Asymmetric polymerization of N‐substituted maleimides with chiral oxazolidine–organolithium

Asymmetric Anionic Polymerization of N-Substituted Maleimides withn-Butyllithium−Methylene-Bridged 2,2-Bis(oxazoline) Complexes

“…The structure of poly(CHMI) obtained with radical initiator could be threo-disyndiotactic configuration because of the smallest steric repulsion. The signal based on the poly(CHMI) main chain appeared only at 43.5 ppm in the 13 C NMR spectrum . The peak at the lower magnetic field of about 43 ppm for the poly(CHMI) initiated by the n -BuLi−( S,S) -Bnbox complex was assigned to threo-disyndiotactic structures.…”

“…The signal based on the poly(CHMI) main chain appeared only at 43.5 ppm in the 13 C NMR spectrum. 15 The peak at the lower magnetic field of about 43 ppm for the poly(CHMI) initiated by the n-BuLi-(S,S)-Bnbox complex was assigned to threo-disyndiotactic structures. Another peak at the higher magnetic field of about 40 ppm was assigned to the threo-diisotactic structure.…”

Asymmetric anionic polymerization of optically active N‐1‐cyclohexylethylmaleimide

“…On the other hand, peaks due to the main chain of the polymers obtained by anionic polymerization appeared at a higher magnetic field of approximately 43 ppm, as shown in Figure 3(A–C). The peaks were assigned to threo‐diisotactic structure in the main chain on the basis of our previous studies 21–23, 25–28. The peak around 175 ppm, ascribed to the carbonyl groups of the polymer with the highest specific rotation [Fig.…”

Syntheses of Chiral N-Substituted Maleimides Bearing Two Polymerizable Groups

“…(100 mL) in sequence, dried over Na2SO4, and concentrated under reduced pressure, crystallized in n-hexane to afford (S)-LMI as a white powder [yield: 6.6 g (72%), mp: 88~89.5°C (lit.35 87~90°C), [α]435 = -41.2° (c = 1.0 g/dL, l = 10 cm, THF)]. 1…”

“…(S)-ALSI was synthesized from (S)-LSI and allyl alcohol by the same method as (S)-ALMI (yield: 52.9%, yellow liquid, bp: 146°C/0.5 mmHg, [α]435 = -92.6° (c = 1.0 g/dL, l = 10 cm, THF)). 1…”