Asymmetric anionic polymerization of optically active N-1-cyclohexylethylmaleimide

Chiral (S)-(−)-N-1-cyclohexylethylmaleimide [(S)-CEMI] and (R)-(+)-N-1-cyclohexylethylmaleimide [(R)-CEMI] were synthesized successfully and then polymerized with chiral complexes of (−)-sparteine or (S,S)-(1-ethylpropylidene)bis(4-benzyl-2-oxazoline) [(S,S)-Bnbox] and organometal as initiators in toluene or tetrahydrofuran to obtain optically active polymers. The effects of the polymerization conditions on the optical activity and structure of poly(N-1-cyclohexylethylmaleimide)s were investigated with gel permeation chromatography, circular dichroism, specific rotation, and ¹³C NMR measurements. Poly[(R)-CEMI] obtained with dimethylzinc (Me₂Zn)/(S,S)-Bnbox had the highest specific rotation ([α]₄₃₅ = +323.7°). Complexes of Bnbox and diethylzinc or Me₂Zn were used very effectively as chiral initiators for the asymmetric anionic polymerization of (S)-CEMI and (R)-CEMI. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4682–4692, 2004