Novel method for synthesis of aryl hydrazones from α-diazo esters: scope and limitations of nucleophiles
作者:Eiko Yasui、Masao Wada、Norio Takamura
DOI:10.1016/j.tet.2008.11.028
日期:2009.1
Aryl hydrazones, the precursor of Fischer indole synthesis, were easily obtained by nucleophilic addition of aryllithium reagents to diazo esters. The aryl hydrazones were converted into indoles in good yields by heating with thionyl chloride in alcohol. Grignard reagent was also a good nucleophile, whereas organozinc reagent did not react with diazo esters. Aryllithium reagents were prepared by reacting
通过芳基锂试剂向重氮酯的亲核加成,很容易获得费歇尔吲哚合成的前体芳基hydr。通过与亚硫酰氯在醇中加热,将芳基酮以良好的产率转化为吲哚。格氏试剂也是良好的亲核试剂,而有机锌试剂则不会与重氮酯反应。芳基锂试剂是通过使在2-,3-,4-或多位具有各种取代基的芳基溴化物与n- BuLi反应制得的。将衍生自溴吡啶的亲核试剂加到重氮酯中也得到。