CuI-catalyzed hydroxylation of aryl bromides under the assistance of 5-bromo-2-(1H-imidazol-2-yl)pyridine and related ligands

A number of substituted 2-pyridin-2-yl-1H-benzoimidazoles and 2-(1H-imidazol-2-yl)pyridines were screened for promoting CuI-catalyzed hydroxylation of aryl bromides, which led to the discovery of the combination of Cut and 5-bromo-2-(1H-imidazol-2-yl)pyridine as an effective catalytic system for this transformation. Both electron-rich and electronic-deficient aryl bromides could be converted into the corresponding substituted phenols in good to excellent yields. (C) 2011 Elsevier Ltd. All rights reserved.