Oxygen atom transfer saturated hydrocarbon oxidation

Ruthenium(in) catalyses the oxidative decarboxylation of n-butyric acid and isobutyric acid by ceric sulfate in aqueous acid. A mechanism for the Ru(III)-catalysed oxidation of o-hydroxybenzoic acid by an acidic solution of bromamine-B (PhS02-NNaBr, BAB) has been proposed based on a kinetic smdy. An ionic mechanism is suggested for the ruthenium(III) analogue of the Udenfriend-type system Ru(III)-EDTA-ascorbate-02, for the selective oxygen-atom transfer to saturated and unsaturated hydrocarbons. The kinetics of the oxidation of p-XC6H4CHPhOH(X =... 

Work in this laboratory has shown also that the Ru(poip)(0)2 complexes (porp = TMP, TDCPP, and TDCPP-Clg) are practically inactive for thermal 02-oxygenation of saturated hydrocarbons . Some activity data for 0.2 mM Ru solutions in benzene under air at 25°C for optimum substrates such as adamantane and triphenylmethane at 6 mM did show selective formation of 1-adamantol and trityl alcohol, respectively, but with turnover numbers of only -0.2 per day the maximum turnover realized was -15 after 40 days for the TDCPP system Nevertheless, this was a non-radical catalytic processes there was < 10% decomposition of the Ru(TDCPP)(0)2, and a genuine O-atom transfer process was envisaged . Quite remarkably (and as mentioned briefly in Section 3.3), at the much lower concentration of 0.05 mM, Ru(TDCPP-Clg)(0)2 in neat cyclooctene gave effective oxidation. For example, at 90°C under 1 atm O2, an essentially linear oxidation rate over 55 h gave about -70% conversion of the olefin with - 80% selectivity to the epoxide however, the system was completely bleached after - 20 h and, as the activity was completely inhibited by addition of the radical inhibitor BHT, the catalysis is operating by a radical process, but in any case the conversion corresponds to a turnover of 110,000 As in related Fe(porp) systems (Section 3.3, ref. 121), the Ru(porp) species are considered to be very effective catalysts for the decomposition of hydroperoxides (eqs. 

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