Acetylation and oxygenation transformations catalyzed by silica-supported dodecatungstophosphoric acid

Abstract

Acetylation of alcohols in refluxing ethyl acetate, and oxidation of aniline and cyclohexanol with 34 % H₂O₂ in the presence of H₃PW₁₂O₄₀ and its supported forms on SiO₂ (20 %, 40 %, and 60 % by weight) as active solid acid catalysts were performed under mild reaction conditions with moderate to good yields and with 100 % selectivity. It is found that the supported H₃PW₁₂O₄₀ was in general 1.4-2.3 times more efficient than the unsupported catalyst in the acetylation and oxygenation reactions. Easy work-up and effective recycling of the heterogeneous catalyst were distinct advantages of the catalytic heterogeneous system.

KEY WORDS: Acetylation, Oxygenation, Dodecatungstophosphoric acid, Heterogeneous, Silica support

Bull. Chem. Soc. Ethiop. 2006, 20(2), 329-334.