MANGANESE(III) MEDIATED REACTIONS OF UNSATURATED SYSTEMS

Manganese(III) mediated reactions of unsaturated systems with carbonyl compounds are discussed in this review which focuses mainly on public ations of the last decade. The process on the whole is highly selectiv e both at the initiation and functionalization steps. Manganese(III) a cetate generates alpha-oxo- and alpha,alpha-dioxoalkyl radicals by reg ioselective oxidation of carbonyl compounds, such as, aldehydes, keton es, acids, diketones, keto esters, and diesters. The functionalization step, which consists of the introduction of alpha-oxo- and alpha,alph a-dioxoalkyl moieties into multiple bond containing substrates, occurs in most cases with high regio-, chemo- and stereoselectivities. The e xtensive exploration of this field has uncovered its huge synthetic po tential and resulted in numerous novel approaches to different classes of organic compounds. Both inter- and intramolecular versions are dis cussed, including for the latter mono and tandem cyclizations. The fir st successful examples of the syntheses of natural products having div erse biological activity complete the discussion to demonstrate the ma turity of the field and its excellent prospects.