Palladium-Catalyzed Aerobic Oxidative Cyclization of N-Aryl Imines: Indole Synthesis from Anilines and Ketones

We report here an operationally simple, palladium-catalyzed cyclization reaction of N-aryl imines, affording indoles via the oxidative linkage of two C-H bonds under mild conditions using molecular oxygen as the sole oxidant. The process allows quick and atom-economical assembly of indole rings from inexpensive and readily available anilines and ketones and tolerates a broad range of functional groups.