Chiral oxime ethers in asymmetric synthesis. Part 5.1 Asymmetric synthesis of 2-substituted 5- to 8-membered nitrogen heterocycles by oxime addition–ring-closing metathesis
作者:James C. A. Hunt、Pierre Laurent、Christopher J. Moody
DOI:10.1039/b207235c
日期:——
Addition of organometallic reagents to chiral oxime ethers 1 derived from an unsaturated aldehyde, or addition of an alkene containing organometallic to chiral aldoxime ethers 2 results in highly stereoselective formation of the hydroxylamines 6. N-Allylation gives the dienes 7 which undergo ring-closing metathesis (RCM) reaction to give the 5-, 6-, and 7-membered nitrogen heterocycles 8. Likewise
在手性化合物中添加有机金属试剂 肟 醚 1来自不饱和醛,或添加 烯烃 含有有机金属至手性 醛肟 醚 2导致高度立体选择性的形成羟胺 6。N-烯丙基化给出二烯7中经历闭环复分解 (RCM)反应生成5元,6元和7元 氮杂环8。同样地,氨基甲酸苄酯类9,也通过立体选择性除了肟醚制备,转化成二烯烃10,该例行RCM给出5到8元的azacycles 11。这肟 添加-RCM 因此,协议是非对称合成的通用方法 氮 杂环,进一步以不饱和杂环转化为手性为例 哌啶,包括生物碱(-)-coniine。