Visible Light-Induced Coupling Cyclization Reaction of α-Diazosulfonium Triflates with α-Oxocarboxylic Acids or Alkynes
作者:Xue-Cen Xu、Dan-Ni Wu、Yong-Xin Liang、Ming Yang、Hai-Yan Yuan、Yu-Long Zhao
DOI:10.1021/acs.joc.2c02267
日期:2022.12.16
provides an efficient method for the generation of diazomethyl radicals from α-diazosulfonium triflates under photochemical conditions. Utilizing the in situ generated diazomethyl radicals as key intermediate, the coupling cyclization reaction of α-diazosulfonium triflates with α-oxocarboxylic acids or alkynes has been achieved. The method affords a diverse set of important 2,5-disubstituted 1,3,4-oxadiazoles
首次开发了α-重氮硫盐的光催化剂自由基裂解。该反应为在光化学条件下从α-重氮三氟甲磺酸盐生成重氮甲基自由基提供了一种有效的方法。利用原位产生的重氮甲基自由基作为关键中间体,实现了α-重氮三氟甲磺酸与α-氧代羧酸或炔烃的偶联环化反应。该方法一步提供了一系列具有出色区域选择性的重要 2,5-二取代 1,3,4-恶二唑和 3,5-二取代-1 H-吡唑。控制实验和 DFT 计算进一步支持涉及自由基途径的反应机制。