Synthesis and characterization of bromonium ylides and their unusual ligand transfer reactions with N-heterocycles.
Synthesis and characterization of bromonium ylides and their unusual ligand transfer reactions with N-heterocycles.
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DOI：
10.1021/ja063492
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发表时间：
2006-07
影响因子：
15
通讯作者：
M. Ochiai;N. Tada;Kentaro Murai;S. Goto;M. Shiro
中科院分区：
文献类型：
--
作者：
M. Ochiai;N. Tada;Kentaro Murai;S. Goto;M. Shiro
首次合成了稳定的脂肪族溴叶立德(RfSO2)2C--Br+C6H4-p-CF3 (Rf = CF3, CF3(CF2)3)并进行了结构表征。 X射线晶体学分析表明叶立德结构具有叶立德碳负离子的sp2杂化并且叶立德键几乎没有双键特征。溴叶立德选择性地将芳基转移至氮杂环，例如吡啶，产生N-芳基吡啶鎓盐。这与碘鎓叶立德的反应形成鲜明对比，碘鎓叶立德通过转基化产生吡啶鎓叶立德。
Stable aliphatic bromonium ylides (RfSO2)2C--Br+C6H4-p-CF3 (Rf = CF3, CF3(CF2)3) have been synthesized and structurally characterized for the first time. X-ray crystallographic analyses indicated a ylide structure with an sp2 hybridization of the ylide carbanions and with little double-bond character for the ylidic bond. The bromonium ylides selectively undergo transfer of the aryl group to nitrogen heterocycles, such as pyridines, yielding N-arylpyridinium salts. This is in a marked contrast to the reaction of the iodonium ylides, which produces pyridinium ylides through transylidations.