Oxidative nucleophilic substitution of hydrogen in nitroarenes by silyl enol ethers

Abstract

Enolates generated by treatment of silyl ketene acetals and enol ethers with fluoride ion sources add to nitroarenes to produce σ H adducts that oxidize either with KMnO 4 to give substituted nitroarenes or with dimethyldioxirane to give substituted phenols. In the latter case the oxidation results in replacement of the nitro group with a hydroxy group. It was shown that high effectiveness of these reactions is not due to stabilization of the σ H adducts via O-silylation but due to the nature of the accompanying cation.