Multiple bonds between transition metals and main-group elements .161. Oxygen-donor adducts of organorhenium(VII) oxides: Syntheses, structures and catalytic properties

N-Oxide adducts of methyltrioxorhenium(VII) (1) are characterized and their catalytic properties in the epoxidation of olefins with hydrogen peroxide are examined. The crystal structure of one of these derivatives is described. Whereas aliphatic N-oxides form temperature-sensitive adducts with 1 and are inactive in the catalytic epoxidation of olefins, aromatic N-oxides adducts of 1 are both stable and catalytically active. The latter complexes show lower activity than 1, but in some cases the selectivity is even higher than that of the N-base adducts of 1. The catalytic active species are of similar type in all examined cases. The structure of the ore-functionalized complex [O3Re(CH2)(2)CH(CH3)OCH3] as well as its catalytic properties in the olefin epoxidation with hydrogen peroxide are reported. The deactivation process of this catalyst is also examined.