A mild alternative to the classical Ullmann coupling for preparation of 3-aryloxy phenols
作者:Bhawyanth Duvvuru、Dinara Amankulova、Sébastien Gauden、Théo Haffemayer、Derrick L.J. Clive
DOI:10.1016/j.tet.2023.133264
日期:2023.3
formed by the action of DBU on 2-bromo-3-(aryloxy)cyclohex-2-en-1-ones which are readily available from 3-chlorocyclohex-2-en-1-ones in two steps: replacement of the chlorine by an aryloxy group (ArOH, K2CO3, refluxing acetone or DMF at 100 °C) and bromination (NBS, DMF, room temperature). The procedure offers a mild alternative to the classical Ullmann reaction and does not require any metal catalyst
m eta -(Aryloxy)phenols 由 DBU 与 2-bromo-3-(aryloxy)cyclohex-2-en-1-ones 作用形成,后者很容易从 3-chlorocyclohex-2-en-1-ones 中获得两个步骤:用芳氧基取代氯(ArOH、K 2 CO 3、在 100 °C 下回流丙酮或 DMF)和溴化(NBS、DMF、室温)。该过程提供了一种温和的替代经典乌尔曼反应的方法,不需要任何金属催化剂。如果原始苯酚 (ArOH) 带有供电子基团,则该方法效果很好,但当取代基吸电子时,芳构化步骤 (DBU) 会伴随 ArO 单元的一些损失。