手性铜钐杂双金属络合物催化反式选择性Henry反应研究

发布时间：2018-09-07 16:34

【摘要】：不对称Henry反应的产物β-硝基醇是很重要的手性中间体,它广泛的用于合成各种手性药物、农药和手性配体。因此,不对称Henry反应吸引了许多的科学家并早已取得了很好的成果。然而,硝基乙烷的不对称Henry反应,却一直存在弱的反应活性和低的非对映选择性的问题。为了解决这一问题,我们开发了一种新颖的手性铜钐杂双金属络合物,通过简便的一锅法催化反式选择性Henry反应。经过一系列的条件优化,我们在最优条件下进行了底物扩展。结果证明该催化体系对芳香醛和杂环醛有很好的手性诱导,反式产物最高可达99%的收率,大于30:1的非对映选择性和98%的对映选择性。通过控制实验的结果和对络合物的ESI-MS分析表明,Cu/Sm/1络合物是反应的活性催化剂。在此基础上,我们提出了四种可能的反应过渡态,综合考虑空间位阻和电子效应的影响,推导出产物构型为反式(1S,2R),这与实际得到的产物构型是一致的。
[Abstract]:尾 -nitroalcohol, the product of asymmetric Henry reaction, is an important chiral intermediate, which is widely used in the synthesis of chiral drugs, pesticides and chiral ligands. Therefore, asymmetric Henry reactions have attracted many scientists and have achieved good results. However, the asymmetric Henry reaction of nitroethane has always had the problems of weak reaction activity and low enantioselectivity. To solve this problem, we have developed a novel chiral copper samarium heterobimetallic complex, which catalyzes the trans-selective Henry reaction by a simple one-pot method. After a series of optimization conditions, we extend the substrate under the optimal conditions. The results show that the catalytic system can induce aromatic aldehydes and heterocyclic aldehydes chirally. The highest yield of trans-products is 99%, which is higher than 30:1 enantioselectivity and 98% enantioselectivity. The results of the controlled experiments and the ESI-MS analysis of the complexes show that the Cu / Sm / 1 complex is the active catalyst for the reaction. On this basis, we propose four possible transition states. Considering the influence of steric hindrance and electron effect, we deduce that the product configuration is trans (1S- 2R), which is consistent with the actual product configuration.
【学位授予单位】：重庆医科大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O621.251

【相似文献】