Recyclable Silica-Supported Iridium Catalysts for Selective Reductive Transformation of Quinolines with Formic Acid in Water
作者:Jing-Fan Zhang、Rui Zhong、Quan Zhou、Xi Hong、Shuang Huang、He-Zhen Cui、Xiu-Feng Hou
DOI:10.1002/cctc.201700128
日期:2017.7.7
the selective transfer hydrogenation of quinoline derivatives to 1,2,3,4-tetrahydroquinolines (THQs) with formic acid in pure water. Moreover, by simply adapting the amount of formic acid used, N-formyltetrahydroquinolines (FTHQs) could be selectively synthesized from quinolines in two-step, one-pot transfer hydrogenation/N-formylation reactions with these supported catalysts. Notably, these supported
介孔二氧化硅(SBA-15)负载的铱催化剂是通过将新开发的环金属化铱2-芳基苯并恶唑配合物与3-(三乙氧基甲硅烷基)-丙基-异氰酸酯(TEPIC)接枝而制备的。负载型催化剂的特征在于:固态NMR光谱,小角X射线散射(SAXS),氮物理吸附,FTIR光谱和电子显微镜分析,这表明铱中心的配位环境以及两个固定后,可保持SBA-15的六方孔结构。这些负载型催化剂已成功应用于在纯水中用甲酸将喹啉衍生物选择性转移加氢成1,2,3,4-四氢喹啉(THQs)。此外,只需简单地调整甲酸的使用量,N-甲酰基四氢喹啉(FTHQs)可以在这些负载型催化剂的两步一锅转移加氢/ N-甲酰化反应中从喹啉选择性合成。值得注意的是,这些负载型催化剂显示出比其均相类似物更好的催化反应性,并且它们可以容易地在喹啉向N-甲酰基四氢喹啉(FTHQ)的转化中重复使用12次,而没有明显的活性损失。