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 ...

Mercury discharge lamps are often used because of their high efficiency; however, the usage mercury will be restricted or forbidden for safety and environmental purposes. Finding alternative solutions to suppress is major interest. The aim this work increase luminous efficacy a commercial-free flat dielectric barrier lamp (Planilum, St Gobain) in order reach necessary conditions as daily lighti...

highly active cu (ii) complex with 1,4-dihydroxy anthraquinone as a cheap and accessable ligand could be used as a catalyst for the preparation of structurally different propargylamines from a one-pot, three-component reaction of terminal alkynes, aldehydes, and secondary amines with high yields under solvent-free conditions. the 1,4-dihydroxy anthraquinone is a very efficient cu(ii) scavenger ...

this study offers an exclusive class of magnetic nanoparticles supported hyperbranched polyglycerol (mnp/hpg) that was functionalized with citric acid (mnp/hpg-ca) as a host immobilization of palladium nanoparticles. the mnp/hpg-ca/pd catalyst was fully characterized using some different techniques such as thermogravimetric analysis (tga), x-ray diffraction (xrd), transmission electron microsco...

A mild and efficient method has been developed for the preparation of substituted coumarins from reaction of various phenols with different β-ketoesters via Pechmann condensation in the presence of Brønsted acidic ionic liquid (N-(4-sulfonic acid) butyl triethylammonium hydrogen sulfate) as an effective catalyst under solvent-free conditions. Different phenols reacted with ethyl acetoacetate to...

Silica sulfuric acid is employed as solid acid catalyst for the clean and less hazardousprotection of carbonyl compounds as 2,4-dinitrophenylhydrazone under solvent-free conditions.