A Transition State Analogue for the Oxidation of Binuclear Palladium(II) to Binuclear Palladium(III) Complexes

Cooperative
metal–metal (M–M) redox chemistry has
the potential to lower activation barriers for redox transformations
relevant to catalysis. Pd2(III,III) complexes, generated
by oxidation of Pd2(II,II) complexes, have recently been
implicated as intermediates in a variety of Pd-catalyzed C–H
oxidation reactions. M–M redox synergy, mediated by Pd–Pd
bond formation and cleavage, has been proposed to facilitate both
oxidation and reductive elimination steps during various Pd-catalyzed
directed C–H oxidation reactions. Herein, we report a transition
state mimic for the oxidation of Pd2(II,II) complexes which
suggests that M–M redox synergy is involved in the oxidation
of Pd2(II,II) complexes to Pd2(III,III) complexes.