A new one-pot, efficient three-component condensation of dimedone, urazole and aromatic aldehydes in the presence of silica supported sodium hydrogen sulfate as an effective heterogeneous catalyst for the synthesis of novel Triazolo[1,2-a]indazole-1,3,8-trione derivatives under solvent-free conditions is described.

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...

A mixture of manganese, cobalt and lead para-amino benzoates supported on silica gel is used to catalyze oxidation of xylenes to toluic acids in presence of oxygen or air. Reactions are clean and catalysts can be recovered easily and reused.

Silica supported phosphorus pentoxide (P2O5·SiO2) is an efficient catalyst for synthesis of 1,3,5-substituted pyrazoles via the condensation of 1,3-diketones and hydrazines. Simplicity of procedure, mild condition, being solvent-free, high yields, and easy workup are some advantages of this protocol.

The partial oxidation of methanol to formaldehyde was studied over highly dispersed vanadia supported on mesoporous silica SBA-15 (VOx/SBA-15). VOx/SBA-15 catalysts were prepared by a novel grafting/ion-exchange method and characterized using UV-VISand Raman spectroscopy. The resulting surface vanadium oxide species (0 – 2.3 V/nm), grafted on the inner pores of the SBA-15 silica matrix, consist...

a novel rice-husk-silica supported n-propyl bipyridinium chloride (rhprbpcl) has been prepared. due to the basicity of rhprbpcl, it was decided to evaluate its catalytic activity in the one-pot preparation of tetrahydrobenzo[b]pyran, dihydropyrano[3,2-c]chromene and dihydropyrano[4,3-b]pyran derivatives. the catalyst was characterized by ft-ir, sem and tga analyses. this methodology offers seve...