Stereoselective Copolymerization of Butadiene and Functionalized 1,3-Dienes

[(Mesitylene)nickel(allyl)(+)][BArF4-] (Ni-1) catalyzes the 1,4-cis selective copolymerization of isoprene and 1,3-butadiene with 15 (RO)(3)Si-, R2N-, RSO2-, RSO2NH-, and (RO)(2)B-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)(3)Si(CH2)(3)C(=CH2)CH=CH2 (1), PhS(O)(2)(CH2)(3)C(=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.