有机化学 ›› 2012, Vol. 32 ›› Issue (08): 1493-1497.DOI: 10.6023/cjoc1202213 上一篇    下一篇

研究论文

氮杂环卡宾的合成及在氢转移反应中的应用

高艳炫, 周宏勇, 李云庆, 王家喜   

  1. 河北工业大学化工学院 天津 300130
  • 收稿日期:2012-02-21 修回日期:2012-03-29 出版日期:2012-08-25 发布日期:2012-04-10
  • 通讯作者: 王家喜 E-mail:jwang252004@126.com
  • 基金资助:

    河北省自然科学基金(No. B2011202087)资助项目.

Synthesis and Application of N-Heterocyclic Carbene in Transfer Hydrogenation

Gao Yanxuan, Zhou Hongyong, Li Yunqing, Wang Jiaxi   

  1. School of Chemical Engineering, Hebei University of Technology, Tianjin 300130
  • Received:2012-02-21 Revised:2012-03-29 Online:2012-08-25 Published:2012-04-10
  • Supported by:

    Project supported by the Natural Science Foundation of Hebei Province (No. B2011202087).

利用氯甲基吡啶与咪唑反应制备了一系列含吡啶取代咪唑L1L5, 考察了所得咪唑衍生物与钌化合物在碱性条件下原位形成的氮杂卡宾钌络合物对苯胺与醇氢转移反应的催化活性. 研究了碱的种类、钌前体、温度等对反应的影响, 结果表明RuCl3·H2O/1-(2-吡啶甲基)-3-甲基碘化咪唑(L3)/KOH催化体系在185℃时对苯胺与乙二醇反应的催化活性较高, 选择性生成N-羟乙基苯胺, TON(单位活性转化的底物分数)可达2130. 此外, 还考察了RuCl3·H2O/L3/KOH催化体系对苯胺与丁醇、环己醇、异丙醇、苯甲醇反应的催化性能. 在催化剂作用下, 醇与苯胺可形成亚胺及仲胺, 伯醇可以自氢转移反应形成酯, 反应产物的结构及选择性取决于醇的结构及反应条件.

关键词: 氮杂环卡宾, 钌, 氢转移反应, N-烷基化反应, 吡啶, 咪唑

A series of pyridine substituted imidazoles L1L5 have been synthesized via reaction of chloromethylpyridine with imidazole. The effects of base, ruthenium precursor and temperature on the activity of catalyst formed in situ of N-heterocyclic carbene ligands with Ru precursor in catalytic hydrogen transfer reaction of aniline with glycol were evaluated. The results showed that the reaction of aniline with glycol promoted by RuCl3·H2O/3-methyl-1(2-pyridinylmethyl)-imidazole iodide (L3)/KOH at 185℃ selectively produced 2-(phenylamino)ethanol with the TON (turnover number) of 2130. In addition, the catalytic properties of RuCl3·H2O/L3/KOH in reaction of aniline with butanol, cyclohexanol, iso-propanol and phenylmethanol were also investigated. Under promotion of catalyst, the aniline reacted with alcohol to produce imine and secondary amine. In addition, the ester was formed by self transfer hydrogenation of primary alcohol. The selectivity and product structures were depended on the structure of alcohol and the reaction conditions.

Key words: N-heterocyclic carbene, ruthenium, transfer hydrogenation, N-alkylation, pyridine, imidazole