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.