نتایج جستجو برای: heterogeneous catalyst
تعداد نتایج: 166602 فیلتر نتایج به سال:
an efficient synthesis route to 1,4-dihydropyrimidine derivatives from reaction of divergent aldehydes with ethylacetoacetate and urea under solvent-free conditions by zno nanoparticles as a relative in expansive, eco-friendly, easy available, non-volatile, non-explosion, thermally robust, recyclable and easy to handle catalyst at 90°c with excellent yields is described. unenhanced reaction tim...
A new catalyst derived from osmium has been prepared, fully characterized and tested in the dihydroxylation of alkenes. The catalyst was prepared by wet impregnation methodology of OsCl3•3H2O on a commercial micro-magnetite surface. The catalyst allowed the reaction with one of the lowest osmium loadings for a heterogeneous catalyst and was selective for the monodihydroxylation of 1,5-dienes. M...
The addition of phenols to aryl-substituted alkynes to form 1,1-diarylalkenes was carried out by using the Fe-Al-MCM-41 catalyst. The catalyst showed remarkable improvement in time and yield in comparison to other solid catalysts. The heterogeneous catalyst can be reused at least three times without a significant loss in activity.
Silica supported phosphomolybdic acid, an eco-friendly heterogeneous catalyst, has been found to be highly efficient for Friedlander synthesis of quinolines in excellent yields. A variety of ketones afford the quinolines smoothly. The catalyst can be easily recovered and reused.
پیرول ترکیب حلقوی پنج عضوی است که دارای فرمول c4h4nh می باشد. این ماده، مایع فرار و بی رنگی است که به سرعت در مجاورت هوا تیره می شود. مشتقات دارای استخلاف پیرول نیز با این نام شناخته می شوند. به طور مثال n-متیل پیرول ماده اولیه سنتز n- متیل کربوکسیلیک اسید است که واحد سازنده بسیاری از داروها در صنعت داروسازی (داروهایی با خصلت آنتی باکتریایی، آنتی ویروسی، آنتی تومور، آنتی اکسیدان و ضد التهاب)و ه...
A new heterogeneous catalyst, hydrophobic TiO4-deposited mesoporous silica, has been designed for the efficient Mukaiyama-aldol condensation, a water-participating Lewis acid-catalyzed reaction between a hydrophobic carbonyl compound and silyl enol ether. The prepared catalyst suspended in water exhibited high catalytic performance as a reusable catalyst for the reaction without a surfactant.
Eggshell was found to be a versatile heterogeneous catalyst for the synthesis of pyrano[3,2-c]quinoline derivatives in good yields. This protocol has the advantages of environmental friendliness, short reaction time, low cost and convenient operation.
Homogeneous transition metal complex catalysts for organic industrial processes are converted to catalysts which are heterogeneous with respect to the reactants, and which have substantially equal catalytic activity to the homogeneous catalysts. This is done by reacting a normally homogeneous transition metal complex catalyst with a metal bridging ligand which substantially duplicates the ligan...
poly (vinylpyrrolidone)-grafted silica as an organic-inorganic hybrid material was used as an effective heterogeneous polymeric cosolvent catalyst in organic reactions. this modified silica catalyzed nucleophilic displacement of alkyl halides for easy preparation of alkyl thiocyanates, alkyl cyanides, alkyl azides and alkyl aryl ethers. furthermore, the catalyst was applied for the conversion o...
A simple, efficient, and green practical approach to Knoevenagel condensation of malononitrile and different aldehydes has been developed using an ionic liquid functionalized on Fe3O4 magnetic nanoparticles as heterogeneous catalyst. This nanostructural catalyst has also been applied for the synthesis of 4H-benzo[b]pyran derivatives in water at room temperature in short reaction time. All of th...
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