the condensation of benzylamine with glyoxal leads to hexabenzylhexaazaisowurtzitane (hbiw) in acetonitrile solvent with citric acid as a green catalyst under both conventional stirring and ultrasonic irradiation conditions. the influence of four variables, including the amount of catalyst, solvent, reaction time and ultrasonic power, on the reaction yield was investigated. the results showed t...

Kinetic Monte Carlo simulation was applied to investigation of kinetics and mechanism of oxalic acid degradation by direct and heterogeneous catalytic ozonation. La-containing perovskites including LaFeO3, LaNiO3, LaCoO3 and LaMnO3 was studied as catalyst for oxalic acid ozonation. The reaction kinetic mechanisms of each abovementioned catalytic systems has been achieved. The rate constants val...

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.

facile and versatile procedures have been explored for the synthesis of tetrahydropyridines and 2,3-dihydroquinazolin-4(1h)-ones. these protocols employ the one-pot multi-component condensation of arylaldehydes and aromatic amines with β-keto esters and isatoic anhydride in chloroacetic acid, respectively. the reactions proceeded smoothly to generate the corresponding products in high yield. we...

In recent year, biocompatible, biodegradable materials (linear polylactic acid-based urethanes) in the solid and/or liquid form have attracted tremendous attention in biomedical application particularly in stent coating. Low molecular weight poly (lactic acid) s (PLA), having narrow molecular weight distribution was by dehydropolycondensation method using tetraphenyltin as a catalyst. Hydroxyl ...

we wish to report a mild and efficient one-pot three-component reaction of an aryl aldehyde, malononitrile and barbituric acid or 4-hydroxycoumarinfor the synthesis ofpyrano[2,3-d]pyrimidine and dihydropyrano[c]chromene derivatives in the presence of iron ore pellet as a natural and reusable catalyst under heterogeneous and green conditions. the present methodology offers several advantages suc...

Sulfonic acid functionalized SBA-15 (SBA-Pr-SO3H) as a new nanoporous acid catalyst was used in the one-pot synthesis of polyhydroquinolines derivatives via the Hantzsch four component condensation reaction of aldehydes, b-ketoesters, dimedone and ammonium acetate under solvent free conditions with short reaction time in excellent yields. SBA-P...

Formic acid (FA) is an attractive compound for H2 storage. Currently, the most active catalysts for FA dehydrogenation use precious metals. Here, we report a homogeneous iron catalyst that, when used with a Lewis acid (LA) co-catalyst, gives approximately 1,000,000 turnovers for FA dehydrogenation. To date, this is the highest turnover number reported for a first-row transition metal catalyst. ...

The silica boron sulfuric acid nanoparticles (SBSANs) as an efficient heterogeneous solid acid catalyst with both Brønsted and Lewis acidic sites catalyzed the preparation of bis-4-hydroxycoumarin derivatives using reaction of aldehydes and 4-hydroxycoumarin under mild and solvent-free condition at room temperature. This new and efficient methodology has advantages in comparison with currently ...