Synthesis of Pyrido‐[2,1‐a]isoquinoline Derivatives via Gold(I)‐Catalyzed Intramolecular Cascade Reaction of Enamides

Abstract

A gold(I)‐catalyzed intramolecular cascade reaction of tertiary enamides has been developed, which provides a method for the preparation of diverse pyrido[2,1‐a]isoquinoline derivatives with good function group tolerance. Preliminary investigation of the reaction mechanism indicate that this process comprises a nucleophilic addition of the enamide to an alkynyl group, followed by the capture of the acyliminium ion by an electron‐rich aromatic component. Additionally, scale‐up experiments and further transformations of pyrido‐[2,1‐a]isoquinolines underscore the utility of this methodology.