نتایج جستجو برای: catalyst free
تعداد نتایج: 553796 فیلتر نتایج به سال:
this study offers an exclusive class of magnetic nanoparticles supported hyperbranched polyglycerol (mnp/hpg) that was functionalized with citric acid (mnp/hpg-ca) as a host immobilization of palladium nanoparticles. the mnp/hpg-ca/pd catalyst was fully characterized using some different techniques such as thermogravimetric analysis (tga), x-ray diffraction (xrd), transmission electron microsco...
A mild and efficient method has been developed for the preparation of substituted coumarins from reaction of various phenols with different β-ketoesters via Pechmann condensation in the presence of Brønsted acidic ionic liquid (N-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate) as an effective catalyst under solvent-free conditions. Different phenols reacted with ethyl acetoacetate to...
Silica sulfuric acid is employed as solid acid catalyst for the clean and less hazardousprotection of carbonyl compounds as 2,4-dinitrophenylhydrazone under solvent-free conditions.
A mild and efficient method has been developed for the preparation of substituted coumarins from reaction of various phenols with different β-ketoesters via Pechmann condensation in the presence of Brønsted acidic ionic liquid (N-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate) as an effective catalyst under solvent-free conditions. Different phenols reacted with ethyl acetoacetate to...
for the first time lactic acid was applied as an efficient and green catalyst for the one-pot three-component synthesis of amidoalkyl naphthols via the condensation between arylaldehydes, 2-naphthol and amides or urea under thermal solvent-free conditions in good to excellent yields. we have demonestrated a mild and efficient eco-friendly tandem synthesis of amidoalkyl naphthols using lactic ac...
a facile and efficient protocol for the synthesis of 1,8-dioxo-octahydroxanthenes has been developed by one-pot knoevenagel condensation, michael addition and cyclodehydration reaction of dimedone (active methylene carbonyl compound) with aromatic aldehydes in the presence of iron (iii) sulfate hydrate as a solid acidic catalyst under solvent-free conditions. various aromatic aldehydes were uti...
a water soluble, bronsted acid, 5-sulfosalicylic acid as an efficient organocatalyst was used for the synthesis of physiologically active 2-substituted benzimidazole derivatives from o-phenylenediamine and aromatic aldehydes in ethanol at reflux condition. cost-effectiveness, use of non-hazardous solvents, metal free and commercially available catalyst, single-step, environmentally friendly gre...
Red mud, one of the mostly produced industrial wastes, was converted into a catalyst with exceptionally high and stable performance for hydrogen production from ammonia. Results showed that iron species produced after reduction of the HCl digested red mud were converted into ε-Fe2N during the induction period of ammonia decomposition reaction at 700 °C. The catalytic performance measurements in...
Abstract A novel basic ionic liquid based on imidazolium cation is designed, synthesized and successfully used as a catalyst for the one-pot synthesis of 4-Oxo-6-aryl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-carbonitrile derivatives. The remarkable features of this new catalyst are its ethyleneoxy bridge which participates in dissolving organic compound in the ionic liquid and its strong base co...
A simple and efficient method for the chemoselective 1,1-diacetate protection of aromatic aldehydes with acetic anhydride by using Ni2+ supported on hydroxyapatite-core-shell magnetic γ-Fe2O3 nanoparticles (γ-Fe2O3@HAp-Ni2+) under solvent free conditions. This method has several advantages, including high yield, short reaction time, simple work-up and recyclable property of the catalyst. The ca...
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