Copper-catalyzed Ullmann coupling under ligand- and additive- free conditions. Part 1: O-Arylation of phenols with aryl halides

O-Arylation of a wide variety of substituted phenols and aliphatic alcohols with aryl halides catalyzed by copper iodide under mild ligand and additive free conditions (nBu4NBr, DMF, K3PO4, reflux, 22 h) is accomplished in good to excellent product yields (up to 95%).