Recent Advances in the Synthesis of Indolines via Dearomative Annulation of N‐acylindoles

Abstract Polycyclic fused indoline derivatives, specifically those bearing tertiary or quaternary carbon stereocenters at C2 and C3 positions, stand as an important class of nitrogen‐containing heterocyclic compounds because they are frequently occurring core structures in a wide variety of alkaloid natural products, pharmaceutical molecules, and functional materials. Over the past few decades, the development of new and versatile synthetic approaches for the construction of indolines has been the focus of a great deal of research initiatives. In this review, recent advances in the dearomative annulation of N‐ acylindoles with diverse nucleophiles are summarized since 2012, which could be divided into five categories: 1) Dearomative Heck reactions of N‐ acylindoles; 2) Visible‐light‐induced reductive dearomatization of N‐ acylindoles; 3) Lewis acid‐catalyzed dearomative reductive reactions of N‐ acylindoles; 4) Asymmetric dearomative Heck reactions of N‐ acylindoles; 5) Dearomative Heck reactions by other closely related N‐ acylindoles reagents.