物理化学学报 >> 2006, Vol. 22 >> Issue (05): 608-615.doi: 10.1016/S1872-1508(06)60021-1

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溴化顺式-溴•氨•二(乙二胺)合钴(III)绝对不对称合成与拆分机理*

章慧;王宪营;陈雷奇;方雪明;高景星;徐志固   

  1. 厦门大学化学化工学院化学系, 固体表面物理化学国家重点实验室, 福建 厦门361005
  • 收稿日期:2005-11-09 修回日期:2005-12-30 发布日期:2006-04-28
  • 通讯作者: 章慧 E-mail:huizhang@jingxian.xmu.edu.cn

Absolute Asymmetry Synthesis and Resolution Mechanism of Chiral cis-bromoamminebis(ethylenediamine) cobalt(III) Bromide

ZHANG Hui;WANG Xian-Ying;CHEN Lei-Qi;FANG Xue-Ming;GAO Jing-Xing XU Zhi-Gu(608)   

  1. State Key Laboratory for Physical Chemistry of Solid Surface, Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, P. R. China
  • Received:2005-11-09 Revised:2005-12-30 Published:2006-04-28
  • Contact: ZHANG, Hui E-mail:huizhang@jingxian.xmu.edu.cn

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摘要： 分别用绝对不对称合成和改进的拆分方法制备标题配合物Λ-(+)D-cis-[CoBr(NH3)(en)2]Br2(1)和Δ-(-)D-cis-[CoBr(NH3)(en)2]Br2(2), 以及制备了cis-[CoBr(NH3)(en)2]Br2·2H2O(3)(en=1,2-乙二胺). 用元素分析、差热-热重、旋光度、UV-Vis、CD 光谱等对产物进行了表征.通过CD 光谱法获得了绝对不对称合成Co(III)配合物的产物ee 值分布图援当利用绝对不对称合成得到的手性Co(III)配合物去“逆向拆分”外消旋溴代樟脑磺酸铵[NH4(dl-BCS)]时只获得部分拆分, 初步认为这与交互拆分过程中阴阳离子之间的有效手性识别有关, 对于手性Co(III)配合物的绝对不对称合成还提出了一个新的反应机理,即“催化-结晶诱导”机理.

关键词: 绝对不对称合成, 手性对称性破缺, 手性Co(III)配合物, 光学拆分, 圆二色光谱, 手性识别

Abstract: The absolute asymmetric synthesis of the title complexes Λ-(+)D-cis-[CoBr(NH3)(en)2]Br2(1) and Δ-(-)D-cis-[CoBr(NH3)(en)2]Br2(2)(en=1,2-ethylenediamine) as well as the improved optical resolution of cis-[CoBr(NH3)(en)2]Br2·2H2O(3) are described in detail. The products were characterized by means of elemental analysis, TG-DTA, optical rotation, UV-Vis, and CD spectra. The distribution of enantiomeric excess(ee) of cis-[CoBr(NH3)(en)2]Br2 in the absolute asymmetric synthesis was obtained by the measurements of their CD spectra. It was found that the complete resolution of rac-cis-[CoBr(NH3)(en)2]Br2·2H2Owas achieved by use of NH4(d-BCS) (ammonium d-α-bromocamphor-π-sulfonate) or NH4(l-BCS) while NH4(dl-BCS) could only be partially resolved by chiral cis-[CoBr(NH3)(en)2]Br2 at the same condition. It is deduced that there are notable differences in the chiral discrimination of the reciprocal resolution between cis-[CoBr(NH3)(en)2]Br2 and NH4BCS.Moreover, a new“catalysis-crystal induction”mechanismin the preparation of the chiral Co(III) complex is put forward.

Key words: Absolute asymmetric synthesis;Chiral symmetry breaking;Chiral cobalt(III) complex, Optical resolution;CD spectra;Chiral discrimination