Ruthenium tetraoxide mediated reactions: The mechanisms of oxidations of hydrocarbons and ethers

The reaction mechanisms for the RuO4-mediated oxidations of saturated hydrocarbons and of ethers were investigated. For both groups of compounds the kinetic influence of the reaction medium and of substituents near the reaction centre was determined together with deuterium isotope effects. The results do not support reaction mechanisms with carbocation intermediates. Reactions by radical pair intermediates are only possible if these collapse at rates faster than 108 s−1. For the oxidation of hydrocarbons the data fit a two step mechanism, a pre-equilibrium followed by a rate-determining concerted reaction. The results from the oxidation of ethers can be explained by a concerted, SE2-like type of reaction.