C–H Activation at a Bidentate Ligand Coordinated to Palladium(II) – an Electrophilic Attack Supported by an External Base

2-(2-Phenylaminopyrimidin-4-yl)pyridines undergo C-H activation at the phenyl ring in the ortho position to the amine nitrogen atom when reacted with (PhCN)2PdCl2 and finally form N,N,C-coordinated palladium(II) complexes in high yields. Five differently substituted complexes were synthesized and characterized by spectroscopy and X-ray structure analysis. The reaction mechanism for the formation of these complexes was elucidated by kinetic experiments, which allowed the calculation of the activation parameters of the complex formation.