1585-07-5Relevant articles and documents
A uniform bimetallic rhodium/iron nanoparticle catalyst for the hydrogenation of olefins and nitroarenes
Nakamula, Ikuse,Yamanoi, Yoshinori,Imaoka, Takane,Yamamoto, Kimihisa,Nishihara, Hiroshi
, p. 5830 - 5833 (2011)
Mix and more than match: Relative to the catalytic activity of pure Rh nanoparticles in a dendrimer cage, Rh/Fe bimetallic nanoparticles in dendrimers have improved catalytic activity towards the hydrogenation of olefins, and unlike Wilkinson catalyst could catalyze nitroarene hydrogenation (see scheme, G4=4th generation dendrimer).
Microwave assisted hydrogenation of olefins by Pd NPs@polystyrene resin using a gas addition kit: A robust and sustainable protocol
Sharma, Anuj S.,Kaur, Harjinder
, p. 18935 - 18941 (2018)
Polystyrene (PS) resin bead supported palladium nanoparticles (Pd NPs@PS resin) were prepared and their catalytic activity for the hydrogenation of olefins was investigated under microwave heating. The hydrogenation of styrene was effectively carried out in EtOH/H2O, in the presence of 0.00035 mmol of the catalyst to afford the corresponding ethylbenzene in high yield within 20 min under microwave heating. The catalyst efficiency measured in terms of turn over number (TON) and turn over frequency (TOF) was found to be 2829 and 8573 (h-1), respectively. The encapsulated palladium nanoparticles were easily recovered by a simple filtration method and reused several times without significant loss in their catalytic activity. Further, the method showed a wide substrate scope under mild reaction conditions, making it a green versatile and highly sustainable protocol.
Metal-Organic Framework-Confined Single-Site Base-Metal Catalyst for Chemoselective Hydrodeoxygenation of Carbonyls and Alcohols
Antil, Neha,Kumar, Ajay,Akhtar, Naved,Newar, Rajashree,Begum, Wahida,Manna, Kuntal
supporting information, p. 9029 - 9039 (2021/06/28)
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.
Chemoselective Hydrogenation of Olefins Using a Nanostructured Nickel Catalyst
Klarner, Mara,Bieger, Sandra,Drechsler, Markus,Kempe, Rhett
supporting information, p. 2157 - 2161 (2021/05/21)
The selective hydrogenation of functionalized olefins is of great importance in the chemical and pharmaceutical industry. Here, we report on a nanostructured nickel catalyst that enables the selective hydrogenation of purely aliphatic and functionalized olefins under mild conditions. The earth-abundant metal catalyst allows the selective hydrogenation of sterically protected olefins and further tolerates functional groups such as carbonyls, esters, ethers and nitriles. The characterization of our catalyst revealed the formation of surface oxidized metallic nickel nanoparticles stabilized by a N-doped carbon layer on the active carbon support.
Copper(II)-Doped ZIF-8 as a Reusable and Size Selective Heterogeneous Catalyst for the Hydrogenation of Alkenes using Hydrazine Hydrate
Nagarjun, Nagarathinam,Arthy, Kannan,Dhakshinamoorthy, Amarajothi
, p. 2108 - 2119 (2021/06/01)
In recent years, synthesis of mixed-metal organic frameworks has received considerable attention due to their superior performance than with mono-metallic metal organic frameworks (MOFs). In the present manuscript, Cu2+ ions are doped within the framework of ZIF-8 (ZIF: Zeolitic Imidazolate Frameworks) to obtain Cu@ZIF-8 and is characterized by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), UV-Visible diffuse reflectance spectra (DRS), scanning electron microscope (SEM) and transmission electron microcope (TEM) studies. The reaction conditions are optimized with styrene as a model substrate using Cu@ZIF-8 as a solid catalyst. Heterogeneity of the reaction is confirmed by leaching test and the solid is reusable for three recycles with no diminishing activity. Further, the structural integrity of Cu@ZIF-8 is also retained after hydrogenation of styrene as evidenced by powder X-ray diffraction. The size selective catalysis of Cu@ZIF-8 is demonstrated by comparing the activity of Cu2+ ions adsorbed over ZIF-8 solid (Cu/ZIF-8) in the hydrogenation of 1-hexene, 1-octene, cyclohexene, cyclooctene and t-stilbene. The catalytic results indicate that Cu/ZIF-8 shows superior activity than Cu@ZIF-8 for all these olefins due to the lack of diffusion to access the active sites (Cu2+). In contrast, Cu@ZIF-8 exhibits higher activity for those olefins with lower molecular dimensions (1-hexene, 1-octene) than the pores of ZIF-8 indicating the facile diffusion of these substrates inside the pores ZIF-8 while poor activity is observed with t-stilbene due to its larger molecular dimension than the pore apertures of ZIF-8. These catalytic data clearly establish the size selective hydrogenation of Cu@ZIF-8 due to the effective confinement provided by ZIF-8 framework and the presence of the active sites within the framework. Furthermore, this is the first report showing the size selective hydrogenation of olefins promoted by Cu@ZIF-8 (mixed-metal MOFs) compared to other noble metal nanoparticles (NPs) embedded over MOFs as catalysts.
Reductive Deamination with Hydrosilanes Catalyzed by B(C6F5)3
Fang, Huaquan,Oestreich, Martin
supporting information, p. 11394 - 11398 (2020/05/25)
The strong boron Lewis acid tris(pentafluorophenyl)borane B(C6F5)3 is known to catalyze the dehydrogenative coupling of certain amines and hydrosilanes at elevated temperatures. At higher temperature, the dehydrogenation pathway competes with cleavage of the C?N bond and defunctionalization is obtained. This can be turned into a useful methodology for the transition-metal-free reductive deamination of a broad range of amines as well as heterocumulenes such as an isocyanate and an isothiocyanate.
Palladium Nanocatalysts Encapsulated on Porous Silica @ Magnetic Carbon-Coated Cobalt Nanoparticles for Sustainable Hydrogenation of Nitroarenes, Alkenes and Alkynes.
Purohit, Gunjan,Rawat, Diwan S.,Reiser, Oliver
, p. 569 - 575 (2019/11/19)
Palladium nanoparticles were impregnated on porous silica shell carbon-coated cobalt nanoparticles, resulting in a magnetically retrievable material that was evaluated in the catalytic hydrogenation of nitroarenes, alkenes and alkynes. The prepared material was characterized by HR-XRD, HR-TEM, elemental mapping EDX, ICP-OES and XPS analyses, revealing highly dispersed palladium nanoparticles within the porous platform that could account for the high activity observed. Mild reaction conditions, easy retrievability of the catalyst with the aid of an external magnet, recycling in four runs with a total leaching of 19 ppm (1.2 % of the initially employed Pd amount), and high stability makes this material attractive for sustainable and environmentally benign applications.
Hydrogenation reaction method
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Paragraph 0034; 0149-0152, (2020/05/14)
The invention relates to a hydrogenation reaction method, and belongs to the technical field of organic synthesis. The hydrogenation reaction method provided by the invention comprises the following steps: carrying out a hydrogen transfer reaction on a hydrogen acceptor compound, pinacol borane and a catalyst in a solvent in the presence of proton hydrogen, so that the hydrogen acceptor compound is subjected to a hydrogenation reaction; the catalyst is one or more than two of a palladium catalyst, an iridium catalyst and a rhodium catalyst; the hydrogen acceptor compound comprises one or morethan two functional groups of carbon-carbon double bonds, carbon-carbon triple bonds, carbon-oxygen double bonds, carbon-nitrogen double bonds, nitrogen-nitrogen double bonds, nitryl, carbon-nitrogentriple bonds and epoxy. The method is mild in reaction condition, easy to operate, high in yield, short in reaction time, wide in substrate application range, suitable for carbon-carbon double bonds,carbon-carbon triple bonds, carbon-oxygen double bonds, carbon-nitrogen double bonds, nitrogen-nitrogen double bonds, nitryl, carbon-nitrogen triple bonds and epoxy functional groups, good in selectivity and high in reaction specificity.
Generalized Chemoselective Transfer Hydrogenation/Hydrodeuteration
Wang, Yong,Cao, Xinyi,Zhao, Leyao,Pi, Chao,Ji, Jingfei,Cui, Xiuling,Wu, Yangjie
supporting information, p. 4119 - 4129 (2020/08/10)
A generalized, simple and efficient transfer hydrogenation of unsaturated bonds has been developed using HBPin and various proton reagents as hydrogen sources. The substrates, including alkenes, alkynes, aromatic heterocycles, aldehydes, ketones, imines, azo, nitro, epoxy and nitrile compounds, are all applied to this catalytic system. Various groups, which cannot survive under the Pd/C/H2 combination, are tolerated. The activity of the reactants was studied and the trends are as follows: styrene'diphenylmethanimine'benzaldehyde'azobenzene'nitrobenzene'quinoline'acetophenone'benzonitrile. Substrates bearing two or more different unsaturated bonds were also investigated and transfer hydrogenation occurred with excellent chemoselectivity. Nano-palladium catalyst in situ generated from Pd(OAc)2 and HBPin extremely improved the TH efficiency. Furthermore, chemoselective anti-Markovnikov hydrodeuteration of terminal aromatic olefins was achieved using D2O and HBPin via in situ HD generation and discrimination. (Figure presented.).
Bidentate NHC-Cobalt Catalysts for the Hydrogenation of Hindered Alkenes
Wei, Zeyuan,Wang, Yujie,Li, Yibiao,Ferraccioli, Raffaella,Liu, Qiang
, p. 3082 - 3087 (2020/10/02)
Herein, we report a series of easily accessible bidentate N-heterocyclic carbene (NHC) cobalt catalysts, which enable the hydrogenation of hindered alkenes under mild conditions. The four-coordinated bidentate NHC-Co(II) complexes were characterized by X-ray diffraction, elemental analysis, ESI-HRMS, and magnetic moment measurements, revealing a distorted-tetrahedral geometry and a high-spin configuration of the metal center. The activity of the in situ formed catalytic system, which was obtained from easily available NHC precursors, CoCl2, and NaHBEt3, was identical with those of well-defined NHC-cobalt catalysts. This highlights the potential utility of this reaction system.
