Access to Functionalized Pyridoindolones Enabled by Rh(III)‐Catalyzed C─H Alkenylation/Cyclization of Indoles with Alkynes

Herein, we report a traceless directing group assisted Rh(III)‐catalyzed C─H cyclization cascade of indoles and (arylprop‐2‐yn‐1‐yl)malonates under redox‐free reaction conditions, thus providing a concise access to structurally diverse functionalized pyridoindolones. This transformation proceed smoothly with a tolerance of various functional groups and moderate to good efficiencies. In addition, the practical and stereoselective construction of 2‐alkenylated NH‐indole scaffold could be accomplished within 30 min by utilizing simple aromatic alkynes. Furthermore, the synthetic value of this strategy was demonstrated by the readily accessible and divergent transformations of products. A preliminary mechanism was also proposed based on a series of deuterating and control experiments.