Copper-catalyzed arylation of heterocycle C-H bonds

A new method for the direct, copper-catalyzed arylation of heterocycle C-H bonds by aryl halides has been developed. In addition to electron-rich five-membered heterocycles, electron-poor pyridine oxides can also be arylated. The best results are obtained by using a combination of lithium tert -butoxide base, aryl iodide coupling partner, and copper iodide catalyst.