- Biomass Sucrose-Derived Cobalt@Nitrogen-Doped Carbon for Catalytic Transfer Hydrogenation of Nitroarenes with Formic Acid
-
Fabrication of non-noble metal-based heterogeneous catalysts by a facile and cost-effective strategy for ecofriendly catalytic transfer hydrogenation (CTH) is of great significance for organic transformations. A cobalt@nitrogen-doped carbon (Co@NC) catalyst was prepared from renewable biomass-derived sucrose, harmless melamine, and earth-abundant Co(AcO)2 as the precursor materials by hydrothermal treatment and carbonization. Co nanoparticles (NPs) were coated with NC shells and uniformly embedded in the NC framework. The as-obtained Co@NC-600 (carbonized at 600 °C) catalyst exhibited excellent catalytic efficiency for CTH of various functionalized nitroarenes with formic acid (FA) as hydrogen donor in aqueous solution. The uniformly incorporated N atoms in the C matrix and the encapsulated Co NPs showed synergistic effects in the CTH reactions. A mechanistic analysis indicated that the protons from FA were activated by Co sites after being captured by N atoms, and then reacted with nitroarenes adsorbed on the surface of the catalysts to generate the corresponding aromatic amines. Moreover, the catalyst showed excellent durability and reusability without obvious decrease in activity even after five reaction cycles. Thus, the study reported herein provides a cost-effective, sustainable strategy for fabrication of biomass-derived non-noble metal-based catalysts for green and efficient catalytic transformations.
- Yuan, Man,Long, Yu,Yang, Jin,Hu, Xiwei,Xu, Dan,Zhu, Yangyang,Dong, Zhengping
-
p. 4156 - 4165
(2018/11/01)
-
- Catalytic Materials Based on Surface Coating with Poly(ethyleneimine)-Stabilized Gold Nanoparticles
-
Gold nanoparticles (AuNPs) can be obtained from HAuCl4 by using poly(ethyleneimine) (PEI) as both reductant and stabilizing agent. However, the known affinity of PEI for different materials has not been exploited to coat them and turn their surface catalytic. We demonstrate that the irradiation of a solution of HAuCl4 and branched PEI 1800 (bPEI2K) with microwave (MW) yields PEI-stabilized AuNPs (MW-PEI@AuNPs) with an average size of 7.6 nm that are catalytically active in the reduction with NaBH4 of different nitroarenes functionalized with a variety of functional groups. Moreover, the as-prepared MW-PE@-AuNPs show affinity for different materials such as polystyrene (standard spectrophotometry disposal cuvettes), polypropylene (Falcon-type tubes), and silica (Silica gel 60), turning their surface catalytic without any additional synthetic step. This feature was exploited to transform standard tubing (Tygon, poly(ether ether ketone), and stainless steel) into flow reactors by simple passage of a solution of MW-PEI@AuNPs. This straightforward functionalization is especially appealing in the case of the stainless-steel tubing, one of the materials more widely used in HPLC, which is of interest for flow nanocatalysis.
- Ortega-Mu?oz, Mariano,Blanco, Victor,Hernandez-Mateo, Fernando,Lopez-Jaramillo, F. Javier,Santoyo-Gonzalez, Francisco
-
p. 3965 - 3973
(2017/09/14)
-
- Platinum nanoparticles onto pegylated poly(lactic acid) stereocomplex for highly selective hydrogenation of aromatic nitrocompounds to anilines
-
A stereocomplexed poly(lactic acid)-polyethyleneglycol copolymer was synthesized and successfully used as recyclable support for Pt nanoparticles, generated by the metal vapor synthesis technique. The confinement of the Pt nanoparticles were determined by thermal analysis. Hydrogenation reactions of chlorinated aromatic nitro compounds, containing other reducible functional groups, to the corresponding anilines occurred with the latter supported Pt nanoparticles in MeOH under very mild reaction conditions (i.e. 30?°C, p(H2)?=?5.0?bar). The covalently attached polyethyleneglycol polymer significantly increased the catalytic activity of the supported Pt nanoparticles compared to an analogous catalytic system which did not contain polyethyleneglycol but the same sized Pt nanoparticles.
- Oberhauser, Werner,Evangelisti, Claudio,Tiozzo, Cristina,Bartoli, Mattia,Frediani, Marco,Passaglia, Elisa,Rosi, Luca
-
-
- Structure and Catalytic Activity of Cr-Doped BaTiO3 Nanocatalysts Synthesized by Conventional Oxalate and Microwave Assisted Hydrothermal Methods
-
In the present study synthesis of BaTi1-xCrxO3 nanocatalysts (x = 0.0 ≤ x ≤ 0.05) by conventional oxalate and microwave assisted hydrothermal synthesis methods was carried out to investigate the effect of synthesis methods on the physicochemical and catalytic properties of nanocatalysts. These catalysts were thoroughly characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), N2 physisortion, and total acidity by pyridine adsorption method. Their catalytic performance was evaluated for the reduction of nitrobenzene using hydrazine hydrate as the hydrogen source. Structural parameters refined by Rietveld analysis using XRD powder data indicate that BaTi1-xCrxO3 conventional catalysts were crystallized in the tetragonal BaTiO3 structure with space group P4mm, and microwave catalysts crystallized in pure cubic BaTiO3 structure with space group Pm3μm. TEM analysis of the catalysts reveal spherical morphology of the particles, and these are uniformly dispersed in microwave catalysts whereas agglomeration of the particles was observed in conventional catalysts. Particle size of the microwave catalysts is found to be 20-35 nm compared to conventional catalysts (30-48 nm). XPS studies reveal that Cr is present in the 3+ and 6+ mixed valence state in all the catalysts. Microwave synthesized catalysts showed a 4-10-fold increase in surface area and pore volume compared to conventional catalysts. Acidity of the BaTiO3 catalysts improved with Cr dopant in the catalysts, and this could be due to an increase in the number of Lewis acid sites with an increase in Cr content of all the catalysts. Catalytic reduction of nitrobenzene to aniline studies reveals that BaTiO3 synthesized by microwave is very active and showed 99.3% nitrobenzene conversion with 98.2% aniline yield. The presence of Cr in the catalysts facilitates a faster reduction reaction in all the catalysts, and its effect is particularly notable in conventional synthesized catalysts.
- Srilakshmi, Chilukoti,Saraf, Rohit,Prashanth,Rao, G. Mohan,Shivakumara
-
p. 4795 - 4805
(2016/06/09)
-
- Gold supported on titania for specific monohydrogenation of dinitroaromatics in the liquid phase
-
Liquid-phase selective monohydrogenation of various substituted dinitroaromatics to the corresponding valuable nitroanilines was investigated on gold-based catalysts. Special attention was paid to the effect of Au particle size on this monoreduction reaction. Interestingly, TiO2 supported gold catalysts containing a relatively larger mean Au particle size (>5 nm) showed far superior chemoselectivity for specific mono-hydrogenation of dinitroaromatics, with the highest performance attainable for the catalyst bearing Au particles of ca. 7.5 nm. Results in the intermolecular competitive hydrogenation showed that the intrinsic higher accumulation rates of the desired nitroanilines associated with the catalyst possessing larger Au particles were responsible for the high chemoselectivity observed. the Partner Organisations 2014.
- Liu, Shuang-Shuang,Liu, Xiang,Yu, Lei,Liu, Yong-Mei,He, He-Yong,Cao, Yong
-
p. 4162 - 4169
(2014/09/29)
-
- Perovskite-type ferromagnetic BiFeO3 nanopowder: A new magnetically recoverable heterogeneous nanocatalyst for efficient and selective transfer hydrogenation of aromatic nitro compounds into aromatic amines under microwave heating
-
Perovskite-type ferromagnetic BiFeO3 nanopowder was readily synthesized via thermal decomposition of Bi[Fe(CN)6].5H2O complex and characterized using thermal analysis (TGA/DSC), X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), magnetic measurement and Brunauer-Emmett- Teller (BET) specific surface area measurements. The magnetic measurements show a ferromagnetic behavior for the BiFeO3 nanoparticles at room temperature. This nanosized ferromagnetic oxide with an average particle size of approximately 20 nm and a specific surface area of 48.5 m2/g was used as a new magnetically recoverable heterogeneous nanocatalyst for the highly efficient and selective reduction of aromatic nitro compounds into their corresponding amines by using propan-2-ol as the hydrogen donor under microwave irradiation. This method is regio- and chemoselective, clean, inexpensive and compatible with the substrates having hydrogenlyzable or reducible functional groups. As compared with conventional heating, this method is very fast and suitable for the large-scale preparation of different substituted anilines as well as other arylamines. The catalyst can also be reused without loss of activity. Iranian Chemical Society 2012.
- Farhadi,Rashidi
-
p. 1021 - 1031
(2013/02/23)
-
- Perovskite-type LaFeO3 nanoparticles prepared by thermal decomposition of the La[Fe(CN)6]·5H2O complex: A new reusable catalyst for rapid and efficient reduction of aromatic nitro compounds to arylamines with propan-2-ol under microwave irradiation
-
Perovskite-type LaFeO3 nanoparticles were readily synthesized via thermal decomposition of the La[Fe(CN)6]·5H2O complex and characterized by using thermal analysis (TGA), X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and BET specific surface area measurement. This nanosized perovskite-type oxide with an average particle size of 35 nm and a specific surface area 38.5 m2/g was used as a new reusable heterogeneous catalyst for highly efficient and selective reduction of aromatic nitro compounds into their corresponding amines by using propan-2-ol as the hydrogen donor under microwave irradiation. This method is regio- and chemoselective, clean, inexpensive and compatible with the substrates having hydrogenlysable or reducible functional groups. As compared with conventional heating, this method is very fast and suitable for large scale preparation of different substituted anilines as well as other arylamines. The catalyst can also be reused without observable loss of its activity.
- Farhadi, Saeid,Siadatnasab, Firouzeh
-
experimental part
p. 108 - 116
(2011/05/19)
-
- Microwave-assisted rapid and efficient reduction of aromatic nitro compounds to amines with propan-2-ol over Nanosized perovskite-type SmFeO 3 powder as a new recyclable heterogeneous catalyst
-
Nanosized perovskite-type SmFeO3 powder, prepared through the thermal decomposition of Sm[Fe(CN)6].4H2O with an average particle diameter of 28 nm and a specific surface area of 42 m2 g-1, was used as a recyclable heterogeneous catalyst for the efficient and selective reduction of aromatic nitro compounds into the corresponding amines by using propan-2-ol as a hydrogen donor (reducing agent) and KOH as a promoter under microwave irradiation. This highly regio-and chemoselective catalytic method is fast, clean, inexpensive, high yielding and also compatible with the substrates containing easily reducible functional groups. In addition, the nanosized SmFeO3 catalyst can be reused without loss of activity.
- Farhadi, Saeid,Siadatnasab, Firouzeh,Kazem, Maryam
-
experimental part
p. 104 - 108
(2011/06/27)
-
- Highly chemo-and regioselective transfer reduction of aromatic nitro compounds using ammonium formate catalyzed by supported gold nanoparticles
-
A highly chemo-and regioselective reduction of a wide diversity of aromatic nitro compounds to the corresponding amines has been achieved by a combination of gold nanoparticles supported on titania and ammonium formate (HCOONH 4) in ethanol at room temperature. Furthermore, a direct and mild route to formanilides from aromatic nitro compounds bearing different functional groups by reductive N-formylation using the gold-mediated transfer reduction protocol is also established.
- Lou, Xia-Bing,He, Lin,Qian, Yue,Liu, Yong-Mei,Cao, Yong,Fan, Kang-Nian
-
supporting information; experimental part
p. 281 - 286
(2011/04/16)
-
- NiO nanoparticles prepared via thermal decomposition of the bis(dimethylglyoximato)nickel(II) complex: A novel reusable heterogeneous catalyst for fast and efficient microwave-assisted reduction of nitroarenes with ethanol
-
NiO nanoparticles with an average size of 12 nm and a high specific surface area of 88.5 m2/g were easily prepared via the thermal decomposition of the complex Ni(dmgH)2 and were characterized by TGA, XRD, FT-IR, TEM and BET surface area measurement. This nanosized transition metal oxide was used as a new heterogeneous catalyst for the reduction of nitroarenes under microwave irradiation. The efficient and selective reduction of aromatic nitro compounds into their corresponding amines was observed by using ethanol as a hydrogen donor (reducing agent) and KOH as a promoter under microwave irradiation. This highly regio-and chemoselective method is fast, simple, inexpensive, high yielding, clean and compatible with several sensitive functionalities, such as halogens,-OH,-OCH3,-CHO,-COCH 3,-COOH,-COOEt,-CONH2,-CN,-CHCH2 and-NHCOCH3. This method is suitable for the large scale preparation of different substituted anilines as well as other arylamines. In addition, the catalytic activity of nanosized NiO is higher than that of the bulk sample.
- Farhadi, Saeid,Kazem, Maryam,Siadatnasab, Firouzeh
-
scheme or table
p. 606 - 613
(2011/04/16)
-
- Excellent catalytic properties over nanocomposite catalysts for selective hydrogenation of halonitrobenzenes
-
A partially reduced Pt/γ-Fe2O3 magnetic nanocomposite catalyst (Pt/γ-Fe2O3-PR) exhibited excellent catalytic properties in the selective hydrogenation of 2, 4-dinitrochlorobenzene and iodonitrobenzenes. The selectivity to 4-chloro-m-phenylenediamine (4-CPDA), meta-iodoaniline (m-IAN), and para-iodoaniline (p-IAN) reached 99.9%, 99.8%, and 99.4%, respectively, at complete conversion of the substrates. The hydrodehalogenation of 4-CPDA and IANs was fully suppressed for the first time over Pt/γ-Fe2O3-PR. It was found that CO chemisorption on the Pt nanoparticles deposited on the partially reduced γ-Fe2O3 and Fe3O4 nanoparticles was very weak, implying a weak tendency of the electronic back-donation from the Pt nanoparticles to the π* antibonding orbitals of the adsorbed molecules. We believe that this is a cause of the superior selectivity to the haloanilines in the hydrogenation reactions of interest over the Pt/γ-Fe2O3-PR catalyst.
- Liang, Minghui,Wang, Xiaodong,Liu, Hongquan,Liu, Haichao,Wang, Yuan
-
p. 335 - 342
(2008/12/20)
-
- Effect of the electronic structure of the radical anions of 4-substituted 1,2-and 1,3-dinitrobenzenes on the regioselectivity of reduction of the nitro groups
-
Theoretical and experimental regularities of the regioselectivity of the reduction of one of the two nitro groups in unsymmetrical dinitrobenzenes were studied. It was found that the regioselectivity of the formation of isomeric nitroanilines depends on the structure of the substrate and the nature of the reducing agent. The reduction regioselectivity model was verified, according to which radical anion protonation is the major reaction direction. Pleiades Publishing, Inc. 2006.
- Orlov,Begunov,Demidova,Rusakov
-
-
- Chemo- and regioselective reduction of nitroarenes, carbonyls and azo dyes over nickel-incorporated hexagonal mesoporous aluminophosphate molecular sieves
-
Nickel-incorporated hexagonal mesoporous aluminophosphate (NiHMA) molecular sieves were found to be highly efficient heterogeneous catalysts for the chemo- and regioselective reduction of nitroarenes and carbonyl compounds as well as the reductive cleavage of azo functions, including bulkier substrates, by the hydrogen transfer method.
- Selvam, Parasuraman,Mohapatra, Susanta K.,Sonavane, Sachin U.,Jayaram, Radha V.
-
p. 2003 - 2007
(2007/10/03)
-
- Guanidinium nitrate: A novel reagent for aryl nitrations
-
Nitration of various aromatic compounds utilising guanidinium nitrate in 85% sulfuric acid as a nitrating agent has been studied.
- Ramana,Malik,Parihar
-
p. 8681 - 8683
(2007/10/03)
-
- Catalytic transfer hydrogenation of nitro and carbonyl compounds over novel Fe(III) substituted hexagonal mesoporous aluminophosphates
-
Catalytic transfer hydrogenation (CTH) of aromatic nitro and carbonyl compounds over novel Fe(III) substituted hexagonal mesoporous aluminophosphate (FeHMA) molecular sieve catalyst showed excellent regioselectivity/chemoselectivity as well as superior recycling capability. Furthermore, the reduction occurs without affecting other functional groups such as -CN, -CHO, -Cl,-CH3,-OCH3 and -NH2.
- Sonavane, Sachin U.,Mohapatra, Susanta K.,Jayaram, Radha V.,Selvam, Parasuraman
-
p. 142 - 143
(2007/10/03)
-
- Catalytic transfer hydrogenation of nitro arenes, aldehydes, and ketones with propan-2-ol and KOH/NaOH over mixed metal oxides
-
Mixed metal oxides such as ZrO2-NiO, ZrO2-CoO, and ZrO2-Fe2O3 effectively reduce nitro arenes, aldehydes and ketones with propan-2-ol and KOH/NaOH in liquid phase reaction. The catalysts also have considerable level of reusability.
- Sonavane, Sachin U.,Jayaram, Radha V.
-
p. 843 - 849
(2007/10/03)
-
- Heterogeneous catalytic transfer hydrogenation of aromatic nitro and carbonyl compounds over cobalt(II) substituted hexagonal mesoporous aluminophosphate molecular sieves
-
Catalytic transfer hydrogenation of aromatic nitro and carbonyl compounds was carried out using novel cobalt(II) substituted hexagonal mesoporous aluminophosphate molecular sieves. The catalyst showed excellent yield with good recycling capability.
- Mohapatra, Susanta K,Sonavane, Sachin U,Jayaram, Radha V,Selvam, Parasuraman
-
p. 8527 - 8529
(2007/10/03)
-
- Regio- and chemoselective catalytic transfer hydrogenation of aromatic nitro and carbonyl as well as reductive cleavage of azo compounds over novel mesoporous NiMCM-41 molecular sieves
-
(equation presented) Regio-and chemoselective reduction of nitroarenes and carbonyl compounds and reductive cleavage of azo compounds, including bulkier molecules, was achieved by the catalytic transfer hydrogenation method (CTH) using a novel nickel-containing mesoporous silicate (NiMCM-41) molecular sieve catalyst. In addition, the catalyst was also found to behave as a truly heterogeneous catalyst as the yield was practically unaffected.
- Mohapatra, Susanta K.,Sonavane, Sachin U.,Jayaram, Radha V.,Selvam, Parasuraman
-
p. 4297 - 4300
(2007/10/03)
-
- Chemoselective conversion of azides to t-butyl carbamates and amines
-
Azides were converted to the corresponding carbamates using a system of 20 mol% of decaborane (B10H14) and 20 weight% of 10% Pd/C in methanol in the presence of di-tert-butyl dicarbonate at rt in high yields and to the corresponding amines using a system of 10 mol% of decaborane and 20 weight% of 10% Pd/C in methanol in the absence of di-tert-butyl dicarbonate at rt in high yields.
- Jung, Yeon Joo,Chang, Yu Mi,Lee, Ji Hee,Yoon, Cheol Min
-
p. 8735 - 8739
(2007/10/03)
-
- Factors controlling regioselectivity in the reduction of polynitroaromatics in aqueous solution
-
Regioselectivities in the bisulfide reduction of 10 polynitroaromatics (PNAs) to monoamine products have been determined; four of these compounds have also been reduced by anoxic sediments in heterogeneous aqueous solution, and the same regioselectivities are observed. Analyses of Austin Model 1- Solvation Model 2 electrostatic potential surfaces for the radical anions of these polynitroaromatic compounds provides a reliable method of predicting the regioselectivity of their reduction. In particular, at their minimum- energy geometries in aqueous solution, it is the more negative nitro group that is selectively reduced. This is consistent with a mechanism where regioselection occurs upon kinetic protonation at the site of maximum negative charge in the radical anion formed after the first electron transfer to the neutral PNA. Inclusion of solvation effects is critical in order to confidently predict the electrostatic preference for the reduction of one nitro group over the others. Sterically uncongested nitroaromatic radical anions have gas-phase geometries in which the nitro group is coplanar with the aromatic ring. However, ortho substituents and solvation effects both oppose this tendency and can lead to nitro groups that are rotated out of the ring plane and pyramidalized.
- Barrows, Susan E.,Cramer, Christopher J.,Truhlar, Donald G.,Elovitz, Michael S.,Weber, Eric J.
-
p. 3028 - 3038
(2007/10/03)
-
- Selective hydrogenation of polynitroaromatic derivatives with noble metal catalysts in the presence of catalytic amounts of iron
-
Hydrogen over PtO2, 5%Pd(c), PdCl2, or 5%Rh(al2O3), in the presence of catalytic amounts of iron and under mild reaction conditions, resulted in the selective reduction of a variety of polynitroaromatic compounds in high yields.
- Theodoridis,Manfredi,Krebs
-
p. 6141 - 6144
(2007/10/02)
-
- THE NUCLEOPHILIC AROMATIC PHOTOSUBSTITUTIONS OF 4,5-DINITROVERATROLE WITH AMINES. PHOTOREDUCTIONS OF AROMATIC DINITROCOMPOUNDS
-
4,5-Dinitroveratrole is effectively photosubstituted by amines with relatively high ionization potential such as methylamine, n-butylamine and ethyl glycinate, but is mainly photoreduced when amines with relatively low ionization potential, such as dimethyl or trimethylamine are used.The photoreduction of several aromatic dinitrocompounds by triethylamine gives nitroanilines.A mechanistic scheme is proposed embracing our photosubstitutions and photoreductions, based on our experimental results and on MINDO/3 calculations of the ground states and the more likely intermediates.
- Marquet, Jorge,Moreno-Manas, Marcial,Vallribera, Adelina,Virgili, Albert,Bertran, Joan,et al.
-
p. 351 - 360
(2007/10/02)
-
- A Comparison of the Reactions of Some Ethyl N-Arylcarbamates with Those of the Corresponding Acetanilides. I. Nitration
-
The reactions of some ethyl N-arylcarbamates and of the corresponding acetanilides towards 1 equiv. of sodium nitrate in concentrated sulfuric acid at 0-5 deg have been compared with one another and have been found to exhibit significant differences.Except in the case of the unsubstituted analogues, nitration of the carbamates was found to occur significantly more quickly than that of the acetanilides as shown by (i) a representative competitive nitration, and (ii) the fact the carbamates containing a nitro group are nitrated smoothly whereas the corresponding nitroacetanilides are slow to react.On the basis of competitive reactions, it is suggested that this difference in reactivity is due to steric factors.
- Rosevear, Judi,Wilshire, John F. K.
-
p. 723 - 733
(2007/10/02)
-
- Azo pigments derived from 2-hydroxy-3-carboxynaphthalene containing a substituted or unsubstituted phthalimide
-
Azo pigments derived from 2-hydroxy-3-carboxy-naphthalene and containing a substituted or unsubstituted phthalimide radical. The majority give red colorations and due to their excellent fastness properties are particularly valuable for use in surface coatings and resins.
- -
-
-