Ligand‐Controlled Palladium(II)‐Catalyzed Regiodivergent Carbonylation of Alkynes: Syntheses of Indolo[3,2‐ c ]coumarins and Benzofuro[3,2‐ c ]quinolinones

Regiodivergent syntheses of indolo[3,2‐ c ]coumarins and benzofuro[3,2‐ c ]quinolinones through a controllable palladium(II)‐catalyzed carbonylative cyclization are established. The chemo‐ and regioselectivity are exclusively tuned by the ligand on the palladium catalyst. The rigid framework of the electron‐deficient ligand promotes the O‐attack/N‐carbonylation cyclization leading to benzofuro[3,2‐ c ]quinolinones, while a sterically bulky and electron‐rich ligand facilitates N‐attack/O‐carbonylation cyclization to generate indolo[3,2‐ c ]coumarins. Furthermore, various other nucleophiles are applicable for delivering a variety of indoloquinolinones, pyranoquinolones, and chromeno[3,4‐c]quinolinones in one step, and serves as a method for creating compound libraries for drug discovery.