SILICA PHOSPHORIC ACID/NaNO₂AS A NOVEL HETEROGENEOUS SYSTEM FOR THE COUPLING OF THIOLS TO THEIR CORRESPONDING DISULFIDES

Synthesis of Nano Magnetite Fe3O4 Based Vanadic Acid: A Highly Efficient and Recyclable Novel Nano-catalyst for the Synthesis of 4,4’-(arylmethylene)-bis(3-methyl-1-phenyl-1H-pyrazol-5-ols)

“…In continuation of our previously reported methodologies for designing, synthesis and applications of tasked specific heterogeneous catalysts such as silica based sulfuric, [22] phosphoric, [23] vanadic acid, [24] and magnetic nano particles [25] In order to confirm the modification of the magnetite surface, the FT-IR spectrum of the prepared materials were obtained and have been shown in Figure 1. can be remained after the surface modification with VO(OH)2 and new peaks attributable to these groups could not be detected in the XRD.…”

7.28 Oxidation of Sulfur, Selenium, and Tellurium

“…Inorganic salts, most of them commercially available, such as Bi(NO 3 ) 3 Á 5H 2 O, 27 Al(NO 3 ) 3 Á 9H 2 O/silica sulfuric acid, 28 and NaNO 2 /silica phosphoric acid, 29 selectively oxidize at room temperature or at higher temperature aromatic, heteroaromatic, and alkyl thiols to disulfides in high yield. The most attractive features of these heterogeneous systems are the easy availability of the reagents and the clean work-up, which often consists of filtering the reaction mixture to remove the inorganic residue and then evaporation of the solvent to give almost pure product.…”

Application of Nanocatalysts in Multi-Component Reactions

“…99 By using nano silica gel instead of silica gel, nano silica phosphoric acid was prepared. This catalyst was used for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones under solvent-free conditions with high yields of the products by Bamoniri and co-workers.…”