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.
In the present of methylimidazolium hydrogen sulfate, the synthesis of arylidene heterobicyclic pyrimidinones is studied by condensation of aromatic aldehyde, cyclopentanone, and urea or thiourea. Using solvent-free conditions, non-toxic and inexpensive materials, simple and clean work-up, short reaction times and good yields of the products are the advantages of this method.
The hydrolysis of sodium borohydride as a source of hydrogen gas is studied at different mole ratios of H+ to NaBH4. The sulfonated porous carbon (SPC) is used as a source of hydrogen ion and catalyst. It is found that the sulfonated porous carbon exhibits high activity for the hydrolysis of NaBH4 to generate hydrogen […]
A convenient and efficient direct protocol for the preparation of antibacterial azo dyes by the reaction of 2-naphthol with aromatic amines in the presence of catalytic amount of N-methyl-2-pyrrolidonium hydrogen sulfate ([H-NMP]HSO4) was carried out under solvent free conditions. This method has some advantages such as: easy work-up and easy separation of catalyst from the […]
Benzyltriphenylphosphonium bromide (BTPB) has been applied as an efficient catalyst for the preparation of bis(indolyl)methanes (BIMs) via electrophilic substitution of indoles with aldehydes in the absence of solvent.
1,2-Diketones have been reacted in one-pot method with 1,2-diamines at room temperature with ZnO nanoparticles as a catalyst. ZnO nanoparticles as an available and reusable catalyst is used for the synthesis of Quinoxalinein improved yields.
The aryl-(Z)-N-[2-amino-1,2-dicyanovinyl]formamidine 2 cyclize in solvent-free conditions and in the presence of a base to give a 5-amino-1-aryl-4-cyanoimidazoles 3. Silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 through reaction with aromatic amines at room temperature and in good to excellent yields. […]
A highly practical and efficient preparation of pyrano[3,2-c]pyridone and pyrano[3,2-c]quinoline derivatives was developed via an ionic liquid mediated and promoted multi-component reaction of malononitrile, aldehyde, and 4-hydroxyquinolin-2(1H)-one or 4-hydroxy-6-methylpyridin-2(1H)-one. The combinatorial syntheses were achieved for the first time without applying extra activation energy at ambient temperature while making use of [BMIm]Cl as a catalyst solvent.
A simple, novel, efficient and three-component procedure for the synthesis of pyrimido[4,5-d]pyrimidine-2,4-dione derivatives by the reaction of 6-amino-1,3-dimethyluracil, aldehyde and 2-benzylisothiourea hydrochloride promoted by ionic liquid 1-butyl-3-methylimidazolium bromide ([BMIm]Br) under solvent-free conditions is reported. The presented method is benefited from operational simplicity, simple workup and reusability of ionic liquid. These products were evaluated in vitro […]
