Cycloaddition of Arynes and Cyclic Enol Ethers as a Platform for Access to Stereochemically Defined 1,2-Disubstituted Benzocyclobutenes
作者:Vijayendar R. Yedulla、Padmanava Pradhan、Lijia Yang、Mahesh K. Lakshman
DOI:10.1002/ejoc.201403250
日期:2015.2
important entities in a multitude of areas, such as complex organic synthesis, materials and polymer chemistry, and electronics. Whereas reactions between arynes and ketene acetals have been well studied, reactions with cyclic enol ethers are unknown. A cis olefin geometry in cyclic enol ethers makes them well suited for formal [2 + 2] cycloaddition with arynes than for competing ene reactions, making them
苯并环丁烯(BCB)是许多领域的重要实体,例如复杂的有机合成,材料和聚合物化学以及电子学。尽管已经很好地研究了芳烃和乙烯酮缩醛之间的反应,但是与环烯醇醚的反应是未知的。环状烯醇醚中的顺式烯烃几何结构使其比竞争性烯烃反应更适合与芳烃进行正式的[2 + 2]环加成反应,从而使其成为有效的反应物。2,3-二氢呋喃,2,3-二氢-3H-吡喃,5-丁基-2,3-二氢呋喃,(S)-2-(((苄氧基)甲基)-2,3-二氢呋喃)的反应带有各种芳烃的4-二氧杂环戊二烯是成功的。使用环状烯醇醚的优点是,尽管两性离子中间体似乎是合理的中间产物,但产物仅限于顺式环结。可以利用它来潜在地获得立体化学定义的1,2-二取代BCB。作为演示,用BBr3进行醚环裂解可提供反式官能化BCB,然后用叠氮化物置换可提供顺式衍生物。DFT计算已用于了解与环加成反应有关的三种芳烃的结构,以及在两种情况下的产物比率的预测评估。还通过D