Room-Temperature Chemoselective Reduction of Nitro Groups Using Non-noble Metal Nanocatalysts in Water

Abstract

Purely aqueous-phase chemoselective reduction of a wide range of aromatic and aliphatic nitro substrates has been performed in the presence of inexpensive Ni- and Co-based nanoparticle catalysts using hydrazine hydrate as a reducing agent at room temperature. Along with the observed high conversions and selectivities, the studied nanoparticle catalysts also exhibit a high tolerance to other highly reducible groups present in the nitro substrates. The development of these potential chemoselective reduction catalysts also provides a facile route for the synthesis of other industrially important fine chemicals or biologically important compounds, where other highly reducible groups are present in close proximity to the targeted nitro groups.

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

“…These systems require longer reaction time (entries 2, 3 and 6), higher amount of additives (entries 3, 4, 5 and 6), difficulties of catalyst separation from the reaction mixture (entries 5 and 6) and higher amounts of catalyst (entries 3-6). [48,65,66,75] …”

“…Seyed Jamal Tabatabaei Rezaei http://orcid.org/0000-0002-1065-752X Ali Ramazani http://orcid.org/0000-0003-3072-7924 [48] B Not tested P4VP = poly(4-vinylpyridine); PVAm = polyvinylamine; PVP = polyvinylpyrrolidone.…”

“…Ni, Co, Fe and Cu metals or oxides). [47][48][49][50][51][52] To take advantage of these characteristics and also as a part of our ongoing research programme on the design of new catalysts for the development of useful and green synthetic methodologies, [15,16,[53][54][55][56][57][58][59] herein, we report a dendritic magnetic catalyst based on Ni(0) nanoparticles, an inexpensive non-noble metal, for selective hydrogenation of nitro and nitrile compounds in the presence of various reducible substituents such as carboxylic acid, ketone, aldehyde and halogen to the respective amines using NaBH 4 as the reducing agent in the aqueous phase. …”

Synthesis of 6-aryl-5H-quinazolino[4,3-b]quinazolin-8(6H)-one derivatives in ionic liquids catalyzed by iodine

“…Benzaldehydes 1 bearing both electron-donating (such as alkyl and alkoxy groups) and electron-withdrawing substituents (such as halogens) on the benzene ring can be used in the direct reaction to synthesize the desired 6-aryl-5H-quinazolino[4,3-b]quinazolin-8(6H)-one derivatives ( Table 3, entries 1-11) in high yields (86-96 %). In addition, other 2-(2-aminophenyl)quinazolin-4(3H)-ones (2b-2d) were prepared according to the corresponding nitro compounds via a reduction reaction by 50 % hydrazine hydrate [26]. And they were then submitted to react with 1 under the same reaction condition.…”

Polymer supported palladium nanocrystals as efficient and recyclable catalyst for the reduction of nitroarenes to anilines under mild conditions in water

“…Numerous protocols for the reduction of aromatic nitro compounds have been reported in the literature [2][3][4][5][6][7]. They include: 1) hydrogenation under H 2 at various pressures promoted by various catalysts [8], such as Pt/C [9], Rh 3 Ni 1 [10], Pd/C [11][12][13], Pd [14,15] and Rh [16] nanoparticles; 2) catalytic reduction in the presence of CO and H 2 O [17] and photocatalytic hydrogenation [18]; 3) catalytic transfer hydrogenation promoted, for example, by Cu [19], Pd [20], palladium/graphene [21], Au [22], Ru [23] or Fe 3 O 4 -Ni [24] nanoparticles with reducing agents other than molecular hydrogen [25,26], including hydrazine [27][28][29][30][31][32], silanes [33,34] and sodium borohydride [35][36][37][38][39][40][41]. In this last case, large use of Au based catalysts has been explored [42].…”