Axially Chiral Binaphthyl Surrogates with an Inner N-H-N Hydrogen Bond
Axially Chiral Binaphthyl Surrogates with an Inner N-H-N Hydrogen Bond
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DOI：
10.1021/ja808213r
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发表时间：
2009-01-14
影响因子：
15
通讯作者：
Tokitoh, Norihiro
中科院分区：
文献类型：
--
作者：
Kawabata, Takeo;Jiang, Changsheng;Tokitoh, Norihiro
新的手性联萘基替代物与内部的氢键已经创建。在它们的H-1 NMR谱中，NH出现在13.0-13.3 ppm处，表明极强的氢键。这些化合物的对映异构体在环境温度下是稳定的，并且通过具有手性固定相的HPLC分离。对映异构体的外消旋化半衰期在20 ℃下为3个月至2年，外消旋化的屏障在27.0至28.2 kcal/mol的范围内。该化合物（R = CHPh 2）的X射线晶体分析表明，包括C=N中心点中心点HN的萘基骨架几乎完全是平面的，萘环和萘环之间的二面角为128度。
Novel chiral binaphtyl surrogates with an inner hydrogen bond have been created. The N H appears at 13.0-13.3 ppm in their H-1 NMR spectrum, indicating extremely strong hydrogen bonding. Enantiomers of these compounds were stable at ambient temperature and separable by HPLC with a chiral stationary phase. The half-lives of racemization of the enantiomer are in the range 3 months to 2 years at 20 degrees C, and the barriers for racemization are in the range 27.0 to 28.2 kcal/mol. An X-ray crystal analysis of the compound (R = CHPh2) shows that the pseudonaphthyl skeleton including C=N center dot center dot center dot H N is almost completely planar and the dihedral angle between the pseudonaphthalene and naphthalene rings is 128 degrees.