Regioselective Protection at <i>N</i>-2 and Derivatization at <i>C</i>-3 of Indazoles
作者:Guanglin Luo、Ling Chen、Gene Dubowchik
DOI:10.1021/jo060607j
日期:2006.7.1
Indazoles are regioselectively protected at N-2 by a 2-(trimethylsilyl)ethoxymethyl (SEM) group using novel conditions. The SEM group can efficiently direct regioselective C-3 lithiation, and the resulting nucleophile can react with a wide range of electrophiles to generate novel indazole derivatives. The SEM group can be removed by treatment with TBAF in THF or aqueous HCl in EtOH.
在新条件下,吲唑在N -2处被2-(三甲基甲硅烷基)乙氧基甲基(SEM)基团区域选择性保护。SEM组可以有效地指导区域选择性C -3锂化,并且所得亲核试剂可以与各种亲电试剂反应生成新的吲唑衍生物。可以通过在THF中的TBAF或在EtOH中的HCl水溶液处理来除去SEM组。