نتایج جستجو برای: recyclable catalyst
تعداد نتایج: 46044 فیلتر نتایج به سال:
A convenient and efficient methodology for the synthesis of densely substituted pyrrole-fused isocoumarins, which employs solid-supported silica sulfuric acid (SSA) as catalyst, has been developed. When the mixture of ninhydrin adducts of acetylacetone/ethyl acetoacetate and primary amines was heated on the solid surface of SSA under solvent-free conditions, the pyrrole-fused isocoumarins were ...
PS-TEMPO, a polymer-supported 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) was successfully applied as a recyclable, active and selective catalyst for the oxidation of alcohols. Bleach, molecular oxygen and air were successfully used as terminal oxidant under conditions suitable for industrial applications. The intrinsic activity and selectivity of TEMPO for primary alcohols to aldehydes were r...
in this research, we have developed cheap recyclable and task-specific acidic ionic liquids (ails) 1-hydrogen-3-methylimidazolium hydrogen sulfate [hmim]hso4, 1-hydrogen-3-methylimidazolium chloride [hmim]cl, 2-pyrrolidonium hydrogensulfate [hnhp]hso4 and applied them in acid catalyzed synthesis of quinoxaline derivatives from 1,2-phenylendiamines and 1,2-dicarbonyl compounds. the products coul...
a novel rice-husk-silica supported n-propyl bipyridinium chloride (rhprbpcl) has been prepared. due to the basicity of rhprbpcl, it was decided to evaluate its catalytic activity in the one-pot preparation of tetrahydrobenzo[b]pyran, dihydropyrano[3,2-c]chromene and dihydropyrano[4,3-b]pyran derivatives. the catalyst was characterized by ft-ir, sem and tga analyses. this methodology offers seve...
benzylaminoalkenones and benzylaminoalkenoates 3 were synthesized from reaction of benzylamine with corresponding 1,3-diketones and 1,3-ketoesters in the presence of catalytic amount of chloroacetic acid under microwave radiation. this method offers several advantages including high yield of products, recyclable of the catalyst and easy experimental work-up procedure.
silica-bonded n-propyldiethylenetriamine sulfamic acid (spdtsa) is employed as a recyclable heterogeneous solid acid catalyst for the synthesis of benzopyrano[2,3-d]pyrimidines through one-pot condensation reaction of salicylaldehydes, malononitrile and secondary amines at room temperature under solvent-free conditions. spdtsa showed much the same efficiency when used in consecutive reaction ...
Sulfuric acid {[3-(3-silicapropyl)sulfanyl]propyl}ester (SASPSPE) is employed as a recyclable catalyst for the synthesis of α-amino nitriles. These syntheses were performed via a one-pot three-component condensation of aldehydes, amines, and trimethylsilyl cyanide under mild reaction conditions at room temperature. The catalyst could be recycled and reused several times without any loss of effi...
Poly(4-vinylpyridine)-supported copper iodide nanoparticles is reported as a new, green and recyclable catalyst for the synthesis of aryl-14H-dibenzo [a-o] xanthenes under solvent-free conditions. This catalyst can be recovered by simple filtration and recycled up to 8 consecutive runs without any loss of their efficiency.
A convenient and efficient one-pot four-component synthesis of 1, 2, 4, 5-tetrasubstituted imidazoles using nano TiO2 as a recyclable catalyst is reported. The results show that the methodology has several advantages such as low loading of catalyst, excellent yield, short reaction time, operational simplicity and solvent-free conditions.
in the current study, a magnetic inorganic–organic nanohybrid material (hpa/tpi-fe3o4) was produced and used as an efficient, highly recyclable and eco-friendly catalyst for the one-pot and multicomponent synthesis of 3,4-dihydroquinoxalin-2-amine, diazepine-tetrazole and benzodiazepine-2-carboxamide derivatives with high yields and in a short range of time (20–35 min). the nanohybrid catalyst ...
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