催化学报 ›› 2021, Vol. 42 ›› Issue (11): 1983-1991.DOI: 10.1016/S1872-2067(21)63834-2

• 论文 • 上一篇    下一篇

双功能MoNi4电极实现水参与的氮杂环化合物转移氢化与脱氢

李孟阳a,c,†, 刘翠波a,†, 黄义a, 韩舒艳a, 张兵a,b,*()   

  1. a天津大学理学院化学系, 分子+研究院, 天津300072
    b天津大学教育部合成生物前沿科学中心, 天津市分子光电科学重点实验室, 天津300072
    c郑州大学化学学院, 河南郑州450001
  • 收稿日期:2021-02-26 修回日期:2021-02-26 接受日期:2021-05-04 出版日期:2021-11-18 发布日期:2021-05-18
  • 通讯作者: 张兵
  • 作者简介:*电话: (022)27406140; 传真: (022)27403475; 电子信箱: bzhang@tju.edu.cn
    第一联系人:共同第一作者.
  • 基金资助:
    国家自然科学基金(21871206);国家自然科学基金(22001192)

Water-involving transfer hydrogenation and dehydrogenation of N-heterocycles over a bifunctional MoNi4 electrode

Mengyang Lia,c,†, Cuibo Liua,†, Yi Huanga, Shuyan Hana, Bing Zhanga,b,*()   

  1. aDepartment of Chemistry, School of Science, Institute of Molecular Plus, Tianjin University, Tianjin 300072, China
    bFrontiers Science Center for Synthetic Biology (Ministry of Education), Tianjin Key Laboratory of Molecular Optoelectronic Sciences Tianjian University, Tianjin 300072, China
    cCollege of Chemistry, Zhengzhou University, Zhengzhou 450001, Henan, China
  • Received:2021-02-26 Revised:2021-02-26 Accepted:2021-05-04 Online:2021-11-18 Published:2021-05-18
  • Contact: Bing Zhang
  • About author:*Tel: +86-22-27406140; Fax: +86-22-27403475; E-mail: bzhang@tju.edu.cn
    Bing Zhang (Department of Chemistry, School of Science, Tianjin University) received his Ph.D. degree from the University of Science and Technology of China in 2007 (with Prof. Yi Xie). He carried out postdoctoral research at the University of Pennsylvania (July 2007 to July 2008, with Prof. Ritesh Agarwal) and worked as an Alexander von Humboldt fellow at the Max Planck Institute of Colloids and Interfaces (August 2008 to July 2009, with Dayang Wang). Currently, he is a Fellow of the Royal Society of Chemistry (FRSC), a senior member of the Chinese Chemical Society, and a professor at Tianjin University. He mainly focuses on the controlled chemical transformation synthesis of designed targeted nanomaterials for water splitting and water-involved transfer hydrogenation reactions. In 2020, he joined the Editorial Board of the Chinese Journal of Catalysis.First author contact:These authors contributed equally to this work.
  • Supported by:
    National Natural Science Foundation of China(21871206);National Natural Science Foundation of China(22001192)

摘要:

氮杂环的催化氢化在有机合成、药物研发、石油化工等领域有着重要应用. 尽管发展了一系列均相和非均相催化加氢体系, 但由于通常使用易燃易爆的氢气或价格昂贵且毒性较高的试剂(如: 水合肼和硼氢化钠)为氢源, 给安全生产及生态环境带来了严重的问题. 此外, 由于动力学同位素效应, 氘代药物具有重要应用. 氮杂环结构作为生物医药的构筑单元与关键中间体, 现有的策略由于没有合适的氘源难以用于氘代氮杂环化合物的合成. 因此, 急需开发一种基于非贵金属催化剂和安全易得氢(氘)源的氮杂环催化氢(氘)化策略.
水相中的电化学氢化可利用水电解原位产生的活性氢替代传统的氢气裂解实现有机氢化产物的合成, 已成为一种理想氢化策略, 被广泛应用于二氧化碳还原、硝酸根还原和生物质氢解等. 本课题组前期研究已经实现了以氘水为氘源的氘代分子的高效电化学合成(Angew. Chem. Int. Ed., 2020, 59, 18527-18531; Angew. Chem. Int. Ed., 2020, 59, 21170-21175; CCS Chem., 2021, 3, 507-515). 然而, 要开发一种电化学的杂环氢化方法, 一方面要克服氮杂环化合物对催化剂的毒化, 另一方面要在电极表面产生大量的活性氢. 因此, 开发具有较好的水离解性能的非贵金属电极材料是实现氮杂芳烃电化学氢化和氘代的关键. 基于上述要求, MoNi4(目前用于碱性电催化水分解制氢的活性较高的非贵金属材料)成为理想的电极材料.
本文以喹喔啉(1,2,3,4-四氢喹喔啉骨架作为重要的结构单元存在于许多生物活性化合物中)作为模板底物, 设计并制备了三维自支撑的MoNi4多孔纳米片为双功能电极, 以水和氘水为氢源和氘源, 实现了喹喔啉及其他氮杂环分子的氢化与氢化, 同时实现了四氢喹喔啉的电化学氧化脱氢. 制备了MoNi4纳米片阵列, 利用扫描电子显微镜、透射电子显微镜、X射线衍射和X光电子能谱等手段进行表征, 评估了其在碱性电解液中用于喹喔啉电化学转移氢化的性能. 结果表明, MoNi4电极加速了动力学缓慢的Volmer步骤, 在仅50 mV的过电势下以80%的法拉第效率实现了喹喔啉的电化学氢化. 电子顺磁共振等证实水电解生成了H*, 并与喹喔啉自由基阴离子偶联实现喹喔啉的氢化. 同时, 该电化学转移氢化方法可很好地应用于一系列喹喔啉衍生物和其他氮杂芳烃化合物. 克级合成体现了该电化学转移氢化方法的潜在应用性. 原位拉曼实验结果表明, 在MoNi4表面形成的NiOOH是实现1,2,3,4-四氢喹喔啉氧化脱氢的重要物种. 此外, 以D2O代替H2O, 可以较好的收率和高达99%的氘化率实现氘代氮杂环的合成. 与传统的氮杂环氢化方法相比, 本文的电化学转移氢化策略具有绿色、温和、高效的特点, 同时拓宽了电化学氢化在合成化学中的应用.

关键词: 电催化, 转移氢化, 氘代, 水为氢源, 双功能电极

Abstract:

A room-temperature electrochemical strategy for hydrogenation (deuteration) and reverse dehydrogenation of N-heterocycles over a bifunctional MoNi4 electrode is developed, which includes the hydrogenation of quinoxaline using H2O as the hydrogen source with 80% Faradaic efficiency and the reverse dehydrogenation of hydrogen-rich 1,2,3,4-tetrahydroquinoxaline with up to 99% yield and selectivity. The in situ generated active hydrogen atom (H*) is plausibly involved in the hydrogenation of quinoxaline, where a consecutive hydrogen radical coupled electron transfer pathway is proposed. Notably, the MoNi4 alloy exhibits efficient quinoxaline hydrogenation at an overpotential of only 50 mV, owing to its superior water dissociation ability to provide H* in alkaline media. In situ Raman tests indicate that the NiII/NiIII redox couple can promote the dehydrogenation process, representing a promising anodic alternative to low-value oxygen evolution. Impressively, electrocatalytic deuteration is easily achieved with up to 99% deuteration ratios using D2O. This method is capable of producing a series of functionalized hydrogenated and deuterated quinoxalines.

Key words: Electrocatalysis, Transfer hydrogenation, Deuteration, Water as the hydrogen source, Bifunctional electrode