A mild alternative to the classical Ullmann coupling for preparation of 3-aryloxy phenols

meta-(Aryloxy)phenols are 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. The method works well if the original phenol (ArOH) carries an electron-donating group, but when the substituent is electron-withdrawing the aromatization step (DBU) is accompanied by some loss of the ArO unit. [Display omitted]