Electron-withdrawing group effect in aryl group of allyl bromides for the successful synthesis of indolizines via a novel [3+3] annulation approach
作者:Sujin Park、Ikyon Kim
DOI:10.1016/j.tet.2015.02.013
日期:2015.4
A new synthetic approach to 6,7-disubstituted indolizines has been developed from pyrrole-2-carboxaldehydes and allyl bromides via two successive base-mediated reactions. As three-carbon units for formation of pyridine moiety of indolizines, allyl bromides easily derived from Morita–Baylis–Hillman (MBH) adducts were employed. We found that positioning electron-withdrawing group(s) at the aromatic ring
通过两个连续的碱介导的反应,由吡咯-2-羧醛和烯丙基溴开发了一种新的合成方法来合成6,7-二取代的吲哚嗪。作为形成吲哚嗪吡啶部分的三碳单元,采用了容易从森田-贝利斯-希尔曼(MBH)加合物衍生的烯丙基溴。我们发现,在烯丙基溴的芳香环上放置吸电子基团是成功闭环的关键,以允许获得具有独特取代方式的吲哚嗪。同样通过该方法组装结构上相关的咪唑并[1,2- a ]吡啶和吡啶并[1,2- a ]吲哚。