Homogenous bimetallic catalysis on amination of ArX and ArX2 in aqueous medium-synergistic effect of dicopper complexes

A dicopper complex [Cu2(bpnp)(OH)(CF3COO)3] (1) (bpnp = 2,7-bis(pyridin-2-yl)-l,8-naphthyridine) was found to be an excellent catalyst on amination of aryl halides and aryl dihalides with ammonia in aqueous solutions leading to the corresponding anilines and aryldiamines, respectively. Catalytic activity of 1 toward amination appears to be superior to those of other mono nuclear copper complexes. Furthermore, the bimetallic catalyst 1 gave exclusively diamination product in the reaction of ArX2 with ammonia, but other copper complexes showed poor selectivity. Kinetic product distribution study suggests that the dicopper metal ions in this catalysis promote the second amination efficiently.

Graphic abstractA highly efficient catalyst for conversion of aryl halides or dihalides with aqueous ammonia into aryl amines or diamines is reported.Figure optionsDownload as PowerPoint slideHighlights
► Efficient amination of aryl halides with aqueous ammonia.
► Double amination of ArX2 can be achieved in one step.
► Synergistic effect of the dimetallic system plays a key role in the activity.