Palladium‐Catalyzed Intermolecular Alkenylation of Indoles by Solvent‐Controlled Regioselective CH Functionalization

Either the C2- or the C3-substituted product can be obtained with the same palladium(II) catalyst in an oxidative intermolecular alkenylation of indoles. A variety of conditions can be used for derivatization at the 3-position; however, the presence of acetic acid is required for the C2-selective process (see scheme). Further elaboration of the products by a similar CH functionalization process leads to the bisalkenylated indoles selectively.