Synthesis of Hafnium and Zirconium Imino−Amido Complexes from Bis-imine Ligands. A New Family of Olefin Polymerization Catalysts

The reaction of 2,6-diisopropylaniline-based bis-imine ligands (4, 9) with M(CH2Ph)(4) (M = Hf, Zr) led to formation of novel imino-amido tribenzyl complexes via migratory insertion of a benzyl group into a C = N bond. Imino-amido complexes were found to undergo unprecedented dibenzyl elimination to form ene-diamido complexes. Imino-amido complexes were found to be active ethylene polymerization catalysts.