Asymmetric Conjugate Addition of Unmodified Propionaldehyde to β- Nitrostyrenes Catalyzed by Readily Available Proline-Based Dipeptidols
作者:Ren-Yong Yang、Chao-Shan Da、Lei Yi、Feng-Chun Wu、Hong Li
DOI:10.2174/157017809787003061
日期:2009.1.1
Organocatalytic asymmetric additions of unmodified aldehydes to β-nitrostyrenes are important carbon-carbon bond formation reactions and have become very attractive recently, because they are metal-free and environmentally benign. This work employed a series of L-proline-based diphenyl dipeptidols to catalyze this reaction. The results showed that these dipeptidols were effective organocatalysts with the yield up to 99%. 3a was optimal with the highest enantioselectivity up to 75% and dr (syn/anti) up to 94/6. In addition, the mechanism of this asymmetric reaction is also discussed.
未改性醛与β-硝基苯炔的有机催化不对称加成反应是重要的碳-碳键形成反应,由于不含金属且对环境无害,近来变得非常有吸引力。这项研究采用了一系列基于 L-脯氨酸的二苯基二肽醇来催化这一反应。结果表明,这些二肽醇是有效的有机催化剂,产率高达 99%。3a 的对映选择性最高,可达 75%,dr(同/反)高达 94/6。此外,还讨论了该不对称反应的机理。