Pd catalyzed coupling of 1,2-dibromoarenes and anilines: formation of N,N-diaryl-o-phenylenediamines

1,2-Dibromoarenes were coupled with aniline derivatives to yield N,N-diaryl-o-phenylenediamines in moderate to good yield using a palladium/phosphine or palladium/carbene catalyst system. Under similar conditions, 1,2,4,5-tetrabromobenzene was coupled with aniline derivatives to produce the corresponding tetrasubstituted derivatives which are oxidized on workup to yield azophenines. The sequential reaction of two different anilines with 1-chloro-2-iodobenzene afforded mixed N,N-diaryl-o-phenylenediamines.