化学
迈克尔反应
对映体
酮
立体选择性
烷基
加合物
对映体过量
溶剂
有机化学
对映选择合成
丙烯酸甲酯
药物化学
加成反应
甲基乙烯基酮
丙烯酸酯
催化作用
聚合物
单体
共聚物
作者
Kaori Ando,Won-Seon Seo,Kiyoshi Tomioka,Kenji Koga
出处
期刊:Tetrahedron
[Elsevier]
日期:1994-01-01
卷期号:50 (46): 13081-13088
被引量:17
标识
DOI:10.1016/s0040-4020(01)89317-0
摘要
Chlorotrimethylsilane promoted asymmetric Michael reaction of the chiral lithioenamines derived from α-alkyl β-keto esters and (S)-valine tert-butyl ester is described. Complementary asymmetric syntheses producing either enantiomers from the same starting material have been realized by changing the solvent system. That is, the lithioenamines react with methyl vinyl ketone or ethyl acrylate in THF in the presence of chlorotrimethylsilane to give, after hydrolysis, the Michael adducts in 57–90% ee. On the other hand, the reaction using toluene-HMPA as a solvent system, instead of THF, affords the corresponding antipodes with enantiomeric purities of 41–77% ee.
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