Mechanisms for Manganese(III) Osidations with Alkenes

Article abstract of DOI:10.1016/S0040-4020(01)87310-5

In the reaction of manganese(III) acetate with carboxylic acids and alkenes, three distinct processes have been identified which involve the alkene and two processes which are independent of alkene.A combination of product studies, rearrangements, dilution experiments and literature kinetic data allow the proposal of a unified mechanistic picture to describe these processes.Specifically, the role of α-H acidity of the carboxylyic acid component, electron deficient radical additions, metal complexed organic radicals, and the importance of an oxo-centered manganese(III) triangle are discussed as they relate to the lactone annulation reaction.Single electron transfer oxidation of alkenes is described as a route toward 1,2-diacetates of alkenes within the 8.1-7.5 eV I.P. range.Three less common modes of Mn(III) reaction are discussed and compared with the two primary processes of lactone annulation and 1,2-diacetate formation.