Ring‐Opening Metathesis Polymerization of Nitrile Substituted cis‐Cyclooctenes

New nitrile-containing polymers have been synthesized by ring-opening metathesis polymerization of cis-cyanocyclooct-4-ene and cis-1,2-dicyanocyclooct-5-ene with a 2(nd) generation Grubbs catalyst [(H(2) IMes)(PCy(3) )Cl(2) Ru = CHPh] (H(2) IMes = N,N'-bis(mesityl)-4,5-dihydroimidazol-2-ylidene). With increasing content of nitrile moieties on the cyclooctene ring the reaction rates decrease from cis-cyclooctene to cis-cyanocyclooct-4-ene and cis-1,2-dicyanocyclooct-5-ene. Contrary to commercially available nitrile rubbers (unhydrogenated and hydrogenated butadiene/acrylonitrile copolymers) in which double bonds, nitrile moieties, and methylene bridges are randomly distributed along the main chain, the new polymers show a regular distribution of structural entities.