A Mild and Efficient Synthesis of Pyrazolo[1,5-a]pyridines Mediated by Triphenylphosphine/Diiodine
作者:Kai Jia、Wenchao Ma、Chao Jiang、Yintao Yan、Chenming Zhang
DOI:10.1055/a-1705-0247
日期:2022.3
A synthesis of 2,3-diaryl-substituted pyrazolo[1,5-a]pyridines in moderate to good yields under metal-free and mild conditions is described. The intramolecular cyclization of the oxime substrates is mediated by PPh3/I2, which leads directly to pyrazolo[1,5-a]pyridines without the formation of a 2H-azirine intermediate. Various substituents on the aryl rings are compatible with the method.
描述了 2,3-二芳基取代的吡唑并 [1,5-a] 吡啶在无金属和温和条件下以中等至良好的产率合成。肟底物的分子内环化是由 PPh3/I2 介导的,它直接导致吡唑并 [1,5-a] 吡啶而不形成 2H-氮丙啶中间体。芳环上的各种取代基都与该方法兼容。