Unusual C-6 lithiation of 2-chloropyridine-mediated by BuLi-Me2N(CH2)2OLi.: New access to 6-functional-2-chloropyridines and chloro-bis-heterocycles
Unusual C-6 lithiation of 2-chloropyridine-mediated by BuLi-Me2N(CH2)2OLi.: New access to 6-functional-2-chloropyridines and chloro-bis-heterocycles
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DOI：
10.1021/ol005538o
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发表时间：
2000-03-23
期刊：
影响因子：
5.2
通讯作者：
Fort, Y
中科院分区：
文献类型：
--
作者：
Choppin, S;Gros, P;Fort, Y
5-氯吡啶与烷基锂的反应一般发生亲核加成，导致氯原子的丢失，而LDA则只发生邻位金属化反应。本文显示，BuLi-Me 2N（CH 2）（2）OLi（BuLi-LiDMAE）超强碱促进了前所未有的区域选择性C-6锂化。该方法已成功地应用于潜在的有用的氯代吡啶和双杂环类化合物的制备。
The reaction of 5-chloropyridine with alkylithium generally results in nucleophilic addition leading to the loss of chlorine atom while exclusive directed ortho metalation is obtained using LDA. Herein it is shown that the BuLi-Me2N(CH2)(2)OLi (BuLi-LiDMAE) superbase promotes an unprecedented regioselective C-6 lithiation. The method was successfully applied to the preparation of potentially useful chlorinated pyridinic and bis-heterocyclic synthons.