Palladium(II)-Catalyzed Remote meta-C-H Functionalization of Aromatic Tertiary Amines.

Pd(II)-catalyzed remote C-H olefination of aromatic tertiary amines was achieved with high meta selectivity. With the assistance of an elaborated template, C-H functionalization of unreactive aryl tertiary amines, hindered by the p-π conjugation between the lone-pair electrons of the nitrogen atom and the phenyl ring, was realized with high meta regioselectivity via a quaternary ammonium salt assembly. The results demonstrate that apart from the distance and geometry of the template, the conformation of the arene substrate also plays a crucial role in the templated-assisted remote C-H functionalization.