Direct carbon-carbon bond formation via reductive soft enolization: a syn-selective Mannich addition of α-iodo thioesters.

The ß-amino carboxylic acid moiety is a key feature of numerous important biologically active compounds. We describe a syn-selective direct Mannich addition reaction that uses α-iodo thioesters and sulfonyl imines and produces ß-amino thioesters. Enolate formation is achieved by reductive soft enolization. The products of the reaction provide straightforward access to biologically important ß-lactams through a variety of known reactions.