A One-Pot Three-Step Synthesis of Z-Trisubstituted Olefins from Arylalkynes and Their Cyclization into 4-Aryl-2H-chromenes
作者:Evelia Rasolofonjatovo、Bret Tréguier、Olivier Provot、Abdallah Hamze、Jean-Daniel Brion、Mouâd Alami
DOI:10.1002/ejoc.201101735
日期:2012.3
Rapid and versatile access to (Z)‐trisubstituted olefins 2 and their cyclization into 4‐aryl‐2H‐chromenes 1 starting fromarylalkynes 3 is described. In a one‐pot fashion, alkynes 3 were first hydrated, then transformed into N‐tosylhydrazones, and finally coupled with ortho‐substituted aryl halides under palladium catalysis to give trisubstituted olefins 2 in good yields and very high to total Z selectivity
描述了快速和通用地获得 (Z)-三取代烯烃 2 及其从芳基炔烃 3 开始环化成 4-芳基-2H-色烯 1 的方法。在一锅法中,炔烃 3 首先水合,然后转化为 N-甲苯磺酰腙,最后在钯催化下与邻位取代的芳基卤化物偶联,以良好的产率和非常高的总 Z 选择性得到三取代的烯烃 2。具有邻位 OMOM(甲氧基甲氧基)取代基的 1,1-二芳基烯烃 2 在对甲苯磺酸的存在下进行快速环化,得到各种 4-芳基-2H-色烯,产率良好至极好。该方法还成功地应用于从所需的芳基丁炔醇 3b 制备 5-芳基-2,3-二氢苯并[b] 氧杂环庚烷 4。