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...

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...

molybdate sulfuric acid (msa) has been prepared and used as catalyst for the biginelli synthesis of some quinazolinones/thiones under solvent-free conditions. the catalyst loading is low and it shows recyclability. this method has advantages such as avoidance of the organic solvents, high yield of pure products, short reaction times and operational simplicity.

sulphuric acid adsorbed on silica gel is a practical and useful catalyst for acetylation of varius alcohols, phenols and amines.

Biodiesel and lactic acid from rapeseed oil was produced using sodium silicate as catalyst. The transesterification in the presence of the catalyst proceeded with a maximum yield of 99.6% under optimized conditions [3% (w/w) sodium silicate, methanol/oil molar ratio 9/1, reaction time 60 min, reaction temperature 60°C, and stirring rate 250 rpm]. After six consecutive transesterification reacti...

Effects of water on the catalytic performances of MoVTeNbO catalyst in the oxidation of propane to acrylic acid have been investigated at different reaction temperatures and different steam contents. Obtained results show that both catalytic performances and catalyst structure are very sensitive to the presence of water vapor in the reaction feed. Presence of water induces some structural modif...

Highly enantioselective protonation of α-halo and alkoxy carboxylic acid-derived ketene disilyl acetals is achieved by using P-spiro chiral diaminodioxaphosphonium barfate as a Brønsted acid catalyst, where the enantiofacial discrimination by the catalyst mainly stems from the recognition of the electronic difference between two substituents on the ketene disilyl acetal.

A highly stereoselective rapid C-glycosylation reaction has been developed between glycal and unactivated alkynes in the presence of coppertriflate and ascorbic acid at low catalyst loading and at room temperature. A wide variety of glycals and aryl acetylenes participate in the reaction smoothly. TfOH generated during the reduction of Cu(OTf)2 by ascorbic acid may be the active catalyst for th...

For the first time, Mo modified Rh/SiO2 was found to be an effective catalyst for the aqueous phase selective hydrogenation of levulinic acid to 1,4-pentanediol. Over such a catalyst, high levulinic acid conversion (100%) and 1,4-pentanediol yield (70%) can be achieved at low temperature (353 K).