Optical Resolution and Configurational Stability of Selenoxides Stabilized by Intramolecular Coordination
作者:Toshio Shimizu、Masao Enomoto、Hideo Taka、Nobumasa Kamigata
DOI:10.1021/jo990993n
日期:1999.10.1
rotations, circular dichroism spectra, and behavior on the optically active column with those of the sulfur analogue, prepared by Andersen's method. Racemization of the optically active selenoxides was accelerated not only in acidic solution but also in basic media. This result indicates there are two different mechanisms for their racemization in acidic and basic media. The stabilization energy of the selenoxides
通过氨基与硒原子分子内配位而构型稳定的2-((二甲基氨基)甲基)苯基烷基(或芳基)亚硒酸酯通过使用旋光色谱柱的高效液相色谱法光学拆分为对映异构体装满氨基甲酸直链淀粉的衍生物/硅胶。这是分离没有大取代基的光学纯亚硒酸盐的第一个实例,也是光学纯烷基芳基亚硒酸盐的首次分离。(-)-异构体的绝对构型可通过比较它们的比旋光度,圆二色性光谱和在光学活性柱上的行为与由安德森方法制备的硫类似物的行为进行比较,以S形表示。光学活性亚硒酸盐的外消旋不仅在酸性溶液中而且在碱性介质中都被加速。该结果表明它们在酸性和碱性介质中外消旋化有两种不同的机理。通过氨基与硒原子的分子内配位,亚硒酸盐的稳定能估计为约1。3 kcal mol(-)(1),基于可变温度(1)H NMR测量。