Umpolung Reaction of α-Imino Thioesters and the Subsequent C-C Bond Formation with the Unexpected Alkylthio Rearrangement
An umpolung reaction of the α-imino thioester was examined, and we found that α-imino thioesters were more effective substrates for the umpolung N-alkylation than conventional α-imino esters and they gave N-alkylated amino thioesters in high yields under mild reaction conditions in a short time. A new type of C-C bond formation followed by an unexpected rearrangement of the alkylthio group took place with the unsaturated ketones to afford the β-alkylthio-α-amino thioesters in high yields with good diastereoselectivity.
On the thermal Pummerer rearrangement of substituted sulfoxides
Sulfoxides bearing thioester and ester groups at the position under heating at ca. 140C undergo Pummerer thermal rearrangement. However, for sulfonyl sulfoxide, a complex mixture of products is formed. Plausible mechanism is advanced(equation presented. 2013