Metal‐Free Oxidative [5+1] Cyclization of 1,5‐Enynes for the Synthesis of Pyrazine 1‐Oxide
作者:Xiao‐Feng Xia、Mingming Zhao、Wei He、Lianghua Zou、Xinxin San、Dawei Wang
DOI:10.1002/adsc.202000756
日期:2020.9.8
A chemo‐selective nitrosylation of 1,5‐enynes via a sequence of NO radical incorporation and intramolecular radical cyclization was reported. The formation of two C−N bonds and one C−O bond make this [5+1] cycloaddition reaction an efficient approach to synthesize pyrazine 1‐oxides in moderate to good yields. Metal‐free, short reaction time and mild conditions render this strategy more practical, eco‐friendly
据报道,通过一系列的NO自由基结合和分子内自由基环化反应,实现了1,5-烯类的化学选择性亚硝基化。两个C–N键和一个C–O键的形成使此[5 + 1]环加成反应成为一种以中等到良好的产率合成吡嗪1-氧化物的有效方法。无金属,短反应时间和温和条件使该策略更加实用,生态友好和方便。该协议的合成效用突出了支架的多样化。