Novel Route to Azobenzenes via Pd-Catalyzed Coupling Reactions of Aryl Hydrazides with Aryl Halides, Followed by Direct Oxidations

[reaction: see text] N-Boc aryl hydrazines undergo Pd-catalyzed coupling reactions with aryl halides to provide N-Boc diaryl hydrazines in excellent yields. The resulting N-Boc diaryl hydrazines were directly oxidized with NBS/pyridine in CH(2)Cl(2) at room temperature to the azobenzenes.