Saigo Kazuhiko, Kobayashi Yuka
Department of Chemistry and Biotechnology Graduate School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Chem Rec. 2007;7(1):47-56. doi: 10.1002/tcr.20100.
Enantiopure 2-naphthylglycolic acid (NGA) and cis-1-aminobenz[f]indan-2-ol (ABI) were rationally designed as new resolving agents on the model of mandelic acid (MA) and cis-1-aminoindan-2-ol (AI), respectively. As expected, NGA and ABI showed superior chiral recognition ability to racemates, compared with MA and AI. In order to clarify any factors governing the chiral recognition abilities of NGA and ABI, the crystal structures of their less- and more-soluble diastereomeric salts were determined by X-ray crystallographic analyses and revealed that CH/pi interactions play an intrinsic role in chiral recognitions. A theoretical investigation was also performed with the periodic ab initio method by using the X-ray crystal structures of the less-soluble salt crystals with AI and ABI to find the unique properties of CH/pi interaction in the crystalline state, which largely contributed to the stabilization of the crystals.
分别以扁桃酸（MA）和顺式-1-氨基茚满-2-醇（AI）为模型，合理设计了对映体纯的2-萘基乙醇酸（NGA）和顺式-1-氨基苯并[f]茚满-2-醇（ABI）作为新型拆分剂。正如预期的那样，与MA和AI相比，NGA和ABI对外消旋体表现出更强的手性识别能力。为了阐明影响NGA和ABI手性识别能力的因素，通过X射线晶体学分析确定了它们溶解度较小和较大的非对映体盐的晶体结构，结果表明C-H/π相互作用在手性识别中起着内在作用。还使用周期从头算方法，利用AI和ABI的溶解度较小的盐晶体的X射线晶体结构进行了理论研究，以发现晶体状态下C-H/π相互作用的独特性质，这在很大程度上有助于晶体的稳定。
