Selective Hydrogenation of Aromatic Nitro Compounds Using Unsupported Nickel Catalysts

Abstract

Dedicated to Professor Jean-René Hamon in grateful recognition of his longstanding support for Chilean-French collaborations.Hydrogenation of nitroarenes has attracted renewed attention since it was discovered that non-noble metal catalysts could selectively reduce nitroarenes with sensitive reducible groups.Here, we report the results of the chemoselective catalytic hydrogenation of nitroarenes with unsupported Ni NPs. Initial catalytic assessments showed high activity and selectivity, reaching conversions up to 99 % and 100 % selectivity towards the substituted anilines containing reducible groups such as halogens and nitrile. The recyclability test showed impressive stability of the catalyst up to the fifth run for the target product. Preliminary studies on the catalytic mechanism of the Ni NPs indicate that the nitrosobenzene might not participate as an intermediate in this reaction. Instead, a hydroxylamino adsorbed on the Ni surface is proposed. This work displays an accessible approach for synthesizing an active and selective catalyst for reducing nitroarenes in the presence of facile reducible substituents.

Preparation and Electrocatalytic Activity of Bimetallic Ni-Cu Micro- and Nanoparticles

“…The product of the p-NPh electrocatalytic hydrogenation is p-aminophenol (p-APh), which is widely used in various fields of industry and, in particular, in the pharmaceutical industry for the production of drugs, such as, for example, acetaminophen and many other drugs based on it. It should be noted that there are many studies in the literature that have tested the developed catalytic systems in the transformation of nitrophenols, which are environmentally hazardous toxic substances, to aminophenols, such as, for example, in [19][20][21][22][23][24][25]. Bimetallic Ni/Cu nanowires synthesized by a liquid-phase reduction also exhibited attractive catalytic characteristics in this process [26].…”