cas 587-02-0, 3-ETHYLANILINE | Articles data

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HZSM-5-Catalyzed Isomerization of Alkylanilines
Zeolite HZSM-5 catalyzes the equilibration of toluidines and ethylanilines by an intramolecular 1,2-shift mechanism.The three xylidines with the 1,2,4-substitution pattern are also interconverted by this catalyst.Larger methylanilines are neither formed nor consumed by the catalyst.
Weigert, F. J.
p. 3296 - 3298
(1987)
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Hollow carbon anchored highly dispersed Pd species for selective hydrogenation of 3-nitrostyrene: metal-carbon interaction
Constructing Pd-C bond between Pd particles and defective hollow nanocarbons (h-NCs) not only enables facile H2 dissociation but also diffusion of the dissociated H species, which makes the Pd/h-NC highly active with a TOF of 21?845 h?1 (>80 times higher than that of the best catalyst in literature), selective (97%), and stable (4 cycles) for selective hydrogenation of 3-nitrostyrene to 3-ethylnitrobenze.
Lou, Yang,Xu, Jia,Wu, Honglu,Liu, Jingyue
p. 13248 - 13251
(2018)
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Development of LM98, a Small-Molecule TEAD Inhibitor Derived from Flufenamic Acid
The YAP-TEAD transcriptional complex is responsible for the expression of genes that regulate cancer cell growth and proliferation. Dysregulation of the Hippo pathway due to overexpression of TEAD has been reported in a wide range of cancers. Inhibition of TEAD represses the expression of associated genes, demonstrating the value of this transcription factor for the development of novel anti-cancer therapies. We report herein the design, synthesis and biological evaluation of LM98, a flufenamic acid analogue. LM98 shows strong affinity to TEAD, inhibits its autopalmitoylation and reduces the YAP-TEAD transcriptional activity. Binding of LM98 to TEAD was supported by 19F-NMR studies while co-crystallization experiments confirmed that LM98 is anchored within the palmitic acid pocket of TEAD. LM98 reduces the expression of CTGF and Cyr61, inhibits MDA-MB-231 breast cancer cell migration and arrests cell cycling in the S phase during cell division.
Mélin, Léa,Abdullayev, Shuay,Fnaiche, Ahmed,Vu, Victoria,González Suárez, Narjara,Zeng, Hong,Szewczyk, Magdalena M.,Li, Fengling,Senisterra, Guillermo,Allali-Hassani, Abdellah,Chau, Irene,Dong, Aiping,Woo, Simon,Annabi, Borhane,Halabelian, Levon,LaPlante, Steven R.,Vedadi, Masoud,Barsyte-Lovejoy, Dalia,Santhakumar, Vijayaratnam,Gagnon, Alexandre
p. 2982 - 3002
(2021/08/03)

Metal-Organic Framework-Confined Single-Site Base-Metal Catalyst for Chemoselective Hydrodeoxygenation of Carbonyls and Alcohols
Chemoselective deoxygenation of carbonyls and alcohols using hydrogen by heterogeneous base-metal catalysts is crucial for the sustainable production of fine chemicals and biofuels. We report an aluminum metal-organic framework (DUT-5) node support cobalt(II) hydride, which is a highly chemoselective and recyclable heterogeneous catalyst for deoxygenation of a range of aromatic and aliphatic ketones, aldehydes, and primary and secondary alcohols, including biomass-derived substrates under 1 bar H2. The single-site cobalt catalyst (DUT-5-CoH) was easily prepared by postsynthetic metalation of the secondary building units (SBUs) of DUT-5 with CoCl2 followed by the reaction of NaEt3BH. X-ray photoelectron spectroscopy and X-ray absorption near-edge spectroscopy (XANES) indicated the presence of CoII and AlIII centers in DUT-5-CoH and DUT-5-Co after catalysis. The coordination environment of the cobalt center of DUT-5-Co before and after catalysis was established by extended X-ray fine structure spectroscopy (EXAFS) and density functional theory. The kinetic and computational data suggest reversible carbonyl coordination to cobalt preceding the turnover-limiting step, which involves 1,2-insertion of the coordinated carbonyl into the cobalt-hydride bond. The unique coordination environment of the cobalt ion ligated by oxo-nodes within the porous framework and the rate independency on the pressure of H2 allow the deoxygenation reactions chemoselectively under ambient hydrogen pressure.
Antil, Neha,Kumar, Ajay,Akhtar, Naved,Newar, Rajashree,Begum, Wahida,Manna, Kuntal
supporting information
p. 9029 - 9039
(2021/06/28)

Zeolite-Encaged Isolated Platinum Ions Enable Heterolytic Dihydrogen Activation and Selective Hydrogenations
Understanding the unique behaviors of atomically dispersed catalysts and the origin thereof is a challenging topic. Herein, we demonstrate a facile strategy to encapsulate Ptδ+ species within Y zeolite and reveal the nature of selective hydrogenation over a Pt@Y model catalyst. The unique configuration of Pt@Y, namely atomically dispersed Ptδ+ stabilized by the surrounding oxygen atoms of six-membered rings shared by sodalite cages and supercages, enables the exclusive heterolytic activation of dihydrogen over Ptδ+···O2- units, resembling the well-known classical Lewis pairs. The charged hydrogen species, i.e., H+ and Hδ-, are active reagents for selective hydrogenations, and therefore, the Pt@Y catalyst exhibits remarkable performance in the selective hydrogenation of α,β-unsaturated aldehydes to unsaturated alcohols and of nitroarenes to arylamines.
Dai, Weili,Deng, Xin,Guan, Naijia,Li, Landong,Liu, Runze,Ma, Ding,Qin, Bin,Qin, Xuetao,Wu, Guangjun
supporting information
p. 20898 - 20906
(2021/12/14)

Highly selective hydrogenation of aromatic ketones to alcohols in water: effect of PdO and ZrO2
Pd/ZrO2and PdO/ZrO2composites, containing Pd or PdO nanoparticles, were prepared using an original one-step methodology. These nanocomposites catalyze the hydrogenation of acetophenone (AP) at 1 bar and 10 bar of H2in an aqueous solution. Compared to unsupported Pd or PdO nanoparticles, a remarkable increase in their activity was achieved as a result of interaction with zirconia. An unsupported PdO hydrogenated AP mainly to ethylbenzene (EB), while excellent regioselectivity towards 1-phenylethanol (PE) was obtained with PdO/ZrO2and it was preserved during recycling. Similarly, regioselectivity to PE was higher with Pd/ZrO2compared to unsupported Pd NPs. PdO and zirconia resulted in high selectivity to alcohols in the hydrogenation of substituted acetophenones.
Alsalahi, W.,Trzeciak, A. M.,Tylus, W.
p. 10386 - 10393
(2021/08/09)

Water-soluble NHC-stabilized platinum nanoparticles as recoverable catalysts for hydrogenation in water
The production of water-soluble and stable metallic nanoparticles that can act as recoverable catalysts still remains a challenge. Herein we report the behavior of a series of water-soluble platinum nanoparticles containing different sulfonated NHC ligands as recoverable catalysts for the hydrogenation of aromatic compounds in pure water. The NHC-protected nanoparticles are found to be active and, in general, can be reutilized with no loss of activity or selectivity, although differences are observed depending on the substitution of the NHC ligand or on the substrate being hydrogenated. Pt leaching was determined to be only 0.03-0.29%. TEM images reveal that the shape of the nanoparticles remains unaltered after catalysis. However, the size of the particles increased, although with no influence on their catalytic properties in many instances.
Baquero, Edwin A.,Chaudret, Bruno,De Jesús, Ernesto,Flores, Juan C.,Gonzalez-Arellano, Camino,Ruiz-Varilla, Andrea M.
p. 2874 - 2881
(2020/06/17)

Finely Controlled Platinum Nanoparticles over ZnO Nanorods for Selective Hydrogenation of 3-Nitrostyrene to 3-Vinylaniline
Metallic platinum nanocatalysts play a key role in the liquid-phase selective hydrogenation of substrates with more than one unsaturated bond. However, the commonly applied explanation for the effects of different electronic and geometric properties of catalysts on reactions remains of a heuristic nature due to the difficulties involved in preparing catalysts with precise structure. In this work, we have directly loaded pre-synthesized metallic platinum nanoparticles onto well-structured ZnO nanorods and then subjected them to thermal treatment in a reductive atmosphere for different temperatures. The effects of the different electronic and geometric properties of the catalysts on the selective reduction of 3-nitrostyrene to 3-vinylaniline as a model reaction have been rigorously explored through an analysis of the catalyst structures and the activity and selectivity profiles. Both the electron transfer from zinc to platinum and the decreased platinum surface density as a result of the formation of PtZn intermetallic compounds are key factors for improving the selectivity for the desired 3-vinylaniline. Azobenzene was detected in the reaction with all the Pt/ZnO catalysts after 10–90 min, which indicates that the reaction follows a condensation mechanism.
Gao, Tongtong,Liu, Zhong-Wen,Shi, Wen,Zhang, Bingsen,Zhang, Liyun,Zhang, Ying
(2020/07/13)

Chemoselective Hydrogenation of Nitroaromatics at the Nanoscale Iron(III)–OH–Platinum Interface
Catalytic hydrogenation of nitroaromatics is an environment-benign strategy to produce industrially important aniline intermediates. Herein, we report that Fe(OH)x deposition on Pt nanocrystals to give Fe(OH)x/Pt, enables the selective hydrogenation of nitro groups into amino groups without hydrogenating other functional groups on the aromatic ring. The unique catalytic behavior is identified to be associated with the FeIII-OH-Pt interfaces. While H2 activation occurs on exposed Pt atoms to ensure the high activity, the high selectivity towards the production of substituted aniline originates from the FeIII-OH-Pt interfaces. In situ IR, X-ray photoelectron spectroscopy (XPS), and isotope effect studies reveal that the Fe3+/Fe2+ redox couple facilitates the hydrodeoxygenation of the -NO2 group during hydrogenation catalysis. Benefitting from FeIII-OH-Pt interfaces, the Fe(OH)x/Pt catalysts exhibit high catalytic performance towards a broad range of substituted nitroarenes.
Fu, Gang,Li, Laiyang,Ming, Jiang,Qin, Ruixuan,Ren, Juan,Wang, Yongke,Wang, Yu,Zhang, Wuyong,Zheng, Nanfeng,Zhou, Wenting
p. 12736 - 12740
(2020/06/01)

Recyclable Pd/C catalyzed one-step reduction of carbonyls to hydrocarbons under simple conditions without extra base
The reductions of carbonyls for the synthesis of hydrocarbons were developed with hydrazine hydrate, hydrogen gas and ammonium formate respectively. The simple, mild and efficient conditions were provided by employing recyclable Pd/C as catalyst in normal solvents at 100 °C and the reactions proceeded smoothly to produce the corresponding products with good to excellent yields. And gram-scale reactions and recycling of the catalyst were also demonstrated. Furtherly, the mechanism has been proposed.
Zhou, Xiao-Yu,Chen, Xia
supporting information

(2019/12/06)

Superhydrophobic nickel/carbon core-shell nanocomposites for the hydrogen transfer reactions of nitrobenzene and N-heterocycles
In this work, catalytic hydrogen transfer as an effective, green, convenient and economical strategy is for the first time used to synthesize anilines and N-heterocyclic aromatic compounds from nitrobenzene and N-heterocycles in one step. Nevertheless, how to effectively reduce the possible effects of water on the catalyst by removal of the by-product water, and to further introduce water as the solvent based on green chemistry are still challenges. Since the structures and properties of carbon nanocomposites are easily modified by controllable construction, a one step pyrolysis process is used for controllable construction of micro/nano hierarchical carbon nanocomposites with core-shell structures and magnetic separation performance. Using various characterization methods and model reactions the relationship between the structure of Ni?NCFs (nickel-nitrogen-doped carbon frameworks) and catalytic performance was investigated, and the results show that there is a positive correlation between the catalytic performance and hydrophobicity of catalysts. Besides, the possible catalytically active sites, which are formed by the interaction of pyridinic N and graphitic N in the structure of nitrogen-doped graphene with the surfaces of Ni nanoparticles, should be pivotal to achieving the relatively high catalytic performance of materials. Due to its unique structure, the obtained Ni?NCF-700 catalyst with superhydrophobicity shows extraordinary performances toward the hydrogen transfer reaction of nitrobenzene and N-heterocycles in the aqueous state; meanwhile, it was also found that Ni?NCF-700 still retained its excellent catalytic activity and structural integrity after three cycles. Compared with traditional catalytic systems, our catalytic systems offer a highly effective, green and economical alternative for nitrobenzene and N-heterocycle transformation, and may open up a new avenue for simple construction of structure and activity defined carbon nanocomposite heterogeneous catalysts with superhydrophobicity.
Duan, Zhiying,Liu, Fangfang,Pang, Shaofeng,Su, Qiong,Wang, Yanbin,Xie, Xin,Zhang, Ping,Zhang, Yujing,Zhou, Feng
p. 1996 - 2010
(2020/04/07)

Pd-Nanoparticles immobilized organo-functionalized SBA-15: An efficient heterogeneous catalyst for selective hydrogenation of C–C double bonds of α,β-unsaturated carbonyl compounds
A novel PdNPs/SBA-NH2-LA catalyst has been prepared by a post-synthetic grafting approach via successive anchoring of propylamine (SBA-NH2) and lipoic acid (SBA-NH2-LA) functional groups followed by palladium nanoparticles immobilization. The Physico-chemical properties of the catalyst were extensively investigated by XRD, N2 adsorption-desorption, XPS, FT-IR, and TEM analysis. The PdNPs/SBA-NH2-LA catalyst is found to be highly selective for the hydrogenation of C–C double bonds of α, β-unsaturated carbonyl compounds. Excellent conversion (95–99 %) and selectivity (>99 %) with high turn over frequency (330?1065 h?1) achieved at room temperature under atmospheric hydrogen pressure within 30?90 min of reaction time. This kind of high activity is expected from its structural and textural integrity of the catalyst.
Burri, David Raju,Narani, Anand,Natte, Kishore,Reddy Kannapu, Hari Prasad
(2020/10/05)

Cu3(BTC)2 metal organic framework as heterogeneous solid catalyst for the reduction of styrenes with silane as reducing agent
In this work, a well known metal organic framework, Cu3(BTC)2 (BTC: 1,3,5-benzenetricarboxylate) is reported as a heterogeneous solid catalyst for the reduction of styrene and its derivatives with silane as a reducing agent. Under these reaction conditions, a quantitative conversion of styrene is achieved with very high selectivity to ethylbenzene. A control experiment with pyridine as a catalyst poison revealed that Cu2+ located within the framework plays a crucial role in promoting this reduction. Further, hot-filtration test indicated the absence of metal leaching and Cu3(BTC)2 is used four times with no significant decay in its activity. In addition, the four times used Cu3(BTC)2 was compared with the fresh solid by powder X-ray diffraction, FT-IR, UV–Visible diffuse reflectance spectra, scanning electron microscope and electron paramagnetic resonance methods and observing no significant changes in its structural integrity, crystallinity and morphology. This process is extended for other styrene derivatives to their respective reduced products.
Anbu, Nagaraj,Dhakshinamoorthy, Amarajothi
(2019/08/12)

Hydrogenation of Functionalized Nitroarenes Catalyzed by Single-Phase Pyrite FeS2 Nanoparticles on N,S-Codoped Porous Carbon
Catalytic hydrogenation of nitroarenes is an industrially very important and environmentally friendly process for the production of anilines; however, highly chemoselective reduction of nitroarenes decorated with one or more reducible groups in a nitroarene molecule remains a challenge. Herein, a novel hybrid non-noble iron-based nanocatalyst (named as FeS2/NSC) was developed, which was prepared from biomass as C and N source together with inexpensive Fe(NO3)3 as Fe source through high-temperature pyrolysis in a straightforward and cost-effective procedure. Comprehensive characterization revealed that single-phase pyrite FeS2 nanoparticles with precisely defined composition and uniform size were homogeneously dispersed on N,S-codoped porous carbon with large specific surface area, hierarchical porous channels, and high pore volume. The resultant catalyst FeS2/NSC demonstrated good catalytic activity for hydrogenation of functionalized nitroarenes with good tolerance of various functional groups in water as a sustainable and green solvent. Compared with bulk pyrite FeS2 and other non-noble metal-based heterogeneous catalysts reported in the literature, a remarkably enhanced activity was observed under mild reaction conditions. More importantly, FeS2/NSC displayed exclusive chemoselectivity for the reduction of nitro groups for nitroarenes bearing varying readily reducible groups.
Duan, Yanan,Dong, Xiaosu,Song, Tao,Wang, Zhaozhan,Xiao, Jianliang,Yuan, Youzhu,Yang, Yong
(2019/09/13)

Hydroxyl Assisted Rhodium Catalyst Supported on Goethite Nanoflower for Chemoselective Catalytic Transfer Hydrogenation of Fully Converted Nitrostyrenes
Control of chemoselectivity is a special challenge for the reduction of nitroarenes bearing one or more unsaturated groups. Here, we report a flower-like Rh/α-FeOOH catalyst for the chemoselective hydrogenation of nitrostyrene to vinylaniline over full conversion, which benefits the new functionalized aminostyrene because the multisubstituted aminostyrenes are usually commercially unavailable. This catalyst does not only show desirable selectivity for the vinylanilines, but also exhibits the inertness to various other reducible groups over wide reaction duration. The catalytic selectivity for the reduction of the nitro group towards vinyl group was investigated by the control experiments and FT-IR analysis. We have found that the abundant hydroxyl groups in the α-FeOOH may contribute to the improvement of catalytic activity and selectivity. Furthermore, the catalyst exhibits excellent stability and keeps its catalytic performance even after 6 cycles. (Figure presented.).
Hu, Zenan,Ai, Yongjian,Liu, Lei,Zhou, Junjie,Zhang, Gang,Liu, Hongqi,Liu, Xiangyu,Liu, Zhibo,Hu, Jianshe,Sun, Hong-bin,Liang, Qionglin
supporting information
p. 3146 - 3154
(2019/05/10)

Chemoselective hydrogenation of 3-nitrostyrene over Ag/TiO2-SiO2 catalyst in a flow reactor
Hydrogenation of 3-nitrostyrene in a flow reactor over silver nanoparticles on TiO2-modified silica affords 3-vinylaniline with selectivity of 97% at the full conversion of the substrate.
Nuzhdin, Alexey L.,Bukhtiyarova, Galina A.,Lin, Tingting,Gerasimov, Evgeny Yu.,Bukhtiyarov, Valerii I.
p. 553 - 555
(2019/10/28)

Defect-mediated selective hydrogenation of nitroarenes on nanostructured WS2
Transition metal dichalcogenides (TMDs) are well known catalysts as both bulk and nanoscale materials. Two-dimensional (2-D) TMDs, which contain single- and few-layer nanosheets, are increasingly studied as catalytic materials because of their unique thickness-dependent properties and high surface areas. Here, colloidal 2H-WS2 nanostructures are used as a model 2-D TMD system to understand how high catalytic activity and selectivity can be achieved for useful organic transformations. Free-standing, colloidal 2H-WS2 nanostructures containing few-layer nanosheets are shown to catalyze the selective hydrogenation of a broad scope of substituted nitroarenes to their corresponding aniline derivatives in the presence of other reducible functional groups. Microscopic and computational studies reveal the important roles of sulfur vacancy-rich basal planes and tungsten-terminated edges, which are more abundant in nanostructured 2-D materials than in their bulk counterparts, in enabling the functional group selectivity. At tungsten-terminated edges and on regions of the basal planes having high concentrations of sulfur vacancies, vertical adsorption of the nitroarene is favored, thus facilitating hydrogen transfer exclusively to the nitro group due to geometric effects. At lower sulfur vacancy concentrations on the basal planes, parallel adsorption of the nitroarene is favored, and the nitro group is selectively hydrogenated due to a lower kinetic barrier. These mechanistic insights reveal how the various defect structures and configurations on 2-D TMD nanostructures facilitate functional group selectivity through distinct mechanisms that depend upon the adsorption geometry, which may have important implications for the design of new and enhanced 2-D catalytic materials across a potentially broad scope of reactions.
Sun, Yifan,Darling, Albert J.,Li, Yawei,Fujisawa, Kazunori,Holder, Cameron F.,Liu, He,Janik, Michael J.,Terrones, Mauricio,Schaak, Raymond E.
p. 10310 - 10317
(2019/11/20)

Room Temperature Iron-Catalyzed Transfer Hydrogenation and Regioselective Deuteration of Carbon-Carbon Double Bonds
An iron catalyst has been developed for the transfer hydrogenation of carbon-carbon multiple bonds. Using a well-defined β-diketiminate iron(II) precatalyst, a sacrificial amine and a borane, even simple, unactivated alkenes such as 1-hexene undergo hydrogenation within 1 h at room temperature. Tuning the reagent stoichiometry allows for semi- and complete hydrogenation of terminal alkynes. It is also possible to hydrogenate aminoalkenes and aminoalkynes without poisoning the catalyst through competitive amine ligation. Furthermore, by exploiting the separate protic and hydridic nature of the reagents, it is possible to regioselectively prepare monoisotopically labeled products. DFT calculations define a mechanism for the transfer hydrogenation of propene with nBuNH2 and HBpin that involves the initial formation of an iron(II)-hydride active species, 1,2-insertion of propene, and rate-limiting protonolysis of the resultant alkyl by the amine N-H bond. This mechanism is fully consistent with the selective deuteration studies, although the calculations also highlight alkene hydroboration and amine-borane dehydrocoupling as competitive processes. This was resolved by reassessing the nature of the active transfer hydrogenation agent: experimentally, a gel is observed in catalysis, and calculations suggest this can be formulated as an oligomeric species comprising H-bonded amine-borane adducts. Gel formation serves to reduce the effective concentrations of free HBpin and nBuNH2 and so disfavors both hydroboration and dehydrocoupling while allowing alkene migratory insertion (and hence transfer hydrogenation) to dominate.
Espinal-Viguri, Maialen,Neale, Samuel E.,Coles, Nathan T.,MacGregor, Stuart A.,Webster, Ruth L.
supporting information
p. 572 - 582
(2019/01/08)

Effects of divalent metal ions of hydrotalcites on catalytic behavior of supported gold nanocatalysts for chemoselective hydrogenation of 3-nitrostyrene
The effect of the divalent metal ions on the hydrotalcite (HT) (MAl-HT; M = Mg, Zn, Ni)-supported thiolated Au25 nanoclusters (NCs) as the precatalysts for the chemoselective hydrogenation of 3-nitrostyrene to 3-vinylaniline was investigated. The highest chemoselectivity was obtained over the Au25/ZnAl-HT-300 (calcined at 300 °C) catalyst, with a maintained selectivity of desired product above 98%. The Au25/NiAl-HT-300 catalyst exhibited the highest activity, although the particle size of gold (3.2 nm) was greater than those of the Au25/MgAl-HT-300 (2.2 nm) and Au25/ZnAl-HT-300 (1.7 nm) catalysts. The in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) results of CO adsorption revealed that Ni interacting intimately with gold could be reduced easily, which affected the catalytic behavior of the Au25/NiAl-HT-300 catalyst. Furthermore, the results of the in situ DRIFTS of the adsorption of nitrostyrene at 10 bar of hydrogen suggested that, besides the condensation route, it also followed the direct route to produce aniline on Au25/NiAl-HT-300, which was different from the other two catalysts. This work provides new insight into the support effect over the gold catalysts for selective hydrogenation reactions.
Tan, Yuan,Liu, Xiao Yan,Li, Lin,Kang, Leilei,Wang, Aiqin,Zhang, Tao
p. 174 - 182
(2018/06/08)

Room-Temperature Chemoselective Reduction of 3-Nitrostyrene to 3-Vinylaniline by Ammonia Borane over Cu Nanoparticles
We report a new strategy of controlling catalytic activity and selectivity of Cu nanoparticles (NPs) for the ammonia borane initiated hydrogenation reaction. Cu NPs are active and selective for chemoselective reduction of nitrostyrene to vinylaniline under ambient conditions. Their activity, selectivity, and more importantly, stability are greatly enhanced by their anchoring on WO2.72 nanorods, providing a room-temperature full conversion of nitrostyrene selectively to vinylaniline (>99% yield). Compared with all other catalysts developed thus far, our new Cu/WO2.72 catalyst shows much enhanced hydrogenation selectivity and stability without the use of pressured hydrogen. The synthetic approach demonstrated here can be extended to prepare various M/WO2.72 catalysts (M = Fe, Co, Ni), with M being stabilized for many chemical reactions.
Shen, Mengqi,Liu, Hu,Yu, Chao,Yin, Zhouyang,Muzzio, Michelle,Li, Junrui,Xi, Zheng,Yu, Yongsheng,Sun, Shouheng
p. 16460 - 16463
(2018/12/11)

Chemoselective Hydrogenation with Supported Organoplatinum(IV) Catalyst on Zn(II)-Modified Silica
Well-defined organoplatinum(IV) sites were grafted on a Zn(II)-modified SiO2 support via surface organometallic chemistry in toluene at room temperature. Solid-state spectroscopies including XAS, DRIFTS, DRUV-vis, and solid-state (SS) NMR enhanced by dynamic nuclear polarization (DNP), as well as TPR-H2 and TEM techniques revealed highly dispersed (methylcyclopentadienyl)methylplatinum(IV) sites on the surface ((MeCp)PtMe/Zn/SiO2, 1). In addition, computational modeling suggests that the surface reaction of (MeCp)PtMe3 with Zn(II)-modified SiO2 support is thermodynamically favorable (ΔG = -12.4 kcal/mol), likely due to the increased acidity of the hydroxyl group, as indicated by NH3-TPD and DNP-enhanced 17O{1H} SSNMR. In situ DRIFTS and XAS hydrogenation experiments reveal the probable formation of a surface Pt(IV)-H upon hydrogenolysis of Pt-Me groups. The heterogenized organoplatinum(IV)-hydride sites catalyze the selective partial hydrogenation of 1,3-butadiene to butenes (up to 95%) and the reduction of nitrobenzene derivatives to anilines (up to 99%) with excellent tolerance of reduction-sensitive functional groups (olefin, carbonyl, nitrile, halogens) under mild reaction conditions.
Camacho-Bunquin, Jeffrey,Ferrandon, Magali,Sohn, Hyuntae,Yang, Dali,Liu, Cong,Ignacio-De Leon, Patricia Anne,Perras, Frédéric A.,Pruski, Marek,Stair, Peter C.,Delferro, Massimiliano
p. 3940 - 3951
(2018/03/29)

Significance of surface oxygen-containing groups and heteroatom P species in switching the selectivity of Pt/C catalyst in hydrogenation of 3-nitrostyrene
The selectivity of 3-nitrostyrene (NS) hydrogenation over 0.5 wt-% Pt catalysts supported on carbon materials can be switched simply by changing reduction temperature. When the reduction temperature was 150 °C, 1-ethyl-3-nitrobenzene (ENB) was mainly produced in a selectivity of 93% at a conversion of 95% (at 100 °C). When the reduction was conducted at a higher temperature of 450 °C, in contrast, the main product was switched to 3-aminostyrene (AS) in a selectivity of 96% at a conversion of 91%. That is, the Pt/C catalysts reduced at low and high temperatures could preferentially catalyze the hydrogenation of vinyl and nitro groups of NS, respectively. This switching of the product selectivity may be ascribed to actions of surface oxygen-containing functional groups and surface hetero P species. The quantity and nature of these surface species were examined in detail by a few different methods. For the low-temperature reduced catalyst, surface acidic groups present close to Pt nanoparticles (～2 nm) would interact with the nitro group of a NS molecule and make its vinyl group more likely to interact with the surface active metal species of Pt nanoparticles; this facilitates the hydrogenation of the latter and produces ENB selectively. For the high-temperature reduced catalyst, however, P species would interact with Pt and form Pt-POx complex, on which a NS molecule is likely to be adsorbed with its nitro group, facilitating the selective production of AS via its hydrogenation. It is demonstrated that surface functional groups and surface hetero atoms (like P), in addition to main active metal species (like Pt), should have direct actions in the catalysis for such a catalyst that exposes a larger quantity of surface functional groups and/or hetero atoms compared to the number of supported metal nanoparticles.
Wu, Qifan,Zhang, Bin,Zhang, Chao,Meng, Xiangchun,Su, Xinluona,Jiang, Shan,Shi, Ruhui,Li, Yan,Lin, Weiwei,Arai, Masahiko,Cheng, Haiyang,Zhao, Fengyu
p. 297 - 307
(2018/06/20)

Bulk iron pyrite as a catalyst for the selective hydrogenation of nitroarenes
Bulk iron pyrite (FeS2) functions as an inexpensive, Earth-abundant, off-the-shelf catalyst capable of selectively hydrogenating a broad scope of substituted nitroarenes to their corresponding aniline derivatives using molecular hydrogen.
Morse, James R.,Callejas, Juan F.,Darling, Albert J.,Schaak, Raymond E.
p. 4807 - 4810
(2017/07/11)

Selective hydrogenation of nitroarenes to aminoarenes using a MoO:X-modified Ru/SiO2 catalyst under mild conditions
Modification of Ru/SiO2 with metal oxides (MoOx, WOx, and ReOx) improved the activity and selectivity in the hydrogenation of 3-nitrostyrene to 3-aminostyrene under mild conditions such as 0.3 MPa H2, 303 K, and no solvent. Ru-MoOx/SiO2(Mo/Ru = 1/2) catalyst was applicable to various substituted nitroarenes, providing the corresponding substituted aminoarenes in high yields (85-99%).
Tamura, Masazumi,Yuasa, Naoto,Nakagawa, Yoshinao,Tomishige, Keiichi
supporting information
p. 3377 - 3380
(2017/03/22)

Oxygen surface groups of activated carbon steer the chemoselective hydrogenation of substituted nitroarenes over nickel nanoparticles
Oxygen surface groups of activated carbon, produced by nitric acid treatment, are not only able to prevent Ni particles from sintering but are also able to preferentially interact with the nitro group of substituted nitroarenes. The resulting Ni/ACOX catalyst is highly active and chemoselective for hydrogenation of nitroarenes to produce functionalized anilines and oximes.
Ren, Yujing,Wei, Haisheng,Yin, Guangzhao,Zhang, Leilei,Wang, Aiqin,Zhang, Tao
supporting information
p. 1969 - 1972
(2017/02/15)

ZnAl-Hydrotalcite-Supported Au25Nanoclusters as Precatalysts for Chemoselective Hydrogenation of 3-Nitrostyrene
Chemoselective hydrogenation of 3-nitrostyrene to 3-vinylaniline is quite challenging because of competitive activation of the vinyl group and the nitro group over most supported precious-metal catalysts. A precatalyst comprised of thiolated Au25nanoclusters supported on ZnAl-hydrotalcite yielded gold catalysts of a well-controlled size (ca. 2.0 nm)—even after calcination at 500 °C. The catalyst showed excellent selectivity (>98 %) with respect to 3-vinylaniline, and complete conversion of 3-nitrostyrene over broad reaction duration and temperature windows. This result is unprecedented for gold catalysts. In contrast to traditional catalysts, the gold catalyst is inert with respect to the vinyl group and is only active with regard to the nitro group, as demonstrated by the results of the control experiments and attenuated total reflection infrared spectra. The findings may extend to design of gold catalysts with excellent chemoselectivity for use in the synthesis of fine chemicals.
Tan, Yuan,Liu, Xiao Yan,Zhang, Leilei,Wang, Aiqin,Li, Lin,Pan, Xiaoli,Miao, Shu,Haruta, Masatake,Wei, Haisheng,Wang, Hua,Wang, Fangjun,Wang, Xiaodong,Zhang, Tao
supporting information
p. 2709 - 2713
(2017/02/26)

Rhodium(i) diphenylphosphine complexes supported on porous organic polymers as efficient and recyclable catalysts for alkene hydrogenation
This paper describes the synthesis and characterization of porous polymeric materials as a support for rhodium(i) cationic coordination compounds and their use as heterogeneous catalysts for alkene hydrogenation. The synthetic strategy was the insertion of a vinyl-moiety in a bis(2-chloroethyl)amine precursor to provide highly porous resins with an enriched modifiable surface. The precursors synthesized were N,N-bis(2-chloroethyl)prop-2-en-1-amine (Alk-POL) and N,N-bis(2-chloroethyl)acrylamide (Acy-POL). The resins were obtained through suspension polymerization of methyl acrylate and divinylbenzene as a co-polymer and cross-linker, respectively. The resin surfaces were functionalized with diphenylphosphine groups followed by Rh(i) metal deposition using [Rh(COD)2]BF4 (COD = 1,5-cyclooctadiene) as the catalyst precursor. The Rh-catalysts were characterized by different physicochemical techniques and assessed for their catalytic performances in the heterogeneous hydrogenation of styrene and its derivatives. It was found that the catalytic activities and selectivity of the heterogenized rhodium complex (Rh-Alk-POL and Rh-Acy-POL) in the hydrogenation reactions were comparable to its homogeneous analogue. Analysis of the spent homogeneous resin Rh-Alk-POL catalyst after the first reaction cycle showed the presence of metallic Rh nanoparticles arising from the reduction of the Rh complex. Extensive recycling and Rh leaching studies were carried out for the Rh-Acy-POL catalyst. Both the activity and selectivity could be maintained for at least seven reaction runs and without metal leaching during the reaction cycles. We have also studied the liquid-phase hydrogenation reaction of various styrene m-substituted derivatives. The Rh-Acy-POL catalyst exhibits excellent catalytic activity for hydrogenation of the substrates and only vinyl-group hydrogenation was detected. Finally, the presence of electron-donating/-withdrawing substituents at the meta-position resulted in different rates of vinyl group hydrogenation. This effect was quantified in terms of the Hammett relationship, in which the catalyst displayed a linear correlation between the Hammett substituent constant (σmeta) and the hydrogenation rate.
Campos, Cristian H.,Belmar, Julio B.,Jeria, Solange E.,Urbano, Bruno F.,Torres, Cecilia C.,Alderete, Joel B.
p. 3398 - 3407
(2017/01/24)

A Simple Setup for Transfer Hydrogenations in Flow Chemistry
By using a packed-bed reactor with a palladium/charcoal catalyst and ammonium formate or triethylsilane as hydrogen/hydride source, various functional groups including nitro groups, azides and alkenes can be efficiently reduced by a transfer hydrogenation process under mild conditions in a simple flow system.
Hutchings, Matthew,Wirth, Thomas
p. 1832 - 1835
(2016/07/16)

Structure Evolution and Hydrogenation Performance of IrFe Bimetallic Nanomaterials
By a reverse microemulsion method, a series of IrFe bimetallic nanomaterials of variable morphologies and compositions is synthesized and characterized by 57Fe M?ssbauer spectroscopy, XRD, XPS, and TEM. The structure evolution, such as IrFe alloy nanoparticles to Ir nanoparticles on Fe2O3 flakes, can be simply tuned by changing the molar ratio of Ir to Fe precursors. In terms of Fe, the relative content of IrFe alloy decreased with the increase of Fe species doped, while that of Fe2O3 flakes increased until reached 100%. The as-prepared IrFe bimetallic nanomaterials were served as catalysts for the selective hydrogenation of 3-nitrostyrene to 3-aminostyrene, and it is found that the catalytic performance was related to the morphology and composition of these nanomaterials. Ir1Fe4 was subsequently identified to be a highly active and exceedingly selective catalyst with good stability and recyclability for the hydrogenation of 3-nitrostyrene, underscoring a remarkable "synergistic effect" of the two metals appearing as the form of Ir nanoparticles loaded on Fe2O3 flakes. For Ir nanoparticles, they act as an active species for the hydrogenation; for Fe2O3 flakes, they favor the preferential adsorption of nitro groups, which account for the better chemoselectivity to objective product.
Lu, Ting,Lin, Jian,Liu, Xin,Wang, Xiaodong,Zhang, Tao
p. 2771 - 2779
(2016/04/10)

Silica supported palladium phosphine as a robust and recyclable catalyst for semi-hydrogenation of alkynes using syngas
This work reports a chemo-selective semi-hydrogenation of alkynes to alkenes using silica supported palladium phosphine catalyst with syngas (CO/H2). This developed methodology is an alternative to classical Lindlar catalyst for chemo-selective semi-hydrogenation of alkynes to alkenes. Various alkynes were smoothly convert to alkenes in 60-97% conversion with 85-98% selectivity. The prepared catalyst was well characterized by Field Emmission Gun Scanning Electron Microscopy (FEG-SEM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray Photoelectron Spectroscopy (XPS), Inductively Coupled Plasma- Atomic Emmission Spectroscopy (ICP-AES) analysis techniques. In addition, catalyst was effectively recycled up to four consecutive run without significant loss in its catalytic activity and selectivity.
Jagtap, Samadhan A.,Sasaki, Takehiko,Bhanage, Bhalchandra M.
p. 78 - 86
(2016/01/25)

Chemoselective hydrogenation of 3-nitrostyrene over a Pt/FeOx pseudo-single-atom-catalyst in CO2-expanded liquids
Chemoselective hydrogenation of substituted nitroarenes containing two reducible groups in one molecule is a highly desired approach to the synthesis of functionalized anilines. To make this process environmentally benign, we used a pseudo-single-atom-catalyst Pt/FeOx and investigated the reaction in supercritical CO2 and CO2-expanded toluene. The results showed that supercritical CO2 afforded excellent selectivity but low reactivity due to the limited substrate solubility in the reaction medium. By contrast, when the reaction proceeded in CO2 expanded toluene, both the conversion of 3-nitrostyrene and the selectivity of 3-vinylaniline reached above 95% under optimum conditions while the organic toluene amount could be reduced by 90% compared to that without CO2. The thermodynamic calculations revealed that the solubility of H2 increased while the viscosity of the reaction system decreased with the CO2 pressure, which facilitated the mass transfer and therefore increased the reaction rate meanwhile keeping the selectivity at a high level.
Xu, Gang,Wei, Haisheng,Ren, Yujing,Yin, Jianzhong,Wang, Aiqin,Zhang, Tao
p. 1332 - 1338
(2016/03/09)

Selective hydrogenation method, catalyst used for the method
PROBLEM TO BE SOLVED: To provide a selective hydrogenation method for selectively hydrogenating, into amino groups with high efficiency, nitro groups of an aromatic compound including carbon-carbon double bonds and nitro groups and a selective hydrogenation method for selectively hydrogenating, into hydroxyl groups, aldehyde groups of a terpenoid including carbon-carbon double bonds and aldehyde groups.SOLUTION: The provided selective hydrogenation method of an aromatic compound including carbon-carbon double bonds and nitro groups or a terpenoid including carbon-carbon double bonds and aldehyde groups features the contact, with a hydrogen gas in the presence of a silver-cerium oxide composite comprising silver component particles and cerium oxide supported on surfaces of the silver component particles within a liquid phase including an organic solvent, of an aromatic compound including carbon-carbon double bonds and nitro groups or a terpenoid including carbon-carbon double bonds and aldehyde groups so as to induce a selective hydrogenation and conversion, into amino groups or hydroxyl groups, of the nitro groups included within the aromatic compound or aldehyde groups included within the terpenoid.
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Paragraph 0069-0071

(2017/05/02)

A Reusable Mesoporous Nickel Nanocomposite Catalyst for the Selective Hydrogenation of Nitroarenes in the Presence of Sensitive Functional Groups
The synthesis of aromatic amines from nitroarenes through hydrogenation is an industrially and academically important reaction. In addition, the employment of base metal catalysts in reactions that are preferentially mediated by rare noble metals is a desirable aim in catalysis and an attractive element-conservation strategy. Especially appealing is the observation of novel selectivity patterns with such inexpensive metal catalysts. Herein, we report a novel mesostructured Ni nanocomposite catalyst. It is the first example of a reusable Ni catalyst that is able to hydrogenate nitroarenes selectively to anilines in the presence of highly sensitive functional groups such as C=C bonds and nitrile, aldehyde, and iodo substituents.
Hahn, Gabriela,Ewert, Julia-Katharina,Denner, Christine,Tilgner, Dominic,Kempe, Rhett
p. 2461 - 2465
(2016/08/24)

Photoinduced Reduction of Nitroarenes Using a Transition-Metal-Loaded Silicon Semiconductor under Visible Light Irradiation
We investigated transition-metal-loaded silicon nanoparticles for the photocatalytic reduction of nitroarene derivatives in the presence of formic acid under visible light irradiation. Formic acid assumes the role of both a hydrogen source and a sacrificial reagent for the introduction of electrons into the generated holes of semiconductors. As such, in the presence of formic acid, photocatalytic reactions smoothly proceed under mild conditions without gaseous hydrogen. In particular, palladium-loaded silicon (Pd/Si) was the most suitable catalyst for the conversion of nitrobenzene to aniline, compared to Pt/Si, Ru/Si, and Pd/C.
Tsutsumi, Ken,Uchikawa, Fumito,Sakai, Kentaro,Tabata, Kenji
p. 4394 - 4398
(2016/07/12)

Continuous flow hydrogenation of nitroarenes, azides and alkenes using maghemite-Pd nanocomposites
Maghemite-supported ultra-fine Pd (1-3 nm) nanoparticles, prepared by a simple co-precipitation method, find application in the catalytic continuous flow hydrogenation of nitroarenes, azides, and alkenes wherein they play an important role in the reduction of various functional groups on the surface of maghemite with catalyst loading (~6 wt% Pd). The salient features of the protocol include expeditious formation of reduced products in high yields under near ambient conditions with recycling of the catalyst (up to 12 cycles) without any decrease in selectivity and yield.
Rathi, Anuj K.,Gawande, Manoj B.,Ranc, Vaclav,Pechousek, Jiri,Petr, Martin,Cepe, Klara,Varma, Rajender S.,Zboril, Radek
p. 152 - 160
(2015/12/31)

The ortho effect on the acidic and alkaline hydrolysis of substituted formanilides
The kinetics of formanilides hydrolysis were determined under first-order conditions in hydrochloric acid (0.01-8 M, 20-60°C) and in hydroxide solutions (0.01-3 M, 25 and 40°C). Under acidic conditions, second-order specific acid catalytic constants were used to construct Hammett plots. The ortho effect was analyzed using the Fujita-Nishioka method. In alkaline solutions, hydrolysis displayed both first- and second-order dependence in the hydroxide concentration. The specific base catalytic constants were used to construct Hammett plots. Ortho effects were evaluated for the first-order dependence on the hydroxide concentration. Formanilide hydrolyzes in acidic solutions by specific acid catalysis, and the kinetic study results were consistent with the AAC2 mechanism. Ortho substitution led to a decrease in the rates of reaction due to steric inhibition of resonance, retardation due to steric bulk, and through space interactions. The primary hydrolytic pathway in alkaline solutions was consistent with a modified BAC2 mechanism. The Hammett plots for hydrolysis of meta- and para-substituted formanilides in 0.10 M sodium hydroxide solutions did not show substituent effects; however, ortho substitution led to a decrease in rate constants proportional to the steric bulk of the substituent.
Desai, Salil Dileep,Kirsch, Lee E.
p. 471 - 488
(2015/06/30)

Palladium nanoparticles supported on fibrous-structured silica nanospheres (KCC-1): An efficient and selective catalyst for the transfer hydrogenation of alkenes
An efficient palladium catalyst supported on fibrous silica nanospheres (KCC-1) has been developed for the hydrogenation of alkenes and α,β-unsaturated carbonyl compounds, providing excellent yields of the corresponding products with remarkable chemoselectivity. Comparison (high-resolution TEM, chemisorption) with analogous mesoporous (MCM-41, SBA-15) silica-supported Pd nanocatalysts prepared under identical conditions, demonstrates the advantage of employing the fibrous KCC-1 morphology versus traditional supports because it ensures superior accessibility of the catalytically active cores along with excellent Pd dispersion at high metal loading. This morphology ultimately leads to higher catalytic activity for the KCC-1-supported nanoparticles. The protocol developed for hydrogenation is advantageous and environmentally benign owing to the use of HCOOH as a source of hydrogen, water as a solvent, and because of efficient catalyst recyclability and durability. The recycled catalyst has been analyzed by XPS spectroscopy and TEM showing only minor changes in the oxidation state of Pd and in the morphology after the reaction, thus confirming the robustness of the catalyst.
Qureshi, Ziyauddin S.,Sarawade, Pradip B.,Albert, Matthias,D'Elia, Valerio,Hedhili, Mohamed N.,K?hler, Klaus,Basset, Jean-Marie
p. 635 - 642
(2015/03/05)

Nanoscale magnetic stirring bars for heterogeneous catalysis in microscopic systems
Nanometer-sized magnetic stirring bars containing Pd nanoparticles (denoted as Fe3O4-NC-PZS-Pd) for heterogeneous catalysis in microscopic system were prepared through a facile two-step process. In the hydrogenation of styrene, Fe3O4-NC-PZS-Pd showed an activity similar to that of the commercial Pd/C catalyst, but much better stability. In microscopic catalytic systems, Fe3O4-NC-PZS-Pd can effectively stir the reaction solution within microdrops to accelerate mass transfer, and displays far better catalytic activity than the commercial Pd/C for the hydrogenation of methylene blue in an array of microdroplets. These results suggested that the Fe3O4-NC-PZS-Pd could be used as nanoscale stirring bars in nanoreactors.
Yang, Shuliang,Cao, Changyan,Sun, Yongbin,Huang, Peipei,Wei, Fangfang,Song, Weiguo
supporting information
p. 2661 - 2664
(2015/03/04)

One step synthesis of Pt-Co/TiO2 catalysts by flame spray pyrolysis for the hydrogenation of 3-nitrostyrene
Supported Pt-Co/TiO2 catalysts were prepared by single step flame spray pyrolysis with Pt at 0.5 wt.% and Co loadings varying at 0, 0.1, 0.2, and 0.5 wt.%. Their catalytic activity was tested in the selective hydrogenation of 3-nitrostyrene. Based on the infrared spectroscopy of adsorbed CO results, the addition of Co led to a higher amount of Pt terrace atoms being formed on the catalyst surface which promoted the selectivity towards ethylnitrobenzene. Nevertheless, the positive effect of Co addition can be observed when the catalysts were reduced at 500°C. Both hydrogenation activity and selectivity of vinylaniline over Pt-Co/TiO2 were drastically increased and surpassed those of monometallic Pt/TiO2 due to the strong interaction between Pt-Co and the migration of TiOx species.
Pisduangdaw, Sukanya,Mekasuwandumrong, Okorn,Fujita, Shin-Ichiro,Arai, Masahiko,Yoshida, Hiroshi,Panpranot, Joongjai
p. 11 - 15
(2015/02/02)

Dual optimization approach to bimetallic nanoparticle catalysis: Impact of M1/M2 ratio and supporting polymer structure on reactivity
A dual optimization approach to nanoparticle catalysis is reported in which both the composition of a bimetallic nanoparticle and the electronic properties of the supporting polystyrene-based polymer can be varied to optimize reactivity and chemoselectivity in nitroarene reductions. Ruthenium-cobalt nanoparticles supported on polystyrene are shown to catalyze nitroarene reductions at room temperature with exceptional activity, as compared with monometallic ruthenium catalysts. Both the identity of the second metal and the M1/M2 ratio show a profound effect on the chemoselectivity of nitroarene reductions. These polymer-supported bimetallic catalysts are shown to react with nearly complete chemoselectivity for nitro group reduction over a variety of easily reducible functional groups. The electronic properties of the supporting polymer also have a significant impact on catalysis, in which electron-deficient polystyrenes enable 100% conversion to the aniline product in just 20 min at room temperature. Polymer effects are also shown to influence the mechanism of the reduction reaction, in addition to accelerating the rate, confirming the impact of the polymer structure on catalytic efficiency. These catalysts are easily prepared in a single step from commercial materials and can be readily recycled without loss of activity.
Udumula, Venkatareddy,Tyler, Jefferson H.,Davis, Donald A.,Wang, Hao,Linford, Matthew R.,Minson, Paul S.,Michaelis, David J.
p. 3457 - 3462
(2015/06/16)

Selective Liquid-Phase Hydrogenation of a Nitro Group in Substituted Nitrobenzenes over Au/Al2O3 Catalyst in a Packed-Bed Flow Reactor
A series of substituted nitrobenzenes with the general formula XC6H4NO2 (X=Cl, CH=CH2, or C(O)CH3) dissolved in toluene were reduced with hydrogen over the 1.9 % Au/Al2O3 catalyst at 60-110 C and 10-20 bar in a three-phase packed-bed reactor operating in up-flow mode. Under these conditions, hydrogenation of isomeric ClC6H4NO2 gives exclusively chloroanilines. Hydrogenation of 3-CH2CHC6H4NO2 and 4-CH3C(O)C6H4NO2 leads to the formation of 3-CH2CHC6H4NH2 and 4-CH3C(O)C6H4NH2 with selectivities of up to 93 and 97 % at substrate conversions of 98 and 100 %, respectively. Smooth catalyst deactivation was observed regardless of which substituted nitrobenzene was taken for hydrogenation. According to the results obtained by temperature-programmed oxidation of the spent catalyst, a carbonaceous deposit formed that might block the catalyst surface. Almost complete regeneration of the supported gold catalyst with retention of its high selectivity to hydrogenation of a nitro group was achieved in a flow of air at temperatures up to 400 C to eliminate carbonaceous deposits.
Nuzhdin, Alexey L.,Moroz, Boris L.,Bukhtiyarova, Galina A.,Reshetnikov, Sergey I.,Pyrjaev, Pavel A.,Aleksandrov, Pavel V.,Bukhtiyarov, Valerii I.
p. 1741 - 1749
(2016/01/25)

One step C-N bond formation from alkylbenzene and ammonia over Cu-modified TS-1 zeolite catalyst
A Cu doped TS-1 zeolite sample was applied to catalyze the formation of C-N bonds on both the ring and the side chain of toluene, as well as other alkylbenzenes. A yield of 3.4% of toluidine was obtained for the amination of toluene, with a 1.0% yield of nitrobenzene. Cyanobenzene was also obtained as the C-N bond product on the side chain with a yield of 1.0%. The selectivity for C-N bond formation was 52.4%. The catalyst promoted the formation of a hydroxylamine intermediate from ammonia and hydrogen peroxide, and then the instantaneously generated amino cation reacted with the substrate to form C-N bonds on both the ring and side chain. Cyanobenzene was produced from the dehydration of benzylamine, formed via the reaction of ammonia and toluene. The formation of C-N bonds on the ring had an ortho-orientation advantage for mono-substituted-benzenes. With the increase in the number of methyl substituents, the yield of the ring products decreased, which might be caused by steric hindrance. the Partner Organisations 2014.
Xia, Sheng,Yu, Tianhua,Liu, Huihui,Li, Guiying,Hu, Changwei
p. 3108 - 3119
(2014/08/18)

Nitrogen and oxygen-doped metal-free carbon catalysts for chemoselective transfer hydrogenation of nitrobenzene, styrene, and 3-nitrostyrene with hydrazine
An activated carbon (AC) was treated by hydrogen peroxide and ammonia to dope oxygen and nitrogen on its surface. The surface-functionalized AC catalysts were used for the transfer reduction of nitrobenzene, styrene, and 3-nitrostyrene by hydrazine hydrat
Fujita, Shin-Ichiro,Watanabe, Hiroyuki,Katagiri, Ayaka,Yoshida, Hiroshi,Arai, Masahiko
p. 257 - 262
(2014/07/22)

'From the mole to the molecule': Ruthenium catalyzed nitroarene reduction studied with 'bench', high-throughput and single molecule fluorescence techniques
Single molecule fluorescence microscopy techniques are used to complement conventional catalysis and high-throughput experiments in order to gain a complete picture of a model reaction. In these experiments a model nitroarene is reduced to an amine where, upon reduction, a red shift in absorption/emission, as well as an increase in emission, is observed. The reaction is studied under bulk reaction conditions by NMR spectroscopy and the fluorescence activation makes it possible to also study this reaction at the single molecule level. Fluorescence correlation spectroscopy is a valuable technique in supporting the proposed reaction mechanism and understanding the nature and duration of molecular 'visits' to catalytic sites, where both the starting material, nitroarene, and the amine product have an affinity for the catalyst. The Royal Society of Chemistry 2014.
Carrillo, Adela I.,Stamplecoskie, Kevin G.,Marin, M. Luisa,Scaiano, Juan C.
p. 1989 - 1996
(2014/06/24)

Hydrogenation of substituted aromatic nitrobenzenes over 1% 1.0 wt.%Ir/ZrO2 catalyst: Effect of meta position and catalytic performance
This study is based on 1%Ir/ZrO2 catalyst which was studied in the hydrogenation of aromatic meta-substituted nitrobenzene in liquid phase. The catalyst was prepared by traditional impregnation method using IrCl3 and it has been characterized in terms of temperature-programmed reduction (TPR), ICP-MS, BET area, X-ray diffraction, HR-TEM and XPS measurements. The hydrogenation was evaluated in a batch type reactor at 298 K using ethanol like a solvent. The catalyst showed the formation of zero valent and partially oxidized Iridium (Irδ+) is established post-TPR and XPS characterization. The metal particle size exhibited a wide distribution with mean size 1.8 nm. Ir/ZrO2 was active in all the hydrogenation reactions with elevated conversion and promoted exclusive NO2 group reduction, resulting in the sole formation of the corresponding amino-compound except for CHO and CHCH2 meta-substituted nitrobenzene. We associate this response to a reducible group competition between NO2 and CHO or CHCH2. Reactant activation on the catalyst generates a negatively charged intermediate, consistent with a nucleophilic mechanism. The presence of electron-donating substituents is shown to decrease NO2 reduction rate. This effect is quantified in terms of the Hammett relationship where a linear correlation between the substituent constant (σi) and rate is established and a reaction constant (ρ) 0.639. The data generated provide the first report of the catalytic action of supported Ir in the hydrogenation of meta-substituted nitroarenes and establish the nature of the hydrogenation en liquid phase.
Campos, Cristian,Torres, Cecilia,Oportus, Marcelo,Pe?a, Miguel A.,Fierro,Reyes, Patricio
p. 93 - 100
(2013/08/23)

Facile reduction of nitroarenes into anilines and nitroalkanes into hydroxylamines via the rapid activation of ammonia· borane complex by supported gold nanoparticles
Gold nanoparticles supported on titania catalyse, even at a ppm loading level, the quantitative reduction of nitroarenes into anilines and nitroalkanes into alkylhydroxylamines by the ammonia× borane complex. No dehalohalogenation was seen in the case of chloro- or bromonitroarenes, while ester, cyano, or carboxylic acid functionalities also remain intact. The nitroarene to aniline reduction pathway does not require nitrosoarenes as intermediate products. Copyright
Vasilikogiannaki, Eleni,Gryparis, Charis,Kotzabasaki, Vasiliki,Lykakis, Ioannis N.,Stratakis, Manolis
supporting information
p. 907 - 911
(2013/05/08)

Chemoselective hydrogenation of the olefinic bonds using a palladium/magnesium-lanthanum mixed oxide catalyst
A palladium/magnesium-lanthanum mixed oxide catalyst is found to be an efficient heterogeneous catalyst for the chemoselective hydrogenation of olefinic double bonds in the presence of various functional groups. The catalyst was recovered by centrifugation and reused for several cycles with consistent activity and selectivity. Copyright
Kantam, Mannepalli Lakshmi,Kishore, Ramineni,Yadav, Jagjit,Sudhakar, Medak,Venugopal, Akula
supporting information; experimental part
p. 663 - 669
(2012/04/23)

Layered double hydroxides supported nano palladium: An efficient catalyst for the chemoselective hydrogenation of olefinic bonds
Chemoselective hydrogenation of olefinic double bonds in the presence of various functional groups using layered double hydroxides supported nanopalladium (LDH-Pd0) catalyst is described. LDH-Pd0 was recovered quantitatively by simple filtration and reused several times with consistent activity and selectivity.
Lakshmi, Kantam M.,Parsharamulu,Manorama
p. 115 - 119
(2013/01/15)

Design of a silver-cerium dioxide core-shell nanocomposite catalyst for chemoselective reduction reactions
Shelling out: A core-shell nanocomposite comprising an Ag nanoparticle core and a CeO2 nanoparticle shell catalyzes the chemoselective reduction of both nitrostyrenes and epoxides while retaining the C=C bonds (see picture). Reactions with the core-shell structures show greater chemoselectivity than conventional oxide-supported metal nanoparticles.
Mitsudome, Takato,Mikami, Yusuke,Matoba, Motoshi,Mizugaki, Tomoo,Jitsukawa, Koichiro,Kaneda, Kiyotomi
supporting information; experimental part
p. 136 - 139
(2012/02/16)

Convenient and selective hydrogenation of nitro aromatics with a platinum nanocatalyst under ambient pressure
A convenient and highly selective platinum nanocatalyst was developed for the hydrogenation of nitro aromatics into the corresponding anilines at room temperature under ambient pressure. The platinum catalyst was highly active and selective for the hydrogenation of nitro aromatic compounds. Reducible groups such as aldehyde, ketone and nitrile were untouched during the hydrogenation of the corresponding nitro compounds, and the corresponding anilines were obtained quantitatively.
Xu, Kunling,Zhang, Yuan,Chen, Xiaorong,Huang, Lei,Zhang, Rui,Huang, Jun
supporting information; experimental part
p. 1260 - 1264
(2011/06/25)

Control of chemoselectivity in hydrogenations of substituted nitro- and cyano-aromatics by cluster-derived ruthenium nanocatalysts
Catalyst precursors 1 and 2, made by ion-pairing [H3Ru 4(CO)12]- with NR4+ groups of functionalized MCM-41 and water-soluble poly(diallyldimethylammonium chloride), PDADMAC, respectively, have been evaluated for the chemoselective hydrogenation of nitro- and cyano-benzaldehydes. They are found to be inert toward -NO2 and -CN groups, but active for the reduction of -CHO and >C=C4 (3) or with (5%)Ru-Al2O3, where both the functional groups are hydrogenated. Kinetic analyses have been carried out for the hydrogenation of 4-nitrobenzaldehyde with 2. Existence of an induction time and two competitive equilibriums followed by the product-forming rate-determining step are inferred from the empirically derived rate expression. The kinetic results, structural evidences, and previous work strongly suggest that the observed chemoselectivity is probably a result of the absence of multiple crystal planes, differing in Miller indices, in the cluster-derived catalysts.
Indra, Arindam,Maity, Niladri,Maity, Prasenjit,Bhaduri, Sumit,Lahiri, Goutam Kumar
experimental part
p. 176 - 183
(2012/02/02)