nano tio2 supported on sio2 (nano tio2@sio2) as a solid lewis acid, was described to be an effective and reusable catalyst for one-pot three-component reaction of benzil, aryl aldehydes and ammonium acetate for the synthesis 2-aryl-4,5-diphenyl-1h-imdazoles synthesis. to explore the high efficacy of the catalytic system the four-component cyclization of benzil, aryl aldehydes, ammonium acetate ...

Background Catalysts improve the rate or selectivity of chemical reactions without being consumed in the chemical reaction. “Supported heterogeneous catalysts” consist of catalytic active sites carried on the surfaces of porous solids, known as “supports”. Such catalytic materials are especially important for chemical manufacturing because they minimize the loss of valuable catalytic materials ...

Nano silica sulfuric acid as a solid acid, was described to be an effective catalyst for one-pot three-component reaction of kojic acid, aryl aldehydes and indoles for the preparation of 2-substituted aryl (indolyl) kojic acid derivatives. The catalyst was prepared by combination of chlorosulfonic acid to nano silica gel. The size of nanoparticles were observed with SEM.All prepared compounds w...

A rapid and efficient method for the synthesis of bis-thiazolidinones has been achieved by pseudo five-component reaction of aldehydes, ethylenediamine and thioglycolic acid in the presence of nano-NiZr4(PO4)6 as catalyst under microwave irradiation. Nano-NiZr4(PO4)6 has been characterized by powder X-ray diffraction, scanning electronic microscopy (SEM), energy dispersive spectroscopy (EDS), v...

BACKGROUND Un-doped and N-doped TiO2 nano-particles with different nitrogen contents were successfully synthesized by a simple sol-gel method, and were characterized by X-ray diffraction, field emission scanning electron microscopy, Energy dispersive X-ray analysis and UV-visible diffuse reflectance spectra techniques. Then enhancement of sonocatalytic degradation of humic acid by un-doped and ...

A  convenient  and  efficient  one-pot  four-component  synthesis  of  1,  2,  4,  5-tetrasubstituted  imidazoles  using  nano  TiO2  as  a  recyclable  catalyst  is  reported.  The results  show  that  the  methodology  has  several  advantages  such  as  low  loading  of catalyst,  excellent  yield,  short  reaction  time,  operational  simplicity  and  solvent-free conditions.

Nano-silica supported boron trifluoride (BF3.SiO2) is an efficient, reusable and eco-friendly catalyst for chemoselective thioacetalization of aldehydes and ketones. So, this catalyst was applied for transthioacetalization of acetals and acylals into their corresponding 1,3-dithiolanes or 1,3-dithianes  in good to excellent yields. The reactions were carried out at room temperature under solven...

cu2o nanoparticles were synthesized by thermal treatment in liquid paraffin without any inert gas protection using nano structures of schiff base copper (ii) complex (1) as precursor. liquid paraffin was used as solvent and reductant. span 80 was applied to control the morphology of cuprous oxide nanoparticles. the nano structure of the complex was characterized by x-ray diffraction measurement...

Nano-Fe3O4 attached to Crosslinked sulfonated polyacrylamide (Cross-PAA-SO3H) as a superior catalyst has been utilized for the preparation of 3-alkyl-4-phenyl-1,3-thiazole-2(3H)-thione derivatives through a three-component reactions of phenacyl bromide or 4-methoxyphenacyl bromide, carbon disulfide and primary amine. The best results were gained in ethanol and we found that the reaction gave co...