催化学报 ›› 2019, Vol. 40 ›› Issue (10): 1548-1556.DOI: 10.1016/S1872-2067(19)63398-X

• 论文 • 上一篇    下一篇

聚合物/碳纳米管复合材料的制备及催化喹啉手性氢化性能

陶琳a,b, 李纯志a,b, 任亦起a,b, 李贺a, 陈建a,b, 杨启华a   

  1. a 中国科学院大连化学物理研究所催化基础国家重点实验室, 辽宁大连 116023;
    b 中国科学院大学, 北京 100049
  • 收稿日期:2019-05-24 修回日期:2019-07-01 出版日期:2019-10-18 发布日期:2019-08-26
  • 通讯作者: 杨启华
  • 基金资助:
    国家自然科学基金(21733009,21621063);中国科学院战略性先导科技专项(XDB17020200).

Synthesis of polymer/CNTs composites for the heterogeneous asymmetric hydrogenation of quinolines

Lin Taoa,b, Chunzhi Lia,b, Yiqi Rena,b, He Lia, Jian Chena,b, Qihua Yanga   

  1. a State Key Laboratory of Catalysis, iChEM, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, Liaoning, China;
    b University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2019-05-24 Revised:2019-07-01 Online:2019-10-18 Published:2019-08-26
  • Supported by:
    This work was supported by the National Natural Science Foundation of China (21733009, 21621063) and the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB17020200).

摘要: 光学活性的1,2,3,4-四氢喹啉结构广泛存在于许多药物分子和天然生物碱中,在生物医药和农药化学等方面具有十分重要的应用.发展光学活性的1,2,3,4-四氢喹啉及衍生物的手性催化合成方法具有重要的学术和工业应用价值.2008年范青华课题组成功将手性二胺-Ru的阳离子型催化剂用于喹啉及衍生物的手性氢化反应中,有效克服了有机膦配体在空气中敏感的问题.近十几年来,喹啉及衍生物的手性氢化研究主要集中在均相催化体系.然而,均相催化体系面临着催化剂循环利用的困难,难以进行连续化工业生产.此外,手性药物合成中间体对纯度要求非常严格,残留贵金属催化剂的分离是均相催化体系中的一大问题.
多相手性催化可有效解决上述问题,然而针对喹啉手性氢化的多相催化体系并不多见.本文中,我们通过自由基聚合的方法制备了骨架中富含手性二胺配体的多孔聚苯乙烯聚合物.在此基础上,通过在聚合过程中加入活性炭或碳纳米管,制备了聚合物/活性炭和聚合物/碳纳米管复合材料.在与Ru金属配合物进行配位和阴离子交换后,制备了一系列含VDPEN-RuOTf活性中心的手性固体催化剂.通过红外光谱、13C核磁共振和元素分析等表征证实了聚合物及聚合物/碳材料复合材料的成功制备,N2吸附表征表明聚合物/活性炭和聚合物/碳纳米管复合材料可以有效减少金属配位引起的聚合物材料比表面积的降低.固体催化剂红外光谱中出现了归属于C-F键及S=O键的特征振动峰,表明固体催化剂中含有VDPEN-RuOTf活性中心.所有的手性固体催化剂在2-甲基喹啉的手性氢化反应中均能得到90%的ee值.研究表明聚合物/碳材料复合材料在相同反应条件下表现出比纯聚合物更好的反应活性,其中聚合物/碳管复合材料在所有手性固体催化剂中表现出最高的反应活性,这可能源于碳管独特的管状形貌.以甲醇为溶剂,手性固体催化剂在循环使用过程中催化活性明显下降,红外光谱表征显示阴离子TfO-的流失是催化剂失活的主要原因.以离子液为溶剂,手性固体催化剂的循环稳定性有所增加,这主要归因于离子液的离子限域作用抑制了TfO-的流失.

关键词: 多相手性氢化, 喹啉, 二胺配体, 聚合物, 碳纳米管

Abstract: The development of heterogeneous catalytic processes is crucial for the synthesis of chiral compounds for both academic and industrial applications. However, thus far, such achievements have remained elusive. Herein, we report the heterogeneous asymmetric hydrogenation of 2-methylquinoline over solid chiral catalysts, which were prepared by the one-pot polymerization of (1R,2R)-N-(4-vinyl-benzenesulfonyl)-1,2-diphenylethane-1,2-diamine (VDPEN) and divinylbenzene (DVB) in the presence or absence of activated carbon (C) or carbon nanotubes (CNTs), followed by Ru coordination and anion exchange. The solid chiral catalysts were fully characterized by N2 sorption analysis, elemental analysis, TEM, FT-IR spectroscopy, and 13C CP-MAS NMR. All the solid chiral catalysts could efficiently catalyze the asymmetric hydrogenation of 2-methylquinoline to afford 2-methyl-1,2,3,4-tetrahydroquinoline with 90% ee. Studies have shown that polymer/C and polymer/CNTs composites are more active than pure polymers. The polymer/CNTs composite exhibited the highest activity among all the solid chiral catalysts under identical conditions, owing to the unique morphology of CNTs. The recycling stabilities of the solid chiral catalysts were greatly improved when ionic liquids (ILs) were employed as solvents; this is mainly attributed to the decreased leaching amount of anions owing to the confinement effect of ILs on ionic compounds.

Key words: Heterogeneous asymmetric hydrogenation, Quinoline, Diamine ligand, Polymer, Carbon nanotube