Department of Applied Chemistry, Saitama University, Saitama, Japan.
Chirality. 2011 Apr;23(4):326-32. doi: 10.1002/chir.20922. Epub 2010 Nov 12.
Solvent-induced chirality control in the enantioseparation of 1-phenylethylamine 1 by N-(p-toluenesulfonyl)-(S)-phenylalanine 2 via diastereomeric salt formation was studied. (S)-1·(S)-2 was preferentially crystallized as a less-soluble salt from aqueous alcohol, while (R)-1·(S)-2 salt was mainly obtained by addition of solvents with a six-membered ring such as dioxane, cyclohexane, tetrahydropyran, and cyclohexene to 2-propanol. Further investigations were carried out from the viewpoints of molecular structures, optical rotation measurement, and X-ray crystallographic analyses. Crystallographic analyses have revealed that incorporation of the six-membered ring solvent molecule in (R)-1·(S)-2 without hydrogen bonds changed the molecular conformation of (S)-2 to stabilize the salt, which changed the selectivity of 1 in the enantioseparation.
溶剂诱导的手性控制在通过非对映异构体盐形成对 1-苯乙胺 1 的对映体分离中的应用研究。（S）-1·（S）-2 优先从水醇溶液中结晶为溶解度较低的盐，而（R）-1·（S）-2 盐主要通过向 2-丙醇中添加六元环溶剂如二恶烷、环己烷、四氢吡喃和环已烯来获得。进一步的研究从分子结构、旋光测量和 X 射线晶体学分析的角度进行了研究。晶体学分析表明，在没有氢键的情况下，将六元环溶剂分子掺入（R）-1·（S）-2 中会改变（S）-2 的分子构象以稳定盐，从而改变了 1 在对映体分离中的选择性。
