Chemoselective synthesis of imine and secondary amine from nitrobenzene and benzaldehyde by Ni3Sn2 alloy catalyst supported on TiO2

• Published in: Molecular catalysis 2021-04, Vol.505, p.111503, Article 111503
• Main Authors: Yamanaka, Nobutaka, Hara, Takayoshi, Ichikuni, Nobuyuki, Shimazu, Shogo
• Format: Article
• Language: English
• Subjects: Benzaldehyde; Imine; Ni3Sn2/TiO2 alloy catalyst; Nitrobenzene; Secondary amine
• ISSN: 2468-8231; 2468-8231
• DOI: 10.1016/j.mcat.2021.111503

[Display omitted] •Non-noble Ni3Sn2/TiO2 alloy was highly selective for the one-pot reductive imination of benzaldehyde with nitrobenzene under H2 atmosphere.•The one-pot reductive amination was also achieved by Ni3Sn2/TiO2 alloy catalyst.•The catalytic activity of nitrobenzene was much higher than that of benzaldehyde and also the hydrogen activity was higher in a more polar solvent.•Ni3Sn2/TiO2 alloy catalyst was reusable without loss of selectivity. Ni3Sn2/TiO2 alloy catalyst prepared by hydrothermal method was applied for the direct one-pot reductive imination of benzaldehyde with nitrobenzene in the presence of H2 gas as a reducing agent. A desired imine, benzylideneaniline, was produced in an excellent yield of 90% without the formation of any by-products. This is due to the chemoselective molecular recognition of Ni3Sn2 alloy nanoparticles supported on TiO2 for the nitro group over the carbonyl group. By prolonging the reaction time, the desired imine was converted into the corresponding secondary amine, N-phenylbenzylamine, with a remarkably high yield of 80% through the catalytic hydrogenation of the CN bond. Finally, we demonstrated that it was easy to reuse the catalyst up to five times.