Palladium-Catalyzed Carbonylative Sonogashira/Annulation Reaction: Synthesis of Indolo[1,2‑b]isoquinolines

A palladium-catalyzed carbonylative Sonogashira/annulation reaction for the synthesis of indolo­[1,2-b]­isoquinolines has been developed. Tetracyclic 6/5/6/6 indoline skeletons were synthesized in moderate to good yields from easily available 2-bromo-N-(2-iodophenyl)­benzamides and terminal alkynes. Notably, this efficient methodology established three C–C bonds and a C–N bond through a one-step transformation and provided a new method for the synthesis of indolo­[1,2-b]­isoquinoline derivatives.