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.