Steric promotion of aromatic C-H bond activation in primary benzylamines

ortho-Palladation of a sterically crowded primary benzylamine, alpha-phenyl neopentylamine, was accomplished in a moderate yield of 50% in the reaction with the weakest of palladation agents (Li2PdCl4) under very mild conditio ns, due to a steric promotion of an aromatic C-H bond activation. The struc ture of dimer 1a thus formed and the palladacycle conformation were establi shed on the basis of H-1-NMR spectroscopy of its mononuclear derivatives wi th [D-5]pyridine (3a) and triphenylphosphane (4a), and an X-ray investigati on of the latter.