Brønsted Acid Catalyzed Friedel–Crafts‐Type Coupling and Dedinitrogenation Reactions of Vinyldiazo Compounds
Brønsted Acid Catalyzed Friedel–Crafts‐Type Coupling and Dedinitrogenation Reactions of Vinyldiazo Compounds
复制标题
布伦斯台德酸催化乙烯基重氮化合物的 Friedel Crafts 型偶联和脱二氮反应
DOI：
10.1002/anie.202004328
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Doyle, Michael P.
中科院分区：
文献类型：
--
作者：
Zheng, Haifeng;Dong, Kuiyong;Wherritt, Daniel;Arman, Hadi;Doyle, Michael P.
描述了使用无金属策略的乙烯基重氮化合物与芳香族化合物的直接Friedel-Crafts型偶联和脱二氮反应。这种布朗斯台德酸催化的方法对于经由乙烯基重氮化合物形成α-重氮基β-碳阳离子（乙烯基重氮离子）、乙烯基碳阳离子和烯丙基或高烯丙基碳阳离子物种是有效的。通过选择合适的亲核试剂选择性地捕获这些中间体，以良好至高的产率和选择性获得三取代的α，β-不饱和酯、β-吲哚取代的重氮酯和二烯。实验的见解牵连的反应机制，涉及选择性质子化的乙烯基重氮化合物和随后释放的二氮，形成乙烯基阳离子，进行分子内的1，3-和1，4-氢化物转移过程以及碎裂。
The direct Friedel–Crafts‐type coupling and dedinitrogenation reactions of vinyldiazo compounds with aromatic compounds using a metal‐free strategy are described. This Brønsted acid catalyzed method is efficient for the formation of α‐diazo β‐carbocations (vinyldiazonium ions), vinyl carbocations, and allylic or homoallylic carbocation species via vinyldiazo compounds. By choosing suitable nucleophilic reagents to selectively capture these intermediates, both trisubstituted α,β‐unsaturated esters, β‐indole‐substituted diazo esters, and dienes are obtained with good to high yields and selectivity. Experimental insights implicate a reaction mechanism involving the selective protonation of vinyldiazo compounds and the subsequent release of dinitrogen to form vinyl cations that undergo intramolecular 1,3‐ and 1,4‐ hydride transfer processes as well as fragmentation.