The N-R-quinolinyl-8-amino ligands HL1–3 (R = 2,6-iPr2C6H3 (HL1), 2,6-Et2C6H3 (HL2), 2,6-Me2C6H3 (HL3)) have been prepared, which reacted readily with one equiv. of rare earth metal tris(alkyl)s to afford the corresponding bis(alkyl) complexes L1Y(CH2SiMe3)2(THF) (1) and L1–3Lu(CH2SiMe3)2(THF) (2–4) viaalkane elimination. Contrastingly, treatment of the in situ generated neodymium tri(alkyl)s with HL1 afforded a mono(alkyl) neodymium complex (5). Complexes 1, 2 and 5 in combination with aluminium alkyls and organoborates established homogenous ternary systems that exhibited versatile catalytic activities and trans-1,4 selectivities for the polymerization of butadiene, depending on the types of aluminium alkyl, organoborate and rare earth metal used. Furthermore, the trans-1,4 selective copolymerization of butadiene and isoprene was achieved by using the ternary system of 1/AlMe3/[Ph3C][B(C6F5)4]. Both the kinetics of copolymerization and the thermal behavior of the copolymers were investigated.