A Practical Route to 2,3-Di-/1,2,3-Trisubstituted Indolizines from<b> α-</b>EWG Ketene <b><i>S</i></b>,<b><i>S</i></b>-Acetals and Their Application in Bis(1-indolizinyl)methane Synthesis
作者:Qun Liu、Shaoguang Sun、Mang Wang*、Hongxia Deng
DOI:10.1055/s-2008-1032144
日期:2008.2
An easy synthesis of 2,3-di-/1,2,3-trisubstituted indo-l-izines has been developed via a formal [3+2] annulation of α-EWG ketene S, S-acetals with 2-pyridine-/2-quinolinecarbaldehyde. The disubstituted products are formed via an intramolecular aza-Michael- addition and subsequent elimination of acetic acid, followed by desulfenylation- assisted by acetic acid, whereas the trisubstituted products are
通过 α-EWG 烯酮 S, S-缩醛与 2-吡啶-的形式 [3+2] 环化,开发了一种简单的 2,3-二-/1,2,3-三取代吲哚-l-茚的合成方法。 /2-喹啉甲醛。二取代产物通过分子内氮杂-迈克尔加成和随后的乙酸消除形成,然后在乙酸辅助下脱硫,而三取代产物通过类似的共轭加成然后消除烷硫醇获得。该策略已应用于通过在催化量的BF 3 ·OEt 2 存在下使2,3-二取代的中氮茚与醛/酮缩合来合成双(1-中氮茚基)甲烷。