Neodymium based Ziegler-Natta systems catalyze the 1,4-cis selective copolymerization of isoprene and 1,3-butadiene with different R2N-and RS-functionalized 1,3-dienes. Incorporation of the functionalized 1,3-diene occurs very efficiently with high comonomer conversions, to yield polymers with typical M-n = 5 X 10(4) to 2 x 10(5) g mol(-1). High (>10 mol %) to very high (45 mol %) incorporation ratios and even homopolymerizations of the functionalized dienes can be achieved readily as observed for e.g. TMS2N(CH2)(3)C(= CH2)CH=CH2 or PhS(CH2)(3)C(=CH2)CH=CH2. Comparison of turnover numbers, microstructure, and molecular weights of the obtain copolymers show little to no adverse impact of the comonomer when compared to butadiene homopolymerizations. Additionally, cleavage of TMS groups in copolymers of 1,3 butadiene or isoprene with TMS2N(CH2)(3)C(=CH2)CH=CH2 results in copolymers bearing primary-NH2 amine groups as functional groups.