The synthesis of various oligopyridines possessing a carboxylate and at least one bromoethyl group is reported. The bipyridine and terpyridine cores were constructed in good yields via a Stille cross-coupling, starting from bromopicolines and ethyl bromopicolinate. The bromomethyl function was obtained by free radical bromination using NBS in benzene or bromine in benzene/water biphasic mixture. The building of two model podands by nucleophilic displacement of benzylic bromine by an amine or by a phenol group is described.
本研究报道了多种具有一个羧基和至少一个
溴乙基的低聚
吡啶的合成。双
吡啶和terpyridine 核心是通过 Stille 交叉偶联法,从
溴邻
吡啶和
溴邻
吡啶甲酸乙酯开始,以良好的收率合成的。
溴甲基官能团是通过在苯中使用
NBS 或在苯/
水双相混合物中使用
溴进行自由基
溴化得到的。文中介绍了通过胺或
苯酚基团对苄基
溴的亲核置换作用建立两种模型荚膜的方法。