Regioselective Generation of Aryllithiums from Substituted Bromobenzenes XC6H4Br (X = 4-Br, 4-I, 4-CN, 2-CN)
作者:Sergiusz Luliński、Janusz Serwatowski、Magdalena Szczerbińska
DOI:10.1002/ejoc.200701126
日期:2008.4
Selected activated bromobenzenes XC6H4Br (X = 4-Br, 4-I, 4-CN, 2-CN) were successfully deprotonated with lithium 2,2,6,6-tetramethylpiperidide (LTMP) in THF at –80 °C. Thus, 2,5-dibromo-, 2-bromo-5-iodo-, 5-bromo-2-cyano-, and 3-bromo-2-cyanophenyllithium were obtained as stable intermediates and could be converted by subsequent reactions into various functionalized derivatives with good yields. A
选定的活化溴苯 XC6H4Br (X = 4-Br, 4-I, 4-CN, 2-CN) 在 –80 °C 下在 THF 中用 2,2,6,6-四甲基哌啶锂 (LTMP) 成功去质子化。因此,获得了 2,5-二溴-、2-溴-5-碘-、5-溴-2-氰基-和 3-溴-2-氰基苯基锂作为稳定的中间体,并且可以通过后续反应转化为各种功能化的收益率良好的衍生品。讨论了溴与碘和氰基的定向效应的竞争。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)