Copper(I)-Catalyzed Asymmetric Interrupted Kinugasa Reaction: Synthesis of α-Thiofunctional Chiral β-Lactams.

A copper(I)-catalyzed asymmetric, three-component interrupted Kinugasa reaction has been developed. Diverse chiral sulfur-containing chiral β-lactams with two consecutive stereogenic centers were synthesized in one step from readily available starting materials in good yields and with excellent diastereo- and enantioselectivity. The key is the interception of in situ formed chiral four membered copper(I) enolate intermediate with sulfur electrophiles.