Mechanistic studies on reaction of [ReH4(η2-H2)(Cyttp)]+ with ketones to give the hydrido-oxo complex [ReH2(O)(Cyttp)]+ (Cyttp = PhP(CH2CH2CH2PCy2)2)

Reaction of [ReH4(η2-H2)(Cyttp)]OTf with ketones (R2CO) yields [ReH2(O)(Cyttp)]OTf and 2 equiv. of the alcohol R2CHOH. On the basis of analysis of the gas evolved and various organic products formed, as well as from isotopic labeling experiments, a mechanism is proposed which involves (a) reduction of rhenium(V) to rhenium(III) and conversion of 1 equiv. of ketone to alcohol by hydride ligands, and (b) reoxidation of rhenium(III) to rhenium(V) and conversion of another equivalent of ketone to alcohol by hydrogen originating from the ketonic R groups.