- Free radical alkylation of the remote nonactivated δ-carbon atom
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A free radical introduction of functionalized alkyl chains into the δ-carbon atom (Michael type alkylation) of alkyl nitrites and alkyl benzenesulfenic-O-esters was achieved.
- Petrovi?, Goran,?ekovi?, ?ivorad
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Read Online
- Chromium-Catalyzed Production of Diols From Olefins
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Processes for converting an olefin reactant into a diol compound are disclosed, and these processes include the steps of contacting the olefin reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst, and hydrolyzing the reduced chromium catalyst to form a reaction product comprising the diol compound. While being contacted, the olefin reactant and the supported chromium catalyst can be irradiated with a light beam at a wavelength in the UV-visible spectrum. Optionally, these processes can further comprise a step of calcining at least a portion of the reduced chromium catalyst to regenerate the supported chromium catalyst.
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Paragraph 0111
(2021/03/19)
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- Disproportionation of aliphatic and aromatic aldehydes through Cannizzaro, Tishchenko, and Meerwein–Ponndorf–Verley reactions
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Disproportionation of aldehydes through Cannizzaro, Tishchenko, and Meerwein–Ponndorf–Verley reactions often requires the application of high temperatures, equimolar or excess quantities of strong bases, and is mostly limited to the aldehydes with no CH2 or CH3 adjacent to the carbonyl group. Herein, we developed an efficient, mild, and multifunctional catalytic system consisting AlCl3/Et3N in CH2Cl2, that can selectively convert a wide range of not only aliphatic, but also aromatic aldehydes to the corresponding alcohols, acids, and dimerized esters at room temperature, and in high yields, without formation of the side products that are generally observed. We have also shown that higher AlCl3 content favors the reaction towards Cannizzaro reaction, yet lower content favors Tishchenko reaction. Moreover, the presence of hydride donor alcohols in the reaction mixture completely directs the reaction towards the Meerwein–Ponndorf–Verley reaction. Graphic abstract: [Figure not available: see fulltext.].
- Sharifi, Sina,Sharifi, Hannah,Koza, Darrell,Aminkhani, Ali
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p. 803 - 808
(2021/07/20)
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- Ruthenium (II) complexes with C2- and C1-symmetric bis-(+)-camphopyrazole ligands and their evaluation in catalytic transfer hydrogenation of aldehydes
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Ruthenium (II) piano-stool complexes with bis-(+)-camphopyrazole ligands of C2 and C1 symmetry were prepared in good yields (66–98%). New C2-C1 ligands and complexes were characterized by multinuclear NMR spectroscopy, FT-IR and elemental analysis. The catalytic performance of the Ru(II)-bis-(+)-camphopyrazole complexes in the transfer hydrogenation of benzaldehyde and valeraldehyde using isopropanol/potassium carbonate and formic acid/triethylamine mixtures as hydrogen donors, was evaluated, resulting in moderate yields (>54%) for the reduction to the desired primary alcohols. The system with isopropanol as hydrogen source proved to be more selective than the analogous system using the azeotropic formic acid/triethylamine mixture, allowing benzyl alcohol to be obtained in quantitative yield (>99%) for a particular catalyst precursor. Furthermore, complexes with C2 symmetry ligands showed higher yields than those with C1 symmetry ligands in all of the evaluated systems.
- Agrifoglio, Giuseppe,Blanco, Christian O.,Dorta, Romano,Herrera, Alberto,Landaeta, Vanessa R.,Llovera, Ligia,Pastrán, Jesús,Venuti, Doménico
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supporting information
(2021/05/10)
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- Effect of Ni/Co mass ratio and NiO-Co3O4loading on catalytic performance of NiO-Co3O4/Nb2O5-TiO2for direct synthesis of 2-propylheptanol from n -valeraldehyde
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In the direct synthesis of 2-propylheptanol (2-PH) from n-valeraldehyde, a second-metal oxide component Co3O4 was introduced into NiO/Nb2O5-TiO2 catalyst to assist in the reduction of NiO. In order to optimize the catalytic performance of NiO-Co3O4/Nb2O5-TiO2 catalyst, the effects of the Ni/Co mass ratio and NiO-Co3O4 loading were investigated. A series of NiO-Co3O4/Nb2O5-TiO2 catalysts with different Ni/Co mass ratios were prepared by the co-precipitation method and their catalytic performances were evaluated. The result showed that NiO-Co3O4/Nb2O5-TiO2 with a Ni/Co mass ratio of 8/3 demonstrated the best catalytic performance because the number of d-band holes in this catalyst was nearly equal to the number of electrons transferred in hydrogenation reaction. Subsequently, the NiO-Co3O4/Nb2O5-TiO2 catalysts with different Ni/Co mass ratios were characterized by XRD and XPS and the results indicated that both an interaction of Ni with Co and formation of a Ni-Co alloy were the main reasons for the reduction of NiO-Co3O4/Nb2O5-TiO2 catalyst in the reaction process. A higher NiO-Co3O4 loading could increase the catalytic activity but too high a loading resulted in incomplete reduction of NiO-Co3O4 in the reaction process. Thus the NiO-Co3O4/Nb2O5-TiO2 catalyst with a Ni/Co mass ratio of 8/3 and a NiO-Co3O4 loading of 14 wt% showed the best catalytic performance; a 2-PH selectivity of 80.4% was achieved with complete conversion of n-valeraldehyde. Furthermore, the NiO-Co3O4/Nb2O5-TiO2 catalyst showed good stability. This was ascribed to the interaction of Ni with Co, the formation of the Ni-Co alloy and further reservation of both in the process of reuse.
- Zhao, Lili,An, Hualiang,Zhao, Xinqiang,Wang, Yanji
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p. 1736 - 1742
(2021/01/20)
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- MOF-derived hcp-Co nanoparticles encapsulated in ultrathin graphene for carboxylic acids hydrogenation to alcohols
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Highly efficient conversion of carboxylic acids to valuable alcohols is a great challenge for easily corroded non-noble metal catalysts. Here, a series of few-layer graphene encapsulated metastable hexagonal closed-packed (hcp) Co nanoparticles were fabricated by reductive pyrolysis of metal-organic framework precursor. The sample pyrolyzed at 400 °C (hcp-Co@G400) presented outstanding performance and stability for converting a variety of functional carboxylic acids and its turnover frequency was one magnitude higher than that of conventional facc-centered cubic (fcc) Co catalysts. In situ DRIFTS spectroscopy of model reaction acetic acid hydrogenation and DFT calculation results confirm that carboxylic acid initially undergoes dehydroxylation to RCH2CO* followed by consecutive hydrogenation to RCH2CH2OH through RCH2COH*. Acetic acid prefers to vertically adsorb at hcp-Co (0 0 2) facet with a much lower adsorption energy than parallel adsorption at fcc-Co (1 1 1) surface, which plays a key role in decreasing the activation barrier of the rate-determining step of acetic acid dehydroxylation.
- Dong, Mei,Fan, Weibin,Gao, Xiaoqing,Zhu, Shanhui
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p. 201 - 211
(2021/06/03)
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- Discovery of Anti-TNBC Agents Targeting PTP1B: Total Synthesis, Structure-Activity Relationship, in Vitro and in Vivo Investigations of Jamunones
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Twenty-three natural jamunone analogues along with a series of jamunone-based derivatives were synthesized and evaluated for their inhibitory effects against breast cancer (BC) MDA-MB-231 and MCF-7 cells. The preliminary structure-activity relationship revealed that the length of aliphatic side chain and free phenolic hydroxyl group at the scaffold played a vital role in anti-BC activities and the methyl group on chromanone affected the selectivity of molecules against MDA-MB-231 and MCF-7 cells. Among them, jamunone M (JM) was screened as the most effective anti-triple-negative breast cancer (anti-TNBC) candidate with a high selectivity against BC cells over normal human cells. Mechanistic investigations indicated that JM could induce mitochondria-mediated apoptosis and cause G0/G1 phase arrest in BC cells. Furthermore, JM significantly restrained tumor growth in MDA-MB-231 xenograft mice without apparent toxicity. Interestingly, JM could downregulate phosphatidylinositide 3-kinase (PI3K)/Akt pathway by suppressing protein-tyrosine phosphatase 1B (PTP1B) expression. These findings revealed the potential of JM as an appealing therapeutic drug candidate for TNBC.
- Hu, Caijuan,Li, Guoxun,Mu, Yu,Wu, Wenxi,Cao, Bixuan,Wang, Zixuan,Yu, Hainan,Guan, Peipei,Han, Li,Li, Liya,Huang, Xueshi
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supporting information
p. 6008 - 6020
(2021/05/06)
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- METHOD FOR PRODUCING BIO ALCOHOL FROM INTERMEDIATE PRODUCTS OF ANAEROBIC DIGESTION TANK
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The present invention relates to a method for producing a bio-alcohol by reacting a mixture of volatile fatty acid with methanol in 2 through 11 in a reactor in the presence of a 280 °C-membered alkaline earth metal catalyst or 400 °C transition metal catalyst formed based on a support.
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Paragraph 0057-0060; 0063; 0065-0066; 0068-0069; 0071
(2021/05/25)
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- The relevance of Lewis acid sites on the gas phase reaction of levulinic acid into ethyl valerate using CoSBA-xAl bifunctional catalysts
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A series of Co supported on Al-modified SBA-15 catalysts has been studied in the gas phase direct transformation of levulinic acid (LA) into ethyl valerate (EV) using a continuous fixed-bed reactor and ethanol as solvent. It was observed that once the intermediate product gamma-valerolactone (GVL) has been formed, the presence of aluminum is required for the selective transformation to EV. Three Lewis acid sites (LAS) are identified (from highest to lowest acid strength): aluminum ions in tetrahedral and octahedral coordination and Co2+sites. The intrinsic activity of these LAS for the key reaction, the GVL ring opening, decreases with the strength of these acid sites, but so does the undesirable formation of coke, also catalyzed by these centers. The best catalyst was that with the highest Al content, CoSBA-2.5Al, that reached an EV yield of up to 70%. This result is associated with the presence of LAS attributed to the presence of Co2+surface species that, although having low intrinsic activity in the selective GVL ring-opening reaction, are highly concentrated in this sample and also possess less activity in the undesirable and deactivating formation of coke. These Co2+LAS have been stabilized by incorporation of aluminum into the support, modifying the reducibility and dispersion of cobalt species. Additionally, the lower proportion of metallic Co species decreases the hydrogenating capacity of this catalyst. This decrease is a positive result because it prevents GVL hydrogenation to undesired products. This catalyst also showed promising stability in a 140 h on-stream run.
- Cecilia, J. A.,Dumesic, J. A.,Jiménez-Gómez, C. P.,López Granados, M.,Maireles-Torres, P.,Mariscal, R.,Mu?oz-Olasagasti, M.
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p. 4280 - 4293
(2021/06/30)
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- Effect of second metal component on the reduction property and catalytic performance of NiO-MOx/Nb2O5-TiO2 for direct synthesis of 2-propylheptanol from n-valeraldehyde
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In order to improve the catalytic performance of NiO/Nb2O5-TiO2, several kinds of the second metal oxide component MOx (M = Pd, Co, Ir or Rh) were separately introduced and their effects on the reduction propert
- An, Hualiang,Wang, Yanji,Zhao, Lili,Zhao, Xinqiang
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- Photocatalytic Reductive C-O Bond Cleavage of Alkyl Aryl Ethers by Using Carbazole Catalysts with Cesium Carbonate
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Methods to activate the relatively stable ether C-O bonds and convert them to other functional groups are desirable. One-electron reduction of ethers is a potentially promising route to cleave the C-O bond. However, owing to the highly negative redox potential of alkyl aryl ethers (Ered -2.6 V vs SCE), this mode of ether C-O bond activation is challenging. Herein, we report the visible-light-induced photocatalytic cleavage of the alkyl aryl ether C-O bond using a carbazole-based organic photocatalyst (PC). Both benzylic and non-benzylic aryl ethers underwent C-O bond cleavage to form the corresponding phenol products. Addition of Cs2CO3 was beneficial, especially in reactions using a N-H carbazole PC. The reaction was proposed to occur via single-electron transfer (SET) from the excited-state carbazole to the substrate ether. Interaction of the N-H carbazole PC with Cs2CO3 via hydrogen bonding exists, which enables a deprotonation-assisted electron-transfer mechanism to operate. In addition, the Lewis acidic Cs cation interacts with the substrate alkyl aryl ether to activate it as an electron acceptor. The high reducing ability of the carbazole combined with the beneficial effects of Cs2CO3 made this otherwise formidable SET event possible.
- Yabuta, Tatsushi,Hayashi, Masahiko,Matsubara, Ryosuke
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p. 2545 - 2555
(2021/02/01)
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- Manganese Catalyzed Direct Amidation of Esters with Amines
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The transition metal catalyzed amide bond forming reaction of esters with amines has been developed as an advanced approach for overcoming the shortcomings of traditional methods. The broad scope of substrates in transition metal catalyzed amidations remains a challenge. Here, a manganese(I)-catalyzed method for the direct synthesis of amides from a various number of esters and amines is reported with unprecedented substrate scope using a low catalyst loading. A wide range of aromatic, aliphatic, and heterocyclic esters, even in fatty acid esters, reacted with a diverse range of primary aryl amines, primary alkyl amines, and secondary alkyl amines to form amides. It is noteworthy that this approach provides the first example of the transition metal catalyzed amide bond forming reaction from fatty acid esters and amines. The acid-base mechanism for the manganese(I)-catalyzed direct amidation of esters with amines was elucidated by DFT calculations.
- Fu, Zhengqiang,Wang, Xinghua,Tao, Sheng,Bu, Qingqing,Wei, Donghui,Liu, Ning
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p. 2339 - 2358
(2021/02/03)
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- Ni2P Nanoalloy as an Air-Stable and Versatile Hydrogenation Catalyst in Water: P-Alloying Strategy for Designing Smart Catalysts
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Non-noble metal-based hydrogenation catalysts have limited practical applications because they exhibit low activity, require harsh reaction conditions, and are unstable in air. To overcome these limitations, herein we propose the alloying of non-noble metal nanoparticles with phosphorus as a promising strategy for developing smart catalysts that exhibit both excellent activity and air stability. We synthesized a novel nickel phosphide nanoalloy (nano-Ni2P) with coordinatively unsaturated Ni active sites. Unlike conventional air-unstable non-noble metal catalysts, nano-Ni2P retained its metallic nature in air, and exhibited a high activity for the hydrogenation of various substrates with polar functional groups, such as aldehydes, ketones, nitriles, and nitroarenes to the desired products in excellent yields in water. Furthermore, the used nano-Ni2P catalyst was easy to handle in air and could be reused without pretreatment, providing a simple and clean catalyst system for general hydrogenation reactions.
- Fujita, Shu,Yamaguchi, Sho,Yamasaki, Jun,Nakajima, Kiyotaka,Yamazoe, Seiji,Mizugaki, Tomoo,Mitsudome, Takato
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supporting information
p. 4439 - 4446
(2021/02/09)
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- Role of Ga3+promoter in the direct synthesis of iso-butanolviasyngas over a K-ZnO/ZnCr2O4catalyst
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The direct synthesis of iso-butanol is an important reaction in syngas (composed of CO and H2) conversion. K-ZnO/ZnCr2O4(K-ZnCr) is a commonly used catalyst. Here, Ga3+is used as an effective promoter to boost the efficiency of the catalyst and retard the production of CO2. X-ray diffraction, X-ray photoelectron spectroscopy, ultraviolet-visible diffuse reflection spectroscopy and electron microscopy were used to characterize the structural variations with different amounts of Ga3+, the results showed that the particle size of the catalyst decreases with the addition of Ga3+. The temperature-programmed desorption of NH3and CO2, and diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTs) analysis of the CO adsorption revealed that the acidity and basicity were altered owing to the different forms of Ga3+adoption. X-ray photoelectron spectroscopy and density functional theory (DFT) calculations revealed that the formation of Ga clusters that are coordinated on the exposed surfaces of ZnCr2O4, and undergo a tetra-coordinated Ga3+exchange with one of the Zn in ZnCr2O4(ZG) and ZnGa2O4, probably depends on the amount of Ga added. The structural evolution of the Ga3+promoted K-ZnO/ZnCr2O4catalysts can be described as follows: (i) the main forms are ZG and Ga coordinated ZnCr2O4, in which the amount of Ga3+is below 1.10 wt%; and (ii) the Ga3+containing compound is gradually changed from ZG to ZnGa2O4and the amount of gallium clusters increased when the amount of Ga3+was higher than 1.10 wt%. The catalytic performance evaluation results show that K-Ga1.10ZnCr exhibits the highest space time yield and selectivity of alcohols, in which the three compounds play different roles in syngas conversion: ZG is the main active site that boosts the efficiency of the catalysts, owing to the intensified CO adsorption and decreased activation energy of CHO formation through CO hydrogenation; ZnGa2O4only modifies the surface basicity and acidity on the catalyst, thereby impacting the carbon chain growth after the CO is adsorbed. The effects of Ga coordinated with ZnCr2O4shows little impact on the CO adsorption owing to the weak electron donating effects of Ga.
- Zhang, Tao,Zeng, Chunyang,Wu, Yingquan,Gong, Nana,Yang, Jiaqian,Yang, Guohui,Tsubaki, Noritatsu,Tan, Yisheng
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p. 1077 - 1088
(2021/02/26)
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- Hydrodeoxygenation of C4-C6 sugar alcohols to diols or mono-alcohols with the retention of the carbon chain over a silica-supported tungsten oxide-modified platinum catalyst
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The hydrodeoxygenation of erythritol, xylitol, and sorbitol was investigated over a Pt-WOx/SiO2 (4 wt% Pt, W/Pt = 0.25, molar ratio) catalyst. 1,4-Butanediol can be selectively produced with 51% yield (carbon based) by erythritol hydrodeoxygenation at 413 K, based on the selectivity over this catalyst toward the regioselective removal of the C-O bond in the -O-C-CH2OH structure. Because the catalyst is also active in the hydrodeoxygenation of other polyols to some extent but much less active in that of mono-alcohols, at higher temperature (453 K), mono-alcohols can be produced from sugar alcohols. A good total yield (59%) of pentanols can be obtained from xylitol, which is mainly converted to C2 + C3 products in the literature hydrogenolysis systems. It can be applied to the hydrodeoxygenation of other sugar alcohols to mono-alcohols with high yields as well, such as erythritol to butanols (74%) and sorbitol to hexanols (59%) with very small amounts of C-C bond cleavage products. The active site is suggested to be the Pt-WOx interfacial site, which is supported by the reaction and characterization results (TEM and XAFS). WOx/SiO2 selectively catalyzed the dehydration of xylitol to 1,4-anhydroxylitol, whereas Pt-WOx/SiO2 promoted the transformation of xylitol to pentanols with 1,3,5-pentanetriol as the main intermediate. Pre-calcination of the reused catalyst at 573 K is important to prevent coke formation and to improve the reusability.
- Betchaku, Mii,Cao, Ji,Liu, Lujie,Nakagawa, Yoshinao,Tamura, Masazumi,Tomishige, Keiichi,Yabushita, Mizuho
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supporting information
p. 5665 - 5679
(2021/08/16)
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- Esterification reaction kinetics of acetic acid and n-pentanol catalyzed by sulfated zirconia
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This study reports experimental data and kinetic modeling of acetic acid esterification with n-pentanol using sulfated zirconia as a catalyst. Reactions were carried out in an isothermal well-mixed batch reactor at different temperatures (50-80°C), n-pentanol to acid molar ratios (1:1-3:1), and catalyst loadings (5-10?wt% in relation to the total amount of acetic acid). The reaction mechanism regarding the heterogeneous catalysis was evaluated considering pseudo-homogeneous, Eley–Rideal, and Langmuir–Hinshelwood model approaches. The reaction mixture was considered a nonideal solution and the UNIQUAC thermodynamic model was used to take into account the nonidealities in the liquid phase. The results obtained indicated that increases in the temperature and catalyst loading increased the product formation, while changes in the n-pentanol to acetic acid molar ratio showed no significant effect. The estimated enthalpy of the reaction was ?8.49?kJ?mol?1, suggesting a slightly exothermic reaction. The Eley–Rideal model, with acetic acid adsorbed on the catalyst as the limiting step, was found to be the most significant reaction mechanism.
- Hamerski, Fabiane,Dusi, Giovana Gon?alves,Fernandes dos Santos, Julia Trancoso,da Silva, Vítor Renan,Pedersen Voll, Fernando Augusto,Corazza, Marcos Lúcio
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p. 499 - 512
(2020/05/25)
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- Reduction of Aldehydes with Formic acid in Ethanol using Immobilized Iridium Nanoparticles on a Triazine-phosphanimine Polymeric Organic Support
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A novel triazine-phosphanimine polymeric organic support (TPA) was synthesized successfully by a controllable one-pot method using melamine (1,3,5-triazine-2,4,6-triamine) and trichlorophosphane (PCl3). The TPA substrate is a material incorporating P and N atoms which can coordinate with metals as a pincer ligand to stabilize them, providing an efficient heterogeneous support to prepare recyclable transition metal catalyst systems. In this study, TPA was used as support to immobilize iridium nanoparticles in the range of ~8 nm on its surface, resulting in the generation of a novel iridium nanocatalyst system (INP-TPA-POP). This catalyst system was characterized using different microscopic and spectroscopic techniques such as FT-IR, TEM, XPS, XRD, SEM, EDX, elemental analysis, ICP and BET analysis. The INP-TPA-POP nanocatalyst exhibited remarkable activity in reduction of aldehydes to alcohols using formic acids as reducing agent in ethanol as solvent.
- Panahi, Farhad,Haghighi, Fatemeh,Khalafi-Nezhad, Ali
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- Chemoselective Electrochemical Hydrogenation of Ketones and Aldehydes with a Well-Defined Base-Metal Catalyst
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Hydrogenation reactions are fundamental functional group transformations in chemical synthesis. Here, we introduce an electrochemical method for the hydrogenation of ketones and aldehydes by in situ formation of a Mn-H species. We utilise protons and electric current as surrogate for H2 and a base-metal complex to form selectively the alcohols. The method is chemoselective for the hydrogenation of C=O bonds over C=C bonds. Mechanistic studies revealed initial 3 e? reduction of the catalyst forming the steady state species [Mn2(H?1L)(CO)6]?. Subsequently, we assume protonation, reduction and internal proton shift forming the hydride species. Finally, the transfer of the hydride and a proton to the ketone yields the alcohol and the steady state species is regenerated via reduction. The interplay of two manganese centres and the internal proton relay represent the key features for ketone and aldehyde reduction as the respective mononuclear complex and the complex without the proton relay are barely active.
- Fokin, Igor,Siewert, Inke
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p. 14137 - 14143
(2020/10/12)
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- Ammonia borane enabled upgrading of biomass derivatives at room temperature
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Simplifying biomass conversion to valuable products with high efficiency is pivotal for the sustainable development of society. Herein, an efficient catalyst-free system using ammonia borane (AB) as the hydrogen donor is described, which enables controllable reaction selectivity towards four value-added products in excellent yield (82-100%) under very mild conditions. In particular, the system is uniquely efficient to produce γ-valerolactone (GVL) at room temperature. Combined in situ NMR and computational studies elucidate the hydrogen transfer mechanism of AB in methanol, the novel pathway of GVL formation from levulinate in water, and a competitive mechanism between reduction and reductive amination in the same system. Moreover, carbohydrates are converted directly into GVL in good yield, using a one-pot, two-step strategy. Products of a rather broad scope are prepared within a short reaction time of 30 min by using this catalyst-free strategy in methanol at room temperature. This journal is
- Meier, Sebastian,Riisager, Anders,Yang, Song,Zhao, Wenfeng
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supporting information
p. 5972 - 5977
(2020/11/03)
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- Preparation of Ni-IL/SiO2and its catalytic performance for one-pot sequential synthesis of 2-propylheptanol from: n -valeraldehyde
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A novel silica-immobilized nickel and acid ionic liquid (Ni-IL/SiO2) catalyst was prepared by combining a bonding procedure with an impregnation operation and was characterized by means of X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA) techniques. Its catalytic performance was evaluated for the one-pot synthesis of 2-propylheptanol (2-PH) via a sequential n-valeraldehyde self-condensation and hydrogenation reaction. As a result, Ni-IL/SiO2 showed an excellent catalytic activity for the one-pot synthesis of 2-PH, affording a 2-PH selectivity of 75.4% at a n-valeraldehyde conversion of 100% and the sum of 2-PH and pentanol selectivity reached 98.6% under the suitable reaction conditions.
- An, Hualiang,Miao, Shuang,Wang, Di,Wang, Yanji,Yang, Qiusheng,Zhao, Xinqiang
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p. 28100 - 28105
(2020/11/03)
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- Selective hydrogenation of 2-pentenal using highly dispersed Pt catalysts supported on ZnSnAl mixed metal oxides derived from layered double hydroxides
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A highly dispersed Pt catalyst supported on ZnSnAl mixed metal oxides (MMO), with Pt in single-atom and small nanoclusters, was produced by the induction of lattice-confined Sn sites in layered double hydroxides (LDHs) and used in the selective hydrogenation of 2-pentenal. Compared with the Pt/Al2O3, Pt-SnOx/Al2O3 and MgSnAl-MMO supported Pt catalysts, the optimized ZnSnAl-MMO supported Pt catalyst gave a higher selectivity to 2-pentenol (82.2%) at 28.5% conversion of 2-pentenal. Based on catalytic evaluation results and catalyst characterization with XRD, Pyridine-IR, H2-TPR, XPS, and HAADF-STEM, it was found that the combined effects of Sn and Zn species promoted the performance of the Pt catalyst by favoring the activation of the CO bond. In addition, due to the size effect and electronic effect on the Pt species, the highly dispersed Pt induced by the lattice-confined Sn sites in ZnSnAl-LDH enhanced the catalytic activity of Pt/Zn(1Sn)(Al)O/Al2O3 by 2.7 times compared with Pt-SnOx/Zn(Al)O/Al2O3.
- Ali, Babar,Lan, Xiaocheng,Wang, Huanjun,Wang, Shiqing,Wang, Tiefeng
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p. 1106 - 1116
(2020/03/11)
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- COMPOSITIONS COMPRISING ODORLESS 1,2-PENTANEDIOL
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Suggested is a cosmetic or pharmaceutical or detergent composition comprising 1,2 pentanediol, wherein said 1,2-pentanediol is obtained from a process comprising the follow ing steps: (a) providing at least one starting material selected from furfuryl alcohol and furfural; (b) reacting at least one of said starting materials with hydrogen in the presence of a heterogeneous catalyst to form 1,2-pentanediol, wherein said heterogeneous catalyst comprises: one or more metals selected from the group consisting of platinum, rhodium, ruthenium, nickel, palladium and iridium in metallic form and/or one or more compounds of metals selected from the group consisting of platinum, rhodium, ruthenium, nickel, palladium and iridium; and one or more support materials selected from the group consisting of activated carbon, aluminum oxide, silicon dioxide, and silicon carbide; and (c) removing the 1,2-pentanediol thus obtained from the reaction mixture.
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Paragraph 00316
(2020/04/25)
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- Regulating Hydrogenation Chemoselectivity of α,β-Unsaturated Aldehydes by Combination of Transfer and Catalytic Hydrogenation
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Two hydrogenation mechanisms, transfer and catalytic hydrogenation, were combined to achieve higher regulation of hydrogenation chemoselectivity of cinnamyl aldehydes. Transfer hydrogenation with ammonia borane exclusively reduced C=O bonds to get cinnamyl alcohol, and Pt-loaded metal–organic layers efficiently hydrogenated C=C bonds to synthesize phenyl propanol with almost 100 % conversion rate. The hydrogenation could be performed under mild conditions without external high-pressure hydrogen and was applicable to various α,β-unsaturated aldehydes.
- Zhou, Yangyang,Li, Zihao,Liu, Yanbo,Huo, Jia,Chen, Chen,Li, Qiling,Niu, Songyang,Wang, Shuangyin
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p. 1746 - 1750
(2020/02/25)
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- Methods and Compositions for Hydrodeoxygenation of Carbohydrates and Carbohydrate Analogs
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This disclosure provides embodiments directed to compositions, methods, and processes to produce compounds having the structure: each of R1-R5 is selected from a hydroxyl group and hydrogen; and R1-R5 include at least one hydroxyl group and at least one hydrogen; and n=0-2. In particular, methods of the disclosure can include reacting a precursor, the precursor containing more oxygen (O) atoms than the compound, with a gas containing hydrogen (H2) in the presence of a catalyst.
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Paragraph 0048-0050
(2020/03/28)
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- Efficient One-Pot Synthesis of Higher Alcohols from Syngas Catalyzed by Iron Nitrides
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Efficient synthesis of higher alcohols from syngas over a single-metal catalyst remains challenging because both active sites for CO dissociation and molecular CO adsorption are required. We report herein that iron nitrides can directly catalyze syngas to higher alcohols with high selectivity. Three iron nitride catalysts (Fe2N, Fe3N, and Fe4N) were fabricated via the nitriding of α-Fe and their structures were confirmed by X-ray diffraction (XRD) and M?ssbauer spectroscopy (MES). Moreover, no carbides were detected even after syngas conversion for Fe2N and Fe3N catalysts, in which the N content was higher than that in Fe4N (iron nitrides transformed to Fe2C partly). The catalytic performance indicated that higher alcohols could be directly produced from syngas with remarkable selectivity (>51 % for C2+OH selectivity in total alcohols) over iron nitrides, which was tentatively ascribed to the unique electronic structure of iron nitrides, as evidenced by DFT calculation. This study proposed a novel method for the selective one-step synthesis of higher alcohols from syngas.
- Li, Linge,Li, Yongwang,Liu, Suyao,Liu, Xingwu,Qing, Ming,Wan, Hongliu,Wang, Hong,Wen, Xiaodong,Yang, Yong,Zhang, Yu
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- Hydrogenolysis of tetrahydrofuran-2-carboxylic acid over tungsten-modified rhodium catalyst
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Catalysts for reduction of tetrahydrofuran-2-carboxylic acid (THFCA), which can be synthesized from furfural via oxidation and hydrogenation, were explored among the combinations of noble metal and reducible metal oxide supported on SiO2. Rh-WOx/SiO2 catalysts showed activity in C-O hydrogenolysis at 2-position of THFCA (to δ-valerolactone and 5-hydroxyvaleric acid) and higher yield ratio of these C-O hydrogenolysis products to carboxylic acid hydrogenation products than other bimetallic catalysts. The activity of Rh-WOx/SiO2 catalysts was highest at W/Rh = 0.25 mol/mol. XRD, TPR, CO adsorption and XAFS characterizations showed that the Rh-WOx/SiO2 (W/Rh = 0.25) catalyst contained Rh metal particles with surface modification with isolated W2+ oxide species. The mechanism that hydride-like species formed on Rh atom attacks the C atom at the α-position (2-position) of adsorbed carboxylate on W atom is proposed based on the similar kinetics and similar catalyst structure to Rh-MOx/SiO2 (M = Re, Mo) which is known to be active in THFA hydrogenolysis to 1,5-pentanediol.
- Asano, Takehiro,Nakagawa, Yoshinao,Tamura, Masazumi,Tomishige, Keiichi
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- Effect of pretreatment conditions on acidity and dehydration activity of CeO2-MeOx catalysts
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A series of MeOx-modified CeO2 (CeO2-MnOx, CeO2-ZnO, CeO2-MgO, CeO2-CaO, and CeO2-Na2O) catalysts were prepared by the impregnation of CeO2 with corresponding metal nitrates. Acidity and oxidation state of cerium were investigated on both oxidized and reduced catalysts by employing Fourier Transform Infrared spectroscopy (FTIR) on adsorbed pyridine and in situ H2-Temperature Programmed Reduction/X-ray Absorption Spectroscopy (H2-TPR/XAS) techniques, respectively. Metal oxide addition tended to alter both type and number of acid sites on ceria. EXAFS data showed a significant difference in NCe-O between unmodified and CeO2-MeOx, suggesting that added MeOx interferes with vacancy formation on ceria during reduction. In comparison with air-pretreated samples, H2-pretreated ones under similar conversion of 1,5 pentanediol exhibited a higher selectivity towards linear alcohols. Alcohol conversion found to correlate with total acidity (i.e., Br?nsted and Lewis). CeO2 benefited from the addition of alkali (Na) or alkaline earth metals (Mg, Ca) by producing unsaturated alcohols.
- Cronauer, Donald C.,Góra-Marek, Kinga,Garcia, Richard,Gnanamani, Muthu Kumaran,Jacobs, Gary,Kropf, A. Jeremy,Marshall, Christopher L.
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- METHOD FOR PRODUCING ALCOHOL
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PROBLEM TO BE SOLVED: To provide a method for producing selectively alcohol from carboxylic acid under mild conditions. SOLUTION: In the presence of a catalyst with M1 and M2 as metal species supported on a support, a substrate is reduced to produce a corresponding alcohol. (M1 is Rh, Pt, Ru, Ir, or Pd; M2 is Sn, V, Mo, W, or Re; the support is ZrO2, hydroxyapatite, Nb2O5, fluoroapatite, or hydrotalcite; the substrate is the formula 1a, 1b, or 1c). SELECTED DRAWING: None COPYRIGHT: (C)2020,JPO&INPIT
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Paragraph 0101-0110
(2020/11/26)
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- Catalytic Hydrogenation of Thioesters, Thiocarbamates, and Thioamides
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Direct hydrogenation of thioesters with H2 provides a facile and waste-free method to access alcohols and thiols. However, no report of this reaction is documented, possibly because of the incompatibility of the generated thiol with typical hydrogenation catalysts. Here, we report an efficient and selective hydrogenation of thioesters. The reaction is catalyzed by an acridine-based ruthenium complex without additives. Various thioesters were fully hydrogenated to the corresponding alcohols and thiols with excellent tolerance for amide, ester, and carboxylic acid groups. Thiocarbamates and thioamides also undergo hydrogenation under similar conditions, substantially extending the application of hydrogenation of organosulfur compounds.
- Luo, Jie,Rauch, Michael,Avram, Liat,Ben-David, Yehoshoa,Milstein, David
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p. 21628 - 21633
(2021/01/11)
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- Optimization of process conditions for nickel-catalyzed selective aerobic O-debenzylation
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An alternative nickel-based catalyst for the aerobic debenzylation of benzyl ethers has been devised in order to provide a complement to the well-known hydrogenolysis strategy as well as to other reductive or oxidative procedures, including vanadium-catalyzed cleavage under molecular oxygen. A systematic study of reaction conditions has led to an optimized procedure from (pentyloxy)methyl)benzene (POMB)that provides selectively target 1-pentyl alcohol (PA), releasing the benzyl group as benzoic acid (BA). The participation of homogeneous species is supported by several experiments, which also reveal the intermediacy of pentyl benzoate.
- Urgoitia, Garazi,SanMartin, Raul,Herrero, María Teresa,Domínguez, Esther
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- DMSO-Triggered Complete Oxygen Transfer Leading to Accelerated Aqueous Hydrolysis of Organohalides under Mild Conditions
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Addition of DMSO is found to greatly accelerate the aqueous hydrolysis of organohalides to alcohols, providing a neutral, more efficient, milder and more economic process. Mechanistic studies using 18O-DMSO and 18O-H2O showed that, contrary to the opinion that DMSO works as a dipolar solvent to enhance water's nucleophilicity, the accelerating effect comes from a complete oxygen transfer from DMSO to organohalides through generation of ROS+Me2?X? salts through C?O bond formation, followed by O?S bond disassociative hydrolysis of ROS+Me2?X? with water. This method is applicable to a wide range of organohalides and thus may have potential for practical industrial application, owing to easy recovery of DMSO from the H2O/DMSO mixture by regular vacuum rectification.
- Liu, Haicheng,Liu, Jianping,Cheng, Xiaokai,Jia, Xiaojuan,Yu, Lei,Xu, Qing
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p. 2994 - 2998
(2019/01/04)
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- A General One-Pot Methodology for the Preparation of Mono- and Bimetallic Nanoparticles Supported on Carbon Nanotubes: Application in the Semi-hydrogenation of Alkynes and Acetylene
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A facile and straightforward methodology for the preparation of monometallic (copper and palladium) and bimetallic nanocatalysts (NiCu and PdCu) stabilized by a N-heterocyclic carbene ligand is reported. Both colloidal and supported nanoparticles (NPs) on carbon nanotubes (CNTs) were prepared in a one-pot synthesis with outstanding control on their size, morphology and composition. These catalysts were evaluated in the selective hydrogenation of alkynes and alkynols. PdCu/CNTs revealed an efficient catalytic system providing high selectivity in the hydrogenation of terminal and internal alkynes. Moreover, this catalyst was tested in the semi-hydrogenation of acetylene in industrially relevant acetylene/ethylene-rich model gas feeds and showed excellent stability even after 40 h of reaction.
- Lomelí-Rosales, Diego A.,Delgado, Jorge A.,Díaz de los Bernardos, Miriam,Pérez-Rodríguez, Sara,Gual, Aitor,Claver, Carmen,Godard, Cyril
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supporting information
p. 8321 - 8331
(2019/06/04)
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- The reductive deaminative conversion of nitriles to alcohols using: Para -formaldehyde in aqueous solution
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We report herein, for the first time, the application of para-formaldehyde (pFA) to the reductive deamination of both aliphatic and aromatic nitriles in aqueous solution under transfer hydrogenation conditions. A broad range of primary alcohols have been synthesized selectively with very good to excellent yields under the optimized conditions. The study disclosed that the air-stable, inexpensive and commercially available catalyst [Ru(p-cymene)Cl2]2 acts as the catalyst precursor in this reaction, converting to other more active catalytic species in the presence of pFA, resulting in its degradation to CO2 and H2. Nitriles are also showed to play a dual role in this transformation, both as a substrate and as a ligand, where the dimeric catalyst structures convert to monomeric ones upon the coordination of nitrile molecules.
- Tavakoli, Ghazal,Prechtl, Martin H. G.
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p. 6092 - 6101
(2019/11/11)
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- Method for preparing alcoholic compound from aliphatic carboxylic acid without catalytic reaction
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The invention discloses a method for preparing an alcoholic compound from an aliphatic carboxylic acid without the catalytic reaction. In an inert gas atmosphere, 4,4,5,5-tetramethyl-1,3,2-dioxa-borolane and the carboxylic acid are evenly stirred and mixed in a dehydration and deoxidization reaction flask, and react for 8-10 hours to obtain a boric acid ester; and the carboxylic acid is acetic acid, caproic acid, valeric acid, heptylic acid, trimethylacetic acid, adipic acid and the like. The aliphatic carboxylic acid efficiently is used to react with borane to implement hydroboration withouta catalyst for the first time, and a novel scheme is provided for the preparation of the boric acid ester through hydroboration of a carbonyl compound and the borane and the further hydrolysis of theboric acid ester into an alcohol.
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- N-butyl lithium based fatty alcohol preparation method
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The invention relates to an n-butyl lithium based fatty alcohol preparation method. In an inert gas atmosphere, borane and aliphatic carboxylic acid are mixed, then n-butyl lithium taken as the catalyst is added to carry out hydroboration reactions; and after the hydroboration reactions, silica gel and methanol are added to carry out hydrolysis reactions to obtain the fatty alcohols. N-butyl lithium can efficiently catalyze the hydroboration reactions between carboxylic acids and borane at a room temperature, the used catalyst only accounts for 0.2 mol% of the carboxylic acids, compared with aconventional catalyst system, a commercial catalyst namely n-butyl lithium is adopted, the reaction conditions are mild, and the yield of fatty alcohols with different substitutes under restricted conditions is high.
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- Biomolecule-derived supported cobalt nanoparticles for hydrogenation of industrial olefins, natural oils and more in water
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Catalytic hydrogenation of olefins using noble metal catalysts or pyrophoric RANEY nickel is of high importance in the chemical industry. From the point of view of green and sustainable chemistry, design and development of Earth-abundant, less toxic, and more environmentally friendly catalysts are highly desirable. Herein, we report the convenient preparation of active cobalt catalysts and their application in hydrogenations of a wide range of terminal and internal carbon-carbon double bonds in water under mild conditions. Catalysts are prepared on multi-gram scale by pyrolysis of cobalt acetate and uracil, guanine, adenine or l-tryptophan. The most active material Co-Ura/C-600 showed good productivity in industrially relevant hydrogenation of diisobutene to isooctane and in natural oil hardening.
- Pews-Davtyan, Anahit,Scharnagl, Florian Korbinian,Hertrich, Maximilian Franz,Kreyenschulte, Carsten,Bartling, Stephan,Lund, Henrik,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 5104 - 5112
(2019/09/30)
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- Combined synergetic and steric effects for highly selective hydrogenation of unsaturated aldehyde
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Enhancing the selectivity to unsaturated alcohols for the hydrogenation of unsaturated aldehydes is of great importance and challenge. Herein, Pt-SnOx@ZIF-8 catalysts with combined synergetic and steric effects were designed for the hydrogenation of 2-pentenal. The selectivity to unsaturated alcohol was enhanced from 4.3% to 61.5% by the synergetic effect between SnOx and Pt active sites and was further enhanced to 80.9% by the steric effect of ZIF-8. In situ FTIR was used to investigate the surface reaction mode over the present catalysts. The results showed that SnOx acted as electrophilic sites for the adsorption and activation of the C[dbnd]O bond and the apertures of ZIF-8 oriented the C[dbnd]O adsorption on the active sites.
- Lan, Xiaocheng,Xue, Kaizhen,Wang, Tiefeng
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- Synthetic Versatility of Lipases: Application for Si-O Bond Formation and Cleavage
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Several commercially available lipases were examined in a study on O-Si bond formation and cleavage applying silicon-based protecting groups and alcohols or the corresponding silyl ethers. With regard to deprotection, from silyl ether to the corresponding alcohol, only the solvent and the lipase were necessary. The influence of the protecting group, the lipase source, and the substituent was investigated to optimize the results. The TMS moiety could be removed in 24 hours of reaction at room temperature in aqueous systems (conv. up to 99%, depending on the substrate and lipase). The reverse reactions, that is, with the protection of the alcohols, were carried out in hexane using different silyl chlorides. The TMS, TES, and TBS moieties were successfully inserted in the primary and secondary alcohols without the need for dry conditions or an inert atmosphere, presenting conversions of up to 99%, depending on the substrate.
- Brondani, Patrícia Bulegon,Mittersteiner, Mateus,Voigt, Morgana Aline,Klinkowski, Bruna Heloisa,Riva Scharf, Dilamara,De Jesus, Paulo Cesar
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supporting information
p. 477 - 485
(2019/01/10)
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- Quantitative Evaluation of the Effect of the Hydrophobicity of the Environment Surrounding Br?nsted Acid Sites on Their Catalytic Activity for the Hydrolysis of Organic Molecules
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Sulfo-functionalized siloxane gels with a variety of surface hydrophobicities were fabricated to elucidate the effect of the environment surrounding the Br?nsted acid site on their catalytic activity for the hydrolysis of organic molecules. A detailed structural analysis of these siloxane gels by elemental analysis, X-ray photoelectron spectroscopy, Fourier-transformed infrared (FT-IR), and 29Si MAS NMR revealed the formation of gel catalysts with a highly condensed siloxane network, which enabled us to quantitatively evaluate the hydrophobicity of the environment surrounding the catalytically active sulfo-functionality. A sulfo group in a highly hydrophobic environment exhibited excellent catalytic turnover frequency for the hydrolysis of acetate esters with a long alkyl chain, whereas not only conventional solid acid catalysts but also liquid acids showed quite low catalytic activity. Detailed kinetic studies corroborated that the adsorption of oleophilic esters at the Br?nsted acid site was facilitated by the surrounding hydrophobic environment, thus significantly promoting hydrolysis under aqueous conditions. Furthermore, sulfo-functionalized siloxane gels with a highly hydrophobic surface showed excellent catalytic activity for the hydrolytic deprotection of silyl ethers.
- Miura, Hiroki,Kameyama, Shutaro,Komori, Daiki,Shishido, Tetsuya
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p. 1636 - 1645
(2019/01/21)
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- Method for preparing n-amyl alcohol through gamma-valerolactone hydrogenation
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The invention provides a method for preparing n-amyl alcohol through gamma-valerolactone hydrogenation. The method comprises the following steps: pouring gamma-valerolactone, a hydrogenation catalystand a solid acid catalyst into a reactor, and carrying out catalytic reaction to generate the n-amyl alcohol and 2-methyltetrahydrofuran in the presence of hydrogen and under heating conditions. The hydrogenation catalyst contains active ingredients which are one or more of Ni, Ru, Cu, and Ag. The method for preparing the n-amyl alcohol through gamma-valerolactone hydrogenation, provided by the invention, has the advantages that the product yield is high and the catalyst is mechanically used for 20 times or above; the combined catalyst has long life and good industrial application prospect.
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Paragraph 0007; 0026-0052
(2019/01/17)
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- Modeling and optimization of lipase-catalyzed hydrolysis for production of (S)-2-phenylbutyric acid enhanced by hydroxyethyl-β-cyclodextrin
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An efficient reactive system was established to produce (S)-2-phenylbutyric acid (2-PBA) through the enzymatic enantioselective hydrolysis of 2-phenylbutyrate ester (2-PBAE) in aqueous medium. Lipase CALA from Canadian antarctica and hexyl 2-phenylbutyrate (2-PBAHE) were identified upon screening as the best enzyme and substrate, respectively. Adding hydroxyethyl-β-cyclodextrin (HE-β-CD) to improve the solubility of the substrate resulted in a 1.5 times increase in substrate conversion while retaining a high enantioselectivity compared with that when HE-β-CD was not added. The effects of lipase concentration, substrate concentration and HE-β-CD concentration, temperature, pH, and reaction time on enantiomeric excess and conversion rate were investigated, and the optimal conditions were identified using response surface methodology (RSM). Under the optimal conditions, namely 50 mg/mL lipase CALA, 30 mmol/L substrate, 60 mmol/L HE-β-CD, pH of 6.5, temperature of 83 °C and reaction time of 18 h, the enantiomeric excess and overall conversion rate were 96.05% and 27.28%, respectively. This work provides an efficient alternative method for improving the conversion of aromatic ester substrates by including β-cyclodextrin in an aqueous hydrolysis reaction system.
- Zhang, Panliang,Cheng, Qing,Xu, Weifeng,Tang, Kewen
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- Continuous Hydrogenation of Ethyl Levulinate to 1,4-Pentanediol over 2.8Cu-3.5Fe/SBA-15 Catalyst at Low Loading: The Effect of Fe Doping
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Bimetallic Cu–Fe catalysts with low loading were prepared for hydrogenation of ethyl levulinate (EL) to 1,4-pentanediol (1,4-PDO). Among them, 2.8Cu-3.5Fe/SBA-15 (Cu/Fe molar ratio of 1:1.5) performed best, capable of converting EL to the key intermediate γ-valerolactone (GVL) at 140 °C with 97 % yield. It can also be used to hydrogenate GVL to 1,4-PDO with 92.6 % selectivity or convert EL to 1,4-PDO in one pot. The high activity of the catalyst at such a low loading was attributed to the highly dispersed metal species and the Fe doping effect. Various characterization methods indicated that Fe acted as both structural and electronic modifier to promote the chemical properties of the Cu species. Besides, the incorporation of Fe provided abundant Lewis acid sites and accelerated the reaction process. CuFeO2 was detected by energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, and XRD. On the basis of a combination of characterization and reaction kinetics, synergistic catalysis by Cu0 and CuFeO2 is considered to be responsible for the excellent performance of the Cu–Fe catalysts.
- Deng, Tianyu,Yan, Long,Li, Xinglong,Fu, Yao
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p. 3837 - 3848
(2019/08/07)
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- A Supramolecular Strategy for Selective Catalytic Hydrogenation Independent of Remote Chain Length
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Performing selective transformations on complex substrates remains a challenge in synthetic chemistry. These difficulties often arise due to cross-reactivity, particularly in the presence of similar functional groups at multiple sites. Therefore, there is a premium on the ability to perform selective activation of these functional groups. We report here a supramolecular strategy where encapsulation of a hydrogenation catalyst enables selective olefin hydrogenation, even in the presence of multiple sites of unsaturation. While the reaction requires at least one sterically nondemanding alkene substituent, the rate of hydrogenation is not sensitive to the distance between the alkene and the functional group, including a carboxylate, on the other substituent. This observation indicates that only the double bond has to be encapsulated to effect hydrogenation. Going further, we demonstrate that this supramolecular strategy can overcome the inherent allylic alcohol selectivity of the free catalyst, achieving supramolecular catalyst-directed regioselectivity as opposed to directing-group selectivity.
- Bender, Trandon A.,Bergman, Robert G.,Raymond, Kenneth N.,Toste, F. Dean
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supporting information
p. 11806 - 11810
(2019/08/22)
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- The highly efficient air oxidation of aryl and alkyl boronic acids by a microwave-assisted protocol under transition metal-free conditions
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Molecular oxygen is the most important green-oxidant due to its excellent properties. However, the effective utilization of molecular oxygen remains a major challenge in modern chemistry. Herein, we report the development a rapid, green and efficient microwave-assisted protocol for the air oxidation of boronic acids to phenols and alcohols under transition metal-free conditions. In the presence of KOH and DMSO, high yields of the expected phenols and alcohol were obtained with microwave-assistance, and a variety of functional groups were tolerated in this procedure. Notably, this transition metal-free method represents a breakthrough in both organic synthesis and green chemistry for the oxidative hydroxylation of boronic acids to phenols and alcohols.
- Yin, Weiyan,Pan, Xizhi,Leng, Wenxi,Chen, Jian,He, Haifeng
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supporting information
p. 4614 - 4618
(2019/09/09)
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- Insights on the One-Pot Formation of 1,5-Pentanediol from Furfural with Co?Al Spinel-based Nanoparticles as an Alternative to Noble Metal Catalysts
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CoAl-spinel nanoparticles prepared by liquid-feed flame spray pyrolysis (L?F FSP) and activated by reduction at different temperatures were used to investigate the hydrogenation process of furfural (FA) under mild conditions. Reduction of the spinel at 500 °C resulted in high FA conversion and selectivity to furfuryl alcohol (FFA, 81 % yield, in 1 hour). Reduction at higher temperatures (i. e., 700 and 850 °C) led to the direct formation of diols (i. e., 1,5-PeD and 1,2-PeD) from FA. The differences in activity are attributed to the formation of surface metallic cobalt nanoparticles upon reduction at high temperature. A maximum of 30 % 1,5-PeD was yielded after 8 hours of reaction under the optimized conditions of150 °C, 30 bar of H2 and with 40 mg of catalyst reduced at 700 °C. This is the first report on the direct catalytic conversion of furfural to1,5-pentanediol with a non-noble metal solid catalyst.
- Gavilà,L?hde,Jokiniemi,Constanti,Medina,del Río,Tichit,álvarez
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p. 4944 - 4953
(2019/09/17)
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- Hydro-Oxygenation of Furfural in the Presence of Ruthenium Catalysts Based on Al-HMS Mesoporous Support
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Ru-containing catalyst based on an Al-HMS mesoporous aluminosilicate was synthesized. The mesoporous support and the catalyst on its basis were characterized by the methods of low-temperature desorption/adsorption of nitrogen, temperature-programmed desorption of ammonia, transmission electron microscopy, X-ray photoelectron microscopy, and energy-dispersive X-ray fluorescence analysis. The synthesized catalyst was investigated in the hydrodeoxygenation of the model compound of bio-oil, furfural, in the presence of H2O. The reaction was carried out at initial hydrogen pressures of 1–7 MPa at 200°C–300°C temperature range. The results revealed that the synthesized catalyst displayed a high activity in the hydrotransformation of furfural. The conversion was 100% in 1 hr at a 5 MPa hydrogen pressure and 200°C.
- Roldugina,Shayakhmetov,Maksimov,Karakhanov
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p. 1306 - 1315
(2019/11/03)
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- Selective Hydrogenolysis of Furfural Derivative 2-Methyltetrahydrofuran into Pentanediol Acetate and Pentanol Acetate over Pd/C and Sc(OTf)3 Cocatalytic System
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It is of great significance to convert platform molecules and their derivatives into high value-added alcohols, which have multitudinous applications. This study concerns systematic conversion of 2-methyltetrahydrofuran (MTHF), which is obtained from furfural, into 1-pentanol acetate (PA) and 1,4-pentanediol acetate (PDA). Reaction parameters, such as the Lewis acid species, reaction temperature, and hydrogen pressure, were investigated in detail. 1H NMR spectroscopy and reaction dynamics study were also conducted to help clarify the reaction mechanism. Results suggested that cleavage of the primary alcohol acetate was less facile than that of the secondary alcohol acetate, with the main product being PA. A PA yield of 91.8 % (150 °C, 3 MPa H2, 30 min) was achieved by using Pd/C and Sc(OTf)3 as a cocatalytic system and an 82 % yield of PDA was achieved (150 °C, 30 min) by using Sc(OTf)3 catalyst. Simultaneously, the efficient conversion of acetic esters into alcohols by simple saponification was carried out and led to a good yield.
- Zhang, Kun,Li, Xing-Long,Chen, Shi-Yan,Xu, Hua-Jian,Deng, Jin,Fu, Yao
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p. 726 - 734
(2018/02/06)
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- Anchored Aluminum Catalyzed Meerwein-Ponndorf-Verley Reduction at the Metal Nodes of Robust MOFs
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Catalytic Meerwein-Ponndorf-Verley reductions of ketones and aldehydes in the presence of isopropyl alcohol were performed at aluminum alkoxide sites that were postsynthetically introduced into robust metal-organic frameworks (MOFs). The aluminum was anchored at the bridging hydroxyl sites inherent in some MOFs. MOFs in the UiO-66/67 family as well as DUT-5 were successfully adapted to this strategy. Incorporation of catalytically active aluminum species greatly enhanced the reactivity of the native MOF at 80 °C in the case of both UiO-66, and was almost solely responsible for catalytic activity in the case of metalated UiO-66 and DUT-5. The site isolation of the catalyst prevented aggregation and complete deactivation of the molecular aluminum catalyst, allowing it to be recovered and recycled in the case of UiO-67. This catalyst also proved to be moderately tolerant to wet isopropyl alcohol.
- Larson, Patrick J.,Cheney, Joseph L.,French, Amanda D.,Klein, David M.,Wylie, Benjamin J.,Cozzolino, Anthony F.
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supporting information
p. 6825 - 6832
(2018/06/26)
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- IRIDIUM-BASED CATALYSTS FOR HIGHLY EFFICIENT DEHYDROGENATION AND HYDROGENATION REACTIONS IN AQUEOUS SOLUTION AND APPLICATIONS THEREOF
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A series of iridium-based catalysts for dehydrogenation of formic acid, and hydrogenation using formic acid as the hydrogen source, and the process using the catalyst(s) to produce hydrogen gas from formic acid solution, or to reduce aldehydes using formic acid, are disclosed and claimed. More specifically, the present invention relates to a group of pentamethylcyclopentadienyl (Cp*) iridium complexes with different Ν,Ν-bidentate ligands that catalyze dehydrogenation from formic acid, and chemo-selective hydrogenation of aldehydes, in the aqueous solution system in a highly efficient, and long life-time manner.
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Page/Page column 13; 18
(2018/11/22)
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- Encapsulation of Crabtree's Catalyst in Sulfonated MIL-101(Cr): Enhancement of Stability and Selectivity between Competing Reaction Pathways by the MOF Chemical Microenvironment
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Crabtree's catalyst was encapsulated inside the pores of the sulfonated MIL-101(Cr) metal–organic framework (MOF) by cation exchange. This hybrid catalyst is active for the heterogeneous hydrogenation of non-functionalized alkenes either in solution or in the gas phase. Moreover, encapsulation inside a well-defined hydrophilic microenvironment enhances catalyst stability and selectivity to hydrogenation over isomerization for substrates bearing ligating functionalities. Accordingly, the encapsulated catalyst significantly outperforms its homogeneous counterpart in the hydrogenation of olefinic alcohols in terms of overall conversion and selectivity, with the chemical microenvironment of the MOF host favouring one out of two competing reaction pathways.
- Grigoropoulos, Alexios,McKay, Alasdair I.,Katsoulidis, Alexandros P.,Davies, Robert P.,Haynes, Anthony,Brammer, Lee,Xiao, Jianliang,Weller, Andrew S.,Rosseinsky, Matthew J.
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supporting information
p. 4532 - 4537
(2018/03/26)
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- Preparation method of alcohol compound
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The invention discloses a preparation method of an alcohol compound. The preparation method is characterized by carrying out ring opening under combined action of an esterifying agent, lewis acid anda hydrogenation catalyst by taking a furan derivative as a raw material, thus obtaining an ester intermediate; further saponifying, thus obtaining the alcohol compound. According to the preparation method disclosed by the invention, the product selectivity is high, byproducts are few, the yield is high, the purity is good, product separation is convenient, and the technology is simple.
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Paragraph 0050; 0054; 0056; 0062; 0064; 0065; 0066; 0068
(2018/09/20)
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