Solid supported Pd(0): an efficient recyclable heterogeneous catalyst for chemoselective reduction of nitroarenes

Unique shortening of carbon chain during reduction of aliphatic nitro compounds to amines in the presence of supercritical isopropanol on alumina

“…Most likely, the nitro-group in compound 3 is reduced to amine 4 through conventional mechanism by catalytic transfer hydrogenation with i-PrOH served as a source of hydrogen [17]. Formation of amine 5 may proceed through the following steps: i-PrOH attaches to a resonance structure of 1-nitropropane 3 to produce oxime 8 which rearranges to carbamate 9; the latter undergoes decarboxylation that gives compound 5.…”

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

“…The direct route is the preferred pathway for the hydrogenation of aromatic nitro compounds promoted by Pd and Au based catalysts [25,37,69], although alternative mechanistic ways have been proposed for Pd/C catalytic systems [70,71].…”

“…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].…”

Preparation of FeO(OH) Modified with Polyethylene Glycol and Its Catalytic Activity on the Reduction of Nitrobenzene with Hydrazine Hydrate

“…Among the hydrogen donors, hydrazine hydrate is a suitable alternative for CTH due to its high activity and low cost. The reduction of nitroarenes with hydrazine hydrate could be catalyzed by a variety of cata-lysts such as Pd [5], Rh [6], Raney Ni [7], actived carbon [8,9], Fe3O4 [10,11] and iron(III) compounds [12], etc. The iron-based compounds are generally cheaper, but their catalytic properties are not desirable.…”