Oxidative radical cyclizations of malonate enolates induced by the ferrocenium ion - a remarkable influence of enolate counterion and additives
Oxidative radical cyclizations of malonate enolates induced by the ferrocenium ion - a remarkable influence of enolate counterion and additives
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DOI：
10.1039/b102211n
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发表时间：
2001-09-21
期刊：
影响因子：
--
通讯作者：
Hartmann, P
中科院分区：
文献类型：
--
作者：
Jahn, U;Hartmann, P
为了推广可循环使用的单电子转移氧化剂六氟磷酸二茂铁引发丙二酸烯醇酸盐的氧化自由基环化反应，研究了一系列只有反离子不同的烯醇酸盐3的反应活性。只有锂的烯醇酸盐被氧化1，与它们的生成方法无关。化学计量比或亚化学计量比的胺的存在是钠、钾、镁的氧化-环化所必需的。3.3的亲核性、胺的亲核性和卤离子的存在决定了内酯7的环化产率。
To generalize oxidative radical cyclizations of malonate enolates induced by recyclable single electron transfer (SET) oxidant ferrocenium hexafluorophosphate 1, the reactivity of a series of enolates 3 that differ only in their counterions was studied. Only lithium enolates were oxidized by 1, irrespective of their generation method. The presence of amines in stoichiometric or substoichiometric amounts is necessary for SET oxidation-bicyclization of Na, K. Mg. Zn, Si, or Ti enolates 3. The nucleophilicity of 3, the amine, and the presence of halide ions determine the bicyclization yield of lactone 7.