نتایج جستجو برای: heterogeneous reaction

تعداد نتایج: 532299  

In this study, silica nanoparticles were used as support to prepare a new heterogeneous catalyst system for application in organic reactions. The reaction of silica nanoparticles with sodium 2-bromoethane-1-sulfonate resulted in the connection of a sulfonic acid group on the surface of silica nanoparticles (NSESA). The synthetic catalyst system was characterized using different microscopic and ...

Asieh Yahyazadeh, Farhad Shirini, Fatamah Tavakoli

The aryl-(Z)-N-[2-amino-1,2-dicyanovinyl]formamidine 2 cyclize in solvent-free conditions and in the presence of a base to give a 5-amino-1-aryl-4-cyanoimidazoles 3. Silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 through reaction with aromatic amines at room temperature and in good to excellent yields. ...

A highly efficient and general method for the synthesis of aryloylamido coumarinsderivatives by a three-component condensation of 4-hydroxycoumarin or 4-hydroxy-6-methylpyran-1-one, aryl glyoxals and benzamide in the presence of nano silica supported tin(II) chloride as a heterogeneous catalyst is established. In this method, SnCl2/nano SiO2 wasused as green and reusable catalyst. Excellent yie...

Asieh Yahyazadeh, Farhad Shirini, Fatamah Tavakoli

The aryl-(Z)-N-[2-amino-1,2-dicyanovinyl]formamidine 2 cyclize in solvent-free conditions and in the presence of a base to give a 5-amino-1-aryl-4-cyanoimidazoles 3. Silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 through reaction with aromatic amines at room temperature and in good to excellent yields. ...

Journal: :iranian journal of catalysis 2015
gisya abdi abdolhamid alizadeh mohammad khodaei mustaffa shamsuddin sohrab ghouzivand

an organosuperbase (n,n-dimethylbiguanide) immobilized on mesoporous and magnetically separable silica supports, was found for the first time, to act as a highly-stable, scalable and efficient heterogeneous catalyst for the henry reaction under mild and neutral condition. several factors such as catalyst amount, solvent and reaction time concerning the reactivity were also discussed. the proced...

Titanium dioxide (TiO2) and Fe3O4 magnetite particles were coated on spherical Kissirises; glucose oxidase (GOx) enzyme was immobilized on Kissiris/Fe3O4/TiO2 by physical adsorption. This catalyst was analyzed by a scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and energy dispersive X-ray (EDX) measurements. The performance of the prepared biocatalyst in the...

The Fe-MCM-22 zeolite was found to be an efficient solid heterogeneous catalyst for synthesis of dihydropyrano [2,3-c] pyrazoles via one pot four component reaction of ethyl acetoacetate, hydrazine hydrate, aromatic aldehyde and malononitrile in aqueous alcohol. The catalyst was synthesized by hydrothermal method under autogenous pressure and modified by Fe (III) ion exchange. The prepared cata...

The Fe-MCM-22 zeolite was found to be an efficient solid heterogeneous catalyst for synthesis of dihydropyrano [2,3-c] pyrazoles via one pot four component reaction of ethyl acetoacetate, hydrazine hydrate, aromatic aldehyde and malononitrile in aqueous alcohol. The catalyst was synthesized by hydrothermal method under autogenous pressure and modified by Fe (III) ion exchange. The prepared cata...

A simple, efficient, and environmentally friendly method has been developed for the synthesis of a series of tricyclic fused pyrazolopyranopyrimidines via a one-pot three-component reaction of barbituric acids, aromatic aldehydes, and 3-methyl-5-pyrazolone in the presence of SBA-Pr-SO3H. SBA-15 mesoporous silica material functionalized with propyl sulfonic acid groups was used as a heterogeneou...

Journal: :journal of nanostructures 2012
g. mohammadi ziarani n. hosseini mohtasham n. lashgari a. badiei m. amanlou

a simple and efficient one-pot three-component synthesis of the biologically important spirooxindole-4h-pyrans was carried out by the reaction of isatin, activated methylene reagents, and 4-hydroxycoumarin in aqueous medium. sba-pr-nh2 was found to be an efficient heterogeneous nanoporous solid basic catalyst (pore size of 6 nm) which can be easily handled and removed from the reaction mixture ...

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