A Mild Copper-mediated Intramolecular Amination of Aryl Halides

A unique combination of copper iodide and cesium acetate was found to mediate intramolecular amination of aryl halides under mild conditions. The reaction proceeds at room temperature with primary or N-benzyl amines and at moderately elevated temperatures with other amine derivatives. The reaction has been applied to the formation of 5-, 6-, and 7-membered rings. Remarkably, halogens at the meta-position were retained, providing a definitive advantage over palladium-catalyzed systems.