Transfer Hydrogenation Of Nitro Compounds Research Articles

Transfer Hydrogenation of Nitro Compounds Catalyzed by Co Atom Cluster Confined in Metal-Organic Frameworks Derived Nitrogen Doped Carbon

Transfer Hydrogenation of Nitro Compounds Catalyzed by Co Atom Cluster Confined in Metal-Organic Frameworks Derived Nitrogen Doped Carbon

Synthesis of an MXene supported Co nanoparticle catalyst for efficient catalytic transfer hydrogenation of nitro compounds with formic acid

The developed 2.6% Co/MXene exhibited excellent catalytic performance for the catalytic transfer hydrogenation of readily available nitroarenes employing HCOOH, leading to the specific generation of essential and versatile formamides.

Cobalt-Doped g-C3N4 Nanosheets for One-Pot Synthesis of Imines under Mild Conditions

The traditional synthesis methods of imines are limited by expensive catalysts, harsh reaction conditions, and low atomic efficiency. The one-pot synthesis of imines using nitrobenzene and benzaldehyde is a promising reaction path. Transition metal catalytic transfer hydrogenation offers advantages in terms of safety. It has attracted the attention of industrial production and academia as an alternative to conventional hydrogenation processes. Herein, we report an environmentally friendly Co/g–C3N4 nanocatalyst that uses inexpensive cobalt as the fundamental source of feedstock; formic acid is applied as the hydrogen donor, and the yield of the synthesis method can reach 96% under mild conditions. Besides, the catalyst proved to be stable and efficient despite five successive cycles of testing. Moreover, the excellent catalytic activity was demonstrated to be derived from the Co–Nx site based on the mechanistic analysis and characterization. For this work, a pathway will be developed to produce transfer hydrogenation of nitro compounds.

Preparation of highly dispersed Ru nanoparticles supported on amine-functionalized magnetic nanoparticles: Efficient catalysts for the reduction of nitro compounds

A supported ruthenium (Ru) nanoparticle on amino-functionalized Fe3O4 (Fe3O4/NH2/Ru) was successfully prepared by a novel and simple one-pot template-free method combined with a metal adsorption-reduction procedure. The characterization results show that the introduced amino group (1,6-hexanediamine) can effectively stabilize the Ru nanoparticles and allow the particles to maintain a narrow size distribution, monodispersity and a regular morphology. Fe3O4/NH2/Ru exhibits excellent catalytic activity for the transfer hydrogenation of nitro compounds by the use of NaBH4 as the hydrogen donor. The higher activity of this catalyst was attributed to the higher dispersion and smaller particle size of Ru nanoparticles, as observed from the characterization results. Moreover, the catalyst can be easily recovered by an external magnetic field, recycled five times and reused without any loss of activity.

Efficient Transfer Hydrogenation of Nitro Compounds to Amines Enabled by Mesoporous N-Stabilized Co-Zn/C.

N-doped metal materials with enhanced stability and abundant porosity have attracted tremendous attention in catalytic reactions. Herein, a simple solvothermal approach was demonstrated to significantly enlarge the pore dimension of conventional microporous zeolitic imidazolate framework (ZIF) incorporated with two kinds of central metals (Co, Zn), while maintaining the original ZIF crystal morphology. Upon further pyrolysis, the resulting mesoporous Co-Zn/N-C material could possess the highly dispersed metal particle on the N-doped carbon, with satisfactory pore volume and surface area. The partial vaporization of Zn and the stabilizing effect of N, illustrated by XRD, HRTEM, HAADF-STEM with mapping, SEM, Raman Spectrum, BET, and TGA, were able to remarkably increase the accessibility of substrate toward active sites and prevent the aggregation of metal particles, respectively. Under mild reaction conditions, the N-stabilized Co-Zn/N-C exhibited good activity and selectivity in transfer hydrogenation of various nitro compounds to corresponding amines, where a synergistic role among Co, Zn, and N was responsible for its superior performance to other tested catalysts. In addition, the N-doped non-noble metal/carbon heterogeneous catalyst was fairly stable and could be reused several times without obvious deactivation.

Highly efficient reduction of nitro compounds: Recyclable Pd/C-catalyzed transfer hydrogenation with ammonium formate or hydrazine hydrate as hydrogen source

Herein, we described a highly efficient heterogeneous Pd/C-catalyzed transfer hydrogenation of nitro compounds for the synthesis of primary amines, using ammonium formate and hydrazine hydrate as hydrogen source independently. The products were obtained with up to >99% yield. Furthermore, gram scale and recycling of catalyst had been tested with well results.

Unprecedented catalytic performance in amine syntheses via Pd/g-C3N4 catalyst-assisted transfer hydrogenation

A Pd/g-C3N4 catalyst exhibited a superb performance in the transfer hydrogenation of nitro compounds to generate their corresponding primary and secondary amines with formic acid as the hydrogen donor in aqueous solution.

Efficient transfer hydrogenation of nitro compounds over a magnetic palladium catalyst

Magnetic hydroxyapatite (HAP) supported Pd nanoparticles (γ-Fe2O3@HAP-Pd) were used for the transfer hydrogenation of nitro compounds with HCOONH4 as hydrogen donors. Aniline was produced in an excellent yield (>99%) in water at 25 °C with 6 equiv. HCOONH4. This process is suitable to a wide range of nitro compounds with excellent yields for most cases. Both the HAP support and the Pd nanoparticles showed a synergistic effect on the transfer hydrogenation of nitro compounds. Furthermore, the γ-Fe2O3@HAP-Pd catalyst was stable.

Pd nanoparticles supported on Fe3O4@C: An effective heterogeneous catalyst for the transfer hydrogenation of nitro compounds into amines

Catalytic reduction of nitro compounds to the amines is of high importance in modern synthetic chemistry. In this study, an efficient method was developed for the transfer hydrogenation of nitro compounds over a magnetic Pd catalyst by the use of NaBH4 as the hydrogen donor. Full nitrobenzene conversion and high selectivity (>99%) of aniline were produced after 1 h at 60 °C in ethanol. The reductions are successfully carried out in presence of a wide variety of other reducible functional groups in the molecule, except halogen and vinyl substitute nitrobenzene. Kinetic studies indicated the active energy for the transfer hydrogenation of nitrobenzene was 20.93 KJ mol−1. The transfer hydrogenation of nitrobenzene was confirmed to proceed via azobenzene as the intermediate. More importantly, the catalyst was very stable without the loss of its catalytic activity.

Catalytic transfer hydrogenation of nitro compounds into amines over magnetic graphene oxide supported Pd nanoparticles

The hydrogenation of nitro compounds into amines is of great importance both from academic and industrial points. In this study, graphene oxide was simultaneously decorated by Fe3O4 and Pd nanoparticles to generate magnetic C–Fe3O4–Pd catalyst, which showed high catalytic activity towards the transfer hydrogenation of nitro compounds by the use of NaBH4 as the hydrogen donor at room temperature. Aniline was produced in a high yield of 99% after 30 min at 25 °C. A wide variety of substituted nitroarenes with other reducible groups were also successfully converted into the corresponding amines with high yields. Kinetic studies revealed the active energy of the transfer hydrogenation of nitrobenzene was 31.1 kJ mol−1. One of the main reasons of the high catalytic activity of the C–Fe3O4–Pd catalyst was due to the fact that the catalyst showed high ability to absorb the substrate on its surface. The transfer hydrogenation of nitrobenzene was confirmed to proceed via azobenzene as the intermediate. More importantly, the catalyst was very stable without the loss of its catalytic activity.

Transfer Hydrogenation of Nitro Compounds with Heteropolyacid Catalysts

12-Molybdophosphoric acid-catalyzed transfer hydrogenation of nitroaromatics in homogeneous phase under mild conditions with hydrazine as hydrogen donor is described. Lower yields were observed withortho- andmeta-substituted than withpara-substituted nitrobenzenes. IR, ESR, NMR, and X-ray photoelectron studies indicated that Mo6+is reduced to Mo5+, which is the active species, and coordinates with the electron-deficient nitro compound; in the process Mo5+is reoxidized.

Catalysis by heteropolyacids: Some new aspects

The following types of reactions catalyzed by heteropolyacids are described: (i) acetalization and ketalization of aldehydes and ketones, (ii) transfer hydrogenation of nitro compounds to amino compounds using sodium borohydride as the hydrogen source, and (iii) selective reduction of nitro compounds and ketones in the presence of aldehydes. The latter is an example of bifunctional catalysis involving acetalization and transfer hydrogenation. The results are presented for various substrates in order to demonstrate the generality of the reactions.