Chiral liquid-crystalline poly(ester/β-sulfoxide)s by asymmetric oxidation of prochiral nematic poly(ester/β-sulfide)s†
Chiral liquid-crystalline poly(ester/β-sulfoxide)s by asymmetric oxidation of prochiral nematic poly(ester/β-sulfide)s†
复制标题
通过前手性向列聚（酯/β-硫醚）的不对称氧化制备手性液晶聚（酯/β-亚砜）†
DOI：
10.1002/macp.1990.021911127
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发表时间：
1990
影响因子：
2.5
通讯作者：
G. Galli
中科院分区：
文献类型：
--
作者：
A. Angeloni;M. Laus;D. Caretti;E. Chiellini;G. Galli
合成了一类新的含SC_6H_4S基团的前手性液晶聚（酯/β-硫醚）_2和_3，然后将其不对称氧化为含SC_6H_4S基团的手性液晶聚（酯/β-亚砜）_4和_5。以手性2-磺酰氧氮杂环丙烷6为不对称氧化剂，该反应具有高的化学选择性和定量产率。对模型聚（酯/β-亚砜）8进行13 C NMR分析，其允许评价不对称氧化产物的不对称诱导和对映体过量。母体聚合物2和3是手性聚合物，而手性改性聚合物4和5是手性聚合物。
A new class of prochiral liquid-crystalline poly(ester/β-sulfide)s 2 and 3 containing the SC6H4S group was prepared, which were then asymmetrically oxidized to chiral liquidcrystalline poly(ester/β-sulfoxide)s 4 and 5 comprising the group. A chiral 2-sulfonyloxaziridine 6 was used as the asymmetric oxidant and the reaction is highly chemoselective with quantitative yield. A 13C NMR analysis of a model poly(ester/β-sulfoxide) 8 is performed, which allows to evaluate the asymmetric induction and the enantiomeric excess for the asymmetric oxidation product. While the parent polymers 2 and 3 are nematic, the chiral modified polymers 4 and 5 are cholesteric.