Catalytic Enantioselective Synthesis of β‐Lactams: Intramolecular Kinugasa Reactions and Interception of an Intermediate in the Reaction Cascade

A planar-chiral Cu/phosphaferrocene–oxazoline catalyst mediates intramolecular Kinugasa reactions to give tricyclic β-lactams with good enantioselectivity. A variant of the process, in which a postulated enolate intermediate is intercepted with an electrophile in a transformation that generates two CC bonds, a CN bond, two new rings, a carbonyl group, and adjacent tertiary and quaternary stereocenters (see scheme), supports the proposed mechanism.