Asymmetric Palladium‐Catalyzed Dearomative Intramolecular N‐Alkylation Reaction: Enantioselective Total Synthesis of (−)‐Spiroquinazoline

Abstract Tricyclic imidazo[1,2‐a]‐indol‐3‐ones have been found in several classes of alkaloids. We report here an asymmetric approach to instal substituted imidazo[1,2‐a]‐indol‐3‐ones, which relied on a Pd/diamidophosphite‐catalyzed intramolecular dearomative allylic substitution of 1,3‐disubstituted indoles derived from 3‐formylindoles and amino acids. Enantioselective total syntheses of (−)‐spiroquinazoline and three related alkaloids were achieved.