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

Abstract

The nitro and nitrile groups in aromatic and aliphatic compounds containing various reducible substituents such as carboxylic acid, ketone, aldehyde and halogen are selectively reduced to the corresponding amines in water as a green solvent with excellent yields by employing NaBH 4 in the presence of Fe 3 O 4 @PAMAM/Ni(0)-b-PEG nanocatalyst. The morphology and structural features of the catalyst were characterized using various microscopic and spectroscopic techniques. The designed catalyst system because of it being covered with hydrophilic polymers is soluble in a wide range of solvents (e.g. water and ethanol) and suitable for immobilizing and stabilizing Ni nanoparticles in aqueous mediums. In addition, the catalyst can be easily recovered from a reaction mixture by applying an external magnetic field and can be reused up to six runs without significant loss of activity.

Cobalt supported on dendronized magnetic nanoparticles: A new highly efficient and recyclable catalyst for the Mizoroki–Heck cross‐coupling reaction

“…Therefore, the model reaction was carried out at different temperatures (Table 2, entries 22, [24][25][26][27]. Therefore, the model reaction was carried out at different temperatures (Table 2, entries 22, [24][25][26][27].…”

“…In the final stage of optimizing the reaction parameters, the effect of temperature on the Mizoroki-Heck reaction was investigated. Therefore, the model reaction was carried out at different temperatures ( Table 2, entries 22, [24][25][26][27]. According to the results, the desired product was obtained in highest yield at 100°C.…”

“…[15] Dendrimers are an attractive type of macromolecules with homogeneous, hyperbranched and spherical structure, with distinguished properties including nanoscale size, multifunctional terminal surfaces, monodispersity, high density of accessible active sites, intensive internal porosity, host-guest potential, and moderate biocompatibility. [20][21][22][23][24][25] So, inspired by the advantages of magnetic PAMAM and the drawbacks of palladium complexes, we were persuaded to immobilize first-row transition metal-PAMAM complexes on MNPs to ameliorate more affordable and eco-friendly heterogeneous palladium-free catalysts for carbon-carbon cross-coupling reaction. [15] These special features make dendrimers promising candidates for effective supports.…”

“…[19] To date there are rare examples of the usage of metal-PAMAM anchored to MNPs with the catalytic demeanor in the organic transformations. [20][21][22][23][24][25] So, inspired by the advantages of magnetic PAMAM and the drawbacks of palladium complexes, we were persuaded to immobilize first-row transition metal-PAMAM complexes on MNPs to ameliorate more affordable and eco-friendly heterogeneous palladium-free catalysts for carbon-carbon cross-coupling reaction. Cobalt-catalyzed couplings have recently been very much considered, because cobalt is non-toxic, readily available, stable in air, low cost and reveals powerful catalytic activities.…”

Designing CoFe2O4/Cellulose@L‐aspargine‐Co Nanocomposite: An Ultra‐Efficient Recyclable Catalyst in the Quick Reduction of Nitro Compounds under Eco‐Friendly Conditions

“…In addition, aromatic amines are important intermediates in pharmaceuticals, industries and dyes [21] . Several methods have been reported for reduction of nitro compounds [22–36] . In many methods, hydrogenation process often ends at an intermediate step or produces by‐products.…”