Recent Progress in Enantioselective Synthesis of γ-Lactams Bearing Chiral α-Quaternary Carbons

The enantioselective construction of γ-lactams bearing chiral α-quaternary carbons represents a significant challenge in organic synthesis due to steric and stereoelectronic constraints. This Synpact highlights recent advances in two complementary strategies: (1) ring decoration of preformed γ-lactams via asymmetric functionalization, and (2) ring construction through transition metal-catalyzed carbonylative cyclization. Emphasis is placed on emerging methods utilizing inert C(O)–H/CN precursors, with a analysis of recent advances, current limitations and future directions.