Asymmetric polymerization of N-triphenylmethylmaleimide with chiral anionic initiators

Abstract

Asymmetric polymerization of N-triphenylmethylmaleimide(TrMI) is performed with chiral anionic initiators in tetrahydrofuran and toluene at −78 and 0°C to obtain optically active polymer. It is found that the (S)-(+)-l-(2-pyrrolidinylmethyl) pyrrolidinelithium [Li-(+)-PMP] and lithium (−)-menthoxide are effective for the asymmetric polymerization of N-triphenylmethylmaleimide in THF. The polymers obtained are characterized by circular dichroism(CD). It is inferred that the propagation reaction of polymerization of TrMI with Li-(+)-PMP is dominated by ion pair mechanism and meanwhile free ion mechanism cannot be ignored based on GPC analysis.