Electrophilic Metal Precursors and a β-Diimine Ligand for Nickel(II)- and Palladium(II)-Catalyzed Ethylene Polymerization

The α-diimine ligand ArN C(Me)C(Me) NAr (Ar = 2,6-C 6 H 3 - i Pr 2 ) reacts with Pd(OAc) 2 in the presence of HBF 4 ·Et 2 O, or Pd(MeCN) 4 (BF 4 ) 2 in the absence of acid, to give ethylene polymerization catalysts. The reactions of a related β-diimine ligand with Pd(MeCN) 4 (BF 4 ) 2 and (1,2-dimethoxyethane)NiBr 2, and the polymerization activity of catalysts derived from it, are discussed.