Iodine/Visible Light Photocatalysis for Activation of Alkynes for Electrophilic Cyclization Reactions
作者:Yuliang Liu、Bin Wang、Xiaofeng Qiao、Chen-Ho Tung、Yifeng Wang
DOI:10.1021/acscatal.7b00799
日期:2017.6.2
Photocatalytic organic synthesis needs photocatalysts to initiate the reactions and to control the reaction paths. Available photocatalytic systems rely on electron transfer or energy transfer between the photoexcited catalysts and the substrates. We explore a concept based on the photopromoted catalyst coupling to the substrate and the phototriggered catalyst regeneration by elimination from the catalytic
光催化有机合成需要光催化剂来引发反应并控制反应路径。可用的光催化系统依赖于光激发催化剂和底物之间的电子转移或能量转移。我们探索了一种基于光促进的催化剂与底物偶联以及通过消除催化循环而使光引发的催化剂再生的概念。催化量的元素I 2用作可见光光催化剂和π路易斯酸,可实现炔烃C≡C键的直接活化,以进行亲电环化反应,这是炔烃最重要的反应之一。可见光对于炔丙基酰胺的碘环化和中间体的去碘化均至关重要。发现单重态氧在I 2的再生中起关键作用。该系统显示出良好的官能团相容性,可用于生成取代的恶唑醛和吲哚醛。因此,这项研究为通过阳光光催化构建杂环醛衍生物提供了一种容易获得的替代催化体系。