Efficient synthesis of aryl hydrazines using copper-catalyzed cross-coupling of aryl halides with hydrazine in PEG-400

An efficient and convenient method for the synthesis of aryl hydrazines is described via copper-catalyzed cross-coupling of aryl halides with aqueous hydrazine in PEG-400. This protocol is applicable to both electron-deficient and electron-rich aryl iodides and bromides, and even to sterically hindered substrates, giving aryl hydrazines in good to excellent yields.