EDS, FT-IR, P-XRD, and VSM analysis.…”

Novel cellulose supported 1,2-bis(4-aminophenylthio)ethane Ni(ii) complex (NiII(BAPTE)(NO3)2-Cell) as an efficient nanocatalyst for the synthesis of spirooxindole derivatives

“…In continuation of our program aimed at developing new methodologies for the preparation of green catalysts, [81][82][83][84][85][86][87][88][89][90] we have reported preparation, characterization and catalytic application of Ni II (BAPTE)(NO 3 ) 2 -Cell as a novel cellulose-based nanocomposite.…”

Molybdic Acid-Functionalized Nano-Fe3O4@TiO2 as a Novel and Magnetically Separable Catalyst for the Synthesis of Coumarin-Containing Sulfonamide Derivatives

“…Due to these benefits and as a continuation of our studies on the preparation of new heterogeneous catalysts, [34][35][36] herein we have developed synthesis and characterization of Fe 3 O 4 @TiO 2 @(CH 2 ) 3 OMoO 3 H as a novel recoverable nanocatalyst. Then, its application was investigated for the synthesis of sulfonamide containing coumarin moieties.…”