Nucleophilic attack at pyridine nitrogen and its use to access a novel mono-anionic ligand for iron-based ethylene polymerisation catalysts.

Addition of MeLi to bis(imino)pyridines results in an unprecedented nucleophilic attack at pyridine nitrogen to afford novel mono-anionic [N,N,N] ligands: their treatment with FeCl3, followed by MAO activation, affords highly active ethylene polymerisation catalysts.