Charting the Chemical Reactivity Space of 2,3-Substituted Furo[2,3-<i>b</i>]pyridines Synthesized via the Heterocyclization of Pyridine-<i>N</i>-oxide Derivatives
作者:Fernando Fumagalli、Flavio da Silva Emery
DOI:10.1021/acs.joc.6b01329
日期:2016.11.4
A concise strategy for the synthesis of 2,3-substituted furo[2,3-b]pyridines is described. Mild, metal-free conditions were successfully applied to produce a range of 2-(alkyl or aryl)-3-ethylcarboxylate-furo[2,3-b]pyridines in yields of 50–91%. Then, the chemical reactivity of this heterocyclic framework was explored to develop straightforward methods for its functionalization. The pyridine moiety
描述了一种合成2,3-取代的呋喃并[2,3- b ]吡啶的简明策略。温和的,无金属的条件已成功地应用于生产一系列2-(烷基或芳基)-3-乙基羧酸酯-呋喃[2,3- b ]吡啶,产率为50-91%。然后,对该杂环框架的化学反应性进行了研究,以开发对其功能化的直接方法。尽管C–H氟化和自由基C–H芳基化过程效率不高,但通过C–H胺化和硼化反应已成功探索了吡啶部分的反应性。另外,尽管呋喃吡啶核在碱性条件下被证明是稳定的,但呋喃部分与肼的开环反应产生了有价值的新吡啶-二氢吡唑啉酮骨架。