Reactivity of Pd(II) Complexes with Electrophilic Chlorinating Reagents: Isolation of Pd(IV) Products and Observation of C−Cl Bond-Forming Reductive Elimination

This communication describes the reactions of PhICl2 and N-chlorosuccinimide with PdII(phpy)2 (phpy = 2-phenylpyridine) to afford the novel PdIV oxidative addition products PdIV(phpy)2(Cl)2 and PdIV(phpy)2(Cl)(succinimide), respectively. These PdIV species are remarkably stable at room temperature. However, upon thermolysis at 80 °C, they undergo competing C−Cl, C−C, and C−N bond-forming reductive elimination reactions. Both the accessibility and the observed reactivity of these complexes provide support for a PdII/IV mechanism in Pd-catalyzed halogenation reactions.