An efficient catalytic route for the preparation of silyl ethers using alumina-supported heteropolyoxometalates

PAULA VILLABRILLE; GUSTAVO ROMANELLI; NANCY QUARANTA; PATRICIA VÁZQUEZ

APPLIED CATALYSIS B-ENVIRONMENTAL

Elsevier Science B.V.

Lugar: Amsterdam; Año: 2010 vol. 96 p. 379 - 386

0926-3373

In the present work the phenol trimethylsilylation with hexamethyldisilazane using molybdophosphovanadatessupported on commercial alumina cylinders as catalysts was studied. These catalysts wereprepared by incipient wetness impregnation also including Fe and Cu as cations, which can be presentas bulk heteropolyacids or in the previously impregnated support. These solids were characterized byseveral techniques such as diffuse reflectance spectroscopy, Fourier transformed infrared spectroscopy,optical and scanning electron microscopies, and X-ray diffraction, among others.The catalytic test was performed under different reaction conditions in order to know the performanceof the synthesized catalysts. The method shows high conversion of phenol under heterogeneous conditions.Phenol trimethylsilyl ether formation was obtained using hexamethyldisilazane as acylating agentand toluene as reaction solvent, with different reuses. In addition, they are environmentally friendlymaterials. The H2PMo11VCuO40 supported on alumina showed higher activity in the tested reaction.Finally, various alcohols and phenols were silylated to trimethylsilyl ethers, under mild conditions, andexcellent yields were obtained.