Regio- and Stereoselective Synthesis of Polysubstituted γ-Lactams Enabled by Photocatalyzed Sequential Radical Aminoalkylation of MBH Acetates

A visible-light photocatalytic method is reported for the regio- and stereoselective synthesis of polysubstituted γ-lactams from N-arylglycines and Morita-Baylis-Hillman (MBH) acetates. The reaction proceeds through sequential radical aminoalkylation of the dual electrophilic MBH acetate by photogenerated α-aminoalkyl radicals, forming a key γ,γ'-diaminobutyl ester intermediate that undergoes regioselective lactamization. This strategy provides a mild and efficient route to privileged γ-lactam scaffolds, demonstrating the rational integration of two versatile synthons in cascade reactions.