Oxygen-promoted C-H bond activation at palladium

[Pd(P(Ar)(tBu)2)2] (1, Ar=naphthyl) reacts with molecular oxygen to form PdII hydroxide dimers in which the naphthyl ring is cyclometalated and one equivalent of phosphine per palladium atom is released. This reaction involves the cleavage of both CH and OO bonds, two transformations central to catalytic aerobic oxidizations of hydrocarbons. Observations at low temperature suggest the initial formation of a superoxo complex, which then generates a peroxo complex prior to the CH activation step. A transition state for energetically viable CH activation across a Pdperoxo bond was located computationally.