Gold(I)-Catalyzed Tandem Cyclization Approach to Tetracyclic Indolines

Two highly stereoselective cationic gold(I)-catalyzed tandem cyclization reactions of alkynylindoles are described. These reactions demonstrated a novel and general strategy to rapidly construct highly functionalized polycyclic indolines. This approach was successfully employed for a formal synthesis of the akuammiline alkaloid minfiensine.