Nitro-Mannich/lactamization cascades for the direct stereoselective synthesis of pyrrolidin-2-ones.

An efficient three-component nitro-Mannich/lactamization cascade of methyl 3-nitropropanoate with in situ formed acyclic imines for the direct preparation of pyrrolidinone derivatives has been developed. The reaction is easy to perform, broad in scope, and highly diastereoselective and may be extended to cyclic imines allowing the direct formation of polycyclic pyrrolidinone derivatives.