作者:Kiyoshi Sakai、Ken-ichi Yamada、Toshihide Yamasaki、Yuichi Kinoshita、Fumiya Mito、Hideo Utsumi
DOI:10.1016/j.tet.2010.02.004
日期:2010.3
Nitroxyl radicals (nitroxides) with unpaired electron are widely used as antioxidants, contrast agents, and spin probes. Although piperidine nitroxyl radicals have many applications, these are mainly tetramethylpiperidine compounds, and only a few reports consider the substitution of N–O surround as a reaction site, such as 2,2,6,6-tetrasubstituted piperidine nitroxyl radicals. Our results revealed
具有不成对电子的硝基氧自由基(硝基氧)被广泛用作抗氧化剂,造影剂和自旋探针。尽管哌啶硝氧基自由基有许多应用,但它们主要是四甲基哌啶化合物,只有少数报道认为将N–O周围的取代物作为反应位点,例如2,2,6,6-四取代哌啶硝氧基自由基。我们的结果表明,2,2,6,6-四甲基哌啶-4-酮化合物的2,6-位被环己基取代,在温和的条件下可生成2,2,6,6-四取代哌啶-4-酮衍生物反应条件。通过使用15 N标记的NH 4 Cl代替14 NH 4 Cl获得了有趣的结果:得到15具有15 N高含量的N标记的2,2,6,6-四取代哌啶-4-一-1-氧基。总之,在温和的条件下,合成硝基氧基自由基的新方法很容易产生2,2,6,6-四取代的哌啶-4-酮。