Stereoselective intramolecular [4+3] cycloadditions of nitrogen-stabilized chiral oxyallyl cations via epoxidation of N-tethered allenamides
Stereoselective intramolecular [4+3] cycloadditions of nitrogen-stabilized chiral oxyallyl cations via epoxidation of N-tethered allenamides
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DOI：
10.1021/ja030416n
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发表时间：
2003-10-22
影响因子：
15
通讯作者：
Hsung, RP
中科院分区：
文献类型：
--
作者：
Xiong, H;Huang, J;Hsung, RP
第一个分子内[4 + 3]环加成反应使用氮稳定的手性氧烯丙基阳离子，通过氮原子连接到呋喃或二烯在这里描述。这些氮稳定的手性氧烯丙基阳离子的形成是通过经由注射器泵添加二甲基二氧杂环丙烷的手性烯丙酰胺的化学选择性环氧化来实现的。随后的环加成可以用一系列不同长度的系链进行，并且当使用具有较短系链的手性丙二烯酰胺时可以获得高的非对映选择性。
The first intramolecular [4 + 3] cycloaddition reaction using nitrogen-stabilized chiral oxyallyl cations that are tethered to furan or diene through the nitrogen atom is described here. Formation of these nitrogen-stabilized chiral oxyallyl cations is achieved by a chemoselective epoxidation of chiral allenamides via syringe pump addition of dimethyl dioxirane. The ensuing cycloaddition can be carried out with a range of different lengths for the tether, and high diastereoselectivities can be obtained when using chiral allenamides with shorter tethers.