Benzimidazole Nitrogen-Directed, Regiocontrolled, Lithiation of Ferrocenyl- and Phenyl-<i>N</i>-<i>n</i>-butylbenzimidazoles
作者:Damien Hérault、Karel Aelvoet、Alexandrea J. Blatch、Abdullah Al-Majid、Christian A. Smethurst、Andrew Whiting
DOI:10.1021/jo061639+
日期:2007.1.1
synthesized to evaluate the influence of the benzimidazole functional group upon their directed lithiation. The regiochemistry of lithiation was studied, as well as the effect of stabilization of the lithiated species by diamine coordination using tetramethyl- ethylenediamine and (−)-sparteine. The lithiations were followed by reaction with a variety of electrophiles to give the disubstituted 2-ferrocenyl-
2- Ferrocenyl-和2-苯基ñ - ñ -butylbenzimidazoles合成在他们涉及锂化来评估苯并咪唑官能团的影响。研究了锂化的区域化学,以及通过使用四甲基-乙二胺和(-)-天冬氨酸的二胺配位来稳定锂化物种的效果。锂化之后,与多种亲电试剂反应,得到二取代的2-二茂铁基-和2-苯基-N-正丁基苯并咪唑化合物。这项研究表明,尽管简单ñ通过在二茂铁基和苯基上的高度区域控制,可以轻松实现苯并咪唑的正丁基官能化,直接锂化。(-)-Sparteine无法在二茂铁体系中提供不对称诱导作用,其低效率可以通过苯并咪唑氮对锂化物种的分子内配位来解释,这优于Sparteine配位。