Brønsted acidic ionic liquid triethylamine-bonded sulfonic acid {[Et3N-SO3H]Cl} efficiently catalyzes the one-pot multi-component condensation of 2-naphthol with arylaldehydes and dimedone (5,5-dimethylcyclohexane-1,3-dione) under solvent-free conditions to afford 12-aryl-8,9,10,12-tetrahydrobenzo[a]xanthen-11-ones in high yields and relatively short reaction times.
1,3-Dibromo-5,5-dimethylhydantoin (DBH) and benzyltriphenylphosphoniumtribromide (BTPTB) were used as efficient catalysts for the promotion of the synthesis of 1,8-dioxo-octahydroxanthene derivatives (DOXOs) via a one-pot three component condensation of aldehydes and cyclic 1,3-dicarbonyl compounds in the absence of solvent.
To be fairly general and catalyst is easily separated by magnetic devices and can be reused without any apparent loss of activity for the reaction. Fe3O4 nanoparticles were prepared by chemical coprecipitation method and was found to be a mild and effective catalyst for the efficient, one-pot, three-component synthesis of 2,4,5-trisubstituted imidazoles at room temperature […]
An one-pot method has been developed for the synthesis of azo dyes via sequential diazotization–diazo coupling of aromatic amines with coupling agents at room temperature in the presence of Bi(NO3)3. 5H2O. Short reaction times, high yields, a clean process, simple methodology, easy work-up and green conditions are advantages of this protocol.
In this paper CuFe2O4, nanocrystalline powders were prepared. Also, the supported Cu ferrite was obtained by impregnation of the supports with Cu and Fe nitrates solutions, for calcination temperature 450 ºC. The samples were characterized by X-ray powder diffraction (XRD) and Fourier transform-infrared spectroscopy (FT-IR). Photocatalytic degradation of acid red 206 in water was studied. […]
An efficient one-pot oxidation/condensation tandem process has been developed for the synthesis of 2-substituted benzimidazole derivatives from benzylic alcohols and 1,2-phenylenediamine with use of urea-hydrogen peroxide/silica phosphoric acid as a bifunctional catalyst. This method provides a rapid and efficient access to 2-substituted benzimidazoles.
α-Amino nitriles are synthesized in a one-pot, three-component coupling of aldehydes (or ketones), aniline, and trimethylsilyl cyanide using a catalytic amount of choline chloride.2ZnCl2 as a bio Lewis acidic ionic liquid. Mild Lewis acidic characteristic of this ionic liquid allows efficient synthesis of α-amino nitriles from acid sensitive aldehydes.
Silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 by reaction with aromatic amines at room temperature in good to excellent yields. Imidate was prepared by treatment of equimolar quantities of triethyl orthoformate and diaminomaleonitrile in refluxing dioxane. All the compounds were […]
Various types of aldehydes undergo crossed-Aldol condensation with ketones in the presence of melamine trisulfonic acid (MTSA) under solvent-free conditions. The reported method is mild, efficient and has the advantages such as using heterogeneous catalysis, short reaction times, high yields of the products and the recyclability of the catalyst.
Nicotine-based ionic liquid has been used as a green catalyst for pyridine-catalyzed Huisgen reaction. It promoted addition of dimethylacetylenedicarboxylate to aldehydes or N-tosyl imines leading to efficient synthesis of 2-benzoylfumarates and 1-azadienes respectively under pyridine free odorless ionic liquid conditions. The improved results were obtained in terms of enhanced yields, with minimal work up.
