Rhodium‐Catalyzed Direct C—H Alkenylation of Indoles with Alkenyl Borates

Main observation and conclusion A new Rh(III)‐catalyzed direct C—H alkenylation of 2,3‐unsubstitued indoles with alkenyl borates through C—H activation followed by transmetallation was described. This protocol provides an efficient method for the synthesis of terminal C2‐alkenylindoles under mild conditions, and also shows broad substrate scope and high functional group tolerance with respect to both components. Furthermore, the C2‐alkenylated indole can be easily transformed into carboline derivative, which is an important polycyclic indole moiety in natural products and drug molecules.