Chin. J. Org. Chem. ›› 2013, Vol. 33 ›› Issue (10): 2143-2147.DOI: 10.6023/cjoc201305042 Previous Articles     Next Articles



易兵a,b, 武高峰b, 周威b, 何华平a   

  1. a 湖南工程学院化学化工学院 生态纺织材料及染整新技术湖南省高校重点实验室 湘潭 411104;
    b 湘潭大学化学学院 环境友好化学与应用省部共建教育部重点实验室 湘潭 411105
  • 收稿日期:2013-05-30 修回日期:2013-07-06 发布日期:2013-07-10
  • 通讯作者: 易兵
  • 基金资助:

    国家自然科学基金(Nos. 21172064, 20972045);湖南省自然科学基金(No. 10JJ2006)和湖南省教育厅重点(No. 10A022)资助项目

Study on Synthesis of Imidazolium-Tagged Chiral Pyrphos Diphosphine Ligands and Their Applications in Asymmetric Hydrogenation

Yi Binga,b, Wu Gaofengb, Zhou Weib, He Huapinga   

  1. a Key Laboratory of Ecological Textile Materials & Novel Dying and Finishing Technology, Hunan Provincial Education Department, School of Chemistry & Chemical Engineering, Hunan Institute of Engineering, Xiangtan 411104;
    b Key Laboratory of Environmentally Friendly Chemistry and Applications, Ministry of Education, School of Chemistry, Xiangtan University, Xiangtan 411105
  • Received:2013-05-30 Revised:2013-07-06 Published:2013-07-10
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Nos. 21172064, 20972045), the Natural Science Foundation of Hunan Province (No.10JJ2006), and the Key Scientific Research Fund of Hunan Provincial Education Department (No. 10A022).

Herein we developed a facile method for preparation of a new functionalized ionic liquids supported chiral diphosphine ligands by grafting homogeneous chiral pyrphos[(R,R)-3,4-bis(diphenylphosphino)pyrrolidine] ligand with C2 axis onto imidazolium ionic liquids supports. Firstly the linker groups having halogen atoms were attached to amino group in pyrphos, and then reacted with N-methylimidazole. The other anion-containing chiral ligands located on ionic liqids (ILs) were synthesized via ion exchange technique. These ligands and the related intermediates were purified by flash column chromatography and were characterized by 1H NMR, 13C NMR, 31P NMR, IR and HRMS techniques. All results were consistent with the compounds synthesized. Then we focused on the catalytic performances and the feasibility of catalyst recycling in rhodium-catalyzed asymmetric hydrogenation of prechiral dehydroamino acid. The results showed that the catalyst generated in situ by imidazolium-tagged pyrphos ligands with BF4 as counteranion and[Rh(COD)2]BF4 exhibited high catalytic activity and enantioselectivity in asymmetric hydrogenation of α-acetamido cinnamic acid in[bmim]BF4/MeOH cosolvent systems, which was similar to the molecule catalyst. The conversion is 100%, and the ee value is up to 97.0%. Moreover, the catalyst could be reused four times without significant loss of activity and enantioselectivity.

Key words: asymmetric hydrogenation, diphosphine ligand, imidazolium ionic liquid, immobilization, catalyst recycling