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 PhICl 2 and N -chlorosuccinimide with Pd II (phpy) 2 (phpy = 2-phenylpyridine) to afford the novel Pd IV oxidative addition products Pd IV (phpy) 2 (Cl) 2 and Pd IV (phpy) 2 (Cl)(succinimide), respectively. These Pd IV 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 Pd II/IV mechanism in Pd-catalyzed halogenation reactions.