Re‐Catalyzed Annulations of Weakly Coordinating N ‐Carbamoyl Indoles/Indolines with Alkynes via C−H/C−N Bond Cleavage

Described herein are rhenium‐catalyzed [3+2] annulations of N ‐carbamoyl indoles with alkynes via C−H/C−N bond cleavage, which provide rapid access to fused‐ring pyrroloindolone derivatives. For the first time, the weakly coordinating O‐directing group was successfully employed in rhenium‐catalyzed C−H activation reactions, enabled by the unique catalytic trio of Re 2 (CO) 10 , Me 2 Zn and ZnCl 2 . Mechanistic studies revealed that aminozinc species plays an important role in the reaction. Based on the mechanistic understanding, a more powerful catalytic trio of Re 2 (CO) 10 , [MeZnNPh 2 ] 2 and Zn(OTf) 2 was devised and applied successfully in the [4+2] annulations of indolines and alkynes affording pyrroloquinolinone derivatives.