Palladium/Norbornene Catalytic System: Chelation as a Tool To Control Regioselectivity of Pd(IV) Reductive Elimination

Palladium/norbomene joint catalysis gives rise to a unique system in which the three most common formal oxidation states of the metal are at work in the same cycle (0, II, and IV). This paper summarizes a selection of synthetic applications and the feasibility of Pd(IV) formation by oxidative addition of aryl halides. On this intermediate, the presence of a suitable chelating group could trigger unexpected aryl-norbornyl coupling, further broadening the scope of readily available polycyclic frameworks.