A very mild, catalytic and versatile procedure for α-oxidation of ketone silyl enol ethers using (salen)manganese(III) complexes; a new, chiral complex giving asymmetric induction. A possible model for selective biochemical oxidative reactions through enol formation

Abstract

Facile, catalytic, selective (racemic and asymmetric) oxidation of ketone silyl enol ethers to give α-oxygenated products proceeds well under very mild, aprotic conditions using a racemic (salen)manganese(III) complex [H₂salen = bis(salicylidene)ethylenediamine] or a new, chiral C₂-symmetric pyrrolidine-based manganese(III) complex as catalyst, with iodosobenzene as the terminal oxidant at ambient temperature.