نتایج جستجو برای: reusable catalyst
تعداد نتایج: 53437 فیلتر نتایج به سال:
A simple and mild method for tetrahydropyranylation of alcohols is reported at room temperature using a catalytic amount of 3-methylimidazolinium hydrogensulfate([Hmim]HSO4) as a green, efficient and reusable catalyst. Using solvent-free conditions, non-toxic and inexpensive materials, modest and clean work-up, short reaction times and high yields of the products are the advantages o...
A green and efficient one-pot three component reaction of 4-hydroxycoumarin or 1,3-dimethylbarbutyric acid, aryl glyoxals and amides (thioacetamide) has been developed in the presence of BF3- SiO2 nanoparticles in water. This method has several advantages such as high to excellent product yields in short reaction time, atom economy, environment friendly, reusable catalyst and no need for chroma...
A series of tri- and tetra- substituted imidazoles were synthesized from benzyl, aldehyde and ammonium acetate in the presence of zeolite as an ecofriendly reusable catalyst under microwave irradiation in the absence of solvent. The yields are high to excellent and the use of microwave irradiation reduces reaction times to few minute.
A very ecofriendly, highly active and reusable mesostructured ZnAlMCM-41(75) catalyst used in the Prins cyclization of olefins has unprecedented catalytic activity among other microporous mesoporous catalysts.
TiO2 nanoparticles/melamine Tri sulfonic acid (MTSA) supported on silica gel as an efficient catalytic system for simple, one pot, solvent-free and environmentally benign process for synthesis of dihydropyrimidines via Biginelli reaction at 110 °C is described. It was found that the catalyst is reusable and exhibited remarkable activity. The catalyst can be easily separated and reused several t...
TiO2 nanoparticles/melamine Tri sulfonic acid (MTSA) supported on silica gel as an efficient catalytic system for simple, one pot, solvent-free and environmentally benign process for synthesis of dihydropyrimidines via Biginelli reaction at 110 °C is described. It was found that the catalyst is reusable and exhibited remarkable activity. The catalyst can be easily separated and reuse...
Nanocrystalline SiO2–HClO4, as a newly reported catalyst, has been used as an efficient and reusable catalyst for the synthesis of pyrimidine derivatives. The procedure can be successfully applied to the efficient synthesis of mono substituted pyrimidine derivatives, using triethyl orthoformate, ammonium acetate, methyl ketone derivatives. In practice, this method is a combination of a satisfac...
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 ...
An efficient method has been developed for synthesis of 1,4-disubstituted 1,2,3-triazoles using the silica-anchored Cu(I) aminothiophenol complex [SiO2-AT-Cu(I)] as a novel heterogeneous catalyst. The prepared catalyst is characterized by the FT-IR spectroscopy, and TGA, SEM, and ICP techniques. Terminal alkynes react with aroyl bromides and sodium azide in the presence of CuI anchor...
An efficient method has been developed for synthesis of 1,4-disubstituted 1,2,3-triazoles using the silica-anchored Cu(I) aminothiophenol complex [SiO2-AT-Cu(I)] as a novel heterogeneous catalyst. The prepared catalyst is characterized by the FT-IR spectroscopy, and TGA, SEM, and ICP techniques. Terminal alkynes react with aroyl bromides and sodium azide in the presence of CuI anchor...
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