Asymmetric Henry reactions of aldehydes with various nitroalkanes catalyzed by copper(II) complexes of novel chiral<i>N</i>-monoalkyl cyclohexane-1,2-diamines
作者:Fei Liu、Shaohua Gou、Lei Li
DOI:10.1002/aoc.3107
日期:2014.3
2‐diamine (3g), the reaction was optimized in terms of the metal ion, temperature, solvent and base. Further experiments indicated that the complex, 3g–Cu(OAc)2, was an efficient catalyst in the asymmetric Henry reaction between different aldehydes and nitromethane, and the desired products have been obtained with high chemical yields (up to 99%) and high enantiomeric excess (up to 93%). The optimized catalyst
从反式-环己烷-1,2-二胺设计合成了许多新颖的手性二胺3(1 R,2 R)-N-单烷基环己烷-1,2-二胺,并将其用于苯甲醛的催化不对称亨利反应和硝基甲烷可提供高收率(高达99%)和良好的对映体过量(高达89%)的β-硝基醇。通过使用配体(1 R,2 R)-N 1-(4-甲基戊烷-2-基)环己烷-1,2-二胺(3g),根据金属离子,温度,溶剂和碱对反应进行了优化。进一步的实验表明,复合物3g –Cu(OAc)2是在不同醛和硝基甲烷之间不对称亨利反应中有效的催化剂,并且以高化学收率(高达99%)和高对映体过量(高达93%)获得了所需的产物。优化催化剂促进各种醛底物和硝基烷的非对映Henry反应,这给了相应的抗与高达99%的产率和83:17 -选择性加合物的抗/顺式选择性。放大至克量后,以良好的选择性(93%ee)以良好的收率(96%)获得了β-硝基醇。在先前提出的过渡态模型的基础上,初步解释了手性诱导机理。版权所有©2014