Synthesis, characterization, and applications of novel di-2-pyridyl imine ligands

Two novel di-2-pyridyl imines, 2,4,6-trimethyl-(di-2-pyridylmethylene)aniline (1) and 2,6-di-isopropyl-(di-2-pyridylmethylene)aniline (2), were prepared through condensation reactions between 2,2′-dipyridyl ketone and 2,4,6-trimethylaniline and 2,6-di-isopropylaniline. They reacted readily with bis(benzonitrile)dichloropalladium(II) to afford palladium imine complexes. The crystal structure of the palladium complex (3) bearing the 2,4,6-trimethyl-(di-2-pyridylmethylene)aniline ligand revealed coordination of a pyridyl group and an imine group to the metal center. The novel ligands were successfully employed in the Suzuki coupling reaction of p-bromoanisole and phenylboronic acid.