Selective Reduction of Nitro Group in Aryl Halides Catalyzed by Silver Nanoparticles Modified with β-CD

In this paper, we first report the selective reduction of nitro group in aryl halides catalyzed by silver nanoparticles modified with β-CD. Taking advantage of hydrophobic lumen and donor–acceptor behavior of β-CD, the halogenated alkyl groups on the aromatic ring can be enveloped in the inner cavity that thereby inhibits the reduction of the halogen. For validating the mechanism proposed by us, different silver nanoparticles were applied in parallel experiments. In our experiments, UV-vis spectra and NMR spectra were used to characterize the selectivity. This strategy represents an outstanding improvement on the synthesis of halogenated aromatic amines in comparison with the traditional route, and greatly expands the application of silver nanoparticles in catalytic field.