A DFT study of reduction of nitrobenzene to aniline with SnCl2 and hydrochloric acid |
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Authors: | Shinichi Yamabe Shoko Yamazaki |
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Institution: | 1. Graduate School of Materials Science, Nara Institute of Science and Technology (NAIST), Nara, Japan;2. Department of Chemistry, Nara University of Education, Nara, Japan |
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Abstract: | A fundamental reduction reaction, nitrobenzene to aniline in SnCl2 and hydrochloric acid, was investigated by density functional theory (DFT) calculations. First, the change of SnCl2 → SnCl42? → Cl4SnH? was discussed, and the reaction path of SnCl42? + H3O+ → Cl4SnH? + H2O was obtained. Starting from nitrobenzene, six elementary processes were found so as to arrive at the protonated aniline. The hydride ion from Cl4SnH? is connected always to the cationic nitrogen, and the proton is always to oxygens. An intermediate Ph?N+H2OH was obtained, which is isomerized to the para O?H adduct protonated imine via the Bamberger rearrangement. This species may undergo the H? acceptance at the sp2 N+H2 center. In the nitrobenzene reduction, the proton enhances the electrophilicity of the nitrogen center, which makes the hydride shift ready. N?H bonds are formed, and N?O bonds are cleaved both by the proton attach and subsequent H2O elimination and by the formal 1,5] OH shift. Copyright © 2016 John Wiley & Sons, Ltd. |
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Keywords: | density functional theory calculations nitrobenzene reduction transition state water cluster |
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