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

A new magnetic nanocatalyst based on the immobilization of tungstic acid onto 3-chloropropyl-grafted TiO-coated FeO nanoparticles (FeO@TiO@(CH)OWOH) was prepared, characterized, and applied for the synthesis of pyrano[2,3-]pyrazole derivatives. The characterization was performed using FT-IR spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and vibrating sample magnetometry (VSM) analysis. Pyranopyrazoles were synthesized in the presence of this novel catalyst a three-component reaction of 3-methyl-1-phenyl-2-pyrazolin-5-one, malononitrile, and aromatic aldehydes with high yields.

Preparation, characterization and catalytic application of nano-FeO@SiO@(CH)OCONa as a novel basic magnetic nanocatalyst for the synthesis of new pyranocoumarin derivatives.

We present a study on the synthesis, characterization and application of sodium carbonate tag silica-coated nano-FeO (FeO@SiO@(CH)OCONa) as a novel and efficient heterogeneous basic catalyst. The described catalyst was fully characterized FT-IR, X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), and field emission scanning electron microscopy (FE-SEM). The reported novel magnetic nanocatalyst presents an excellent activity and catalytic performance for the synthesis of a novel series of pyranocoumarins through the reaction of dialkyl acetylenedicarboxylates and 5,7-dihydroxy coumarin derivatives at 100 °C under solvent-free conditions.