Substituted α-Alkylidene Cyclopentenones via the Intramolecular Reaction of Vinyl Cations with Alkenes
作者:Magenta J. Hensinger、Nicholas J. Dodge、Matthias Brewer
DOI:10.1021/acs.orglett.9b04255
日期:2020.1.17
Substituted α-alkylidene cyclopentenones are formed in up to 93% yield by the intramolecular capture of vinyl cations with pendent alkenes. An increased level of substitution at the β-position of the β-hydroxy-α-diazoketone starting material changed the course of the reaction to instead give a lactone product. A reaction path that involves bond reorganization via an acylium ion intermediate is proposed
通过用侧链烯烃分子内捕获乙烯基阳离子,可以高达93%的产率形成取代的α-亚烷基环戊烯酮。在β-羟基-α-重氮酮起始原料的β-位上增加的取代水平改变了反应的过程,而是得到了内酯产物。提出了一种通过酰基离子中间体进行键重组的反应路径来解释这些结果。底物范围研究表明,更稳定的乙烯基阳离子可产生更高的α-亚烷基环戊烯酮收率。这项研究提供了一种温和而有效的方法来形成α-亚烷基环戊烯酮,可补充CH插入和Nazarov环化策略。