A new strategy for the synthesis of pyridines from <i>N</i>-propargylic β-enaminothiones
作者:Yilmaz Kelgokmen、Metin Zora
DOI:10.1039/c8ob03180k
日期:——
A new method for the synthesis of 2,4,5-trisubstituted pyridines from N-propargylic β-enaminothiones is reported. β-Enaminothiones were prepared by thionation of the corresponding β-enaminones with Lawesson's reagent. When treated with diisopropylamine in DMF at room temperature, N-propargylic β-enaminothiones yielded 2,4,5-trisubstituted pyridines in moderate to high yields, along with small amounts
报道了一种由N-炔丙基β-烯胺硫酮合成2,4,5-三取代吡啶的新方法。通过用Lawesson试剂对相应的β-烯胺酮进行硫磺化制备β-烯胺酮。当在室温下在DMF中用二异丙胺处理时,N-炔丙基β-烯胺硫酮以中等至高产率生成2,4,5-三取代的吡啶,以及少量的2-亚甲基-2,3-二氢-1,4-硫氮平。发现该反应对于广泛范围的N-炔丙基β-烯氨基硫酮是通用的,并且耐受具有吸电子和供电子取代基的芳族,杂芳族和脂族基团的存在。该方法可以扩展到内部炔烃系结的N-炔丙基β-烯胺硫酮。这种操作简单的方法可以快速访问具有药理学意义的官能化吡啶的文库。