- Long term continuous chemoenzymatic dynamic kinetic resolution of rac-1-phenylethanol using ionic liquids and supercritical carbon dioxide
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The long term continuous dynamic kinetic resolution (DKR) of rac-phenylethanol in IL/scCO2 biphasic systems was carried out by simultaneously using immobilized lipase (Novozym 435) and acidic zeolite catalysts at 50 °C and 100 bar, providing go
- Lozano, Pedro,De Diego, Teresa,Mira, Corina,Montague, Kimberley,Vaultier, Michel,Iborra, Jose L.
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- Au-catalyzed electrochemical oxidation of alcohols using an electrochemical column flow cell
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A novel green system for the electrochemical oxidation of alcohols is demonstrated using a column flow cell. Voltammetric analysis revealed that the oxidation of 1-phenylethanol and benzaldehyde are promoted by using both an Au-electrode and an alkaline medium. To conduct such reaction with a column flow cell, we developed a method to modify a carbon-fiber thread with Au nanoparticles. The column carbon-fiber thread electrode modified with Au nanoparticles showed a high surface area, enabling the efficient electrochemical oxidation of various alcohols.
- Suga, Tatsuya,Shida, Naoki,Atobe, Mahito
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- Iron Porphyrin catalysed Oxidation of Propanal and Cyclohexene by Molecular Oxygen
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A variety of tetraphenylporphinatoiron(III) complexes are shown to catalyse the aerobic oxidation of propanal to propionic acid, and with cyclohexene as a co-substrate to effect conversion to cyclohexene oxide.
- Rodgers, Kenton R.,Arafa, Isam M.,Goff, Harold M.
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- Catalytic carbonylation of ethylene in the presence of the Pd(acac)2-m-Ph2PC6H4So3Na(H)-AcOH system
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Catalytic systems based on phosphine complexes of palladium have been developed for synthesizing propionic acid (monocarbonylation) and alternating (1:1) ethylene-carbon monoxide copolymers, i.e., polyketones (polycarbonylation). m-(Diphenylphosphino)benzenesulfonic acid or its sodium salt were used as ligands.Monocarbonylation proceeds at atmospheric pressure in dioxane or acetic acid solvents.Under high pressure, the reaction pathway can change from monocarbonylation, which occurs in the presence of the sodium salt of the ligand, to polycarbonylation when the sodium ion at the sulfo group is completely replaced by a proton.This change in reaction selectivity is observed when the process is performed in acetic acid.When the ligand is present both in the acid and the neutral form, products of di- and oligocarbonylation are formed along with propionic acid and the polyketone.These products were characterized by 1H and 13C NMR spectra as alternating keto acids C2H5(COCH2CH2)nCOOH, where n = 1-3.Kinetic equations were derived for the selective synthesis of propionic acid and polyketones. - Key words: carbonylation of ethylene; propionic acid; polyketone; Pd-based catalysts.
- Chepaikin, E. G.,Bezruchenko, A.P.,Leshcheva, A. A.,Boiko, G. N.
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- Crystal structure of Escherichia coli diaminopropionate ammonia-lyase reveals mechanism of enzyme activation and catalysis
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Pyridoxal 5′-phosphate (PLP)-dependent enzymes utilize the unique chemistry of a pyridine ring to carry out diverse reactions involving amino acids. Diaminopropionate (DAP) ammonia- lyase (DAPAL) is a prokaryotic PLP-dependent enzyme that catalyzes the degradation of D- and L-forms of DAP to pyruvate and ammonia. Here, we report the first crystal structure of DAPAL from Escherichia coli (EcDAPAL) in tetragonal and monoclinic forms at 2.0 and 2.2 A resolutions, respectively. Structures of EcDAPAL soaked with substrates were also determined. EcDAPAL has a typical fold type II PLP-dependent enzyme topology consisting of a large and a small domain with the active site at the interface of the two domains. The enzyme is a homodimer with a unique biological interface not observed earlier. Structure of the enzyme in the tetragonal form had PLP bound at the active site, whereas the monoclinic structure was in the apo-form. Analysis of the apo and holo structures revealed that the region around the active site undergoes transition from a disordered to ordered state and assumes a conformation suitable for catalysis only upon PLP binding. A novel disulfide was found to occur near a channel that is likely to regulate entry of ligands to the active site. EcDAPAL soaked with DL-DAP revealed density at the active site appropriate for the reaction intermediate aminoacrylate, which is consistent with the observation that EcDAPAL has low activity under crystallization conditions. Based on the analysis of the structure and results of site-directed mutagenesis, a two-base mechanism of catalysis involving Asp120 and Lys77 is suggested.
- Bisht, Shveta,Rajaram, Venkatesan,Bharath, Sakshibeedu R.,Kalyani, Josyula Nitya,Khan, Farida,Rao, Appaji N.,Savithri, Handanahal S.,Murthy, Mathur R. N.
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- Selective gas phase hydrogenation of maleic anhydride over Ni-supported catalysts: Effect of support on the catalytic performance
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The gas phase hydrogenation of maleic anhydride to obtain γ-butyrolactone was studied using Ni supported on SiO2, SiO2-Al2O3 and zeolite H-BEA as catalysts. The samples were prepared by incipient wetness impregnation and characterized by N2 adsorption at -196 °C (Sg), X-ray diffraction (XRD), temperature programmed reduction (TPR), temperature programmed desorption of NH3 (TPD-NH3) and chemisorption of H2. The reaction was carried out at 170 °C and 220 °C in a fixed bed reactor operating at atmospheric pressure. From the characterization results, it was determined that the degree of Ni2+-support interaction varies according to the following pattern: Ni/HBEA > Ni/SiO2-Al 2O3 > Ni/SiO2. All catalysts were very active in the hydrogenation of maleic anhydride to succinic anhydride. However, hydrogenolytic activity and stability of nickel-based catalyst varies with the degree of interaction Ni2+-support. Ni/H-BEA, in which Ni 2+-support interaction is the highest, was active in the hydrogenolysis of succinic anhydride to γ-butyrolactone but it was not stable. By contrast, Ni/SiO2-Al2O3 and Ni/SiO2, with medium or low degree of Ni2+-support interaction, were more stable than Ni/H-BEA. In addition, Ni/SiO 2-Al2O3, with a medium degree of Ni 2+-support interaction, was the most stable and selective to γ-butyrolactone, especially when the reaction was carried out at 220 °C.
- Regenhardt, Silvina A.,Meyer, Camilo I.,Garetto, Teresita F.,Marchi, Alberto J.
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- Preparation of highly active and reusable heterogeneous Al 2O3-Pd catalysts by the sol-gel method using bayberry tannin as stabilizer
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A novel heterogeneous Al2O3-Pd catalyst has been prepared by the sol- gel method; bayberry tannin (BT) was used as stabilizer to prevent the migration and aggregation of Pd species during calcination. According to N2 adsorption/ desorption determination, Al 2O3-Pd has a mesoporous structure and its specific area is as high as 336.5 m2/g. Transmission electron microscopy observation indicated that the size of the Pd particles was greatly reduced by the presence of BT. On the basis of X-ray photoelectron spectra analysis, it was found that the most of Pd nanoparticles were dispersed in the pores, implying that BT can prevent migration of Pd particles from the pores to the outer surface of Al 2O3 during calcination. For comparison, Al 2O3-Pd* was prepared by the sol-gel method but without use of BT. In the hydrogenation of acrylic acid, Al2O 3-Pd had high catalytic activity and excellent reusability compared with commercial and traditionally prepared heterogeneous Pd catalysts. The turnover number of Al2O3-Pd is as high as 11,328.0 mol/ mol after recycling seven times, which is much higher than that of a commercial Pd-C catalyst (8048.0 mol/mol). Springer Science+Business Media B.V. 2012.
- Wang, Yanping,Huang, Xin,Liao, Xuepin,Shi, Bi
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- Palladium(II) and/or copper(II)-catalyzed carboxylation of small alkanes such as methane and ethane with carbon monoxide
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Small alkanes such as methane and ethane react with carbon monoxide in the presence of transition metal catalysts to give the corresponding carboxylic acids in high yields.For the reaction of ethane, the Pd(OAc)2/Cu(OAc)2 mixed catalyst is the best, whereas that of methane proceeds most efficiently by the Cu(OAc)2 catalyst system. Key words: Palladium; Carbon monoxide; Alkane activation; Copper; Methane; Ethane
- Nakata, Kazuyuki,Yamaoka, Yoshinori,Miyata, Tsutomu,Taniguchi, Yuki,Takaki, Ken,Fujiwara, Yuzo
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- Characterization of Propionyl Phosphate Hydrolysis Kinetics by Data-Rich Experiments and In-Line Process Analytical Technology
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In-depth characterization of reaction kinetics often requires a considerable amount of experimental results under various conditions. Recent advances in data-rich experimentation enable the collection of sufficient data to investigate reactions with only a limited number of experiments. In this study, we developed a cost-efficient, robust approach by utilizing data-rich experimentation to characterize propionyl phosphate hydrolysis reaction kinetics. Specifically, an Fourier transform infrared (FTIR)-based process analytical technology (PAT) and off-line NMR calibration allowed the establishment of a quantitative FTIR multivariant model. This PAT was then integrated with repeated temperature scanning (RTS) to generate a massive database in a single experiment. The data were subsequently used for kinetic analysis, and two key characteristic reaction parameters (the activation energy and pre-exponential factor) were determined on the basis of the assumption of first-order kinetics. We envision that the integrative platform developed in this study can be broadly applied to investigations of the kinetics of a wide range of similar liquid-phase reactions.
- Yang, Cuixian,Feng, Hanzhou,Stone, Kevin
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- Novel scorpionate and pyrazole dioxovanadium complexes, catalysts for carboxylation and peroxidative oxidation of alkanes
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The dioxovanadium(V) complexes [VO2(3,5-Me2Hpz)3] [BF4] (1) (pz = pyrazolyl), [VO2{SO3C(PZ)3}] (2), [VO2{HB(3,5-Me2pz)3}] (3) and [VO2(HC(pz)3}j[BF4] (4), bearing pyrazole or scorpionate ligands, were obtained by reaction of triethyl vanadate [VO(OEt)3] with hydrotris(3,5-dimethyl-1-pyrazolyl)methane [HC(3,5-Me2pz)3] or 3,5-dimethylpyrazole (3,5-Me2HpZ; 1), lithium tris(1-pyrazolyl)methanesulfonate {Li[SO3C(pz)3], 2}, potassium hydrotris(3,5-dimethyl-l-pyrazolyl)borate {K[HB (3,5-Me2pz)3], 3} and hydrotris(1-pyrazolyl)methane [HC(pz)3, 4], respectively. Treatment of [VO(OEt)3] with potassium hydrotris(1-pyrazolyl)borate (K[HB(pz)3]) led to the mixed η3-tris(pyrazolyl)-borate and η2-bis(pyrazolyl)borate oxovanadium(IV) complex [VO{HB(pz)3}{H2B(pz)2}, 5]. The compounds were characterized by elemental analyses, IR, NMR and EPR spectroscopy, FAB and ESI mass spectrometry, cyclic voltammetry and, for 5, also by single crystal X-ray diffraction analysis. All complexes exhibit catalytic activity in the single-pot carboxylation [in trifluoroacetic acid/potassium peroxodisulfate (CF3COOH/K2S2O8)] of gaseous alkanes (methane and ethane) to carboxylic acids (yields up to 40%, TONs up to 157) and in the peroxidative oxidation [in water/acetonitrile (H2O/NCMe)] of liquid alkanes (cyclohexane and cyclopentane) to the corresponding alcohols and ketones (yields up to 24%, TONs up to 117), under mild conditions.
- Silva, Telma F. S.,Luzyanin, Konstantin V.,Kirillova, Marina V.,Fatima Guedes Da Silva,Martins, Luisa M. D. R. S.,Pombeiro, Armando J. L.
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- Selective Carbonylation of Propane in HF-SbF5: Control of the Activation Step via the Hydrocarbon/Carbon Monoxide Ratio
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The selectivity of propane carbonylation in HF-SbF5 is found to depend on the propane/CO ratio, and is rationalized in terms of two competing activation processes for the alkane.
- Delavarenne, Serge,Simon, Michel,Fauconet, Michel,Sommer, Jean
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- CO2 as oxidant: an unusual light-assisted catalyst free oxidation of aldehydes to acids under mild conditions
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A novel visible light-driven catalyst-free oxidation of aldehydes using CO2 both in batch and flow photoreactors to get corresponding acids along with the formation of CO in the effluent gas is described.
- Aniya, Vineet,Jain, Suman L.,Khan, Shafiur Rehman,Khatri, Praveen K.,Kumari, Alka,Naresh, K.,Ray, Anjan,Saini, Sandhya
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p. 2208 - 2211
(2022/02/17)
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- Cu(II)-Based Ionic Liquid Supported on SBA-15 Nanoparticles Catalyst for the Oxidation of Various Alcohols into Carboxylic Acids in the Presence of CO2
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In this paper, we have produced carboxylic acids by the oxidation of various alcohols in the presence of CO2 using SBA-15/IL supported Cu(II) (SBA-15/IL/Cu(II)) as nanocatalyst. The obtained products showed to have excellent yields by taking into account of SBA-15/IL/Cu(II) nanocatalyst. In addition, the analysis of EDX, SEM, TGA, TEM, XPS, and FT-IR showed the heterogeneous structure of SBA-15/IL/Cu (II) catalyst. It is determined that, after using SBA-15 excess, the catalytic stability of the system was enhanced. Moreover, hot filtration provided a full vision in the heterogeneous catalyst nature. The recycling as well as reuse of the catalyst were studied in cases of coupling reactions many times. Moreover, we have studied the mechanism of the coupling reactions. Graphic Abstract: [Figure not available: see fulltext.]
- Peng, Qi,Hou, Dejian,Chen, Yanwu,Lin, Litian,Sadeghzadeh, Seyed Mohsen
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p. 1308 - 1320
(2021/07/26)
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- Transformation of Thioacids into Carboxylic Acids via a Visible-Light-Promoted Atomic Substitution Process
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A visible-light-promoted atomic substitution reaction for transforming thiocacids into carboxylic acids with dimethyl sulfoxide (DMSO) as the oxygen source has been developed, affording various alkyl and aryl carboxylic acids in over 90% yields. The atomic substitution process proceeds smoothly through the photochemical reactivity of the formed hydrogen-bonding adduct between thioacids and DMSO. A DMSO-involved proton-coupled electron transfer (PCET) and the simultaneous generation of thiyl and hydroxyl radicals are proposed to be key steps for realizing the transformation.
- Fu, Qiang,Liang, Fu-Shun,Lou, Da-Wei,Pan, Gao-Feng,Wang, Rui,Wu, Min,Xie, Kai-Jun
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supporting information
p. 2020 - 2024
(2022/03/31)
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- An efficient and ultrastable single-Rh-site catalyst on a porous organic polymer for heterogeneous hydrocarboxylation of olefins
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A heterogeneous hydrocarboxylation process of olefins to obtain carboxylic acids with one more carbon was first realized using a single-Rh-site catalyst formed on porous organic polymer (Rh1/POPs). The in situ formation of hydrophilic porous ionic polymer from hydrophobic POPs with the help of CH3I led to high activity and superb stability.
- Yuan, Qiao,Song, Xiangen,Feng, Siquan,Jiang, Miao,Yan, Li,Li, Jingwei,Ding, Yunjie
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supporting information
p. 472 - 475
(2021/01/25)
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- carba Nicotinamide Adenine Dinucleotide Phosphate: Robust Cofactor for Redox Biocatalysis
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Here we report a new robust nicotinamide dinucleotide phosphate cofactor analog (carba-NADP+) and its acceptance by many enzymes in the class of oxidoreductases. Replacing one ribose oxygen with a methylene group of the natural NADP+ was found to enhance stability dramatically. Decomposition experiments at moderate and high temperatures with the cofactors showed a drastic increase in half-life time at elevated temperatures since it significantly disfavors hydrolysis of the pyridinium-N?glycoside bond. Overall, more than 27 different oxidoreductases were successfully tested, and a thorough analytical characterization and comparison is given. The cofactor carba-NADP+ opens up the field of redox-biocatalysis under harsh conditions.
- D?ring, Manuel,Sieber, Volker,Simon, Robert C.,Tafertshofer, Georg,Zachos, Ioannis
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supporting information
p. 14701 - 14706
(2021/05/13)
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- PROCESS FOR THE PREPARATION OF C3-5 SATURATED ALIPHATIC CARBOXYLIC ACIDS
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A process for the preparation of a saturated aliphatic carboxylic acid with 3 to 5 carbon atoms by oxidation of the corresponding aldehyde with oxygen in which (a) the corresponding aldehyde is converted with oxygen at a temperature of 40 to 150°C and an oxygen partial pressure of 0.001 to 1 MPa to obtain a mixture containing the saturated aliphatic carboxylic acid and ≤ 2 mol-% of the corresponding aldehyde with respect to the saturated aliphatic carboxylic acid, (b) the mixture obtained in step (a) is thermally treated in the liquid phase at a temperature of 80 to 250°C and a pressure of 0.1 to 2 MPa abs for 0.25 to 100 hours, and (c) the mixture obtained in step (b) is distilled in a distillation apparatus to obtain a distillate containing ≥ 90 wt.-% of the saturated aliphatic carboxylic acid and having an active oxygen content of 0 to 25 wt.-ppm based on the distillate.
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Page/Page column 19
(2021/07/17)
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- Influence of Solvents on the Oxidation Kinetics of Aldehydic Group Compounds by Diethylammonium Chloro-chromate
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The redox studies of some compounds containing aldehydic functional groups by diethylammonium chloro-chromate (DEACC) in dimethylsulfoxide leading a product forming to acid of correspondimg order. Reactions are found to be in unit order with oxidant while a fractional order (less than unity) was found w. r. t. reductants. The redox reactions are influenced with acid, the acid dependence is governed by this equation: kobs = a + b[H+]. When isomeric form of aldehyde, that is Me-CDO is oxidised with the same oxidant it was observed a considerable K. I.E. (Deuterium effect; kH/kD = 05.69 at 298 K). The reaction of Acetaldehyde was done in various non aqueous medium, soluble or miscible in DMSO. The effect of solvent is studied fitting our data in the solvent model of Taft's and Swain's applied for this purpose. Rate constants are correlating very well with already reported Taft's values of s*; further the reaction constants are negative in nature. Suitable mechanism involving are proposed with transfer of hydride ion.
- Bishnoi, Pramila,Chandora, Divya,Ganpatram,Prakash, Om,Sharma, Vinita
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p. 1329 - 1335
(2022/01/24)
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- Green, homogeneous oxidation of alcohols by dimeric copper(II) complexes
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Three pyrazole derivatives, 3,5-dimethyl-1H-pyrazole (DMPz) (I), 3-methyl-5-phenyl-1H-pyrazole (MPPz) (II), and 3,5-diphenyl-1H-pyrazole (DPPz) (III), were prepared via reacting semicarbazide hydrochloride with the acetylacetone, 1-phenylbutane-1,3-dione, and 1,3-diphenylpropane-1,3-dione, respectively. Complexes 1–3 were isolated by reacting CuCl2·2H2O with I–III, respectively, and characterized by CHNS elemental analyses, FT-IR, UV-Vis, 1H and 13C NMR, EPR spectra, and TGA/DTA. Molecular structures of the pyrazole derivatives I–III and copper(II) complexes 2 and 3 were studied through single-crystal XRD analysis to confirm their molecular structures. Overlapping of hyperfine splitting in the EPR spectra of the dimeric copper(II) complexes 1–3 indicates that both copper centers do not possess the same electronic environment in solution. The copper(II) complexes are dimeric in solid state as well as in solution and catalyze the oxidation of various primary and secondary alcohols selectively. Catalysts 1–3 show more than 92% product selectivity toward ketones during the oxidation of secondary alcohols. Surprisingly primary alcohols, which are relatively difficult to oxidize, produce carboxylic acid as a major product (48%–90% selectivity) irrespective of catalytic systems. The selectivity for carboxylic acid rises with decreasing the carbon chain length of the alcohols. An eco-friendly and affordable catalytic system for oxidation of alcohols is developed by the utilization of H2O2, a green oxidant, and water, a clean and greener solvent, which is a notable aspect of the study.
- Maurya, Abhishek,Haldar, Chanchal
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p. 885 - 904
(2020/12/18)
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- Hydrolysis of amides to carboxylic acids catalyzed by Nb2O5
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Hydrolysis of amides to carboxylic acids is an industrially important reaction but is challenging due to the difficulty of cleaving the resonance stabilized amidic C-N bond. Twenty-three heterogeneous and homogenous catalysts were examined in the hydrolysis of acetamide. Results showed that Nb2O5was the most effective heterogeneous catalyst with the greatest yield of acetic acid. A series of Nb2O5catalysts calcined at various temperatures were characterized and tested in the hydrolysis of acetamide to determine the effects of crystal phase and surface properties of Nb2O5on catalytic performance. The high catalytic performance observed was attributed mainly to the facile activation of the carbonyl bond by Lewis acid sites that function even in the presence of basic inhibitors (NH3and H2O). The catalytic studies showed the synthetic advantages of the present method, such as simple operation, catalyst recyclability, additive free, solvent free, and wide substrate scope (>40 examples; up to 95% isolated yield).
- Siddiki,Rashed, Md. Nurnobi,Touchy, Abeda Sultana,Jamil, Md. A. R.,Jing, Yuan,Toyao, Takashi,Maeno, Zen,Shimizu, Ken-Ichi
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p. 1949 - 1960
(2021/03/26)
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- Solvent-free oxidation of straight-chain aliphatic primary alcohols by polymer-grafted vanadium complexes
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Oxidovanadium(IV) complexes [VO(tertacac)2] (1), [VO(dipd)2] (2), and [VO(phbd)2] (3) were synthesized by reacting [VO(acac)2] with 2,2,6,6-tetramethyl-3,5-hepatanedione, 1,3-diphenyl-1,3-propanedione, and 1-phenyl-1,3-butanedione, respectively. Imidazole-modified Merrifield resin was used for the heterogenization of complexes 1–3. During the process of heterogenization, the V4+ center in complex 2 converts into V5+, whereas the other two complexes 1 and 3 remain in the oxidovanadium(IV) state in the polymer matrix. Theoretically, calculated IPA values of 1–3 suggest that 2 is prone to oxidation compared with 1 and 3, which was also supported by the absence of EPR lines in 5. Polymer-supported complexes Ps-Im-[VIVO(tertacac)2] (4), Ps-Im-[VVO2(dipd)2] (5), and Ps-Im-[VIVO(phbd)2] (6) were applied for the solvent-free heterogenous oxidation of a series of straight-chain aliphatic alcohols in the presence of H2O2 at 60°C and showed excellent substrate conversion specially for the alcohols with fewer carbon atoms. Higher reaction temperature improves the substrate conversion significantly for the alcohols containing more carbon atoms such as 1-pentanol, 1-hexanol, and 1-heptanol while using optimized reaction conditions. However, alcohols with fewer carbon atoms seem less affected by reaction temperatures higher than the optimized temperature. A decreasing trend in the selectivity(%) of carboxylic acid was observed with increasing carbon atoms among the examined alcohols, whereas the selectivity towards aldehydes increased. The order of efficiency of the supported catalysts is 4 > 6 > 5 in terms of turnover frequency (TOF) values and substrate conversion, further supported by theoretical calculations.
- Chaudhary, Nikita,Haldar, Chanchal,Kachhap, Payal
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- Sustainable production of propionic acid: catalytic deoxygenation of lactic acid over MoOx/Fe
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The synergistic effect between Mo and Fe on deoxygenation of lactic acid to propionic acid was studied in this work. The catalyst structure and its chemical composites were characterized by XRD, FT-IR and EDS, respectively. The morphology of the catalyst was observed by SEM, and the reducibility was evaluated by H2-TPR. According to its structure characterization, Mo species were coated on the surface of iron powders as MoO3, and the interactions between Mo and Fe species were investigated by H2-TPR under calcination at high temperatures. A reduction peak at 650 °C moved toward low temperatures with the addition of an iron component, suggesting that iron promoted the reduction of Mo species. Due to this reason, catalytic performances are rapidly enhanced, being far more superior to any one of the Mo-Fe components. However, an excess of Fe content,ca.Fe/Mo molar ratios >0.908, decreases the activity on lactic acid deoxygenation, suggesting that the redox property of the catalyst is a major factor. Catalysts with Co and Ni substituting for Fe displayed lower selectivity to propionic acid, demonstrating that regulating appropriately the redox properties is a key to improve lactic acid deoxygenation again. The hydrothermal temperature and calcination temperature have an important influence on the formation of MoO3and its decomposition, which then affects its activity. Inspiringly, the catalyst with a Fe/Mo molar ratio of 0.908 offered an excellent stability, which proceeded efficiently for 120 h on stream under a high LHSV of 37 h?1at 390 °C.
- Chen, Zhi,Dai, Yunsheng,Li, Xinli,Pang, Jun,Tang, Congming,Wang, Hongqin,Yang, Chenglong
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p. 15831 - 15839
(2021/09/22)
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- A Mild, General, Metal-Free Method for Desulfurization of Thiols and Disulfides Induced by Visible-Light
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A visible-light-induced metal-free desulfurization method for thiols and disulfides has been explored. This radical desulfurization features mild conditions, robustness, and excellent functionality compatibility. It was successfully applied not only to the desulfurization of small molecules, but also to peptides.
- Qiu, Wenting,Shi, Shuai,Li, Ruining,Lin, Xianfeng,Rao, Liangming,Sun, Zhankui
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supporting information
p. 1255 - 1258
(2021/05/05)
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- Honeycomb-structured solid acid catalysts fabricated via the swelling-induced self-assembly of acidic poly(ionic liquid)s for highly efficient hydrolysis reactions
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The development of heterogeneous acid catalysts with higher activity than homogeneous acid catalysts is critical and still challenging. In this study, acidic poly(ionic liquid)s with swelling ability (SAPILs) were designed and synthesized via the free radical copolymerization of ionic liquid monomers, sodium p-styrenesulfonate, and crosslinkers, followed by acidification. The 31P nuclear magnetic resonance chemical shifts of adsorbed trimethylphosphine oxide indicated that the synthesized SAPILs presented moderate and single acid strength. The thermogravimetric analysis results in the temperature range of 300–345 °C revealed that the synthesized SAPILs were more stable than the commercial resin Amberlite IR-120(H) (245 °C). Cryogenic scanning electron microscopy testing demonstrated that SAPILs presented unique three-dimensional (3D) honeycomb structure in water, which was ascribed to the swelling-induced self-assembly of the molecules. Moreover, we used SAPILs with micron-sized honeycomb structure in water as catalysts for the hydrolysis of cyclohexyl acetate to cyclohexanol, and determined that their catalytic activity was much higher than that of homogeneous acid catalysts. The equilibrium concentrations of all reaction components inside and outside the synthesized SAPILs were quantitatively analyzed using a series of simulated reaction mixtures. Depending on the reaction mixture, the concentration of cyclohexyl acetate inside SAPIL-1 was 7.5–23.3 times higher than that outside of it, which suggested the high enrichment ability of SAPILs for cyclohexyl acetate. The excellent catalytic performance of SAPILs was attributed to their 3D honeycomb structure in water and high enrichment ability for cyclohexyl acetate, which opened up new avenues for designing highly efficient heterogeneous acid catalysts that could eventually replace conventional homogeneous acid catalysts.
- Chen, Bihua,Deng, Xi,Ding, Tong,Gao, Guohua,Ma, Sanguan,Ni, Bing,Wang, Xin,Zhang, Dawei,Zhang, Yongya
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p. 297 - 309
(2020/07/25)
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- Quaternary phosphonium polymer-supported dual-ionically bound [Rh(CO)I3]2– catalyst for heterogeneous ethanol carbonylation
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A single-Rh-site catalyst (Rh-TPISP) that was ionically-embedded on a P(V) quaternary phosphonium porous polymer was evaluated for heterogeneous ethanol carbonylation. The [Rh(CO)I3]2– unit was proposed to be the active center of Rh-TPISP for the carbonylation reaction based on detailed Rh L3-edge X-ray absorption near edge structure (XANES), X-ray photoelectron spectroscopy (XPS), and Rh extended X-ray absorption fine structure (EXAFS) analyses. As the highlight of this study, Rh-TPISP displayed distinctly higher activity for heterogeneous ethanol carbonylation than the reported catalytic systems in which [Rh(CO)2I2]? is the traditional active center. A TOF of 350 h?1 was obtained for the reaction over [Rh(CO)I3]2–, with >95% propionyl selectivity at 3.5 MPa and 468 K. No deactivation was detected during a near 1000 h running test. The more electron-rich Rh center was thought to be crucial for explaining the superior activity and selectivity of Rh-TPISP, and the formation of two ionic bonds between [Rh(CO)I3]2– and the cationic P(V) framework ([P]+) of the polymer was suggested to play a key role in firmly immobilizing the active species to prevent Rh leaching.
- Ding, Yunjie,Jiang, Zheng,Liu, Yang,Lyu, Yuan,Ren, Zhou,Song, Xiangen,Zheng, Changyong
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p. 606 - 617
(2020/09/01)
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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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- Superior CNT-supported bimetallic RuCu catalyst for the highly selective hydrogenolysis of glycerol to 1,2-propanediol
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Selective hydrogenation of glycerol to 1,2-propanediol (1,2-PD) is a promising route for sustainable production of platform chemicals. Herein, a bimetallic RuCu catalyst supported on multiwall carbon nanotubes (RuCu/MWCNT) is reported that shows superior catalytic performance leading to 93.4% 1,2-PD selectivity under mild reactions conditions.
- Albert, Jakob,Bukowski, Anna,Fiedler, Bodo,Sherbi, Magdy,Velichkova, Hristiana,Wesner, Anne,Wisniewski, Valea Kim
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p. 6649 - 6653
(2021/10/25)
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- METHOD FOR PRODUCING OXIDATION REACTION PRODUCT OF HYDROCARBON OR DERIVATIVE THEREOF
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The present invention is intended to provide a method that can produce an oxidation reaction product of a hydrocarbon or a derivative thereof in an aqueous phase using a hydrocarbon or a derivative thereof as a raw material. In order to achieve the above object, the method for producing an oxidation reaction product of a hydrocarbon or a derivative thereof of the present invention includes the step of: irradiating a reaction system with light in a presence of a raw material and a halogen oxide radical to react, wherein the raw material is a hydrocarbon or a derivative thereof, the reaction system is a reaction system containing an aqueous phase, the aqueous phase contains the raw material and the halogen oxide radical, and in the reaction step, the raw material is oxidized to produce an oxidation reaction product of the raw material.
- -
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Paragraph 0099; 0103
(2022/01/04)
-
- AEROBIC ELECTROCATALYTIC OXIDATION OF HYDROCARBONS
-
This invention is directed to a method of oxygenating hydrocarbons with molecular oxygen, O2, as oxidant under electrochemical reducing conditions, using polyoxometalate compounds containing copper such as Q10 [Gu4(H2O)2(B-α-PW9O)2] or Q12{ [Cu(H2O)]3[(A-α- PW9O34)2(NO3)-] } or solvates thereof as catalysts, wherein Q are each independently selected from alkali metal cations, alkaline earth metal cations, transition metal cations, NH4+,H+ or any combination thereof.
- -
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Paragraph 0074
(2022/01/04)
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- Oxidation of aromatic and aliphatic aldehydes to carboxylic acids by Geotrichum candidum aldehyde dehydrogenase
-
Oxidation reaction is one of the most important and indispensable organic reactions, so that green and sustainable catalysts for oxidation are necessary to be developed. Herein, biocatalytic oxidation of aldehydes was investigated, resulted in the synthesis of both aromatic and aliphatic carboxylic acids using a Geotrichum candidum aldehyde dehydrogenase (GcALDH). Moreover, selective oxidation of dialdehydes to aldehydic acids by GcALDH was also successful.
- Hoshino, Tomoyasu,Yamabe, Emi,Hawari, Muhammad Arisyi,Tamura, Mayumi,Kanamaru, Shuji,Yoshida, Keisuke,Koesoema, Afifa Ayu,Matsuda, Tomoko
-
-
- Highly selective production of propionic acid from lactic acid catalyzed by NaI
-
Propionic acid (PA), a valuable chemical widely used in the food and feed industry, is currently produced by the petrochemical industry. Selective production of PA from bio-based lactic acid (LA) is difficult due to the high activation energy of the hydroxyl group at the α position of the carboxyl group. Herein, a metal-free catalytic system for the highly selective transformation of bio-based LA to PA, which was used as the solvent to simplify the separation step, is reported using NaI as the catalyst. Under the optimal reaction conditions, a >99% yield of PA can be obtained from LA. A heat-induced radical-activated hydrogen mechanism was proposed based on the kinetic study and intermediate capture. The metal-free system can be reused five times without any loss in activity, and the PA product is easily separated. In addition, a two-step method using cellulose as the raw material to produce PA was conducted. This strategy offers a green and efficient approach to synthesize PA from biomass resources. This journal is
- Feng, Huan,Li, Teng,Liu, Shengqin,Rong, Nianxin,Wang, Yantao,Yang, Weiran
-
supporting information
p. 7468 - 7475
(2020/11/23)
-
- Highly efficient oxidation of alcohols to carboxylic acids using a polyoxometalate-supported chromium(iii) catalyst and CO2
-
Direct catalytic oxidation of alcohols to carboxylic acids is very attractive, but economical catalysis systems have not yet been well established. Here, we show that a pure inorganic ligand-supported chromium compound, (NH4)3[CrMo6O18(OH)6] (simplified as CrMo6), could be used to effectively promote this type of reaction in the presence of CO2. In almost all cases, oxidation of various alcohols (aromatic and aliphatic) could be achieved under mild conditions, and the corresponding carboxylic acids can be achieved in high yield. The chromium catalyst 1 can be reused several times with little loss of activity. Mechanism study and control reactions demonstrate that the acidification proceeds via the key oxidative immediate of aldehydes.
- Han, Sheng,Wang, Ying,Wei, Yongge,Wu, Zhikang,Yu, Han
-
p. 3150 - 3154
(2020/06/19)
-
- Method for preparing carboxylic acid by green catalytic oxidation of aliphatic primary alcohol
-
The invention relates to a method for preparing carboxylic acid by green catalytic oxidation of aliphatic primary alcohol. The method comprises the following steps of: adding aliphatic primary alcoholinto a reaction solvent, adding an N-hydroxyphthalimide-copper oxide catalyst, introducing oxygen during reaction, and carrying out reaction at 50-80DEG C under normal pressure for 6-24h to obtain carboxylic acid with high yield. Compared with the prior art, the method has the advantages that the oxidizing agent is green and environment-friendly, the catalyst is cheap and easy to prepare, easy toseparate from the product, convenient to recycle, the reaction conditions are mild and the like, therefore the method is a green oxidation method of aliphatic primary alcohol.
- -
-
Paragraph 0051-0054
(2020/12/30)
-
- Mechanistic Investigation of the Nickel-Catalyzed Carbonylation of Alcohols
-
The carbonylation of alcohols represents a straightforward and atom-efficient methodology for the preparation of carboxylic acids. It is desirable to perform these reactions under precious metal-free and low-pressure conditions, with regioselectivity control. In this work, we present a detailed mechanistic study of a catalytic system based on NiI2, which can carbonylate benzylic alcohols in a highly regioselective manner to the corresponding branched carboxylic acids, core motifs for nonsteroidal drugs. The combination of catalytic amounts of nickel and iodide is crucial for efficient catalytic and regioselective conversion. Quantum-chemical computations were used to evaluate the underlying mechanistic processes. They revealed that a combination of two mechanisms is responsible for the observed reactivity and that the oxidative addition of alkyl halides to the Ni(0) species follows a radical oxidation pathway via two one-electron steps.
- Comba, Peter,Ghosh, Tamal,Hashmi, A. Stephen K.,Krieg, Saskia,Menche, Maximilian,Paciello, Rocco,Rück, Katharina S. L.,Sabater, Sara,Sch?fer, Ansgar,Schaub, Thomas
-
supporting information
(2020/03/19)
-
- Production of isobutyric acid from methanol by: Clostridium luticellarii
-
Renewable methanol can be used as a feedstock to generate value-added multicarbon components through fermentation technologies. Recently, researchers reported the production of isobutyric acid using methanol as an electron donor with open culture systems dominated by Eubacterium sp. and Clostridium sp. Here we report the ability of Clostridium luticellarii wild-type strain to produce isobutyric acid from methanol and CO2 & H2. When growing on methanol, the supplementation of acetic and butyric acid enhanced isobutyric acid final concentration, selectivity and production rate. A maximum of 5.04 ± 0.08 g L-1 isobutyric acid was produced at a rate of 0.420 ± 0.012 g L-1 d-1and selectivity of 0.70 electron per electron of total products in batch with acetic and butyric acid as electron acceptors. The pH was also found to be a major factor influencing isobutyric acid formation with maximal production at pH 6.50. Finally, in addition to its ability to produce isomers, C. luticellarii was able to perform C2-unit elongation from methanol. Overall, this study positions C. luticellarii as a promising platform for the production of isocarboxylic acids.
- Petrognani, Camille,Boon, Nico,Ganigué, Ramon
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p. 8389 - 8402
(2020/12/31)
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- Electrochemical oxidation of amoxicillin on carbon nanotubes and carbon nanotube supported metal modified electrodes
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The electrolysis of amoxicillin (AMX) was carried out on CNT, Pt/CNT and Ru/CNT modified electrodes based on Carbon Toray in 0.1 M NaOH, 0.1 M NaCl and 0.1 M Na2CO3/NaHCO3 buffer (pH 10) media with the aim of studying the significance of two factors, electrode material and pH, on the oxidative degradation and mineralization of AMX. For this purpose, the electrolysis products were identified by HPLC-MS and GC–MS, and quantified by HPLC-UV-RID and IC. The highest carbon mineralization efficiency, corresponding to 30% of the oxidized AMX, was found for Pt/CNT modified electrode in carbonate buffer medium. Regarding to the AMX conversion, the results show that the effect of pH is higher than that of the electrode material. Principal component analysis allowed to determine the experimental parameters vs. product distribution relationship and to elucidate the oxidation pathways for the studied electrodes. The results show that the hydroxylation of the aromatic ring and the nitrogen atom play an important role on the efficient degradation of AMX.
- Ferreira, Marta,Kuzniarska-Biernacka, Iwona,Fonseca, António M.,Neves, Isabel C.,Soares, Olívia S.G.P.,Pereira, Manuel F.R.,Figueiredo, José L.,Parpot, Pier
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p. 322 - 331
(2019/07/10)
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- Preparation method for synthesizing propiolic acid and derivatives thereof
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The invention provides a preparation method for synthesizing propiolic acid and derivatives thereof. The synthetic route of the method comprises the following steps: firstly, under anhydrous and anaerobic conditions, adding magnesium metal, elemental iodine and a solvent into a reactor, uniformly stirring the reactants, and then dropwise adding halogenated hydrocarbon to react to generate a hydrocarbyl magnesium halide Grignard reagent; dropwise adding terminal alkyne into the reactor for Grignard exchange reaction to obtain alkynyl magnesium halide; and finally, introducing CO2 into the reactor, carrying out nucleophilic addition reaction, and hydrolyzing the product to obtain the propiolic acid compound. The preparation method provided by the invention is simple, safe and mild in operation condition.
- -
-
Paragraph 0013
(2020/10/14)
-
- PRODUCTION METHOD OF AMIDE COMPOUND
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PROBLEM TO BE SOLVED: To provide a production method of an amide compound, which can use a variety of carboxylic acid halides and can produce a desired amide compound at a yield higher than a batch process by suppressing a side reaction. SOLUTION: Provided is a production method of an amide compound using a flow type reactor, in which the flow type reactor includes: a first flow path; a second flow path; a first mixing means provided at a confluent part of the first flow path and the second flow path; and a third flow path that is connected to the first mixing means and arranged on a down stream side of the first mixing means, the production method comprising: a mixing step of obtaining a mixed liquid by circulating a first liquid containing the carboxylic acid halide in the first flow path, circulating a second liquid containing an amine compound having a molecular weight of 1,000 or less, an inorganic alkali and water in the second flow path, and mixing the first liquid and the second liquid by the first mixing means to obtain a mixture; and a reaction step of obtaining an amide compound by circulating the mixed liquid in the third flow path and reacting the carboxylic acid halide and the amine compound in the third flow path. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2020,JPO&INPIT
- -
-
Paragraph 0134-0137
(2020/10/08)
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- A cobalt-substituted Keggin-Type polyoxometalate for catalysis of oxidative aromatic cracking reactions in water
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Efficient detoxification of harmful benzene rings into useful carboxylic acids in water is indispensable for achieving a clean water environment. We report herein that oxidative aromatic cracking (OAC) reactions in water were achieved using a catalytic system with a cobalt-substituted Keggin-Type polyoxometalate (Co-POM) as a catalyst, an Oxone monopersulfate compound as a sacrificial oxidant and sodium bicarbonate as an additive under mild conditions. Sodium bicarbonate plays a crucial role in the selective OAC reactions by Co-POM using ethylbenzenesulfonate as a model substrate. The reactive species was characterized to be a cobalt(iii)-oxyl species based on 31P NMR, UV-vis spectroscopic, kinetic, and theoretical analyses. The electrophilicity of the cobalt(iii)-oxyl species was demonstrated by a linear relationship with a negative slope in the Hammett plots of initial rates obtained from the OAC reactions of m-xylenesulfonate derivatives. Besides, we have verified the degradation pathway of the OAC reactions using benzene as a model substrate in the catalytic system. The degradation was initiated by an electrophilic attack of the cobalt(iii)-oxyl species on benzene to yield phenol followed by producing catechol, muconic acid, maleic/fumaric acid, tartaric acid derivatives and formic acid on the basis of 1H NMR spectroscopic analysis.
- Hong, Dachao,Kitagawa, Yasutaka,Kon, Yoshihiro,Shimoyama, Yoshihiro,Tamura, Satoru
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p. 8042 - 8048
(2020/12/28)
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- PROCESS FOR THE DIRECT CONVERSION OF ALKENES TO CARBOXYLIC ACIDS
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Process for the direct conversion of alkenes to carboxylic acids.
- -
-
Paragraph 0029-0032
(2019/07/10)
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- Synthesis of Carboxylic Acids by Palladium-Catalyzed Hydroxycarbonylation
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The synthesis of carboxylic acids is of fundamental importance in the chemical industry and the corresponding products find numerous applications for polymers, cosmetics, pharmaceuticals, agrochemicals, and other manufactured chemicals. Although hydroxycarbonylations of olefins have been known for more than 60 years, currently known catalyst systems for this transformation do not fulfill industrial requirements, for example, stability. Presented herein for the first time is an aqueous-phase protocol that allows conversion of various olefins, including sterically hindered and demanding tetra-, tri-, and 1,1-disubstituted systems, as well as terminal alkenes, into the corresponding carboxylic acids in excellent yields. The outstanding stability of the catalyst system (26 recycling runs in 32 days without measurable loss of activity), is showcased in the preparation of an industrially relevant fatty acid. Key-to-success is the use of a built-in-base ligand under acidic aqueous conditions. This catalytic system is expected to provide a basis for new cost-competitive processes for the industrial production of carboxylic acids.
- Sang, Rui,Kucmierczyk, Peter,Dühren, Ricarda,Razzaq, Rauf,Dong, Kaiwu,Liu, Jie,Franke, Robert,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 14365 - 14373
(2019/09/06)
-
- Highly selective conversion of glyceric acid to 3-iodopropionic acid by hydriodic acid mediated hydrogenation
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Glycerol, generated in abundance as the by-product in the process of biodiesel production and saponification, has seen attempts to convert it into value-added chemicals. However, due to the low selectivity of hydrogenolysis of the secondary hydroxyl group, valuable 1,3-substituted chemicals are difficult to obtain from glycerol by chemocatalysis. In this work, glyceric acid (GA), a renewable biomass from glycerol, was quantitatively converted to 3-iodopropionic acid (3-IPA) at 373 K in 3 h by hydroiodic acid mediated hydrogenation. As the reductant in this process, HI is oxidized to I2 and then regenerated in situ by metal catalysts and H2. The reaction pathway was proposed by intermediate identification and verified by a kinetics study and computational method. The catalytic system was shown to be stable and can be reused several times without loss in activity. As a 1,3-substituted chemical, 3-IPA is not only a potential monomer to form poly-3-hydroxypropionic acid, but also a good platform molecule to produce useful chemicals, e.g. 3-hydroxypropionic acid (3-HPA) and acrylic acid (AA), due to its highly reactive nature.
- Li, Teng,Liu, Shengqin,Wang, Bing,Long, Jingen,Jiang, Jun,Jin, Ping,Fu, Yao,Yu, Haizhu,Yang, Weiran
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p. 4434 - 4442
(2019/08/21)
-
- Method for preparing propionic acid by catalytic conversion of lactic acid
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The invention discloses a method for preparing propionic acid by catalytic conversion of lactic acid, comprising the following steps: Step 1: using molybdenum disulfide as a raw material to prepare alithium intercalation layer molybdenum disulfide by an intercalation method, and placing the lithium intercalation layer molybdenum disulfide in distilled water and peeling, filtering, and drying to obtain molybdenum disulfide with sulfur vacancies on the surface; Step 2, preparing 100 parts by weight of a lactic acid aqueous solution having a mass concentration of 5 to 80 wt%, adding 1 to 10 parts by weight of molybdenum disulfide with sulfur vacancies on the surface, reacting in the hydrogen atmosphere, at the hydrogen partial pressure of 0.5-9.0 MPa and at the reaction temperature of 180-250 DEG C for 2-20 h, so as to finally obtain propionic acid in the reaction liquid. By the above method, the hydrodeoxygenation reaction activity of lactic acid can be promoted, the conversion rate oflactic acid is enhanced, and the selectivity and yield of propionic acid are increased.
- -
-
Paragraph 0028; 0031; 0032; 0034-0036; 0037-0039
(2019/10/01)
-
- Ultra-Fast Synthesis of Multivalent Radical Nanoparticles by Ring-Opening Metathesis Polymerization-Induced Self-Assembly
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We report the straightforward, time-efficient synthesis of radical core–shell nanoparticles (NPs) by polymerization-induced self-assembly. A nitroxide-containing hydrophilic macromolecular precursor was prepared by ring-opening metathesis copolymerization of norbornenyl derivatives of TEMPO and oligoethylene glycol and was chain-extended in situ with norbornene in ethanolic solution, leading to simultaneous amphiphilic block copolymer formation and self-assembly. Without any intermediate purification from the monomers to the block copolymers, radical NPs with tunable diameters ranging from 10 to 110 nm are obtained within minutes at room temperature. The high activity of the radical NPs as chemoselective and homogeneous, yet readily recyclable catalysts is demonstrated through oxidation of a variety of alcohols and recovery by simple centrifugation. Furthermore, the NPs show biocompatibility and antioxidant activity in vitro.
- Le, Dao,Dilger, Marco,Pertici, Vincent,Diabaté, Silvia,Gigmes, Didier,Weiss, Carsten,Delaittre, Guillaume
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supporting information
p. 4725 - 4731
(2019/03/07)
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- An efficient and durable hierarchically porous KLA/TiPO catalyst for vapor phase condensation of lactic acid to 2,3-pentanedione
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Sustainable production of 2,3-pentanedione from bio-lactic acid via a vapor condensation reaction over KLA/TiPO (KLA: potassium lactate) was investigated in this work. A KNO3 precursor supported on the surface of TiPO was in situ converted to basic sites in a KLA/TiPO catalyst. KLA together with Ti4+(Lewis acidic site) make up the acid-base pairs in the KLA/TiPO catalyst, resulting in excellent activity for the condensation of lactic acid to 2,3-pentanedione. The loading amount of KNO3 was shown to have an important influence on the catalytic performance, since the acid-base properties of the catalysts were found to vary with the addition of KNO3. Reaction conditions such as lactic acid feed flow rate and lactic acid concentration were also discussed. Both lactic acid conversion and 2,3-pentanedione selectivity increased with elevated lactic acid feed flow rates, indicating the existence of an external diffusion resistance of the lactic acid reactant during the catalytic reactions. However, the lactic acid feed flow rate increased to 1.0 mL h?1 (corresponding to LA liquid hourly space velocity (LHSV) = 2.6 H?1), and the external diffusion resistance was efficiently eliminated. Enhancing the LA concentration improved the selectivity of 2,3-pentanedione, suggesting that the reaction order of the lactic acid molecule for lactic acid conversion to 2,3-pentanedione is higher than the other side reactions. Encouragingly, in retaining 30-45% of the lactic acid conversion, the condensation reaction with a 2,3-pentanedione selectivity of around 73% proceeded efficiently for at least 116 h on stream. The long-term stability of the present catalyst was found to be related to its hierarchical pores, which ameliorated the mass transfer effect of the reactant and product, except for the appropriate acid-base properties for lactic acid condensation to 2,3-pentanedione.
- Zhang, Ju,Li, Xinli,Pang, Jun,Zou, Weixin,Tang, Congming,Dong, Lin
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supporting information
p. 5972 - 5979
(2019/04/17)
-
- Preparation method of ramelteon
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The invention relates to the technical field of insomnia drugs, and discloses a preparation method of ramelteon. The method comprises the following step of: 1) adding triethyl phosphonoacetate and 400-600 ml of tetrahydrofuran into a 2L three-necked bottle and carrying out ice-water bath below 40 DEG C. According to the preparation method of ramelteon, ethyl acrylate and chloroform are stirred anddissolved, bromine is dropwise added at a normal temperature, bromine is dropwise added again after reaction is carried out for 1 hour, reaction is carried out for 2 hours, a water layer is extractedby concentrated hydrochloric acid, washing is carried out with water, saturated sodium hydrogen sulfite solution and saline water in sequence, anhydrous sodium sulfate is dried and filtered, and thefiltrate is decompressed and steamed to remove a solvent and then decompressed and dried below 60 DEG C so as to ensure that the reaction can be completely carried out, the purity of the prepared ramelteon is greatly improved, and the problems that the manufacture process is long in time, the ratio of the ramelteon in the extract is low, the preparation efficiency of the ramelteon is low and the preparation cost of the ramelteon is greatly increased are avoided.
- -
-
Paragraph 0021; 0024; 0026; 0029; 0031; 0034
(2019/01/17)
-
- Effect of CaO Addition on Nickel Catalysts Supported on Alumina for Glycerol Steam Reforming
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Abstract: Hydrogen production by glycerol steam reforming is an attractive alternative, as it represents the conversion of a waste in a high-added value product. In this work, three catalysts were synthesized by wet impregnation of nickel precursor in different supports: γ-Al2O3 prepared by boehmite calcination, α-Al2O3 and 15 wt% CaO-γ-Al2O3 prepared by wet impregnation of calcium oxide precursor in γ-Al2O3. A commercial catalyst for methane steam reforming was also evaluated. Catalytic tests were performed at 500?°C, glycerol feed of 20% v/v and GHSV of 200,000?h?1. The calcium oxide incorporation reduced the formation of nickel aluminate phase (NiAl2O4) and the amount and strength of catalyst acidity, while increasing the amount and strength of basic sites. Furthermore, it was the only catalyst that has not presented deactivation in 30?h of reaction, showing the highest glycerol conversion and hydrogen yield after 24?h of reaction. Ni/γ-Al2O3 and Ni/α-Al2O3 presented a severe deactivation, which was associated with coke formation. The synthesized catalysts presented better catalytic performance for glycerol steam reforming in comparison with commercial catalyst, in terms of higher glycerol conversion, glycerol conversion to gas and hydrogen yield. Graphical Abstract: [Figure not available: see fulltext.]
- Menezes, Jo?o Paulo da S. Q.,Jácome, Flávia C.,Manfro, Robinson L.,Souza, Mariana M. V. M.
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p. 1991 - 2003
(2019/05/15)
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- CeO2 promoting allyl alcohol synthesis from glycerol direct conversion over MoFe/CeO2 oxide catalysts: morphology and particle sizes dependent
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MoFe-N, MoFe/c–CeO2, MoFe/p1–CeO2, and MoFe/p2–CeO2 (where N, c, and p stand for non-supported, nanocube, and nanoparticle) oxide catalysts were designed for gas-glycerol direct catalytic conversion into allyl alcohol. The catalysts also were characterized by XRD, TEM, BET, H2-TPR, and NH3-TPD. Mo–Fe oxides were highly dispersed on the surface of c-CeO2 and p-CeO2 supports, different with the MoFe-N consist of crystalline Fe2(MoO4)3 and Fe2O3 crystalline phase. The support effect and special natural property of CeO2 significantly improve the allyl alcohol selectivity from gas-glycerol over MoFe/CeO2. The p-CeO2 with low particle sizes and crystalline degree was superior to high-crystalline nanocube c-CeO2 to promote its interaction with the MoFe oxide active components, and improve the surface acid site concentration and reducibility of MoFe/CeO2 as well as catalytic activity and stability for allyl alcohol synthesis from gas-glycerol without any extra hydrogen donors. Over the MoFe/p2–CeO2, the glycerol conversion reached 97.1%, and the selectivity of allyl alcohol, enthanal, propanoic acid, and acrylic acid were 23.3%, 8.6%, 12.6%, and 7.8%, respectively, yielding allyl alcohol of 22.6%.
- Lan, Hai,Zeng, Jia,Zhang, Biao,Jiang, Yi
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p. 1565 - 1580
(2018/12/13)
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- Catalytic Oxidative Cracking of Benzene Rings in Water
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Efficient degradation of harmful benzene rings in water is indispensable for achieving a clean water environment. We report herein unprecedented catalytic oxidative benzene cracking (OBC) in water using a ruthenium(II)-aqua complex having an N-heterocyclic carbene ligand as a catalyst and a cerium(IV) salt as a sacrificial oxidant under mild conditions. The OBC reactions produced carboxylic acids such as formic acid, which can be converted to dihydrogen directly from the OBC solution using a rhodium(III) catalyst with adjustment of the solution pH to 3.3. The OBC reactions can be applied to monosubstituted benzene derivatives such as ethylbenzene, chlorobenzene, and benzoic acid. Initial rates of the OBC reactions showed a linear relationship in the Hammett plot with a negative slope, indicating the electrophilicity of a Ru(III)-oxyl complex as the reactive species in the catalytic OBC reaction. Also, we discuss a plausible mechanism of the catalytic OBC reactions based on the kinetic analysis and the product stoichiometry for the OBC reaction of nonvolatile sodium m-xylene sulfonate. The addition of an electrophilic radical to the aromatic ring to form arene oxide/oxepin is proposed as the initial step of the OBC reaction.
- Shimoyama, Yoshihiro,Ishizuka, Tomoya,Kotani, Hiroaki,Kojima, Takahiko
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p. 671 - 678
(2019/01/08)
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- Well-dispersed nickel nanoparticles on the external and internal surfaces of SBA-15 for hydrocracking of pyrolyzed α-cellulose
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Catalysts comprising nickel supported on SBA-15 were prepared by wet impregnation and co-impregnation methods. Wet impregnation was performed by directly dispersing an Ni(NO3)2·6H2O aqueous solution into SBA-15, whereas in co-impregnation, ethylene glycol (EG) was added to nickel nitrate aqueous solution prior to dispersion into SBA-15. After drying and calcination, NiO/SBA-15w and NiO/SBA-15c were produced. Later, after the reduction process, Ni/SBA-15w and Ni/SBA-15c were obtained. The prepared catalysts were evaluated for the hydrocracking of pyrolyzed α-cellulose. The TEM images revealed that the catalysts prepared by wet impregnation showed inhomogeneous distribution of nickel loading, whereas catalysts prepared by co-impregnation using EG exhibited homogeneous distribution and formed no nickel aggregates. During hydrocracking of pyrolyzed α-cellulose, Ni/SBA-15c with total acidity, nickel loading, particle size, and specific surface area of 7.27 m mol g?1, 5.20 wt%, 3.17 nm, and 310.0 m2 g?1, respectively, exhibited the best catalytic performance compared to other prepared catalysts with 67.35 wt% conversion of liquid product with maximum selectivity in producing 13.09 wt% of 3-methyl-pentane. Moreover, Ni/SBA-15w with total acidity, nickel loading, particle size, and specific surface area of 10.87 m mol g?1, 8.15 wt%, 7.01 nm, and 628.0 m2 g?1, respectively, produced 69.89 wt% liquid product without hydrocarbons. Study of selectivity towards the formation of liquid hydrocarbons was carried out via double step hydrocracking using Ni/SBA-15w, and 18.55 wt% of n-hexane was produced in the liquid product.
- Trisunaryanti, Wega,Suarsih, Endah,Triyono,Falah, Iip Izul
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p. 1230 - 1237
(2019/01/23)
-
- METHOD FOR THE DEACYLATION AND/OR DEALKYLATION OF COMPOUNDS
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The present invention in general relates to a method for the deacylation and/or dealkylation (both O-dealkylation as well as C-dealkylation) of compounds, more specifically of aromatic compounds. The method is characterized by contacting the compound with an acid-containing aqueous reaction mixture using high temperature and high pressure conditions. The invention also provides a method for preparing a compound suitable for further deacylation using the method of the invention.
- -
-
Page/Page column 23; 33
(2019/02/15)
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- New insights for the valorisation of glycerol over MgO catalysts in the gas-phase
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Aqueous glycerol solutions of up to 50 wt% were reacted over magnesium oxide catalysts at temperatures greater than 300 °C, the reactivity of which was compared to catalyst-free reactions. Under catalyst-free conditions, modest levels of dehydration to hydroxyacetone were observed at temperatures >400 °C in a steel reactor tube and >320 °C over silicon carbide. For reactions over MgO, the product distribution becomes more diverse, resulting in the formation of methanol, acetaldehyde, ethylene glycol, 1,2-propanediol and acetic acid. The methanol space-time-yield over MgO catalyst samples (0.5 g) was found to be highest at 400 °C (205 g h-1 kgcat-1) with a 50 wt% solution of glycerol, or with a glycerol concentration of 10 wt%; 255 g h-1 kgcat-1 over 0.1 g of catalyst. Despite the high glycerol conversion achieved, the MgO catalyst was found to be stable over 48 h, following a modest decrease in glycerol conversion during the initial 2 h of reaction. Post-reaction characterisation revealed that the level of coking at high glycerol conversions (>90%) was ≥120 mg gcat-1. The carbon mass balance determined by GC analysis for a typical reaction was 75% and so the carbon lost from catalyst coking only represents a modest quantity of the missing carbon; typically 10%. MgO was also found to promote the formation of high molecular weight products via condensation reactions, which were responsible for the remainder of the missing carbon; ca. 15%. Therefore, the total organic content of the post-reaction mixture and coke was calculated to be 94% of the starting solution. We conclude that the catalyst surface directs the formation of methanol, however, the results indicate that the reaction conditions are crucial to obtain optimum yields.
- Smith, Louise R.,Smith, Paul J.,Mugford, Karl S.,Douthwaite, Mark,Dummer, Nicholas F.,Willock, David J.,Howard, Mark,Knight, David W.,Taylor, Stuart H.,Hutchings, Graham J.
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p. 1464 - 1475
(2019/03/26)
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- Influence of the structure of trigonal Mo-V-M3rd oxides (M3rd?=?-, Fe, Cu, W) on catalytic performances in selective oxidations of ethane, acrolein, and allyl alcohol
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Crystalline “MoVO”, “MoVCuO”, “MoVFeO” and “MoVWO” catalysts with a trigonal symmetry were successfully synthesized and characterized. The influence of the as-obtained structures on catalytic performances in selective oxidation reactions was investigated. MoVFeO and MoVCuO accomodated Fe and Cu species inside heptagonal channels, while W in MoVWO was incorporated in pentagonal {Mo6O21}6? units. Whereas MoVO and MoVWO showed catalytic activity in the selective oxidation of ethane and acrolein, MoVFeO and MoVCuO performed very poorly in the same reaction, suggesting that the presence of empty heptagonal channels is related to ethane and acrolein activations. In the selective oxidation of allyl alcohol, substantial amounts of acrolein (formed by oxidative dehydrogenation) and propanal (formed by isomerization) were formed as primary products over MoVO and MoVWO, whereas MoVFeO and MoVCuO preferentially promoted the formation of acrolein. It was found that the local crystal structure around the heptagonal channel was related with a modification of the reaction pathway for the selective oxidation of allyl alcohol. Due to the prevention of isomerization over MoVFeO, a high acrylic acid yield of 83.1% from allyl alcohol was achieved at 350 °C over this sample.
- Ishikawa, Satoshi,Murayama, Toru,Katryniok, Benjamin,Dumeignil, Franck,Araque, Marcia,Heyte, Svetlana,Paul, Sébastien,Yamada,Iwazaki, Mizuki,Noda, Nagisa,Ueda, Wataru
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- Desulfurization method of organic compounds containing mercapto or disulfide bond
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The invention relates to a desulfurization method of organic compounds, in particular, organic compounds containing mercapto or a disulfide bond. The method comprises following steps: dissolving organic compounds containing mercapto or a disulfide bond by a solvent; adding a phosphine reagent and an initiator; and carrying out reactions in the presence of light to convert the substrate into corresponding desulfurization products. The organic compounds containing mercapto or a disulfide bond is R-SH or R-S-S-R; wherein R represents a primary carbon group, a secondary carbon group, a tertiary carbon group, an aryl group, or an acyl group. The reactions do not need any metal, and the reaction conditions are mild. Moreover, the desulfurization method has the advantages of high yield, wide substrate application range, and multiple suitable solvents, and is widely suitable for multiple kinds of mercapto-removing reactions and desulfurization reactions of disulfide.
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Paragraph 0026
(2019/10/01)
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- The promoter effect of Co on the catalytic activity of the Cu oxide active phase supported on Al2O3 in the hydrogenolysis of glycerol
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The promoting effect of cobalt oxide on alumina-supported Cu oxide catalysts for the hydrogenolysis of glycerol was investigated. A series of Co(y)Cu/Al2O3 oxide catalysts with a fixed Cu loading of 7 wt% and a variable Co loading from 0 to 1.5 wt% was prepared by successive wet impregnation. The catalysts were characterized by X-ray diffraction (XRD), nitrogen sorption, temperature programmed reduction (TPR), ultraviolet-diffuse reflectance spectroscopy (UV-DRS), temperature programmed desorption of ammonia (TPD-NH3), and X-ray photoelectron spectroscopy (XPS). The catalysts were tested in a batch reactor at 220 °C and 5 MPa of H2. The activity of the catalysts on a per mole of Cu basis increased with Co content up to the plateau, and subsequently decreased at higher Co content. The increase of activity is attributed to the combined effect of the distortion of the octahedral geometry of CuO by the presence of CoO and the increase in the number of surface acid sites. In contrast, the subsequent decrease of activity at higher loading is related to the formation of less reducible, less acidic, and less active aluminates. The selectivity of products did not vary substantially with Co loading, indicative of the existence of active sites of similar characteristics on all the catalysts. Overall, all the catalysts favored the route comprising of C-O hydrogenolysis followed by hydrogenation, at the expense of the pathway involving C-C hydrogenolysis, leading to the predominant formation of 1,2-propanediol (1,2-PDO). This is probably due to the prevalence of metallic active sites over acidic sites on the surface, ensuring that partial removal of oxygen occurred without the loss of carbon atoms.
- Sepúlveda,Cruces,Gajardo,Seguel,García,Salinas,Fierro,Ghampson,Serpell,Escalona
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p. 15636 - 15645
(2019/10/19)
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- Low Temperature Oxidation of Ethane to Oxygenates by Oxygen over Iridium-Cluster Catalysts
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Direct selective oxidation of light alkanes, such as ethane, into value-added chemical products under mild reaction conditions remains a challenge in both industry and academia. Herein, the iridium cluster and atomically dispersed iridium catalysts have been successfully fabricated using nanodiamond as support. The obtained iridium cluster catalyst shows remarkable performance for selective oxidation of ethane under oxygen at 100 °C, with an initial activity as high as 7.5 mol/mol/h and a selectivity to acetic acid higher than 70% after five in situ recycles. The presence of CO in the reaction feed is pivotal for the excellent reaction performance. On the basis of X-ray photoelectron spectroscopy (XPS) analysis, the critical role of CO was revealed, which is to maintain the metallic state of reactive Ir species during the oxidation cycles.
- Jin, Renxi,Peng, Mi,Li, Ang,Deng, Yuchen,Jia, Zhimin,Huang, Fei,Ling, Yunjian,Yang, Fan,Fu, Hui,Xie, Jinglin,Han, Xiaodong,Xiao, Dequan,Jiang, Zheng,Liu, Hongyang,Ma, Ding
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supporting information
p. 18921 - 18925
(2019/11/05)
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- A study of the oxidehydration of 1,2-propanediol to propanoic acid with bifunctional catalysts
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The gas-phase oxidehydration (ODH) of 1,2-propanediol to propionic acid has been studied as an intermediate step in the multi-step transformation of bio-sourced glycerol into methylmethacrylate. The reaction involves the dehydration of 1,2-propanediol into propionaldehyde, which occurs in the presence of acid active sites, and a second step of oxidation of the aldehyde to the carboxylic acid. The two reactions were carried out using a cascade strategy and multifunctional catalysts, made of W-Nb-O, W-V-O and W-Mo-V-O hexagonal tungsten bronzes, the same systems which are also active and selective in the ODH of glycerol into acrylic acid. Despite the similarities of reactions involved, the ODH of 1,2-propanediol turned out to be less selective than glycerol ODH, with best yield to propanoic acid no higher than 13percent, mainly because of the parallel reaction of oxidative cleavage, occurring on the reactant itself, which led to the formation of C1-C2 compounds.
- Bandinelli, Claudia,Basile, Francesco,Cavani, Fabrizio,Concepcion, Patricia,De Maron, Jacopo,Dimitratos, Nikolaos,Lambiase, Barbara,Nieto, Jose Manuel Lopez,Tabanelli, Tommaso
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- An Efficient Aerobic Oxidation Protocol of Aldehydes to Carboxylic Acids in Water Catalyzed by an Inorganic-Ligand-Supported Copper Catalyst
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A method for the aerobic oxidation of aldehydes to carboxylic acids in water by using an inorganic-ligand-supported copper catalyst was developed. This method was performed with the use of atmospheric oxygen as the sole oxidant under extremely mild aqueous conditions, and furthermore, a wide range of aldehydes with various functional groups were tolerated. The copper catalyst could be recycled and used in successive reactions at least six times without any appreciable degradation in performance. This method is operationally simple and avoids the use of high-costing, toxic, air/moisture-sensitive, and commercially unavailable organic ligands. The generality of this method gives it potential to be used on the industrial scale.
- Yu, Han,Ru, Shi,Zhai, Yongyan,Dai, Guoyong,Han, Sheng,Wei, Yongge
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p. 1253 - 1257
(2018/02/16)
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- Method for preparing low carbon acid from low carbon alcohol
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The present invention provides a method for preparing a low carbon acid from a low carbon alcohol, particularly a method for preparing a low carbon acid in a homogeneous reaction system by catalytically oxidizing a low carbon alcohol, wherein the oxidant of the catalytic oxidation reaction is hydrogen peroxide or t-butyl hydroperoxide, and the catalyst is a water-soluble or alcohol-soluble heteropolyphosphatotungstate or a tungstic acid catalyst. According to the present invention, the preparation method has advantages of simpleness, low production cost, environmental friendliness and high product yield.
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Paragraph 0015; 0026
(2018/11/04)
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