Hydrogenation of nitroarenes using defined iron–phosphine catalysts

Abstract

A novel iron-catalyzed hydrogenation of nitroarenes to the corresponding amines is reported. An in situ combination of Fe(BF4)2·6H2O and phosphine allows for highly selective hydrogenation of a broad range of aromatic and nitroarenes tolerating different functional groups.

Chemoselective Hydrogenation of Nitroarenes Catalyzed by Molybdenum Sulphide Clusters

“…Advantageously,c ompared to the existingh omogeneous Fe-basedc atalyst system reported to date for the hydrogenation of nitroarenes, no stoichiometric amountso fs trong acids such as trifluoroacetic acid are required to achieve significant reactivity. [6] As expected, no reactivity was observed for the ligand-catalyzed reaction in the absence of complex 3 ( Table 1, entry 15). Hence,w ef ocusedo ur attentiono nt he catalytic activity of the well-defined [Mo 3 S 4 Cl 3 L 3 ] + cluster,L= dnbpy (L1), and its analogousd men (L4)] derivative.…”

“…In this particular case, the use of phosphorous-based ligands led to ad etrimental activity.H owever,i nt he presence of the diimine, 4,4'-dinonyl-2,2'-dipyridyl (dnbpy; L1), 4,4'-di-tert- butyl-2,2'-dipyridyl (dbbpy; L2), or diamine N,N'-dimethylethylenediamine (dmen; L4)l igands, the yield was improved up to 98-99 %( Ta ble 1, entries 5,6,8). Advantageously,c ompared to the existingh omogeneous Fe-basedc atalyst system reported to date for the hydrogenation of nitroarenes, no stoichiometric amountso fs trong acids such as trifluoroacetic acid are required to achieve significant reactivity.…”

“…One of the most fundamental hydrogenation reactions in chemistry involves the use of nitroarenes as starting materials, since the resulting anilines are key building blocks and central intermediates for the chemical,p harmaceutical and agrochemical industries. [3][4][5] Despite the significant progress achieved duringl ast decades in both homogeneous [6][7][8][9][10][11][12][13][14] and heterogeneous catalysis, [15][16][17][18][19][20][21][22][23][24][25][26][27] the environmentally benign chemoselective hydrogenation of nitroarenes conducted atm ild conditions and using non-noble metal based catalysts remains an actuala nd important topic for both academia and industry.…”

“…[42] In this respect, the work of Martins on related molybdenum complexes is also noteworthy. [43] In addition, Royo and Herein, we describe an atom efficient and general protocol for the chemoselective hydrogenation of nitroarenes to anilines catalyzed by well-defined diimino and diamino cubane-type Mo 3 ( [6](BF 4 )), (dmen = N,N'-dimethylethylenediamine) salt. Applying these catalysts, high selectivity in the hydrogenationo ff unctionalized nitroarenes has been accomplished.…”

Chemo‐selective reduction of nitro and nitrile compounds using Ni nanoparticles immobilized on hyperbranched polymer‐functionalized magnetic nanoparticles

“…[34] For example, the catalytic reductions of nitro groups in the presence of metal complexes, metal sulfides or metal powder have various practical drawbacks, such as toxic by-products and difficulty in reuse. [35,36] And the reduction of nitriles with LiAlH 4 and NaBH 4 often leads to a mixture of primary, secondary and tertiary amines. [37,38] [39][40][41][42][43][44][45][46] These catalytic systems constitute a major task for the development of green synthetic methodologies and are of importance in organic chemistry.…”