Copper‐Catalyzed γ‐C(sp ³ )−H Lactamization and Iminolactonization

Abstract Despite extensive efforts to develop γ‐lactamization reactions for pyrrolidinone synthesis using either cyclometallation, C−H insertion, or radical C−H abstraction strategies, γ‐lactamization reactions of aliphatic amides using practical catalysts and common protecting groups remain extremely rare. Herein we report copper‐catalyzed γ‐C(sp 3 )−H lactamization and iminolactonization of tosyl‐protected aliphatic amides using inexpensive Selectfluor as the sole oxidant. A switchable selectivity of γ‐lactams or γ‐iminolactones can be obtained by using two different sets of reaction conditions. Notably, structurally diverse spiro‐, fused‐, and bridged‐lactams and iminolactones, as well as isoindolinones are accessible by this method. Further derivatization of the γ‐lactam products enables the synthesis of a range of biologically important motifs, including γ‐amino acids, δ‐amino alcohols, and pyrrolidines.