- Photoinduced hydrometalation and hydrogenation of activated olefins with molybdenum and tungsten dihydrides (Cp2MH2)
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The early-transition-metal hydrides Cp2MoH2, Cp2WH2, and Cp2ReH rapidly form a series of electron donor-acceptor (EDA) complexes with various activated olefins as shown by the spontaneous appearance of vivid colors, the absorption energies of which correlate with the electron affinity of the olefinic acceptor and the oxidation (ionization) potential of the hydridometal donor in accord with Mulliken theory. Deliberate excitation of the charge-transfer absorption band leads to the quantitative hydrometalation of fumaronitrile by Cp2MoH2 at 25°C, and the structure of the σ hydrido alkyl adduct Cp2Mo(CHCNCH2CN)H (I) has been established by X-ray crystallography, (space group P21, monoclinic, with a = 8.090 (3) A?, b = 10.282 (4) A?, c = 8.316 (3) A?, β = 116.92 (3)°, V = 617 A?3, Z = 2, R = 0.028, Rw = 0.028 for 1802 reflections with I > 3σ having 2θ ≤ 60°). Under the same photochemical conditions, the tungsten analogue Cp2WH2 effects quantitative hydrogenation and leads to succinonitrile together with the olefinic π-adducts to tungstenocene in high yields. (In both cases, the thermal (dark) processes are nonexistent) The charge-transfer mechanism for olefin hydrometalation and hydrogenation stemming from charge separation in the EDA complex (i.e. [Cp2MH2?+,>C--C ?ox of the hydridometal species and the subsequent facile proton transfer from the labile cation radical Cp2MH2?+ (M = Mo, W) to the acceptor moiety. The close similarity of the photoinduced process for olefin hydrometalation and hydrogenation of various activated olefins with those effected thermally at higher temperatures is discussed.
- Ko,Bookman,Kochi
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- Nickel promoted functionalization of CO2 to anhydrides and ketoacids
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The reductive functionalization of carbon dioxide into high value organics was accomplished via the coupling with carbon monoxide and ethylene/propylene at a zerovalent nickel species bearing the 2-((di-t-butylphosphino)methyl)pyridine ligand (PN). An initial oxidative coupling between carbon dioxide, olefin, and (PN)Ni(1,5-cyclooctadiene) afforded five-membered nickelacycle lactone species, which were produced with regioselective 1,2-coupling in the case of propylene. The propylene derived nickelacycle lactone was isolated and characterized by X-ray diffraction. Addition of carbon monoxide, or a combination of carbon monoxide and diethyl zinc to the nickelacycle lactone complexes afforded cyclic anhydrides and 1,4-ketoacids, respectively, in moderate to high yields. The primary organometallic product of the transformation was zerovalent (PN)Ni(CO)2. This journal is
- Greenburg, Zoe R.,Jin, Dong,Williard, Paul G.,Bernskoetter, Wesley H.
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- Selective hydrogenation of maleic anhydride over Pd/Al2O3 catalysts prepared via colloid deposition
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Pd/Al2O3 catalysts were prepared via colloid deposition and the performance of the catalysts was examined in the selective hydrogenation of maleic anhydride to succinic anhydride. When the reaction was carried on in a batch system with 1,4-dioxane as the solvent (353 K and 1.0 MPa), high conversion of maleic anhydride (>98%) and high selectivity (>99%) for succinic anhydride were observed after 5 h. The as-prepared Pd/Al2O3 catalyst also showed excellent performance in solvent-free system and fixed-bed systems. The maleic anhydride (MA) conversion was greater than 98%, and high selectivity (>99%) for succinic anhydride was obtained after 1600 h in a fixed bed reacter. The results showed that the activity of the Pd/Al2O3 catalysts was excellent due to its high active surface area. [Figure not available: see fulltext.]
- Yuan, Hongjing,Zhang, Chunlei,Huo, Weitao,Ning, Chunli,Tang, Yong,Zhang, Yi,Cong, Dequan,Zhang, Wenxiang,Luo, Jiahuan,Li, Su,Wang, Zhenlu
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- Heterogeneous catalysts for the cyclization of dicarboxylic acids to cyclic anhydrides as monomers for bioplastic production
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Cyclic anhydrides, key intermediates of carbon-neutral and biodegradable polyesters, are currently produced from biomass-derived dicarboxylic acids by a high-cost multistep process. We present a new high-yielding process for the direct intramolecular dehydration of dicarboxylic acids using a reusable heterogeneous Lewis acid catalyst, Nb2O5·nH2O. Various dicarboxylic acids, which can be produced by a biorefinery process, are transformed into the corresponding cyclic anhydrides as monomers for polyester production. This method is suitable for the production of renewable polyesters in a biorefinery process.
- Rashed, Md. N.,Siddiki,Ali, Md. A.,Moromi, Sondomoyee K.,Touchy, Abeda S.,Kon, Kenichi,Toyao, Takashi,Shimizu, Ken-Ichi
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- Clay catalysis: A convenient and rapid formation of anhydride from carboxylic acid and isopropenyl acetate under microwave irradiation
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The Montmorillonite KSF catalyses the synthesis of anhydrides from carboxylic acids in the presence of isopropenyl acetate under microwave irradiations.
- Villemin,Labiad,Loupy
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- Vanadium(v) oxoanions in basic water solution: A simple oxidative system for the one pot selective conversion of l-proline to pyrroline-2-carboxylate
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The unprecedented, direct chemical oxidation of l-proline to pyrroline-2-carboxylate was achieved in water (pH 9-10) by means of NH4VO3/NH3 or V2O5/MOH (K = Na, K), and the anion was fully characterized as ammonium or alkaline metal salts. Quantitative yield and higher atom economy performance were achieved with the latter system, the alkaline salts being more stable than the ammonium one. Different mixed valence V(iv)/V(v) compounds precipitated from the reaction mixtures depending on the nature of the employed base. A possible reaction mechanism is proposed according to DFT calculations. The analogous reaction of trans-4-hydroxy-l-proline with NH4VO3/NH3 afforded pyrrole-2-carboxylic acid in 81% yield, while sarcosine underwent prevalent decomposition under similar experimental conditions. Instead, no reaction was observed with primary (glycine, l-alanine, l-phenylalanine) and tertiary α-amino acids (N,N-dimethyl-l-phenylalanine, N,N-dimethylglycine).
- Biancalana, Lorenzo,Tuci, Giada,Piccinelli, Fabio,Marchetti, Fabio,Bortoluzzi, Marco,Pampaloni, Guido
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- Mechanism of synthesis of maleic and succinic anhydrides by carbonylation of acetylene in solutions of palladium complexes
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The mechanism of synthesis of maleic and succinic anhydrides from acetylene and CO in the PdBr2 - LiBr - organic solvent catalytic system was studied using the procedure of advancement and discrimination of hypotheses. The hypotheses were obtained using the data bank on elementary steps and the Comb1 combinatorial program. The discrimination of the hypotheses was based on the data of NMR and IR spectroscopy, studies of isotope exchange, the role of potential organic intermediates, the kinetic isotope effect, and one-factor kinetic experiments. The most probable mechanism of synthesis of maleic anhydride includes insertion of acetylene and CO into the Pd - Pd bond of the Pd1 complex, which is formed from Pd11 at the initial step of the process. Succinic anhydride results from the intramolecular transformation of the hydride complex of palladium and maleic anhydride. The palladium hydride complexes detected in the contact solution apparently play the crucial role in the conjugation of oxidation, reduction, and addition type reactions.
- Bruk,Oshanina,Kozlova,Temkin,Odintsov
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- Efficient cyclodehydration of dicarboxylic acids with oxalyl chloride
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Literature examples illustrating the use of oxalyl chloride to prepare dicarboxylic acid anhydrides are surprisingly limited. At the same time, we have discovered a method involving the use of this readily available reagent which allowed the preparation of novel cyclic anhydrides where other, more conventional, methods had failed. Herein, we demonstrate that the method is applicable to a wide diversity of substrates, delivers good to excellent yields of cyclic anhydrides without chromatographic purification and can be considered a synthetic tool of choice whenever dicarboxylic acid cyclodehydration is required.
- Kantin, Grigory,Chupakhin, Evgeny,Dar'in, Dmitry,Krasavin, Mikhail
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- Gas-phase hydrogenation of maleic anhydride to γ-butyrolactone at atmospheric pressure over Cu-CeO2-Al2O3 catalyst
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Cu-CeO2-Al2O3 catalyst, prepared by co-precipitation method, was investigated for the gas-phase hydrogenation of maleic anhydride (MA) to γ-butyrolactone (GBL) at atmospheric pressure and the catalyst deactivation was also studied. Effects of catalyst composition, reaction temperature, and liquid hourly space velocity (LHSV) of raw material on the catalytic performance of Cu-CeO2-Al2O3 catalyst were investigated. The catalyst (molar ratio of Cu:Ce:Al = 1:1:2) showed better catalytic performance, in which both the conversion of MA and the selectivity of GBL kept 100% within two hours under the reaction conditions of 6 mL catalyst, 0.1 MPa, 220-280 °C, 30 mL min-1 H2, 0.6 h-1 LHSV of 20 wt.% MA/GBL. As for Cu-CeO2-Al 2O3 catalyst, smaller crystallite size of Cu and higher Cu surface area are favorable to increase its catalytic performance. The deactivation of Cu-CeO2-Al2O3 catalyst is due to formation of the compact wax-like deposition on the catalyst surface, which is probably ascribed to the strong adsorption of succinic anhydride and then polymerization on the catalyst surface. The catalytic performance of the regenerated catalyst can be recovered completely by the regeneration method of N2-air-H2 stage treatment.
- Yu, Yang,Guo, Yanglong,Zhan, Wangcheng,Guo, Yun,Wang, Yanqin,Wang, Yunsong,Zhang, Zhigang,Lu, Guanzhong
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- Ni/Al2O3 catalysts derived from spinel NiAl2O4 for low-temperature hydrogenation of maleic anhydride to succinic anhydride
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Ni/Al2O3 catalysts were derived from spinel NiAl2O4 with different Ni content ((2.5, 5 and 7.5) wt%). The catalysts were obtained by H2 reduction and were investigated for the low-temperature hydrogenation of maleic anhydride (MA) to produce succinic anhydride (SA). The characterization results showed that Ni0 active sites were mainly derived during the H2 reduction from spinel NiAl2O4. Among the catalysts studied, employing the optimum preparation and reaction conditions with Ni(5%)/Al2O3 yielded the highest catalytic performance. A near-100% conversion of MA and ~90% selectivity to SA were achieved at 120 °C and 0.5 MPa of H2 with a weighted hourly space velocity (MA) of 2 h?1.
- Li, Jie,Ren, Yuanhang,Yue, Bin,He, Heyong
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- Pd/C modified with Sn catalyst for liquid-phase selective hydrogenation of maleic anhydride to gamma-butyrolactone
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Pd catalysts suffered from poor selectivity and stability for liquid-phase hydrogenation of maleic anhydride (MA) to gamma-butyrolactone (GBL). Thus, Pd/C catalysts modified with different Sn loadings were synthesized, and characterized by XRD, XPS, TEM and elemental mapping. The types of alloy phase and the amounts of the surface Pd-SnOx sites altered along with Sn/Pd mass ratios from 0–1.0 synthesized in the process of preparation. The maximum reaction rate was 0.57?mol-GBL/(mol-Pd?min) and selectivity was 95.94% when the Sn/Pd mass ratio was 0.6. It might be attributed to the formation of Pd2Sn alloy and less amounts of Pd-SnOx sites.
- Li, Rongrong,Zhao, Jia,Han, Deman,Li, Xiaonian
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- Active ruthenium catalysts prepared by Cacumen Platycladi leaf extract for selective hydrogenation of maleic anhydride
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Ruthenium-based catalysts were prepared by a biogenic method via Cacumen Platycladi leaf extract and tested in the liquid phase hydrogenation of maleic anhydride to the corresponding succinic anhydride. The reaction conditions were optimized by varying the Ru loading, reaction temperature, hydrogen pressure, reaction time and organic solvents to achieve the superb catalytic performance. Reusability tests and comparison with commercial catalysts were also studied on the biosynthesized Ru-based catalysts. Furthermore, a variety of characterization techniques, such as TEM, HRTEM, EDS and XPS showed the effectively introduction of ruthenium nanoparticles into the carbon supports. The analyses of FTIR and TG confirmed that the plant extract served as both reducing and protecting agents.
- Huang, Yangqiang,Ma, Yao,Cheng, Youwei,Wang, Lijun,Li, Xi
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- State of Palladium Complexes in the PdBr2–LiBr–CH3CN–H2O Catalytic System, Used to Obtain Succinic Anhydride
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Abstract: UV–Vis spectroscopy is used to study the PdBr2–LiBr–CH3CN system at different concentrations of palladium and lithium bromides. The resulting data are mathematically processed using hypotheses that include the formation of monomeric and dimeric palladium complexes. Equilibrium constants of the stages of monomer and dimer complexation are calculated, along with the extinction coefficients of palladium complexes. The spectra of individual monomeric and dimeric palladium complexes are reproduced within the model, allowing for the formation of four monomeric and three dimeric complexes. UV–Vis and IR spectroscopy are used to analyze the state of palladium complexes in the PdBr2–LiBr–CH3CN system after contact with СО, and directly during the carbonylation of acetylene into succinic anhydride.
- Putin, A. Yu.,Katsman,Bruk
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- Continuous-Flow Production of Succinic Anhydrides via Catalytic β-Lactone Carbonylation by Co(CO)4?Cr-MIL-101
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Industrial synthesis of succinic acid relies on hydrocarbon oxidation or biomass fermentation routes that suffer from energy-costly separation processes. Here we demonstrate an alternate route to succinic anhydrides via β-lactone carbonylation by heterogeneous bimetallic ion-pair catalysis in Co(CO)4--incorporated Cr-MIL-101 (Co(CO)4Cr-MIL-101, Cr-MIL-101 = Cr3O(BDC)3F, H2BDC = 1,4-benzenedicarboxylic acid). Postsynthetically introduced Co(CO)4- facilitates CO insertion to β-lactone substrates activated by the Lewis acidic Cr(III) centers of the metal-organic framework (MOF), leading to catalytic carbonylation with activity and selectivity profiles that compare favorably to those reported for homogeneous ion-pair catalysts. Moreover, the heterogeneous nature of the MOF catalyst enables continuous production of succinic anhydride through a packed bed reactor, with room temperature β-propiolactone carbonylation activity of 1300 molAnhydride·molCo-1 over 6 h on stream. Simple evaporation of the fully converted product stream yields the desired anhydride as isolated solids, highlighting the unique processing advantages conferred by this first example of heterogeneous β-lactone carbonylation pathway.
- Park, Hoyoung D.,Dinca, Mircea,Román-Leshkov, Yuriy
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- An Efficient One-Pot Synthesis of Bis Butenolides
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3,3′,4,4′-Tetramethyl-5,5′-dioxo-2,2′-bifuran-2,2′(5H,5′H) diyl diacetate was obtained from the reaction between 2,3-dimethyl maleic anhydride and acetic anhydride in the presence of zinc in toluene. This easy synthetic route gave bis butenolide in excellent yield.
- Bayat, Mohammad,Fox, Joseph M.
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- A convenient method for synthesis of symmetrical acid anhydrides from carboxylic acids with trichloroacetonitrile and triphenylphosphine
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Various carboxylic acids are converted into the corresponding carboxylic acid anhydrides treated with trichloroacetonitrile and triphenylphosphine in the presence of triethylamine at room temperature.
- Kim,Jang
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- Pyrene derived functionalized low molecular weight organic gelators and gels
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Pyrene derived binary functionalized low molecular weight organic gelators (FLMOGs) and gels thereof in selected organic solvents were synthesized and characterized. The functionality refers to a functional group that does not take part in formation of the supramolecular gel network, but remains free and available for other purposes, such as to bind nanoparticles or other molecules into the gel structure. Functional groups were observed to disturb gel formation strongly, if they interact with each other within the same supramolecule due to the formation of competitive structures. Preventing such interactions restored the original gel properties. A gel with weaker supramolecular bonding than the binding between the functional groups was successfully made by separating the functional groups by distance. The π-π-interaction was found to be of negligible significance to the supramolecular binding energy, but probably essential to align the molecules to a one-dimensional chain and bring them into the range of van der Waals forces mainly responsible for the binding in this system. Solvent was observed to increase the binding energy of the supramolecule. All molecules were characterized by spectroscopic techniques and elemental analysis. Selected gels were characterized with rheometry, scanning electron microscopy, UV- and fluorescence spectroscopy. Gelation kinetics and hysteresis were measured by UV-spectroscopy and a fast gelation process was observed for all the gelators studied. The melting enthalpies were measured by DSC and calculated theoretically by PM3 level of theory. The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
- Hahma, Arno,Bhat, Shreedhar,Leivo, Kimmo,Linnanto, Juha,Lahtinen, Manu,Rissanen, Kari
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- Maleic anhydride hydrogenation to succinic anhydride over mesoporous Ni/TiO2 catalysts: Effects of Ni loading and temperature
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Catalytic hydrogenation of maleic anhydride for the production of succinic anhydride can be a viable alternative to the higher energetic demand route based in the dehydration of succinic acid. In this sense, the metallic Ni catalysts supported on mesoporous TiO2 (anatase) substrate demonstrated to be very active and 100% selective in the liquid phase hydrogenation of maleic anhydride (MA) to succinic anhydride (SA). The catalysts, which were prepared via wet impregnation method with different Ni loading (5, 10 and 15?wt.%), were characterized by chemical analysis (ICP-AES), N2 physical adsorption-?desorption, H2-?temperature programmed reduction (H2-?TPR)?, X-ray diffraction (XRD)?, high resolution transmission electron spectroscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). The Ni species interaction with support was investigated by TPR and by performing five catalyst recycling tests. After catalyst activation by reduction, the increase of Ni particle size with an increase of Ni loading was relatively small (from 6.9 to 8.9?nm) due to enhance of the metal-support interaction. After the first catalytic cycle, the optimized 5%Ni/TiO2 catalyst showed a small decrease in the Ni loading attributed to metal leaching during time course of reaction. Besides this, the 5%Ni/TiO2 catalyst exhibited a good stability during five continuous cycles with a very high yield of SA after 5 cycles. Finally, temperature experiments performed for the best system shown that the reaction temperature does not affect the SA selectivity in the temperature range studied (323?K–398?K).
- Torres, Cecilia C.,Alderete, Joel B.,Mella, Claudio,Pawelec, Barbara
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- Selective hydrogenation of maleic anhydride to succinic anhydride catalyzed by metallic nickel catalysts
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Maleic anhydride was selectively hydrogenated to succinic anhydride over metallic nickel catalysts, such as Raney Ni and Ni nanoparticles, in liquid phase at reaction temperature lower than 130 °C. When the Raney Ni catalyst in solvents with different polarities catalyzed the hydrogenation of maleic anhydride to succinic anhydride, the solvent with high polarity favored the hydrogenation of maleic anhydride to succinic anhydride as compared to that with low polarity. When the hydrogenation reaction was catalyzed by Raney Ni catalyst at 100 °C and H2 pressure of 2.5 MPa for 360 min in acetic anhydride, the conversion of maleic anhydride and the selectivity of succinic anhydride were 99.6% and 100%, respectively. In solvent-free reaction system, γ-butyrolactone as a byproduct with the maximum selectivity of 14.8% was produced at 130 °C. All of the Ni nanoparticles with average diameters ranging from 8 to 313 nm showed higher catalytic activity than Raney Ni in liquid phase hydrogenation of maleic anhydride to succinic anhydride. When the Ni nanoparticles with an average diameter of 8 nm were used as the catalysts in the liquid phase hydrogenation at 80 °C and 2 MPa of H 2 for 150 min and the weight ratio of catalyst to maleic anhydride was 1:100, the conversion of maleic anhydride and the selectivity of succinic anhydride were 99.8% and 100%, respectively. The small particle size and the polycrystalline structure of Ni nanoparticles played important roles in the liquid phase selective hydrogenation of maleic anhydride to succinic anhydride.
- Feng, Yonghai,Yin, Hengbo,Wang, Aili,Xie, Tao,Jiang, Tingshun
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- NICKEL(0)-INDUZIERTE C-C-VERKNUEPFUNG ZWISCHEN KOHLENDIOXID UND ETHYLEN SOWIE MONO- ODER DI-SUBSTITUIERTEN ALKENEN
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The nickel(0)-induced coupling of CO2 with ethylene or with mono- or di-substituted alkenes is described.The regioselectivity of this reaction has been determined.
- Hoberg, Heinz,Schaefer, Dietmar
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- New catalytic systems for oxidative carbonylation of acetylene to maleic anhydride
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A classification of polyfunctional catalytic systems based on discrimination of the main component (the catalyst participating in all stages of the formation of the product of catalytic reaction) and elucidating the functions of additional components of a catalytic system is suggested. The role of additional components in a number of new palladium-based catalytic systems used in the synthesis of maleic anhydride by oxidative carbonylation of acetylene was studied. It was established that the functions of Co and Fe phthalocyanine complexes (PcCo and Pc*Fe, respectively) in the mechanism of the process are different.
- Bruk,Kozlova,Marshakha,Oshanina,Temkin,Kaliya
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- N, N′-Bis(trifluoromethanesulfonyl) Dicarboxylic Acid Amides
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Glutaric, adipic, and sebacic acids reacted with 2 equiv of N-sulfinyltrifluoromethanesulfonamide in the presence of thionyl chloride as a catalyst to give the corresponding N, N′-bis(trifluoromethanesulfonyl) diamides. Under similar conditions, succinic and 4-nitrophthalic acids underwent dehydration to the corresponding anhydrides.
- Belovezhets, L. A.,Shainyan, B. A.,Sterkhova, I. V.,Tolstikova, L. L.
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- Selective liquid-phase hydrogenation of maleic anhydride to succinic anhydride on biosynthesized Ru-based catalysts
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Ru-based catalysts, supported on activated carbon and carbon nanotubes, were synthesized by a simple and eco-friendly bioreduction method and tested in the liquid-phase hydrogenation of maleic anhydride. Over 2.0% Ru/AC, succinic anhydride was produced with a maximum yield of 99.2% without further hydrogenation to γ-butyrolactone. Well-defined spherical shapes with uniform small size of Ru nanoparticles and the residual plant biomass were responsible for the excellent catalytic activities and stabilities.
- Ma, Yao,Huang, Yangqiang,Cheng, Youwei,Wang, Lijun,Li, Xi
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- Selective hydrogenation of maleic anhydride to γ-butyrolactone over Pd/Al2O3 catalyst using supercritical CO2 as solvent
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A selective hydrogenation of maleic anhydride to either γ-butyrolactone or succinic anhydride over simple Pd/Al2O3 catalyst under supercritical CO2 medium is described for the first time which has considerable promise for both lab-scale as well as industrial selective hydrogenations of low vapor pressure compounds without employing environmentally harmful organic solvents.
- Pillai, Unnikrishnan R.,Sahle-Demessie, Endalkachew
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- Quantitative Evaluation of the gem-Dimethyl Effect on the Succinic Acid Anhydride Equilibrium. Conformations of the Acids and Anhydrides by Empirical Force Field Calculations
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In order to evaluate quantitatively the gem-dimethyl effect on the succinic acid anhydride equilibrium, the conformations of succinic acid and its 2-methyl-, racemic 2,3-dimethyl-, tetramethyl-, and racemic 2,3-di-t-butyl-derivatives have been calculated by means of Allinger's 1977 empirical force field.An extension of the field was developed to calculate the conformations of the respective anhydrides.The calculated preferred conformations compare well with existing experimental data.No low-energy hydrogen-bonded minima for the acids were obtained.Increased substitution in the acids caused conformational changes facilitating ring closure: smaller torsion angles of conformations with gauche carboxy groups, favourable bond length and angle deformations, and a reduced number of preferred conformations.In the anhydrides, substitution leads to a twist around the C(2)-C(3) bond of the ring.The ΔΔH values estimated for the diacid anhydride equilibria agree well with experimental data in water indicating that the main cause of the observed gem-dimethyl effect in the anhydrides is relief of intramolecular strain arising on substitution in the acids.
- Ivanov, Petko M.,Pojarlieff, Ivan G.
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- Addition Reaction of Carboxylic Anhydrides to the Carbon-Nitrogen Double Bond of Unsubstituted Cyclic Imidates
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Acyclic and cyclic (SAn and GAn) carboxylic anhydrides were added at room temperature to the C=N bond of unsubstituted cyclic imidates of 2-oxazoline (OZO) and 5,6-dihydro-4H-1,3-oxazine (OZI) to give addition products quantitatively.In contrast to these findings, the reactions of acetyl halides with OZO and OZI yielded ring-opened products and the reactions of carboxylic anhydrides with 2-benzyl-2-oxazoline (BzOZO) afforded also the ring-opened products.The bicyclic addition product of OZO with SAn is equilibrated with a mixture of starting materials.The stereochemistry of addition products having a six-membered ring system is discussed.
- Kobayashi, Shiro,Isobe, Michihisa,Saegusa, Takeo
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- Conversion of succinic acid over Ni and Co catalysts
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Liquid-phase hydrogenation of succinic acid (SA) over supported Ni and Co catalysts was investigated at 200 °C and 6 MPa of H2. Reduced and passivated catalysts with the same surface metal density (2.5 atoms of metal per nm2 of support) were prepared by incipient wetness impregnation. The catalysts were characterized by X-ray diffraction (XRD), N2 adsorption, X-ray photoelectron spectroscopy (XPS), temperature-programmed reduction (TPR), CO-chemisorption, and temperature-programmed desorption of NH3 (TPD-NH3). The Ni and Co catalysts supported over SiO2 showed different product distribution, due to the adsorption of the SA over the surface of catalysts, determined by DFT calculations. The Co/SiO2, Co/SiO2-Al2O3, and Co/Al2O3 catalysts showed different product distribution, which was correlated with total acidity from TPD-NH3 results. In general, the Co catalysts promoted the hydrogenation process; however, the highest total acidity showed by Co/Al2O3 also promoted the dehydration process. Finally, the initial rate follows the trend according to the dispersion determined by CO-chemisorption.
- Rojas, Mabel,Zarate, Ximena,Canales, Roberto I.,Dongil, Ana Belen,Pazo, Cesar,Saavedra-Torres, Mario,Escalona, Néstor
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- CONFORMATION OF SUCCINIC ACID DERIVATIVES BY DOUBLE 13C-LABELLING
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Three-bonded carbon/carbon couplings (3Jcc) are used, in conjunction with MM2 calculations, to examine conformational equilibria in several di-13C-labelled succinic acid derivatives.
- Menger, F.M.,Lee, L. H.
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- Rhodium-catalysed, Carbon Dioxide-mediated Aerobic Oxidation of Ethers
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In the presence of carbon dioxide (NBD = 2,5-norbornadiene) 1 catalyses the aerobic oxidation of ethers to esters with coproduction of formic acid.
- Fazlur-Rahman, A. K.,Tsai, Jing-Cherng,Nicholas, Kenneth M.
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- Synthesis of succinic anhydride from maleic anhydride on Ni/diatomite catalysts
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The characteristics and catalytic properties of Ni(5 wt%)/diatomite, Ni(5 wt%)/γ-Al2O3, Ni(5% wt)/Bentonite clay and Ni(5 wt%)/attapulgite clay were investigated and compared in terms of catalytic activities for liquid-phase hydrogenation of maleic anhydride (MA). The results showed that the diatomite support exhibited the highest activity and selectivity. Using Ni(7 wt%)/diatomite catalyst, the 100% conversion of MA and 96.20% selectivity to SA were obtained for MA hydrogenation at 190 C. The X-ray diffraction (XRD) studies showed that there is only NiO on the support and no elemental nickel (Ni0) and Ni2O3 was detected in unreduced samples. XRD and H2 temperature-programmed reduction (TPR) studies also showed that NiO species were all converted to metallic nickel (Ni0) after reduction at 350 C.
- Guo, Shaofei,Shi, Li
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- Preparation of Ni- or Pt-Containing Cyclic Esters by Oxidative Addition of Cyclic Carboxylic Anhydrides and Their Properties
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Metal containing cyclic ester complexes, L (L=1,2-bis(diphenylphosphino)ethane (dpe) or 2,2'-bipyridine (bpy); R1, R2=H or CH3) and Ln )L=tricyclohexylphosphine (PCy3) or dpe; n=1 or 2), have been prepared by oxidative addition of cyclic carboxylic anhydrides to zero-valent metal complexes.These complexes have been characterized by elemental analysis and spectroscopies (IR as well as 1H-, 13C1H>-, and 31P1H>-NMR) and chemical rectivities.Rate of the oxidative addition of succinic anhydride to Ni(bpy)(cod) (cod=1,5-cyclooctadiene) is expressed by a second order rate equation, R=k, and temperature dependence of k gives the activation energy of 68 kJ mol-1.The reaction of methylsuccinic anhydride with Ni(cod)2 in the presence of tertiary phosphine or bpy affords two isomers, Ln and Ln, corresponding to two modes of C-O bond cleavage in methylsuccininc anhydride promoted by Ni; dependence of the ratio between the two isomers on the kind of ligand added and reaction conditions has been examined.
- Sano, Kenji,Yamamoto, Takakazu,Yamamoto, Akio
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- Hydrogenation of maleic anhydride to succinic anhydride over nickel/clay catalysts
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Hydrogenation of maleic anhydride (MA) to succinic anhydride (SA) over Ni/clay catalysts prepared by an impregnation method has been studied at different temperatures, Ni contents, pressures and weighted hourly space velocity (WHSV). The catalytic activity was greatly influenced by the temperature, Ni content, WHSV and pressure. A 97.1 % MA conversion with 99.6 % selectivity to SA was obtained over 5 %wt catalyst at 180 °C and at a pressure of 1 MPa H2. The catalysts were characterized by an array of techniques, including X-ray diffraction (XRD), H2 temperature-programmed reduction (TPR) and thermogravimetric analysis (TGA). XRD and TPR studies showed that nickel was present as Ni2? species on the support. Increasing the calcination temperature up to 650 °C led to the destruction of the support structure, as observed by TGA, while a calcination temperature of 550 °C gave the best results. Catalyst deactivation studies showed that the catalyst has a long lifetime, the yield of SA remaining better than 90 % even after a reaction time of 60 h. Studies on the catalyst induction showed that the presence or absence of an induction period was determined by the type of hydrogenation catalyst. Springer Science+Business Media Dordrecht 2012.
- Guo, Shaofei,Tian, Weiping,Shi, Li
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- Selective gas-phase conversion of maleic anhydride to propionic acid on Pt-based catalysts
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Pt-based catalysts, supported on Al2O3, SiO 2 and SiO2-Al2O3, were prepared by incipient wetness impregnation and tested in the gas phase hydrogenation of maleic anhydride at atmospheric pressure and 240 C. In these conditions, the hydrogenolytic activity pattern was: Pt/SiO2 > Pt/Al 2O3 > Pt/SiO2-Al2O3, which is just the opposite of the support acidity trend. These metal Pt-based catalysts showed high selectivity to propionic acid, which was always higher than 80%. The selectivity pattern to this product was: Pt/Al2O 3 > Pt/SiO2 > Pt/SiO2-Al 2O3. Both activity and selectivity patterns may be explained on the basis of metal-support interaction and support acidity.
- Regenhardt,Trasarti,Meyer,Garetto,Marchi
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Read Online
- Carbon Dioxide as Modulator of the Oxidative Properties of Dioxygen in the Presence of Transition Metal Systems
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In the presence of transition metal ( Fe, Rh) catalysts, CO2 can modulate the oxidative properties of O2 towards tetrahydrofuran (THF) and styrene; the intermediate formation of metal-peroxocarbonate species, , seems to play a key role in these processes.
- Aresta, Michele,Fragale, Carlo,Quaranta, Eugenio,Tommasi, Immacolata
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Read Online
- Photocatalytic valorization of furfural to value-added chemicals via mesoporous carbon nitride: a possibility through a metal-free pathway
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Strategizing the exploitation of renewable solar light could undoubtedly provide new insight into the field of biomass valorization. Therefore, for the first time, we reported a heterogeneous photocatalytic oxidation route of renewable furfural (FUR) to produce industrial feedstocks maleic anhydride (MAN) and 5-hydroxy-2(5H)-furanone (HFO) under simulated solar light (AM 1.5G) using molecular oxygen (O2) as a terminal oxidant and mesoporous graphitic carbon nitride (SGCN) as a photocatalyst. SGCN showed an excellent photoconversion (>95%) of FUR with 42% and 33% selectivity to MAN and HFO, respectively. Moreover, an excellent selectivity towards MAN (66%) under natural sunlight indicates a pioneering route for the sustainable production of MAN. In addition, the underlying mechanistic route of the FUR photo-oxidation was investigated via various experiments including scavenger studies, substrate studies, and electron spin resonance (ESR) studies which constructively proved the pivotal role of singlet oxygen (1O2) and holes (h+) in FUR photo-oxidation.
- Battula, Venugopala R.,Chauhan, Deepak K.,Giri, Arkaprabha,Kailasam, Kamalakannan,Patra, Abhijit
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p. 144 - 153
(2022/01/19)
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- Pd/BN catalysts for highly efficient hydrogenation of maleic anhydride to succinic anhydride
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A 0.33 wt% Pd/BN catalyst has been proved highly active for the liquid-phase selective hydrogenation of maleic anhydride (MA) to succinic anhydride (SA) at room temperature and highly selective to SA within a wide temperature range, far beyond the Pd/Al2O3 and Pd/MgO catalysts. An SA productivity of 6000 KgSA KgPd?1 h?1 and a high TOF value of 9.0 s?1 can be achieved at room temperature on the Pd/BN, and the high SA selectivity over 99.7% can be retained at the reaction temperature up to 150 oC. Detailed structural characterizations and reactant-adsorption/desorption tests have demonstrated that the support effect on MA hydrogenation is related not only to the adsorption configurations of MA on Pd, which exhibits the indirect effect of the support via the electronic interaction with Pd, but also to the direct adsorption of MA on the support itself. In particular, for our catalysts with the low Pd loading, the difference of metal centers is largely masked by the adsorption of the support itself. For the Pd/BN, the predominant MA adsorption on Pd through a di-σ mode, the weak MA adsorption with a small amount on BN, and a high H-spillover ability are responsible for its high activity and selectivity. Moreover, it has been also revealed that the catalyst prereduction temperature can change the catalytic performance of the Pd/BN through an integrated effect including the removal of residual chlorine on Pd and the growth of Pd particles.
- Cao, Zhou,Sheng, Guangzhe,Sun, Changyong,Wang, Jiandian,Xia, Wenjun,Xie, Xiaowei
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- Metal-free photocatalytic aerobic oxidation of biomass-based furfural derivatives to prepare γ-butyrolactone
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Efficient catalytic oxidative C-C bond cleavage with dioxygen is useful and challenging to prepare oxygenated fine chemicals from biomass. Herein, we report a catalytic strategy for the preparation of γ-butyrolactone (GBL) by photocatalytic oxidation of tetrahydrofurfuryl alcohol (THFA), tetrahydrofurfuric acid (THFCA), or other furfural derivatives at room temperature under visible-light irradiation. Metal-free mesoporous graphitic carbon nitride was used as the photocatalyst and O2was used as the oxidant. The effects of various semiconductor catalysts, light sources with different wavelengths, and the reaction time on the photocatalytic oxidation of THFA to GBL were separately investigated. Furthermore, the reaction mechanism was investigated through serious control experiments and the reaction pathway was investigated through density functional theory (DFT) calculations.
- Zhu, Rui,Zhou, Gongyu,Teng, Jia-Nan,Liang, Wanying,Li, Xinglong,Fu, Yao
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p. 1758 - 1765
(2021/03/09)
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- MENTHOL DERIVATIVE-CONTAINING COMPOSITION
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PROBLEM TO BE SOLVED: To provide a menthol derivative-containing composition that suppresses a menthol-derived odor and sustains a refreshed feeling. SOLUTION: A composition contains (A) a menthol derivative or an alkali metal salt or an alkaline earth metal salt thereof, and (B) menthol or an alkali metal salt or an alkaline earth metal salt thereof. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPOandINPIT
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Paragraph 0055
(2021/04/09)
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- Application of two-dimensional MoS2 catalyst in catalyzing selective hydrogenation of maleic anhydride to prepare succinic anhydride
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The invention relates to the field of catalysts, and particularly discloses application of a two-dimensional MoS2 catalyst in catalyzing selective hydrogenation of maleic anhydride to prepare succinic anhydride. A preparation method of the two-dimensional MoS2 catalyst comprises the following steps: mixing ammonium molybdate and thiourea in water, conducting reacting at 180-240 DEG C for 12-24 hours, collecting a product after the reaction is finished, conducting washing for multiple times, and conducting drying to obtain the two-dimensional MoS2 catalyst. The two-dimensional MoS2 catalyst provided by the invention has high conversion rate and high selectivity for preparing succinic anhydride by selective hydrogenation of maleic anhydride.
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Paragraph 0033-0036; 0043-0060
(2021/06/21)
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- The menthol derivative salt and its use (by machine translation)
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[Problem] in stability and excellent cooling sensation of menthol derivative salt, containing composition. (1) Represented by the general formula [a] (A) menthol derivative salt. (In the formula, the M, 2Na+ , 2K+ , Ca2 + And mg2 + Selected from cationic) (2) is represented by the following general formula (B) menthol derivative salt. (In the formula, the M, Na+ , K+ , 1/2 Ca2 + And 1/2 mg2 + Selected from cationic)[Drawing] no (by machine translation)
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Paragraph 0067
(2020/03/26)
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- MENTHOL DERIVATIVE SALTS AND USES THEREOF
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PROBLEM TO BE SOLVED: To provide menthol derivative salts excellent in cool feeling, and compositions containing the same. SOLUTION: A composition contains (A) a menthol derivative salt represented by the general formula (1) in the figure, where M represents a cation of a metal, and (B) a menthol derivative salt. SELECTED DRAWING: None COPYRIGHT: (C)2020,JPOandINPIT
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Paragraph 0056
(2020/05/02)
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- Acrylonitrile Derivatives from Epoxide and Carbon Monoxide Reagents
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The present invention is directed to reactor systems and processes for producing acrylonitrile and acrylonitrile derivatives. In preferred embodiments of the present invention, the processes comprise the following steps: introducing an epoxide reagent and carbon monoxide reagent to at least one reaction vessel through at least one feed stream inlet; contacting the epoxide reagent and carbon monoxide reagent with a carbonylation catalyst to produce a beta-lactone intermediate; polymerizing the beta-lactone intermediate with an initiator in the presence of a metal cation to produce a polylactone product; heating the polylactone product under thermolysis conditions to produce an organic acid product; optionally esterifying the organic acid product to produce one or more ester products; and reacting the organic acid product and/or ester product with an ammonia reagent under ammoxidation conditions to produce an acrylonitrile product.
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Paragraph 0194; 0196
(2019/01/15)
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- Synthesis, Antiproliferative Activity, and Effect on Carcinoma A549 Cell Microtubules of New Tubuloclustin Analogs
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Combretastatin analogs of the antitumor agent tubuloclustin {N-[7-(adamant-2-yloxy)-7-oxoheptanoyl]-Ndeacetylcolchicine} were prepared via esterification of combretastatin by monoesters of pimelic or adipic acid with adamantan-2-ol or (adamantan-1-yl)methanol. These conjugates were stable and cytotoxic to human lung carcinoma A549 cells (EC50 ≈ 50 – 70 nM) and caused depolymerization of microtubules and slight clustering of tubulin. Tubuloclustin analogs with shortened linkers were prepared via amidation by N-deacetylcolchicine of monoesters of adipic or succinic acids with adamantan-1-ol or (adamantan-1-yl)methanol. The conjugate N-[6-(adamantyl)-6-oxohexanoyl]-N-deacetylcolchicine was more active (EC50 ≈ 4 nM) than tubuloclustin and promoted strong tubulin clusterization. All compounds induced apoptosis of A549 cells. Tests in vivo of N-[6-(adamantyl)-6-oxoheaxnoyl]-N-deacetylcolchicine on carcinoma A549 experimental models were concluded to be promising.
- Zefirov,Evteeva, Yu. A.,Fatkulin,Schulz,Kuznetsov,Zefirova
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p. 423 - 428
(2019/09/16)
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- Rethinking Basic Concepts-Hydrogenation of Alkenes Catalyzed by Bench-Stable Alkyl Mn(I) Complexes
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An efficient additive-free manganese-catalyzed hydrogenation of alkenes to alkanes with molecular hydrogen is described. This reaction is atom economic, implementing an inexpensive, earth-abundant nonprecious metal catalyst. The most efficient precatalyst is the bench-stable alkyl bisphosphine Mn(I) complex fac-[Mn(dippe)(CO)3(CH2CH2CH3)]. The catalytic process is initiated by migratory insertion of a CO ligand into the Mn-alkyl bond to yield an acyl intermediate which undergoes rapid hydrogenolysis to form the active 16e Mn(I) hydride catalyst [Mn(dippe)(CO)2(H)]. A range of mono- A nd disubstituted alkenes were efficiently converted into alkanes in good to excellent yields. The hydrogenation of 1-alkenes and 1,1-disubstituted alkenes proceeds at 25 °C, while 1,2-disubstituted alkenes require a reaction temperature of 60 °C. In all cases, a catalyst loading of 2 mol % and a hydrogen pressure of 50 bar were applied. A mechanism based on DFT calculations is presented, which is supported by preliminary experimental studies.
- Weber, Stefan,St?ger, Berthold,Veiros, Luis F.,Kirchner, Karl
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p. 9715 - 9720
(2019/10/14)
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- Preparation method of maleic anhydride
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Biomass-based acetylpropionic acid is taken as a raw material, and catalytic oxidation means is adopted to prepare maleic anhydride. According to the method, a manganese compound is taken as a catalyst, oxygen or air is taken as an oxidant, and acetylpropionic acid is catalyzed to prepare maleic anhydride. The method is simple in reaction operation, mild in condition, high in acetylpropionic acidconversion rate, and good in maleic anhydride selectivity, and has important application prospects.
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Paragraph 0029-0033
(2018/03/28)
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- PRODUCTION METHOD OF CARBOXYLIC ACID ANHYDRIDE AND PRODUCTION METHOD OF γ-BUTYROLACTONE
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PROBLEM TO BE SOLVED: To provide an industrially advantageous method for efficiently producing a carboxylic acid anhydride by conducting a dehydration condensation reaction of a carboxylic acid with a catalyst using the carboxylic acid as a raw material, and to accelerate the reaction so as to obtain succinic anhydride with a higher yield than in the conventional method according to the invention. SOLUTION: In a method for producing a carboxylic acid anhydride, when the carboxylic acid anhydride is produced by dehydration condensation reaction of a raw material dicarboxylic acid, the dehydration condensation reaction is conducted in the presence of an organic phosphorous compound, in which it is preferable that the raw material dicarboxylic acid is succinic acid, the carboxylic acid anhydride is succinic anhydride, and the organic phosphorous compound is a phosphine compound. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0042; 0043; 0044; 0045; 0046; 0047; 0048-0050
(2018/05/30)
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- METHODS FOR PRODUCTION OF TEREPHTHALIC ACID FROM ETHYLENE OXIDE
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The present invention provides methods for the production of terephthalic acid and derivatives thereof using ethylene oxide, carbon monoxide and furan as feedstocks. The process is characterized by high yields and high carbon efficiency. The process can utilize 100% biobased feedstocks (EO via ethanol, CO via biomass gasification, and furan via known processes from cellulosic feedstocks).
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Page/Page column 26-28
(2017/01/23)
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- Succinic anhydride-modified cellulose-based drug controlled-release carrier and preparation method thereof
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The invention discloses a succinic anhydride-modified cellulose-based drug controlled-release carrier and a preparation method thereof. Succinic anhydride-modified cellulose is applied to controlled-release domperidone, and a carboxy group can be combined with secondary amine hydrogen and carbonyl oxygen in the domperidone to generate a hydrogen bond, so that the domperidone can be loaded on the succinic anhydride-modified cellulose; and meanwhile, sites for hydrogen bond interaction formed between the succinic anhydride-modified cellulose and the domperidone are increased through the carboxy group and an esteryl group and the drug-loading stability of the succinic anhydride-modified cellulose is strengthened, so that release of the domperidone is retarded.
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Paragraph 0048; 0049
(2017/08/31)
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- MENTHOL DERIVATIVE POTASSIUM SALT AND APPLICATIONS THEREOF
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PROBLEM TO BE SOLVED: To provide a menthol derivative excellent in water solubility, and applications thereof. SOLUTION: A menthol derivative potassium salt is represented by the general formula (1) in the figure, where X and Y are each independently a hydrogen atom or OH group. SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0031
(2018/08/23)
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- Method for synthesizing pyridazinone drug intermediate butanedioic anhydride
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The invention provides a method for synthesizing a pyridazinone drug intermediate butanedioic anhydride. The method includes the following steps that, 0.61 mol of a 1-carboxyl-propanamide solution, 1.3-1.5 mol of a 2-bromine-phenylacetic acid solution, 300 ml of nitromethane and 0.61 mol of cuprous chloride are added into a reaction container provided with a stirrer and a reflux condenser, the stirring speed is controlled at 130-160 rpm, the solution temperature is raised to 70-75 DEG C, reflux is conducted for 3-5 hours, the solution temperature is lowered to 10-13 DEG C, solid is dissolved out, suction filtration is conducted, a salt solution is washed, methylbenzene is washed, recrystallization is conducted in ethidene diamine, and the crystal butanedioic anhydride is obtained.
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Paragraph 0015; 0016
(2016/12/12)
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- Catalytic oxidative C-C bond cleavage route of levulinic acid and methyl levulinate
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Recently, obtaining value-added chemicals from biomass resources has attracted considerable attention. Levulinic acid is one of the most important biomass platform compounds, which could be obtained from carbohydrate biomass. In this work, levulinic acid was selectively converted into C4 product, including succinic anhydride, via catalytic oxidation with a manganese catalyst in acetic anhydride. Moreover, an unexpected product of maleic anhydride was obtained, which greatly differs from that of levulinate ester. The pathway for formation of maleic anhydride was studied by monitoring and confirming intermediates α-angelica lactone and its derivative 2-methyl-5-oxotetrahydro-2-furanyl acetate. Based on the obtained mechanistic information, the different behaviour between the oxidative cleavage of levulinic acid and levulinate ester was further discussed.
- Xia, Fei,Du, Zhongtian,Liu, Junxia,Ma, Yangyang,Xu, Jie
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p. 72744 - 72749
(2016/08/09)
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- Efficient oxidation of ethers with pyridine N-oxide catalyzed by ruthenium porphyrins
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We found that oxidation of cyclic ethers with the Ru porphyrin-heteroaromatic N-oxide system gave lactones or/and ring-opened oxidized products with regioselectivity. A relatively high kinetic isotope effect was observed in the ether oxidation, suggesting that the rate-determining step is the first hydrogen abstraction.
- Kato, Nobuki,Hamaguchi, Yu,Umezawa, Naoki,Higuchi, Tsunehiko
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p. 411 - 416
(2015/05/13)
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- Resin, optical material, and optical device
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The purpose of the invention is to provide a resin, which has a high refractive index, excellent heat resistance and moldability, and high transparency, and is useful as a material for configuring optical devices, etc. The invention provides a resin comprising acyl hydrazone bonds and having a number average molecular weight of 500-500,000, wherein the acyl hydrazone bond equivalent is 100-4000.
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- Hydrogenations without hydrogen: Titania photocatalyzed reductions of maleimides and aldehydes
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A mild procedure for the reduction of electron-deficient alkenes and carbonyl compounds is described. UVA irradiations of substituted maleimides with dispersions of titania (Aeroxide P25) in methanol/acetonitrile (1:9) solvent under dry anoxic conditions led to hydrogenation and production of the corresponding succinimides. Aromatic and heteroaromatic aldehydes were reduced to primary alcohols in similar titania photocatalyzed reactions. A mechanism is proposed which involves two proton-coupled electron transfers to the substrates at the titania surface.
- Manley, David W.,Buzzetti, Luca,MacKessack-Leitch, Andrew,Walton, John C.
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p. 15324 - 15338
(2015/01/16)
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- Succinic anhydrides from epoxides
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Catalysts and methods for the double carbonylation of epoxides are disclosed. Each epoxide molecule reacts with two molecules of carbon monoxide to produce a succinic anhydride. The reaction is facilitated by catalysts combining a Lewis acidic species with a transition metal carbonyl complex. The double carbonylation is achieved in single process by using reaction conditions under which both carbonylation reactions occur without the necessity of isolating or purifying the product of the first carbonylation.
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Page/Page column 24; 25; 26
(2013/07/25)
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- PROCESS FOR THE PRODUCTION OF ACID ANHYDRIDES FROM EPOXIDES
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A method of making acid anhydrides from epoxide and carbon monoxide feedstocks is presented. In various aspects, the method includes steps of reacting the contents of a feed stream comprising an epoxide, a solvent, a carbonylation catalyst and carbon monoxide to produce a first carbonylation product stream comprising a beta-lactone, then reacting the contents of the first carbonylation product stream with additional carbon monoxide to produce a second carbonylation product stream comprising an acid anhydride, and separating at least a portion of the acid anhydride from the second carbonylation product stream to produce: i) an acid anhydride product stream comprising the separated portion of acid anhydride; and ii) a recycling stream comprising the carbonylation catalyst, and finally adding the recycling stream to the feed stream.
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Page/Page column 50; 51
(2013/08/28)
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- A highly efficient and selective nickel/clay catalyst for liquid phase hydrogenation of maleic anhydride to succinic anhydride
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Three Ni-based catalysts with different clay as support were prepared and tested in the hydrogenation of maleic anhydride, among which Ni/clay1 showed best activity and selectivity. Over Ni/clay1 catalyst prepared by impregnation method, 97.14% conversion of maleic anhydride and 99.55% selectivity to succinic anhydride were obtained at 180 °C under a pressure of 1 MPa. Catalytic activity was greatly influenced by the temperature and weighted hourly space velocity. Catalyst deactivation studies showed that this catalyst have a long life time, the yield of MA still higher than 90% even after a reaction time of 60 h. X-ray diffraction (XRD) and H2 temperature programmed reduction (TPR) were use to investigate the properties of the catalyst. XRD and TPR studies showed that Ni was present as Ni2+ on the support, which indicated that there was no elemental nickel (Ni0) and Ni2O3 in the unreduced samples. The formation of Ni was strong impact on catalytic activity.
- Tian, Weiping,Guo, Shaofei,Shi, Li
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experimental part
p. 1643 - 1646
(2012/08/08)
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- Unconventional titania photocatalysis: Direct deployment of carboxylic acids in alkylations and annulations
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Under dry, anaerobic conditions, TiO2 photocatalysis of carboxylic acid precursors resulted in carbon-carbon bond-forming processes. High yields of dimers were obtained from TiO2 treatment of carboxylic acids alone. On inclusion of electron-deficient alkenes, efficient alkylations were achieved with methoxymethyl and phenoxymethyl radicals. In reactions with maleic anhydride or maleimides, phenoxyacetic acid produced chromenedione derivatives in addition to adducts. These photocatalytic reactions are simple and cheap to perform, and the TiO2 is easily removed by filtration. The anaerobic photocatalysis strategy offers a range of synthetic possibilities.
- Manley, David W.,McBurney, Roy T.,Miller, Phillip,Howe, Russell F.,Rhydderch, Shona,Walton, John C.
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supporting information; experimental part
p. 13580 - 13583
(2012/10/08)
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- PROCESS FOR BETA-LACTONE PRODUCTION
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The present application provides a method for producing an beta-lactone product. The method includes the steps of: reacting an epoxide, a solvent with a carbonylation catalyst and carbon monoxide to produce a reaction stream comprising a beta-lactone then separating a portion of the beta-lactone in the reaction stream from the solvent and carbonylation catalyst to produce: i) a beta-lactone stream with the beta-lactone, and ii) a catalyst recycling stream including the carbonylation catalyst and the high boiling solvent; and adding the catalyst recycling stream to the feed stream.
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Page/Page column 15
(2012/05/21)
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- In Vivo Polynucleotide Delivery Conjugates Having Enzyme Sensitive Linkages
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The present invention is directed compositions for delivery of RNA interference (RNAi) polynucleotides to cells in vivo. The compositions comprise amphipathic membrane active polyamines reversibly modified with enzyme cleavable dipeptide-amidobenzyl-carbonate masking agents. Modification masks membrane activity of the polymer while reversibility provides physiological responsiveness. The reversibly modified polyamines (dynamic polyconjugate or DPC) are further covalently linked to an RNAi polynucleotide or co-administered with a targeted RNAi polynucleotide-targeting molecule conjugate.
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- Catalytic, enantio- and diastereoselective synthesis of γ-butyrolactones incorporating quaternary stereocentres
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A new, highly enantio- and diastereoselective catalytic asymmetric formal cycloaddition of aryl succinic anhydrides and aldehydes which generates paraconic acid (γ-butyrolactone) derivatives is reported.
- Manoni, Francesco,Cornaggia, Claudio,Murray, James,Tallon, Sean,Connon, Stephen J.
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supporting information; experimental part
p. 6502 - 6504
(2012/07/31)
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- Quaternary ammonium salt detergents for use in fuels
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A quaternary ammonium salt detergent made from the reaction product of the reaction of: (a) a hydrocarbyl substituted acylating agent and a compound having an oxygen or nitrogen atom capable of condensing with said acylating agent and further having a tertiary amino group; and (b) a quaternizing agent suitable for converting the tertiary amino group to a quaternary nitrogen and the use of such quaternary ammonium salt detergents in a fuel composition to reduce intake valve deposits.
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- METHOD FOR PRODUCING CARBOXYLIC ANHYDRIDE AND ARYLBORONIC ACID COMPOUND
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When phthalic acid is heated in heptane under azeotropic reflux conditions in the presence of a catalytic amount of an arylboronic acid compound (such as 2,6-(diisopropylaminomethyl)phenylboronic acid or 2,6-bis(diisopropylaminomethyl)phenylboronic acid), phthalic anhydride is obtained in high yield.
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Page/Page column 14
(2012/01/13)
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- Efficient and convenient synthesis of symmetrical carboxylic anhydrides from carboxylic acids with sulfated zirconia by phase transfer catalysis
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An efficient and convenient procedure for the synthesis of symmetrical carboxylic anhydrides from carboxylic acids with sulfated zirconia by PEG-1000 phase transfer catalysis has been developed. The reactions proceeded under mild and solvent-free conditions to provide the carboxylic anhydrides in good to excellent yields. The product can be isolated by a simple extraction with organic solvent, and the catalyst system can be recycled or reused without any significant loss of catalytic activity.
- Hu, Yu Lin,Zhao, Xing E.,Lu, Ming
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experimental part
p. 255 - 262
(2012/04/17)
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