نتایج جستجو برای: magnetic acid catalyst
تعداد نتایج: 1108805 فیلتر نتایج به سال:
A Simple and environmentally friendly procedure for the one-pot multi-component synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives has been developed by one pot three component reaction of various aldehydes, β-dicarbonyl, and urea in the presence of catalytic amount of tris (trihexyltetradecylphosphonium) gadolinium hexachloride [P6,6,6,14]3 [GdCl6] as a solid acid catalyst without any ad...
The acetylation of various alcohols and phenols was performed successfully using acetic anhydride in the presence of Citric acid coated magnetite nanoparticles as catalyst under solvent-free condition and at 45 °C. The catalyst showed high thermal stability and was recovered and reused at least 5 times without any considerable loss of activity. The present process is environmentally benign and ...
A new magnetic nanocatalyst has been prepared using immobilization of vanadate onto aminopropyl functionalized SiO2/Fe3O4(VO3-/NH3+-SiO2/Fe3O4). The obtained magnetic catalyst was characterized by FT-IR, XRD, VSM and SEM techniques and used for sulfoxidation of sulfide compounds to the correspondingsulfoxides in presence of H2O2 as oxidant at room temperature. The optimum of reaction conditions...
The four-component Hantzsch condensation reaction of dimedone, ethyl acetoacetate, ammonium acetate, and various aromatic and aliphatic aldehydes in the presence of catalytic amount of a magnetic nanoparticle-supported tribromide, as a green catalyst, under solvent‐free conditions at 80 °C affords functionalized 5-oxo-hexahydroquinolines in good to excellent yields. The magnetic Fe3O...
a mild and green method has been developed for the preparation of coumarins derivatives through the one-pot reactions. in our study,various phenols and ethyl acetoacetate compound in which we used silica-supported boron sulfonic acid [sio2/b(so4h)3] as a new, highly efficient and tri-functional inorganic brønsted acid catalyst were processed under solvent-free condition and thermal. the catalys...
This study offers an exclusive class of magnetic nanoparticles supported hyperbranched polyglycerol (MNP/HPG) that was functionalized with citric acid (MNP/HPG-CA) as a host immobilization of palladium nanoparticles. The MNP/HPG-CA/Pd catalyst was fully characterized using some different techniques such as thermogravimetric analysis (TGA), x-ray diffraction (XRD), transmission electron microsco...
A new immobilized palladium-pyridine complex on γ-Fe2O3 magnetic nanoparticles was synthesized and characterized by SEM, TEM, TGA, ICP, XPS, XRD, FT-IR and CHN analysis. The catalytic activity of synthesized catalyst has been investigated in Heck, Suzuki and Sonogashira coupling reactions using a series of aryl halides. The catalyst was easily isolated from the reaction mixture by an external m...
A facile and eminent method has been reported for the preparation of amido alkyl naphthols. Amido naphthol derivatives were synthesized by condensation pyrazole aldehydes, β-naphthol acetamide in presence a heterogeneous SiO2 supported sodium hydrogen sulphate catalyst using acetic acid as solvent. This protocol is advantageous its shorter reaction hours, simplest workup technique, excellent yi...
The four-component Hantzsch condensation reaction of dimedone, ethyl acetoacetate, ammonium acetate, and various aromatic and aliphatic aldehydes in the presence of catalytic amount of a magnetic nanoparticle-supported tribromide, as a green catalyst, under solvent‐free conditions at 80 °C affords functionalized 5-oxo-hexahydroquinolines in good to excellent yields. The magnetic Fe3O...
in this thesis, barium ferrite nano particles were prepared by sol-gel method. their structural and magnetic properties of samples have been investigated using thermo gravimetric analysis (tg-dta), x-ray powder diffractometer (xrd), fourier transform infrared (ftir), scanning electron microscopy (sem), field emission scanning electron microscopy (fesem), ac susceptometer, vibrating sample magne...
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