Studies in Chlorin Chemistry. II. A Versatile Synthesis of Dihydrodipyrrins
作者:William G. O'Neal、William P. Roberts、Indranath Ghosh、Peter A. Jacobi
DOI:10.1021/jo050907l
日期:2005.9.1
Dihydrodipyrrins are key building blocks for the synthesis of hydroporphyrins, many of which have important biological activity. The title compounds were prepared in stereo- and regioselective fashion by a three-step sequence consisting of (1) Pd(0)-catalyzed coupling-cyclization of 2-iodopyrroles with γ-alkynoic acids to afford enelactones of the desired substitution pattern, (2) methylenation at
二氢双吡咯啉是合成氢卟啉的关键组成部分,其中许多具有重要的生物学活性。标题化合物以立体和区域选择性方式通过三步顺序制备,该步骤由以下三个步骤组成:(1)Pd(0)催化2-碘吡咯与γ-链烷酸的偶联环化反应,得到所需取代图案的烯内酯,( 2)使用Petasis试剂在内酯羰基上进行亚甲基化,和(3)原位烯醇醚水解和胺化所得的1,4-二酮以封闭吡咯啉环(9个实例)。每个步骤的收率通常很高,尽管在没有被双取代取代的底物中,芳构化为二吡咯甲烷是竞争性的副反应。