INTRAMOLECULAR ANODIC OLEFIN COUPLING REACTIONS - A USEFUL METHOD FOR CARBON-CARBON BOND FORMATION
INTRAMOLECULAR ANODIC OLEFIN COUPLING REACTIONS - A USEFUL METHOD FOR CARBON-CARBON BOND FORMATION
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DOI：
10.1021/ja00019a038
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发表时间：
1991-09-11
影响因子：
15
通讯作者：
NEW, DG
中科院分区：
文献类型：
--
作者：
HUDSON, CM;MARZABADI, MR;NEW, DG
已经检验了分子内阳极烯烃偶联反应用于影响碳-碳键形成的效用。 研究的所有成功环化均使用烷基或甲硅烷基烯醇醚作为参与的烯烃之一。 烯醇醚可以与简单的烷基烯烃、苯乙烯和烯丙基硅烷偶联，分离产率范围为 57% 至 84%。 发现这些反应对于生成五元环和六元环均有效。 环化的最佳条件是使用网状玻璃碳阳极、未分割电池中的恒流条件以及50%甲醇/四氢呋喃或20%甲醇/二氯甲烷电解质溶液中的高氯酸锂。 使用烯丙基硅烷作为参与的烯烃之一可以实现烯烃产物的区域特异性形成。 除了烯属产物外，这些反应还产生少量甲硅烷基未消除的环化醚产物。 氘标记研究表明，至少一半的醚副产物是由甲氧基（最初是起始烯醇醚的一部分）分子内迁移到碳-β到甲硅烷基而产生的。 发现这种类型的分子内迁移反应参与许多报道的环化反应。
The utility of intramolecular anodic olefin coupling reactions for effecting carbon-carbon bond formation has been examined. All of the successful cyclizations studied utilized either an alkyl or silyl enol ether as one of the participating olefins. The enol ethers could be coupled to simple alkyl olefins, styrenes, and allylsilanes in isolated yields ranging from 57 to 84%. The reactions were found to be effective for generating both five- and six-membered rings. The best conditions for cyclization utilized a reticulated vitreous carbon anode, constant-current conditions in an undivided cell, and a lithium perchlorate in either 50% methanol/tetrahydrofuran or 20% methanol/dichloromethane electrolyte solution. The use of an allylsilane as one of the participating olefins allowed for the regiospecific formation of olefinic products. In addition to the olefinic products, these reactions produced a small amount of a cyclized ether product in which the silyl group had not been eliminated. Deuterium-labeling studies showed that at least half of this ether byproduct arose from intramolecular migration of the methoxy group that was initially part of the starting enol ether to the carbon-beta to the silyl group. Intramolecular migration reactions of this type were found to participate in a number of the reported cyclization reactions.