Studies of functional diene oligomers with an amino end group, 1. Synthesis of functional oligomers of isoprene with one diisopropylamino end group

Lithium diisopropylamide in the presence of diisopropylamine initiates the polymerization of isoprene to form oligomers with one diisopropylamino end group. The molecular weight of the oligomers formed is strongly dependent on the mole ratio diisopropylamine/lithium diisopropylamide. For instance, more than 70% of the oligomers obtained have an average molecular weight of 1 000, provided the reaction is run with an initial mole ratio 1:2 of amine to amide. Reactivities of several allylamine derivatives including the oligomers with amino end groups were studied in regard to their ability as chain transfer agents in the anionic polymerization of isoprene. According to the 1 H NMR analysis, these oligomers contain 90% 1,4‐ and 10% 3,4‐enchainments.