نتایج جستجو برای: heterogeneous reaction
تعداد نتایج: 532299 فیلتر نتایج به سال:
In this work, SO3H-functionalizedphthalimide (SFP) as a SO3H-containing solid acid is prepared by the reaction of phthalimide with chlorosulfonic acid, and characterized by FT-IR, 1H and 13C NMR, Mass, TG, DTG, XRD and SEM. Then, it is utilized as a highly efficient, heterogeneous and green catalyst for the one-pot multi-component condensation of dime...
A one pot green three‐component coupling reaction of aldehyde, phenylacetylene, and amine derivatives in the presence of copper (II)–thioamide combination as a novel and efficient heterogeneous catalyst under solvent–free conditions is reported. The catalyst displayed high activity and afforded the corresponding propargylamines in good to high yields. The key to this procedure was the generatio...
Bamboo is one of the important biopolymers which is used in chemistry. In this work, for the first time, a solid acid catalyst from bamboo was prepared from the reaction of sawdust bamboo and chlorosulfonic acid. Relevant properties of catalyst were investigated by FT-IR, XRD, SEM and TGA. The sulfonated bamboo (bamboo-SO3H) with several acid functional groups was utilized as highly ...
An environmentally benign procedure for the synthesis of vicinal nitrohydrins via the regioselective ring opening reaction of epoxides with nitrite anion using silica-bound 3-{2-[poly(ethylene glycol)]ethyl}-substituted 1-methyl-1H-imidazol-3-ium bromide as an effective heterogeneous phase transfer catalyst was described. Short reaction time, high yield of products, simple work-up proc...
Silica Vanadic Acid, SVA, (oxo-vanadium has been supported on silica) as a dual Lewis and Bronsted acid ability was prepared and efficiently catalyzed one-pot multi-component condensation of enolizable ketones or alkyl acetoacetates with aromatic aldehydes, acetonitrile and acetyl chloride. The described reaction was produced β-acetamido ketone or ester derivatives in high to excellent yields i...
The reaction of 3-chloropropyl boehmite nanoparticles with caffeine and sulfuric acid afforded BNPs-3-propyl-imidazolopyridinium hydrogen sulfate [BNPs-Caff]HSO4 as a new BNPs-supported ionic liquid (IL) catalyst. [BNPs-Caff]HSO4 proved to be an efficient heterogeneous catalyst for the synthesis of pyrazolopyranopyrimidines via a one-pot four-component reaction of...
3,4-Dihydropyrimidinones and their derivatives are synthesized via Biginelli routes involving an aromatic aldehydes, ethylacetoacetates and urea in one-pot procedure by using CdS nanoparticles as efficient heterogeneous catalyst in solvent-free conditions. Compared with classical Biginelli reaction reported in 1893, this new method provides much improved modification in terms of simplicity. The...
silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 by reaction with aromatic amines at room temperature in good to excellent yields. imidate was prepared by treatment of equimolar quantities of triethyl orthoformate and diaminomaleonitrile in refluxing dioxane. all the compounds were characterized fully by ...
in this study, an efficient and green process for the synthesis of dihydropyrimidin-2(1h)-ones from aromatic benzaldehydes, ethyl acetoacetate and urea using al-mcm-41 as heterogeneous catalyst and microreactor under solvent-free conditions has been developed. the advantages of this method are easy work-up procedure, regeneration of the catalyst, clean and neutral reaction conditions.
various types of aldehydes undergo crossed-aldol condensation with ketones in the presence of melamine trisulfonic acid (mtsa) under solvent-free conditions. the reported method is mild, efficient and has the advantages such as using heterogeneous catalysis, short reaction times, high yields of the products and the recyclability of the catalyst.
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