Transition metals tungsten trioxide

Transition metal catalysts not only increase the reaction rate but may also affect the outcome of the oxidation, especially the stereochemistry of the products. Whereas hydrogen peroxide alone in acetonitrile oxidizes alkenes to epoxides [729], osmic acid catalyzes syn hydroxylation [736], and tungstic acid catalyzes anti hydroxylation [737]. The most frequently used catalysts are titanium trichloride [732], vanadium pentoxide [733,134], sodium vanadate [735], selenium dioxide [725], chromium trioxide [134], ammonium molybdate [736], tungsten trioxide [737], tungstic acid [737],... [Pg.7]

J. W. Johnson, A. J. Jacobson, S. M. Rich, and J. F. Brody, New layered compounds with transition-metal oxide separated by covalently bound organic ligands. Molybdenum and tungsten trioxide-pyridine, J. Am. Chem. Soc., 103, 5246-5247 (1981). [Pg.284]