Epoxidation reactions of carbonyl compounds (aldehydes and a ketone) mediated by sulfanyl ferrocenes have been successfully achieved in a one-pot reaction, under mild conditions. This reaction implies intermediary formation of a sulfonium salt (a ferrocenyl one was observed for the first time by 1H NMR) and then an ylide. The diastereoselectivity of the formation of stilbene oxide was unusual: the effect of steric hindrance and aromatic nature of the sulfide substituents have been evidenced. A catalytic asymmetric example with a planar chiral ferrocene is described.
sulfur - ylides - epoxidations - aldehydes - ferrocene - stereoselectivity
