Chitosan-Promoted Reduction of Nitroaromatics by B2(NMe2)4 under Wet Ball Milling Conditions

Abstract The environmentally friendly reduction of nitro compounds to their corresponding amino compounds has been a practical and challenging task. In this paper, a method has been developed for the reduction of nitroaromatics to aromatic amines by ball milling. The method uses cheap and available tetrakis(dimethylamino)diboron as the reducing agent and NaOH as the base, and the reduction reaction can be achieved by wet ball milling assisted by chitosan. A range of nitroaromatic compounds containing a variety of alkyl, halogen, polynitro, and other groups were chemoselectively reduced to the corresponding anilines in good yields. This protocol will enrich functional group transformations of nitroaromatics to amines.