Migration of hydrogen from metal to alkene promoted by dioxygen addition. Oxygen atom transfer from a cis-(alkyl)(η2-dioxygen) complex of rhodium to organic and inorganic substrates

The novel cis-(σ-alkyl)(η2-O2) complexes of rhodium [(THF)(EtOH)Naμ-EtOH2μ-(CO2R)CH2CH(CO2R)Rh(η2-O2)(triphos)2Na(EtOH)(THF)][BPh4]2·2EtOH (R = Me,3; Et,4) have been synthesized by reaction of dioxygen with the hydrides (triphos)(RhH(η2-alkene) followed by NaBPh4 addition (alkene = dimethyl fumarate,1; diethyl fumarate,2) (triphos = MeC(CH2PPh2)3). The structure of4 has been determined by X-ray diffraction. Oxygen atom transfer reactions from the η2-O2 complexes to various inorganic and organic substrates have been studied.