Iridium-Catalyzed Cross-Coupling Reactions of Alkenes by Hydrogen Transfer.

A range of Ru-, Rh-, or Pd-catalyzed vinylic C-H/C-H cross-coupling reactions of olefins have been demonstrated to provide 1,3-dienes, using a quantitative amount of metal oxidants. Although transfer hydrogenation and C-H alkenylation are two important areas that evolved independently, we herein report the first iridium-catalyzed cross-coupling reactions of alkenes by integration of directed C(alkenyl)-H alkenylation and transfer hydrogenation to obviate the usage of a metal oxidant, employing a hydrogen acceptor such as inexpensive chloranil.