caa a22 4500 475844114 CHVBK 20180406123909.0 cr unu---uuuuu 170329e20000801xx s 000 0 eng 10.1023/A:1009050804228 doi (NATIONALLICENCE)springer-10.1023/A:1009050804228 Modulating the hydroxylamine accumulation in the hydrogenation of substituted nitroarenes using vanadium-promoted RNi catalysts [Elektronische Daten] [M. Studer, S. Neto, H.-U. Blaser] The effect of vanadium promotion of Raney nickel on aryl hydroxylamine accumulation in the catalytic hydrogenation of electron deficient aromatic nitro compounds was investigated. High accumulation of 70-80% was observed with unmodified Raney nickel. Vanadium promoters were able to modulate the accumulation and depending on the modifier used, an increase (up to 86%) or a decrease (down to 11%) was found. Higher rates were obtained in the former (up to a factor 1.3), lower ones in the latter case (down to a factor 0.1) compared to the unmodified system. Supported or unsupported NH4VO3 was usually the most efficient modifier for obtaining low accumulation and reasonable rates, but the optimum concentration and modification procedure had to be determined for every substrate separately. In cases of low accumulation, the vanadium promoters worked as disproportionation catalysts. Dehalogenation was not significantly influenced by the presence of promoters: in all cases dehalogenation took only place after both the nitro arene and aryl hydroxylamine compound had been consumed completely. Kluwer Academic Publishers, 2000 hydrogenation of aromatic nitro compounds nationallicence Raney nickel nationallicence vanadium promoter nationallicence modified catalysts nationallicence aryl hydroxylamine nationallicence chloronitrobenzene nationallicence Studer M. aut Neto S. aut Blaser H.-U aut Topics in Catalysis Kluwer Academic Publishers-Plenum Publishers 13/3(2000-08-01), 205-212 1022-5528 13:3<205 2000 13 11244 https://doi.org/10.1023/A:1009050804228 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1009050804228 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Studer M. aut NATIONALLICENCE 700 1- Neto S. aut NATIONALLICENCE 700 1- Blaser H.-U aut NATIONALLICENCE 773 0- Topics in Catalysis Kluwer Academic Publishers-Plenum Publishers 13/3(2000-08-01), 205-212 1022-5528 13:3<205 2000 13 11244 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer