Transition-Metal-Catalyzed Direct C-H Functionalization under External-Oxidant-Free Conditions.

The use of an 'internal' oxidant contained within a directing group has emerged as a practical strategy in metal-catalyzed direct C-H activations in recent years, owing to its being highly sustainable. This review presents the rapid advances of this novel strategy through analyzing and comparing the different types of internal oxidant in transition-metal-catalyzed C-H activation reactions. [ABSTRACT FROM AUTHOR]