Azumaya Isao, Kato Takako, Okamoto Iwao, Yamasaki Ryu, Tanatani Aya, Yamaguchi Kentaro, Kagechika Hiroyuki, Takayanagi Hiroaki
School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Minato-ku, Shirokane, Tokyo 108-8641, Japan.
Org Lett. 2003 Oct 16;5(21):3939-42. doi: 10.1021/ol035509o.
[reaction: see text] 1,2-Bis(N-benzenesulfonyl-N-methylamino)benzene (2), which has no fixed asymmetric element, was crystallized from ethyl acetate as chiral crystals belonging to space group P4(1)2(1)2 (No. 92) or P4(3)2(1)2 (No. 96). The array of molecules built by the CH-pi interaction along the c-axis forms an enantiomeric helical superstructure in each individual crystal. The absolute configurations of the chiral crystals of 2 were determined by X-ray crystal structure analysis using the Flack parameter method. The solid-state CD spectra of the chiral crystals in KBr were mirror images. The equilibrium between the two enantiomers in solution is fast during crystallization at ambient temperature, and the energy barrier (DeltaG()) is estimated to be 11.7 +/- 0.3 kcal/mol (233 K).
[反应：见正文] 1,2-双（N-苯磺酰基-N-甲基氨基）苯（2），其没有固定的不对称元素，从乙酸乙酯中结晶为属于空间群P4(1)2(1)2（编号92）或P4(3)2(1)2（编号96）的手性晶体。沿着c轴通过CH-π相互作用构建的分子阵列在每个单晶中形成对映体螺旋超结构。通过使用弗拉克参数法的X射线晶体结构分析确定了2的手性晶体的绝对构型。手性晶体在KBr中的固态圆二色光谱是镜像。在环境温度下结晶过程中，溶液中两种对映体之间的平衡很快，并且能垒（ΔG()）估计为11.7±0.3 kcal/mol（233 K）。
