Stereo- and Regioselectivity of Reactions of Siliranes with Aldehydes and Related Substrates

Silylene transfer to allylic sulfides: formation of substituted silacyclobutanes

Silylene transfer to allylic sulfides results in a formal 1,2-sulfide migration. The rearrangement yields substituted silacyclobutanes, not the expected silacyclopropanes. The silacyclobutanes were elaborated by insertions of carbonyl compounds selectively into one carbon-silicon bond. A mechanism for the 1,2-sulfide migration is proposed involving an episulfonium ion intermediate.

Dearomatization reactions of aryl-substituted silaaziridines

Silaaziridines with an aryl group on either the carbon or the nitrogen atom undergo dearomatization reactions upon treatment with benzaldehyde. The reactions form new bonds ortho to the nitrogen substituents with high diastereoselectivity. These dearomatization processes likely are driven by relief of the considerable ring strain of the silaaziridine.