Selective ammoximation of ketones and aldehydes catalyzed by a trivanadium-substituted polyoxometalate with H2O2 and ammonia

The ammoximation of different ketones and aldehydes to their corresponding oximes catalyzed by K-6[PW9V3O40]center dot 4H(2)O was carried out with hydrogen peroxide and ammonia in isopropanol at room temperature. High yields of oximes were obtained in this catalytic system. This catalytic system was proved to be heterogeneous by the ammoximation activity of removal of catalyst and the elemental analysis of the filtrate after reaction. A possible procedure for the ammoximation catalyzed by K6[PW9V3O40]center dot 4H(2)O with H2O2 and NH3 center dot H2O was proposed. The fresh and used catalysts were characterized by IR and P-31 MAS NMR, which revealed the good stability of the catalyst. (C) 2012 Elsevier B.V. All rights reserved.