Cyclobutene vs 1,3-Diene Formation in the Gold-Catalyzed Reaction of Alkynes with Alkenes: The Complete Mechanistic Picture
作者:M. Elena de Orbe、Laura Amenós、Mariia S. Kirillova、Yahui Wang、Verónica López-Carrillo、Feliu Maseras、Antonio M. Echavarren
DOI:10.1021/jacs.7b03005
日期:2017.8.2
The intermoleculargold(I)-catalyzed reaction between arylalkynes and alkenes leads to cyclobutenes by a [2 + 2] cycloaddition, which takes place stepwise, first by formation of cyclopropyl gold(I) carbenes, followed by a ring expansion. However, 1,3-butadienes are also formed in the case of ortho-substituted arylalkynes by a metathesis-type process. The corresponding reaction of alkenes with aryl-1
芳基炔烃与烯烃之间的分子间金(I)催化反应通过[2 + 2]环加成反应逐步生成环丁烯,该过程逐步进行,首先形成环丙基金(I)卡宾,然后进行环扩环。但是,在邻位的情况下也会形成1,3-丁二烯复分解型方法取代了芳基炔烃。烯基与芳基炔烃对应的烯烃与芳基-1,3-丁二炔的相应反应仅产生环丁烯。在密度泛函理论计算的基础上,提出了炔烃与烯烃的金(I)催化反应的综合机理,表明生成环丁烯或二烯的两条途径的能量非常接近。关键中间体是环丙基金(I)卡宾,它们是通过逆向布赫纳反应从立体定义的1a,7b-二氢-1 H-环丙烷[ a ]萘独立生成的。
KOMENDANTOV, M. I.;PANASYUK, T. B., ZH. ORGAN. XIMII, 1985, 21, N 7, 1437-1442