Rh(III)‐Catalyzed [4+2] Cascade Annulation of chromene‐2‐Carboxamides With Alkynes: Direct Access to Chromeno[2,3‐ c ]pyridine‐1,5‐Dione Derivatives

We herein report a Rh(III)‐catalyzed [4+2] cascade annulation reaction between chromene‐2‐carboxamides and alkynes. This protocol allows for the efficient synthesis of a broad range of chromeno[2,3‐ c ]pyridine‐1,5‐dione derivatives. The transformation is initiated by site‐selective C(sp 2 )─H bond activation, followed by a sequential cyclization process. In one pot, new C─C and C─N bonds are constructed accompanied by the cleavage of one C─O bond, thus achieving excellent atom and step economy. This transformation features mild conditions and broad functional group compatibility. Furthermore, this work provides a practical synthetic route to the valuable chromeno[2,3‐ c ]pyridine fused scaffold, which exhibits promising application potential in pharmaceutical chemistry.