Bimetallic Coordination Insertion Polymerization of Unprotected Polar Monomers: Copolymerization of Amino Olefins and Ethylene by Dinickel Bisphenoxyiminato Catalysts

Dinickel bisphenoxyiminato
complexes based on highly substituted p- and m-terphenyl backbones were synthesized,
and the corresponding atropisomers were isolated. In the presence
of a phosphine scavenger, Ni­(COD)2, the phosphine-ligated syn-dinickel complexes copolymerized α-olefins and
ethylene in the presence of amines to afford 0.2–1.3% α-olefin
incorporation and copolymerized amino olefins and ethylene with a
similar range of incorporation (0.1–0.8%). The present rigid
catalysts provide a bimetallic strategy for insertion polymerization
of polar monomers without masking of the heteroatom group. The effects
of the catalyst structure on the reactivity were studied by comparisons
of the syn and anti atropisomers and the p- and m-terphenyl systems.