Inverting Conventional Chemoselectivity in Pd-Catalyzed Amine Arylations with Multiply Halogenated Pyridines.

A new catalyst system capable of selective chloride functionalization in the Pd-catalyzed amination of 3,2- and 5,2- Br/Cl-pyridines is reported. A reaction optimization strategy employing ligand parametrization led to the identification of 1,1'-bis[bis(dimethylamino)phosphino]ferrocene "DMAPF", a readily available yet previously unutilized diphosphine, as a uniquely effective ligand for this transformation.