Oxidative C−H Activation/C−C Bond Forming Reactions:  Synthetic Scope and Mechanistic Insights

This paper describes a new palladium-catalyzed method for C−H activation/carbon−carbon bond formation with hypervalent iodine arylating agents. This transformation has been applied to a variety of arene and benzylic substrates containing different directing groups (pyridines, quinolines, oxazolidinones, and amides) and proceeds with high levels of regiocontrol. Mechanistic experiments provide preliminary evidence in support of an unusual mechanism for this transformation involving a Pd(II)/Pd(IV) catalytic cycle.