MULTIPLE BONDS BETWEEN ATOMS OF MAIN GROUP ELEMENTS AND TRANSITION-METALS .108. STOICHIOMETRIC AND CATALYTIC-OXIDATION OF ELECTRON-POOR OLEFINS WITH OSMIUM TETRAOXIDE - A NOVEL OXIDATION METHOD FOR FLUOROOLEFINS

In contrast to current opinion, osmium tetraoxide reacts even with very electron-poor olefins. For example, both partially and fully fluorinated osmate(VI)esters 2 are thus formed from fluoroolefins 1 by cycloaddition. Hydrolysis of the osmate(VI) esters leads to the corresponding 1,2-diols 3 and, eventually, consecutive fluoroorganic products by HF elimination. A catalytic version of this route opens a new, general, and efficient entry to oxidation products in fluoroolefin chemistry. Tetrahalide ethylene derivatives of formula py2O2Os(OCX2CX2O) (X = Cl, F) split off oxalyl halide upon thermal treatment with the complexes py2O2OsX2 thus being formed in good yields.