H5CoW12O40 supported on nano silica from rice husk ash: A green bifunctional catalyst for the reaction of alcohols with cyclic and acyclic 1,3-dicarbonyl compounds
abundant agricultural by-product. The present research work deals with the production of nanosilica powders, with high surface area and in amorphous form, from RHA using optimized technique. 12-Tungestocobaltic acid, H5CoW12O40 (CoW), was supported on silica from RHA to produce silica supported CoW (CoW/NSiO2) as a nano catalyst. The characterization data derived from FT-IR reveal that the Keggin structure
benzylation of 1,3-dicarbonylcompounds. β-Keto enol ethers were obtained when cyclic1,3-dicarbonylcompounds used in this conditions instead of linear ones. The present methodology offers a practical, simple, mild, environmentally friendly, and time-saving method for etherification. Very low loading of catalyst, ease of workup, ease of handling, and reusability of catalyst are other advantages of