An efficient synthesis of polyhydroquinoline derivatives was reported via four-component coupling reactions of aldehydes, 1,3-dicarbonyl ketones (dimedone or 1,3-cyclohexanedione), ethyl acetoacetate or methyl acetoacetate and ammonium acetate in the presence of a catalytic amount of nanocrystalline TiO2 under solvent free conditions. The reported method is mild, rapid and has the advantages su...

Alkali and alkaline earth metals hydrogen sulfate catalyzed the one-pot three component condensation reactions of aldehydes, 1,3-dicarbonyl compounds and urea or thiourea under solvent-free conditions leading to 3,4-dihydropyrimidin-2(1H)-ones in high yields at 80 °C. Our results showed that Biginelli reaction not only is pH dependent, but the cation of catalyst plays an importan...

A simple and environmentally benign procedure for the synthesis of 14-aryl-14H-dibenzo[a,j]xanthenes by a one-pot condensation of 2-naphthol with aromatic aldehyde in the presence of [Et3NH][HSO4] as an acidic ionic liquid catalyst under solvent-free conditions has been developed. The reaction work-up is very simple and the catalyst can be easily separated from the reaction mixture and reused s...

In this study, multi component Hantzsch reaction was carried out between various  Aromatic Aldehyde with Dimedone,Ethyl acetateand ammonium acetate to produce polyhydroquinolinederivatives under solvent-free conditions at 110oC by a (Zinc oxide  nanocatalyst) as effective Lewis acid. The remarkable advantages offered by this method compared with other methods are a green catalyst, si...

— An attempt is made to provide a more rigorous basis for the description of solvent effects on chemical reactions by taking into account the various free energy contributions involved in the transfer of a substrate from the gas to the solution phase. It is shown that the solvent influence on various chemical and physical processes can be represented in a semiquantitative or even quantitative w...

methoxymethylation of a variety of alcohols was performed using formaldehyde dimethyl acetal in the presence of 1,3-dichloro-5,5-dimethyl hydantoin [dcdmh] and poly n,n′-dibromo-n-ethyl naphthyl-2,7-disulfonamide [pbns] as catalysts at room temperature and under solvent-free conditions. our experiments show that primary and secondary alcohols can be smoothly converted into the corresponding mom...

2-amino-substituted ketones react with α-methylene ketones under solvent-free conditions at 90 °c in thepresence of a catalytic amount of zirconium dodecylphosphonate to create the corresponding quinolinesin excellent yields. this procedure recommends numerous advantages such as easy work-up, use of mild,reusable and safe catalyst, short reaction timeand high yields. the new compounds have been...

This Account presents a theoretical formulation for proton-coupled electron transfer reactions. The active electrons and transferring protons are treated quantum mechanically, and the free energy surfaces are obtained as functions of collective solvent coordinates corresponding to the proton and electron transfer reactions. Rate expressions have been derived in the relevant limits, and methodol...

The three-dimensional “reference interaction site model” (3D-RISM) integral equation theory is a statisticalmechanical approach to predict liquid state structural and thermodynamic features. It is based on approximate solute-solvent correlation functions to be computed on a 3D grid as a function of the interaction potential between the solute and the solvent sites, circumventing the need of cos...

A Simple and environmentally friendly  procedure for the one-pot multi-component synthesis of 3,4-dihydropyrimidin-2(1H)-one derivatives has been developed by one pot three component reaction of various aldehydes, β-dicarbonyl, and urea in the presence of catalytic amount of tris (trihexyltetradecylphosphonium) gadolinium hexachloride [P6,6,6,14]3 [GdCl6] as a solid acid catalyst without any ad...