Stereoselective Copolymerization of Butadiene and Functionalized 1,3-Dienes

[(Mesitylene)­nickel­(allyl)⁺]­[BAr^F₄^–] (Ni-1) catalyzes the 1,4-cis selective copolymerization of isoprene and 1,3-butadiene with 15 (RO)₃Si-, R₂N-, RSO₂-, RSO₂NH-, and (RO)₂B-functionalized 1,3-dienes. Incorporation of the functionalized 1,3-diene occurs very efficiently with high comonomer conversions, as observed, for example, for copolymerizations of 1,3-butadiene with (EtO)₃Si­(CH₂)₃C­(CH₂)­CHCH₂ (1), PhS­(O)₂(CH₂)₃C­(CH₂)–CHCH₂ (7), or (pinB)­C­(CH₂)­C­(CH₃)CH₂ (15), while copolymerization rates vary from strongly to slightly decreased when compared to butadiene homopolymerizations.