Butadienic Building Blocks from 2-Nitrothiophene as Precursors of Nitrogen Heterocycles: Intriguing Dichotomic Behavior
作者:Lara Bianchi、Gianluca Giorgi、Massimo Maccagno、Giovanni Petrillo、Valeria Rocca、Fernando Sancassan、Carlo Scapolla、Elda Severi、Cinzia Tavani
DOI:10.1021/jo701460k
日期:2007.11.1
exploitation for the synthesis of heterocycles, sulfides 10 and sulfones 11, derived from the initial ring-opening of 2-nitrothiophene (5) with pyrrolidine/AgNO3 in EtOH, were reacted with diazomethane. Interesting dichotomic behavior was found to yield pyrazolines 17 from 10 and isoxazolines 18 (as the main products) from 11. Intriguingly enough, in the latter case, an unexpected apparent C−C methylene
为了利用它们的合成杂环的目的,使2-硝基噻吩(5)与吡咯烷/ AgNO 3在EtOH中的初始开环衍生的硫化物10和砜11与重氮甲烷反应。发现有趣的二分行为从10产生吡唑啉17和从11产生异恶唑啉18(作为主要产物)。足够令人感兴趣的是,在后一种情况下,还观察到了意外的明显的CC亚甲基插入,从而导致了作为第二产物的同源环丙烷19。