Palladium/Norbornene Catalyzed ortho Amination/Cyclization of Aryl Iodide: Process to 3-Methyl-indole Derivates and Controllable Reductive Elimination against the Second Amination.

A palladium/norbornene cooperative catalyzed selective C-H bond amination of aryl iodides was explored, providing an efficient tool for constructing benzocyclic molecules. When ortho-substituted iodobenzene was involved, the C-H bond amination and following Heck cyclization efficiently delivered a 3-methyl-indole scaffold. On the other hand, we realized the controllable synthesis of monoaminated benzo-cyclobutanyl scaffold. The possible coordination of an installed terminal alkenyl group with palladium and steric hindrance were proposed to be responsible for the monoamination selectivity.