- Kinetics of the Acid-catalysed Hydrolysis of Dodecylsulphate and Dodecyldiethoxysulphate Surfactants in Concentrated Micellar Solutions. Part 1. - Effects of Acid and Surfactant Concentrations and of the Nature and Concentration of Counterions
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The rates of the acid-catalysed hydrolysis of sodium dodecylsulphate (SDS) and sodium dodecyldiethoxysulphate (SDE2S) have been investigated in concentrated surfactant solutions (0.035 - 0.6 mol dm-3).The acid concentration dependence of the initial rates shows a 'saturation' effect, whereas increasing surfactant concentrations above the c.m.c. lead to a maximum in the k2,obs values, beyond which they decrease sharply.These results are discussed in terms of the ion-exchange pseudophase model of the miceller reaction.The nature of the counterion has an effect on k2,obs, the values following the sequence NH4 > Li > Na >> Mg.This has been ascribed to differences in the ion-exchange constants, KH/X, of these cations in the Stern layer of the micelles with the hydrogen ion.Maintaining the total counterion concentration and the ratio of concentrations of surfactant counterion to the concentration of hydrogen ion constant (at 30, i.e. 0.6 : 0.02 mol dm-3) largely eliminates the decrease in the k2,obs values with increasing surfactant concentration, as expected from the pseudo-phase ion-exchange model.Quantitative agreement between theory and experiment is less good, however, owing at least partly to deviations from ideality in solutions of high ionic strength.
- Garnett, Christopher J.,Lambie, Alan J.,Beck, William H.,Liler, Milica
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- Acid-catalyzed hydrolysis of sodium dodecyl sulfate
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The acid-catalyzed hydrolysis of sodium dodecyl sulfate (1) and the effect of 1-dodecanol (2) on this hydrolysis were investigated. The rate of hydrolysis was followed by measuring the rate of production of HSO4- using a pH-stat. The rate constant (κ(H+)) below the critical micelle concentration (CMC) increased with increasing concentrations of 2, up to a mole ratio of 0.5 for 2 to 1, after which the hydrolysis rate was independent of the concentration of 2. These results suggest the possible formation of a complex between 1 and 2. A micellar solution of pure sodium dodecyl sulfate (20 mM) hydrolyzed 50 times faster than that of a premicellar solution at the same pH. Plots of log κ versus pH were linear with a slope of -1 at pH 4.3. At a constant pH, the addition of NaCl resulted in a decrease in the rate of hydrolysis of a micellar solution. This is probably due to the reduction of concentration of protons at the micelle surface. Furthermore, κ(H+) was also decreased by the addition of 2 in the region where 2 is solubilized in the micelle; again, this was probably due to the reduction of the charge density (σ) on the surface of the micelle.
- Nakagaki,Yokoyama
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- The hydrolysis of C12 primary alkyl sulfates in concentrated aqueous solutions. Part 1. General features, kinetic form and mode of catalysis in sodium dodecyl sulfate hydrolysis
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As part of an investigation into the observed rapid hydrolysis of sodium primary alkyl sulfates in commercial concentrated aqueous mixtures (typically 70% by weight of surfactant) at 80 °C, the rate of hydrolysis of sodium dodecyl sulfate (SDS) in water has been followed acidimetrically over a wide range of initial SDS concentrations in aqueous buffers, in the presence of added sulfuric acid (0.20 mol kg-1) and also in unbuffered, initially neutral solution. First order rate coefficients derived from the initial rates of sulfuric acid-catalysed reactions showed unexpected, non-monotonic variations with increasing initial [SDS] at constant [H2SO4] and with [H2SO4] at 70% SDS. Reactions in initially neutral solutions were found to have an autocatalytic form arising from the existence of both an uncatalysed and an acid catalysed pathway from reactants to products. Both pathways are characterised by rate coefficients (derived by computer simulation of the initial phase of the hydrolysis) that vary with the initial [SDS]; those for the acid-catalysed pathway show similar but less dramatic variation than observed in reactions in the presence of sulfuric acid. Possible reasons for the difference in behaviour are discussed. The autocatalysis observed in initially neutral solutions is shown to arise from the production of hydrogen sulfate ions during the hydrolysis, but experiments in buffer solutions at both high and low SDS concentrations show the characteristics of specific hydrogen ion catalysis. Solvent kinetic deuterium isotope effects on both pathways are, however, small. Examination of the dodecanol produced by SDS hydrolysis at low and high initial concentrations in18O-enriched water showed no incorporation of the label, signifying exclusive S-O cleavage in the acid-catalysed pathway. It is argued that the results, taken in conjunction with literature data, are consistent with an SN2 displacement of sulfate ion by water in the uncatalysed hydrolysis pathway. While, for the hydrogen ion catalysed pathway, a previously suggested unimolecular cleavage of SO3 from dodecyl hydrogen sulfate, with concerted intramolecular proton transfer, appears more consistent with the observations, proton transfer concerted with direct transfer of SO3 to a preassociated water molecule is a plausible alternative.
- Bethell,Fessey,Namwindwa,Roberts
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- An effective hydrolysis of crowded chiral esters
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Trifluoromethanesulfonic acid-coated silica in the absence of solvents is an effective reagent for hydrolysis of sterically crowded chiral esters giving chiral acids in good chemical and optical yield. On the other hand, the method was unsuitable for the
- Vávra, Jan,Streinz, Ludvík,Vodi?ka, Petr,Budě?ínsky, Milo?,Koutek, Bohumír
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- A practical and efficient procedure for reduction of carboxylic acids and their derivatives: use of KBH4-MgCl2
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The use of KBH4-MgCl2 to reduce carboxylic acids and their derivatives to the corresponding alcohols or the respective reduced products is described. Methyl (S)-3,4-O-isopropylidene-3,4-dihydroxy butanoate 2 used as a reference substrate was reduced with KBH4 and MgCl2 in 1:1 mol ratio to (S)-1,2-O-isopropylidene-1,2,4-butanetriol 1.
- Qiu, You-Chun,Zhang, Fu-Li,Zhang, Chun-Nian
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- Cleavage of protecting groups catalysed by π-acceptors
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The cleavage of protecting groups is caused by the acidic adducts produced from the methanolysis of acceptors.
- Tanemura, Kiyoshi,Nishida, Yoko,Suzuki, Tsuneo,Satsumabayashi, Koko,Horaguchi, Takaaki
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- Selective conversion of coconut oil to fatty alcohols in methanol over a hydrothermally prepared Cu/SiO2 catalyst without extraneous hydrogen
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A novel one-pot approach selects a hydrothermally synthesized Cu/SiO2 catalyst (consisting of Cu2O·SiO2 and Cu0 surface species) to catalyze the reduction of a series of fatty esters, fatty acids, and coconut oil to fatty alcohols at 240 °C in methanol without extraneous hydrogen, attaining around 85% conversion and 100% selectivity.
- Wu, Liubi,Li, Lulu,Li, Bolong,Zhao, Chen
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- Thermodynamics of the lipase-catalyzed esterification of 1-dodecanoic acid and 1-dodecanol in organic solvents
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Lipase immobilized on controlled-pore glass beads was used to catalyze the esterification of 1-dodecanol and 1-dodecanoic acid in organic solvents. Equilibrium measurements were performed in hexane, heptane, cyclohexane, 2,2,4-trimethylpentane, and toluene at the temperature T = 298.15 K. The equilibrium constants correlate well with the (octanol+water) partition coefficients and the dielectric constants of the solvents. The saturation molalities and the (2,2,4-trimethylpentane+water) partition coefficients of 1-dodecanol, 1-dodecanoic acid, and dodecyl dodecanoate have been determined at T = 298.15 K. The equilibrium constant of the esterification reaction in water has also been calculated.
- Tewari
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- A glucose-activatable trimodal glucometer self-assembled from glucose oxidase and MnO2 nanosheets for diabetes monitoring
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Daily monitoring of blood glucose is of great importance for the treatment of diabetes mellitus. Herein, we present an ensemble glucometer with a sandwich structure formed by the spontaneous entrapment of glucose oxidase (GOD) onto manganese dioxide nanosheets (MnO2 NSs) via the hydrophobic effect and hydrogen bond interaction. Within the hybrid glucometer, the ultrathin MnO2 NSs act as an enzyme nanosupport and target-activated signal transducer. Trimodal self-indication by fluorescence (FL) and UV-absorbance (UV) and magnetic resonance signal (MRS) activation with glucose-specificity provides multiple response signals to glucose. Taking account of its operational simplicity and convenience, even being observable by the naked eye, a detection limit as low as 0.1 ;M was obtained by using the ensemble glucometer in a colorimetric assay, whilst the precision for 11 replicated detections of 10 M glucose was 3.5% (relative standard deviation, RSD). Notably, the value of the Michaelis-Menton constant of GOD involved the presented glucometer is estimated to be 0.051 mM, showing an exceptional enhanced enzymatic activity of free GOD measured by far. The designed glucometer, with its high sensitivity and simplicity highlighted, was capable of routine blood glucose monitoring for type-I diabetes mellitus in rats. Furthermore, the fully integrated platform can be readily generalized in principle for a number of biomarkers for point of care diagnostics in the future.
- Chen, Jin-Long,Li, Li,Wang, Shuo,Sun, Xiao-Yan,Xiao, Lu,Ren, Jia-Shu,Di, Bin,Gu, Ning
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- NEW GLYCOSPHINGOLIPIDS FROM MARINE ORGANISM
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The structure of several ceramides and cerebrosides, from three marine sponges and a soft coral collected in the Red Sea, are reported.Specifically, the structure detemination of ptiloceramide, halicerebroside A and amphicerebrosides B-F was achieved folloving suitable degradations and NMR measurements.
- Hirsch, S.,Kashman, Y.
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- Benzimidazoline-dimethoxypyrene. An effective promoter system for photoinduced electron transfer promoted reductive transformations of organic compounds
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2-(p-Methoxyphenyl)-1,3-dimethylbenzimidazoline (ADMBI) and 2-(o-hydroxyphenyl)-1,3-dimethylbenzimidazoline (HPDMBI) are used as reducing reagents in 1,8-dimethoxypyrene (1,8-DMP) sensitized, photoinduced electron transfer (PET) reactions. This system was effectively used for PET induced, reductive transformations of various organic substrates, including α,β-epoxy ketones, the olefin tethered 2-bromomethyl-l-tetralone, and o-allyloxy-iodobenzene, as well as for the deprotection reactions of dodecyl-2-benzoylbenzoate and N-sulfonylindole. The results of studies show that 1,8-DMP is a more effective sensitizer than the previously used 9-methylcarbazole for deprotection of N-methyl-4-picolinium ester.
- Hasegawa, Eietsu,Hirose, Harumi,Sasaki, Kosuke,Takizawa, Shinya,Seida, Takayuki,Chiba, Naoki
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- Reaction Pathway and Selective Hydrogenation on Catalyst Derived from Oxidation Treatment of Mg2Cu Alloy
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A catalyst derived from oxidation treatment of Mg2Cu alloy was studied in a gas-phase continuous-flow reactor under atmospheric pressure to investigate the specific selectivity for hydrogenation.In order to propose the reaction pathways for hydrogenation of long chain unsaturated ester, reactivities of characteristic functional groups were tested.The reactions of ester and aldehyde groups showed higher selectivity to alcohols than to paraffins.We concluded from competitive reactions of two reactants that hydrogenation of unsaturated bond group was inhibited by the adsorption of ester or aldehyde group.The effect of partial pressure on each reaction rate was summarized into the Langmuir equation.The main route to unsaturated alcohol and reasons for the increased selectivity to alcohol are discussed.
- Chikamatsu, Nobuyasu,Tagawa, Tomohiko,Goto, Shigeo
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- Transformation of methyl laurate into lauryl alcohol over a Ru-Sn-Mo/C catalyst by using zerovalent iron and water as an in situ hydrogen source
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Hydrogenation and hydrogenolysis reactions, which are used in the chemical industry for the synthesis of organic compounds, are very expensive operations because of the need for facilities that can liquefy, transport, and store the hydrogen produced through steam reforming of natural gas. We have therefore developed a novel approach for hydrogenation that does not require the use of high-cost facilities. Using this, zerovalent iron (Fe) and water (H2O) are introduced as an in situ hydrogen donor system for the transformation of methyl laurate into lauryl alcohol over a Ru-based catalyst. This combination of a Ru-Sn-Mo/C catalyst with a Fe/H2O system showed significantly higher transformation rates for the conversion of methyl laurate into lauryl alcohol than a conventional reaction system that uses pressurized hydrogen. The reason for this is that the new system produces lauric acid as an intermediate during the reaction, which is more efficiently hydrogenized into lauryl alcohol over the Ru-Sn-Mo/C catalyst. The Fe/H2O system played two important roles: a hydrogen source for the hydrogenation reaction and a catalyst for the generation of lauric acid by methyl laurate hydrolysis.
- Sagata, Kunimasa,Hirose, Mina,Hirano, Yoshiaki,Kita, Yuichi
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- Influence of Higher Alcohols on Acid-Catalyzed Hydrolysis of Sodium Dodecyl Sulfate. Effect of Complex Formation
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The order of effectiveness of 1-alkanols for increasing the rate of acid-catalyzed hydrolysis of sodium dodecyl sulfate is 1-dodecanol>-tetradecanol>>1-decanol.The effect of 1-alkanols on this hydrolysis is discussed from the viewpoint of formation of complexes composed of SDS and 1-alkanol.
- Nakagaki, Masayuki,Yokoyama, Shoko
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- Structural characterization of solid trivalent metal dodecyl sulfates: From aqueous solution to lamellar superstructures
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Metal dodecyl sulfates of trivalent aluminium, chromium, lanthanum and gadolinium were prepared by addition of the corresponding salts to aqueous solutions of sodium dodecyl sulfate at the natural pH (ca. 6). Using X-ray diffraction, FT-IR and NMR spectroscopy, DSC, thermogravimetry and polarizing light thermomicroscopy it is shown that metal dodecyl sulfates are formed with lamellar structures. These have different degrees of hydration, which depend upon the metal ion. In some cases there is evidence for coexistence of different lamellar phases. The metal is strongly bound electrostatically to the sulfate group, and although the alkyl chain is in an extended conformation, there are suggestions of local disordering of the methylene groups adjacent to the anionic head group. SEM with an EDS probe on the trivalent metal complexes shows a 1:3 ratio at the surface identical to the bulk structure. Studies by SEM and AFM provide evidence of periodicity, which is likely to be induced by the lamellar, layered structures. Differences are observed in the thermal behavior, which appear to reflect both the coordination behavior of the metal ion and the degree of hydration.
- Pereira, Rui F. P.,Valente, Artur J. M.,Burrows, Hugh D.,De Zea Bermudez, Veronica,Carvalho, Rui A.,Castro, Ricardo A. E.
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- Preparation of cyclohexene-d10 by H/D-exchange reaction
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Preparation of fully deuterium-labeled cyclohexene by H/D-exchange reaction was performed efficiently in the presence of ruthenium catalyst under irradiation of microwaves. The reaction proceeds via a repetition of hydroruthenation and β-elimination. Copyright
- Ishibashi, Kenichi,Matsubara, Seijiro
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- Anchored Aluminum Catalyzed Meerwein-Ponndorf-Verley Reduction at the Metal Nodes of Robust MOFs
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Catalytic Meerwein-Ponndorf-Verley reductions of ketones and aldehydes in the presence of isopropyl alcohol were performed at aluminum alkoxide sites that were postsynthetically introduced into robust metal-organic frameworks (MOFs). The aluminum was anchored at the bridging hydroxyl sites inherent in some MOFs. MOFs in the UiO-66/67 family as well as DUT-5 were successfully adapted to this strategy. Incorporation of catalytically active aluminum species greatly enhanced the reactivity of the native MOF at 80 °C in the case of both UiO-66, and was almost solely responsible for catalytic activity in the case of metalated UiO-66 and DUT-5. The site isolation of the catalyst prevented aggregation and complete deactivation of the molecular aluminum catalyst, allowing it to be recovered and recycled in the case of UiO-67. This catalyst also proved to be moderately tolerant to wet isopropyl alcohol.
- Larson, Patrick J.,Cheney, Joseph L.,French, Amanda D.,Klein, David M.,Wylie, Benjamin J.,Cozzolino, Anthony F.
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- Lithium amidotrihydroborate, a powerful new reductant. Transformation of tertiary amides to primary alcohols
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Lithium amidotrihydroborate (LiH2NBH3, LAB) is a new and highly nucleophilic reducing agent that is easily prepared by deprotonation of the commercial reagent borane-ammonia complex (H2NBH3) with n-BuLi in tetrahydrofuran (THF) at 0°C. LAB is found to be a superior reagent for the transformation of tertiary amides into the corresponding primary alcohols.
- Myers, Andrew G.,Yang, Bryant H.,Kopecky, David J.
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- Mechanism of supported Ru3Sn7 nanocluster-catalyzed selective hydrogenation of coconut oil to fatty alcohols
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As a promising hydrotreating catalyst, it was previously reported that Ru?OSn (Ru electronically interacts with Sn oxides) on RuSn/SiO2 was the active site for fatty acid hydrogenation, but here in this work we found that Ru3Sn7 nanoclusters on RuSn/SiO2 were responsible for the selective hydrogenation of diverse fatty acids and coconut oil to fatty alcohols. The XPS results indicated no interaction between Snδ+ and Ru0, suggesting that SnOx may exist as isolated species. In contrast, the binding energy shifts of Ru0 and Sn0 in the XPS spectra demonstrated a strong interaction, as a result of the formation of Ru3Sn7 alloy nanoclusters. It was demonstrated that the highest yield of fatty alcohol was obtained with a Sn/Ru ratio of 7/3 (hydrogenation rate: 2.45 g g-1 h-1), and the careful selection of the Sn/Ru ratio and reduction temperatures greatly suppressed the formation of Sn and SnO2 phases. The ratio of the stearyl alcohol formation rate to its consumption rate was 40.8 with Ru3Sn7/SiO2 under the selected conditions. In catalysts with a Sn/Ru ratio higher than 7/3, the presence of additional SnO2 catalyzes the formation of undesired esters at a rate of 0.31 g g-1 h-1. Excess SnO2 would be reduced to Sn at temperatures higher than 600 °C, while Sn can catalyze ester by-product formation at a rate of 0.88 g g-1 h-1. The DFT calculations showed that CH3COOH adsorbs on the Ru3Sn7 (111) surface via Sn-O interactions at the two top sites of adjacent surface Sn atoms, and such adsorption was mainly due to the electrostatic interactions between the molecule and the positively charged surface Sn atoms. The charge density difference (CDD) plots of co-adsorbed CH3CO? and OH? intermediates indicated the bonding relationships between Sn-O and Ru-α-C, suggesting that the surface Sn atoms also took part in the catalytic reaction as an important surface sorption site as well as a Ru3Sn7 structure component, while Ru atoms bonded with α-C and hydrogenated the adsorbed intermediate species with the adsorbed H? to the final alcohol. A further indication that Ru3Sn7 was the active species in the bimetallic Ru-Sn catalyst was given by the much lower energy barrier for hydrogenation of acetic acid in Ru3Sn7 (111) (81.0 kJ mol-1) compared to Ru (0001) (123.5 kJ mol-1).
- Luo, Zhicheng,Bing, Qiming,Kong, Jiechen,Liu, Jing-Yao,Zhao, Chen
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- Elucidation of the mechanism of titanocene-mediated epoxide opening by a combined experimental and theoretical approach
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(Figure Presented) Steric effects govern the catalytic reductive epoxide ring opening. This is the result of combined experimental and theoretical studies, which revealed interesting features of the catalyst structure, substrate binding, transition state (see picture), and reaction energies. In light of these, highly selective conditions for the ring opening can be proposed.
- Daasbjerg, Kim,Svith, Heidi,Grimme, Stefan,Gerenkamp, Mareike,Mueck-Lichtenfeld, Christian,Gansaeuer, Andreas,Barchuk, Andriy,Keller, Florian
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- Highly efficient conversion of fatty acids into fatty alcohols with a Zn over Ni catalyst in water
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A new route to convert fatty acids into fatty alcohols under hydrothermal conditions with a Zn reductant over an Ni catalyst is presented. The highest yield of fatty alcohols from fatty acids (81.4%) was achieved at 300 °C for 2 h with a water filling of 40%. The Zn and Ni used in this research were both commercially available powders, and thus this process provides a highly efficient and simple method for reducing fatty acids into fatty alcohols.
- Gao, Xia,Tong, Daming,Zhong, Heng,Jin, Binbin,Jin, Fangming,Zhang, Hua
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- Deactivation mechanism of Cu/Zn catalyst poisoned by organic chlorides in hydrogenation of fatty methyl ester to fatty alcohol
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The mechanism of deactivation of Cu/Zn catalyst poisoned by organic chlorides in hydrogenation of methyl laurate to lauryl alcohol in a slurry phase was studied in a stirred autoclave. The catalystwas prepared by co-precipitation, and the un-poisoned and poisoned catalysts were characterized using XRD, BET, ICP-AES and SEM, respectively. The results indicated that both of catalytic activity and selectivity decreased with increasing amount of chlorides in methyl laurate. According to the characterization of the catalysts, the main causes for the chlorine deactivation of the Cu/Zn catalyst were that the chlorides could modify the valence state of active sites, decrease the BETsurface area, and promote the growth of crystal and catalyst agglomeration. Further investigation indicated that chlorine atom decomposed from the chlorides combined with ZnO to produce ZnCl2, which could be dissolved in the liquid and promote ester-exchange reaction to lauryl laurate as Lewis acid.
- Huang, Hui,Wang, Shaohong,Wang, Shujia,Cao, Guiping
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- Water: The ideal hydrogen-atom source in free-radical chemistry mediated by TiIII and other single-electron-transfer metals?
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(Chemical Equation Presented) Hydrogen-atom transfer from water to free radicals can be mediated by aqua complexes of titanium(III) (see scheme). Asymmetric epoxidation in combination with [Cp2TiCl]/H 2O-mediated reductive epoxide opening can be viewed as an alternative with complementary stereoselectivity to the hydroboration-epoxidation method for the enantioselective synthesis of anti-Markovnikov alcohols from alkenes.
- Cuerva, Juan M.,Campa?a, Araceli G.,Justicia, José,Rosales, Antonio,Oller-López, Juan L.,Robles, Rafael,Cárdenas, Diego J.,Bu?uel, Elena,Oltra, J. Enrique
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- Manganese-Catalyzed Hydrogenation of Sclareolide to Ambradiol
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The hydrogenation of (+)-Sclareolide to (?)-ambradiol catalyzed by a manganese pincer complex is reported. The hydrogenation reaction is performed with an air- and moisture-stable manganese catalyst and proceeds under relatively mild reaction conditions at low manganese and base loadings. A range of other esters could be successfully hydrogenated leading to the corresponding alcohols in good to quantitative yields using this easy-to-make catalyst. A scale-up experiment was performed leading to 99.3 % of the isolated yield of (?)-Ambradiol.
- Zubar, Viktoriia,Lichtenberger, Niels,Schelwies, Mathias,Oeser, Thomas,Hashmi, A. Stephen K.,Schaub, Thomas
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- Defunctionalization of sp3 C–Heteroatom and sp3 C–C Bonds Enabled by Photoexcited Triplet Ketone Catalysts
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A general strategy for enabling a light-induced defunctionalization of sp3 C–heteroatom and sp3 C–C bonds with triplet ketone catalysts and bipyridine additives is disclosed. This protocol is characterized by its broad scope without recourse to transition metal catalysts or stoichiometric exogeneous reductants, thus offering a complementary technique for activating σ sp3 C–C(heteroatom) bonds. Preliminary mechanistic studies suggest that the presence of 2,2′-bipyridines improves the lifetime of ketyl radical intermediates.
- An, Juzeng,Gu, Yiting,Martin, Ruben,Wakeling, Matthew,Yin, Hongfei
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p. 1031 - 1036
(2022/01/19)
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- Hydrodeoxygenation of non-edible bio-lipids to renewable hydrocarbons over mesoporous SiO2-TiO2 supported NiMo bimetallic catalyst
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Ni-catalysts are promising candidate for fatty acid hydrodeoxygenation (HDO), but are limited by their quite poor HDO selectivity. Herein, a mesoporous Ni-Mo/SiO2-TiO2 catalyst was prepared by precipitation and impregnation method and used for methyl laurate HDO, yielding 96.3% n-dodecane yield at full methyl laurate conversion. Non-edible bio-lipids such as jatropha oil and waste cooking oil also converted to n-C14+16+18 hydrocarbons with yields of 94.3% and 92.4%, respectively. Besides, Ni-Mo/SiO2-TiO2 shows strong chemoselectivity towards the HDO of ester groups. Experimental results showed that Mo-addition and Ti/Si molar ratio strongly influenced HDO selectivity. Oxygen vacancies formed on partial reduced TiO2 surface securely bond Ni NPs and activate C[dbnd]O/C–O bonds, improving Ni NPs dispersion and promoting R–COOCH3→R–CHO reduction. Additional, Mo-addition switches reactant adsorption configuration from η1(C)-acyl to η2(C,O)-aldehyde, promoting the formation of R–CH2OH intermediate. Moreover, abundant Br?nsted acidic sites (Mo4+–OH, Mo6+–OH, hydroxy groups) facilitate the HDO of R-CH2OH to R-CH3.
- Ba, Wenxia,Fu, Lin,Li, Xin,Li, Yongfei,Liu, Yuejin,Zhang, Simiao,Zhao, Jingxuan
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- Borane evolution and its application to organic synthesis using the phase-vanishing method
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Although borane is a useful reagent, it is difficult to handle. In this study, borane was generated in situ from NaBH4 or nBu4NBH4 with several oxidants using a phase-vanishing (PV) method. The borane generated was directly reacted with alkenes, affording the desired alcohols in good yields after oxidation with H2O2 under basic conditions. The selective reduction of carboxylic acids with the evolved borane was examined. The organoboranes generated by the PV method successfully underwent Suzuki–Miyaura coupling. Using this PV system, reactions with borane can be carried out easily and safely in a common test tube.
- Soga, Nene,Yoshiki, Tomo,Sato, Aoi,Kawamoto, Takuji,Ryu, Ilhyong,Matsubara, Hiroshi
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supporting information
(2021/03/26)
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- Redox-active ligand based Mn(i)-catalyst for hydrosilylative ester reduction
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Herein a Mn(i) catalyst bearing a redox-active phenalenyl (PLY) based ligand is reported for the efficient hydrosilylation of esters to alcohols using the inexpensive silane source polymethylhydrosiloxane (PMHS) under mild conditions. Mechanistic investigations suggest a strong ligand-metal cooperation where a ligand-based single electron transfer (SET) process initiates the reaction through Si-H bond activation.
- Chakraborty, Soumi,Das, Arpan,Mandal, Swadhin K.
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supporting information
p. 12671 - 12674
(2021/12/04)
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- Scope and limitations of biocatalytic carbonyl reduction with white-rot fungi
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The reductive activity of various basidiomycetous fungi towards carbonyl compounds was screened on an analytical level. Some strains displayed high reductive activities toward aromatic carbonyls and aliphatic ketones. Utilizing growing whole-cell cultures of Dichomitus albidofuscus, the reactions were up-scaled to a preparative level in an aqueous system. The reactions showed excellent selectivities and gave the respective alcohols in high yields. Carboxylic acids were also reduced to aldehydes and alcohols under the same conditions. In particular, benzoic, vanillic, ferulic, and p-coumaric acid were reduced to benzyl alcohol, vanillin, dihydroconiferyl alcohol and 1-hydroxy-3-(4-hydroxyphenyl)propan, respectively.
- Zhuk, Tatyana S.,Skorobohatko, Oleksandra S.,Albuquerque, Wendell,Zorn, Holger
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supporting information
(2021/02/02)
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- Synergistic Effect in Ir- or Pt-Doped Ru Nanoparticles: Catalytic Hydrogenation of Carbonyl Compounds under Ambient Temperature and H2Pressure
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Poly(vinylpyrrolidone) (PVP)-stabilized Ir- or Pt-doped (10 at. ?%) Ru NPs with the average diameters of 1.3-1.5 nm (RuIr or RuPt) were prepared by a coreduction of the corresponding metal precursors. RuIr and RuPt showed remarkable activity for the hydrogenation of aromatic, cyclic, and aliphatic carbonyl compounds at 30 °C under 0.2 MPa of H2, whereas the monometallic NPs of Ru, Ir, and Pt did not show any activity under the same conditions. In particular, RuPt converted the aliphatic aldehyde and cyclohexanone to the corresponding alcohols at 30 °C under atmospheric H2 pressure. Remarkable synergistic effects were ascribed to the provision of highly active sites for H2 and enhancement of the nucleophilicity of the adsorbed hydrides.
- Ichikuni, Nobuyuki,Masuda, Shinya,Matsuda, Shotaro,Takano, Shinjiro,Tsukuda, Tatsuya
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p. 10502 - 10507
(2021/08/31)
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- Discovery of Anti-TNBC Agents Targeting PTP1B: Total Synthesis, Structure-Activity Relationship, in Vitro and in Vivo Investigations of Jamunones
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Twenty-three natural jamunone analogues along with a series of jamunone-based derivatives were synthesized and evaluated for their inhibitory effects against breast cancer (BC) MDA-MB-231 and MCF-7 cells. The preliminary structure-activity relationship revealed that the length of aliphatic side chain and free phenolic hydroxyl group at the scaffold played a vital role in anti-BC activities and the methyl group on chromanone affected the selectivity of molecules against MDA-MB-231 and MCF-7 cells. Among them, jamunone M (JM) was screened as the most effective anti-triple-negative breast cancer (anti-TNBC) candidate with a high selectivity against BC cells over normal human cells. Mechanistic investigations indicated that JM could induce mitochondria-mediated apoptosis and cause G0/G1 phase arrest in BC cells. Furthermore, JM significantly restrained tumor growth in MDA-MB-231 xenograft mice without apparent toxicity. Interestingly, JM could downregulate phosphatidylinositide 3-kinase (PI3K)/Akt pathway by suppressing protein-tyrosine phosphatase 1B (PTP1B) expression. These findings revealed the potential of JM as an appealing therapeutic drug candidate for TNBC.
- Hu, Caijuan,Li, Guoxun,Mu, Yu,Wu, Wenxi,Cao, Bixuan,Wang, Zixuan,Yu, Hainan,Guan, Peipei,Han, Li,Li, Liya,Huang, Xueshi
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supporting information
p. 6008 - 6020
(2021/05/06)
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- Enantiomeric synthesis of natural alkylglycerols and their antibacterial and antibiofilm activities
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Alkylglycerols (AKGs) are bioactive natural compounds that vary by alkyl chain length and degree of unsaturation, and their absolute configuration is 2S. Three AKGs (5l–5n) were synthesised in enantiomerically pure form, and were characterised for the first time together with 12 other known and naturally occurring AKGs (5a–5k, 5o). Their structures were established using 1H and 13C APT NMR with 2D-NMR, ESI-MS or HRESI-MS and optical rotation data, and they were tested for their antibacterial and antibiofilm activities. AKGs 5a–5m and 5o showed activity against five clinical isolates and P. aeruginosa ATCC 15442, with MIC values in the range of 15–125 μg/mL. In addition, at half of the MIC, most of the AKGs reduced S. aureus biofilm formation in the range of 23%–99% and P. aeruginosa ATCC 15442 biofilm formation in the range of 14%–64%. The antibiofilm activity of the AKGs assessed in this work had not previously been studied.
- Fernández Montoya, Deicy J.,Contreras Jordan, Luis A.,Moreno-Murillo, Bárbara,Silva-Gómez, Edelberto,Mayorga-Wandurraga, Humberto
-
supporting information
p. 2544 - 2550
(2019/11/13)
-
- A facile and versatile electro-reductive system for hydrodefunctionalization under ambient conditions
-
A general electrochemical system for reductive hydrodefunctionalization is described, employing the inexpensive and easily available triethylamine (Et3N) as a sacrificial reductant. This protocol is characterized by facile operation, sustainable conditions, and exceptionally wide substrate scope covering the cleavage of C-halogen, N-S, N-C, O-S, O-C, C-C and C-N bonds. Notably, the selectivity and capability of reduction can be conveniently switched by simple incorporation or removal of an alcohol as a co-solvent.
- Huang, Binbin,Guo, Lin,Xia, Wujiong
-
supporting information
p. 2095 - 2103
(2021/03/26)
-
- Selective Production of Linear Aldehydes and Alcohols from Alkenes using Formic Acid as Syngas Surrogate
-
Performing carbonylation without the use of carbon monoxide for high-value-added products is an attractive yet challenging topic in sustainable chemistry. Herein, effective methods for producing linear aldehydes or alcohols selectively with formic acid as both carbon monoxide and hydrogen source have been described. Linear-selective hydroformylation of alkenes proceeds smoothly with up to 88 % yield and >30 regioselectivity in the presence of single Rh catalyst. Strikingly, introducing Ru into the system, the dual Rh/Ru catalysts accomplish efficient and regioselective hydroxymethylation in one pot. The present processes utilizing formic acid as syngas surrogate operate simply under mild condition, which opens a sustainable way for production of linear aldehydes and alcohols without the need for gas cylinders and autoclaves. As formic acid can be readily produced via CO2 hydrogenation, the protocols represent indirect approaches for chemical valorization of CO2.
- Chen, Junjun,Hua, Kaimin,Liu, Xiaofang,Deng, Yuchao,Wei, Baiyin,Wang, Hui,Sun, Yuhan
-
p. 9919 - 9924
(2021/05/31)
-
- SUPPORTED HETEROGENEOUS CATALYST, PREPARATION AND USE THEREOF
-
A supported heterogeneous catalyst comprises rhodium and vanadium on a support, wherein the supported heterogeneous catalyst is preparable by depositing vanadium on a supported rhodium catalyst by impregnation. A process for preparing the aforementioned catalyst and a process for converting an amide into an amine in the presence of the aforementioned catalyst are provided.
- -
-
Page/Page column 21
(2021/06/11)
-
- PROCESS FOR CONVERTING AMIDE TO AMINE
-
Provided is a process for converting an amide into an amine comprising hydrogenation of the amide at a temperature not higher than 130°C and a hydrogen pressure not higher than 50 bar in the presence of a supported heterogeneous catalyst preparable by a method comprising depositing vanadium on a supported noble metal catalyst by impregnation.
- -
-
Page/Page column 22
(2021/06/11)
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- Titanocenes as Photoredox Catalysts Using Green-Light Irradiation
-
Irradiation of Cp2TiCl2 with green light leads to electronically excited [Cp2TiCl2]*. This complex constitutes an efficient photoredox catalyst for the reduction of epoxides and for 5-exo cyclizations of suitably unsaturated epoxides. To the best of our knowledge, our system is the first example of a molecular titanium photoredox catalyst.
- Flowers, Robert A.,Gans?uer, Andreas,Hilche, Tobias,Oloyede, Ugochinyere N.,Rietdijk, Niels R.,Slak, Daniel,Zhang, Zhenhua
-
supporting information
p. 9355 - 9359
(2020/04/30)
-
- Manganese-catalysed transfer hydrogenation of esters
-
Manganese catalysed ester reduction using ethanol as a hydrogen transfer agent in place of dihydrogen is reported. High yields can be achieved for a range of substrates using 1 mol% of a Mn(i) catalyst, with an alkoxide promoter. The catalyst is derived from a tridentate P,N,N ligand.
- Oates, Conor L.,Widegren, Magnus B.,Clarke, Matthew L.
-
supporting information
p. 8635 - 8638
(2020/08/21)
-
- Hydrosilylation of Esters Catalyzed by Bisphosphine Manganese(I) Complex: Selective Transformation of Esters to Alcohols
-
Selective and efficient hydrosilylations of esters to alcohols by a well-defined manganese(I) complex with a commercially available bisphosphine ligand are described. These reactions are easy alternatives for stoichiometric hydride reduction or hydrogenation, and employing cheap, abundant, and nonprecious metal is attractive. The hydrosilylations were performed at 100 °C under solvent-free conditions with low catalyst loading. A large variety of aromatic, aliphatic, and cyclic esters bearing different functional groups were selectively converted into the corresponding alcohols in good yields.
- Bagh, Bidraha,Behera, Rakesh R.,Ghosh, Rahul,Khamari, Subrat,Panda, Surajit
-
supporting information
p. 3642 - 3648
(2020/04/20)
-
- Biphenyl tridentate ligand ruthenium complex and production method and application thereof
-
The invention relates to production methods of a novel biphenyl tridentate ligand and a ruthenium complex of the novel biphenyl tridentate ligand and application of the ruthenium complex of the novelbiphenyl tridentate ligand in reaction of hydrogenation of an ester compound to an alcohol compound. A method for using the biphenyl tridentate ligand ruthenium complex for catalyzing hydrogenation ofthe ester compound to the alcohol compound is characterized by comprising the steps of using the biphenyl tridentate ligand ruthenium complex which is 0.001-0.1 mol% of the amount of substance of theester compound as a catalyst, adding alkali which is 1-10 mol% of the amount of substance of the ester compound, and catalyzing hydrogenation of the ester compound to the corresponding alcohol compound under conditions of 60-100 DEG C and 30-70 MPa hydrogen pressure. The biphenyl tridentate ligand and the ruthenium complex of the biphenyl tridentate ligand are convenient to produce and stable instructure, and the ruthenium complex of the biphenyl tridentate ligand shows excellent catalytic activity in the hydrogenation reaction of the ester compound. The defects of rigorous reaction conditions of high temperature, high pressure and the like needed by existing homogeneous or heterogeneous catalytic system hydrogenated fat compounds and high dosages of catalysts are overcome, the dosage ofthe catalyst is little, the reaction conditions are mild, the selectivity of the reaction is good, and the economical efficiency and the safety of the production system are improved.
- -
-
Paragraph 0108-0114
(2019/07/17)
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- Merging Catalysis in Single Electron Steps with Photoredox Catalysis - Efficient and Sustainable Radical Chemistry
-
We describe a combination of catalysts that allows the coupling of titanocene(III) catalysis with photoredox catalysis. Oxidation of radical intermediates by a photoredox catalyst opens novel catalytic mechanisms for reductive epoxide ring opening and redox-neutral epoxide radical arylation. In the former case, the requirement of metallic reductants and stoichiometric acidic additives is bypassed.
- Zhang, Zhenhua,Richrath, Ruben B.,Gans?uer, Andreas
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p. 3208 - 3212
(2019/04/13)
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- Photoinduced Hydroxylation of Organic Halides under Mild Conditions
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Presented in this paper is photoinduced hydroxylation of organic halides, providing a mild access to a range of functionalized phenols and aliphatic alcohols. These reactions generally proceed under mild reaction conditions with no need for a photocatalyst or a strong base and show a wide substrate scope as well as excellent functional group tolerance. This work highlights the unique role of NaI that allows a challenging transformation to proceed under mild reaction conditions.
- Cai, Yue-Ming,Xu, Yu-Ting,Zhang, Xin,Gao, Wen-Xia,Huang, Xiao-Bo,Zhou, Yun-Bing,Liu, Miao-Chang,Wu, Hua-Yue
-
supporting information
p. 8479 - 8484
(2019/10/16)
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- Oxidative Dehydroxymethylation of Alcohols to Produce Olefins
-
Catalyst compositions for the conversion of aldehyde compounds and primary alcohol compounds to olefins are disclosed herein. Reactions include oxidative dehydroxymethylation processes and oxidative dehydroformylation methods, which are beneficially conducted in the presence of a sacrificial acceptor of H2 gas, such as N,N-dimethylacrylamide.
- -
-
Paragraph 0062
(2019/09/06)
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- Normal Alpha Olefin Synthesis Using Dehydroformylation or Dehydroxymethylation
-
The present invention discloses processes for producing normal alpha olefins, such as 1-hexene, 1-octene, 1-decene, and 1-dodecene in a multistep synthesis scheme from another normal alpha olefin. Also disclosed are reactions for converting aldehydes, primary alcohols, and terminal vicinal diols into normal alpha olefins.
- -
-
Paragraph 0132; 0133
(2019/09/06)
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- Diaminodiphosphine tetradentate ligand and ruthenium complex thereof, and preparation methods and applications of ligand and complex
-
The invention discloses a diaminodiphosphine tetradentate ligand and a ruthenium complex thereof, and preparation methods and applications of the ligand and the complex, and provides a ruthenium complex represented by a formula I, wherein L is a diaminodiphosphine tetradentate ligand represented by a formula II, and X and Y are respectively and independently chlorine ion, bromine ion, iodine ion,hydrogen negative ion or BH4. According to the present invention, the ruthenium complex exhibits excellent catalytic activity in the catalytic hydrogenation reactions of ester compounds, has high yield and high chemical selectivity, is compatible with conjugated and non-conjugated carbon-carbon double bond, carbon-carbon triple bond, epoxy, halogen, carbonyl and other functional groups, and hasgreat application prospects.
- -
-
Paragraph 0301-0303; 0305
(2019/11/04)
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- Novel clamp metal complex and application thereof
-
The invention discloses a method for preparing a novel clamp-shaped complex and application of the novel clamp-shaped complex in the reaction of catalytic hydrogenation of carboxylic acid ester compounds to produce corresponding alcohols and reaction of carbon dioxide catalytic hydrogenation to form formamide compounds. Carboxylic acid esters and hydrogen as raw materials or carbon dioxide, hydrogen and amine compounds as raw materials are reacted in an organic solvent condition or a solvent-free condition in the presence of a transition metal complex as a catalyst to respectively form the corresponding alcohol compounds and/or corresponding formamide compounds. The method has the advantages of being high in reaction efficiency, good in selectivity, mild in conditions, economical, environmentally-friendly, and simple in operation, and has good promotion and application prospects.
- -
-
Paragraph 0410-0412; 0430-0433; 0507-0510
(2019/04/26)
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- Method for preparing fatty alcohols with same carbon number by catalytic hydrodeoxygenation from fatty acid and/or fatty acid ester
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The invention provides a method for preparing fatty alcohols with the same carbon number by catalytic hydrodeoxygenation from fatty acid and/or fatty acid ester. The method comprises the following step: in a reaction vessel, carrying out hydrodeoxygenation reaction on the fatty acid and/or fatty acid ester and hydrogen in the presence of a catalyst at a low temperature of 100-240 DEG C and under alow hydrogen pressure of 0.1-5 MPa to obtain desired fatty alcohol products with the same carbon number. According to the invention, the fatty alcohols with the same carbon number is prepared from the fatty acid and/or fatty acid ester through an active metal modified MeaXbAlc composite catalyst as defined herein. The method has the advantages of high conversion rate, good selectivity, mild reaction conditions, stable catalyst and the like, and has quite good industrial application prospect.
- -
-
Paragraph 0060; 0061; 0062; 0066; 0068; 0069; 0070; 0072
(2019/05/08)
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- General and Phosphine-Free Cobalt-Catalyzed Hydrogenation of Esters to Alcohols
-
Catalytic hydrogenation of esters is essential for the sustainable production of alcohols in organic synthesis and chemical industry. Herein, we describe the first non-noble metal catalytic system that enables an efficient hydrogenation of non-activated esters to alcohols in the absence of phosphine ligands (with a maximum turnover number of 2391). The general applicability of this protocol was demonstrated by the high-yielding hydrogenation of 39 ester substrates including aromatic/aliphatic esters, lactones, polyesters and various pharmaceutical molecules.
- Shao, Zhihui,Zhong, Rui,Ferraccioli, Raffaella,Li, Yibiao,Liu, Qiang
-
supporting information
p. 1125 - 1130
(2019/10/22)
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- n-Butyllithium (1 mol %)-catalyzed Hydroboration of Aldehydes and Ketones with Pinacolborane
-
A practical and efficient protocol for the hydroboration of aldehydes and ketones using a pinacolborane and alkyl lithium system is demonstrated. A systematic evaluation showed that 1 mol % n-butyllithium afforded catalyzed hydroboration of aldehydes and ketones in a short reaction time under ambient conditions. Excellent yield, functional group tolerance, short reaction time, low catalyst loading, and gram-scale synthesis are the salient features of the proposed protocol.
- Yang, Su Jin,Jaladi, Ashok Kumar,Kim, Jea Ho,Gundeti, Shankaraiah,An, Duk Keun
-
-
- Enzymatic One-Step Reduction of Carboxylates to Aldehydes with Cell-Free Regeneration of ATP and NADPH
-
The direct generation of aldehydes from carboxylic acids is often a challenging synthetic task but undoubtedly attractive in view of abundant supply of such feedstocks from nature. Though long known, biocatalytic carboxylate reductions are at an early stage of development, presumably because of their co-factor requirement. To establish an alternative to whole-cell-based carboxylate reductions which are limited by side reactions, we developed an in vitro multi-enzyme system that allows for quantitative reductions of various carboxylic acids with full recycling of all cofactors and prevention of undesired over-reductions. Regeneration of adenosine 5′-triphosphate is achieved through the simultaneous action of polyphosphate kinases from Meiothermus ruber and Sinorhizobium meliloti and β-nicotinamide adenine dinucleotide 2′-phosphate is reduced by a glucose dehydrogenase. Under these conditions and in the presence of the carboxylate reductases from Neurospora crassa or Nocardia iowensis, various aromatic, heterocyclic and aliphatic carboxylic acids were quantitatively reduced to the respective aldehydes.
- Strohmeier, Gernot A.,Eitelj?rg, Inge C.,Schwarz, Anna,Winkler, Margit
-
supporting information
p. 6119 - 6123
(2019/04/13)
-
- Selective Hydroboration of Carboxylic Acids with a Homogeneous Manganese Catalyst
-
Catalytic reduction of carboxylic acid to the corresponding alcohol is a challenging task of great importance for the production of a variety of value-added chemicals. Herein, a manganese-catalyzed chemoselective hydroboration of carboxylic acids has been developed with a high turnover number (>99?000) and turnover frequency (>2000 h-1) at 25 °C. This method displayed tolerance of electronically and sterically differentiated substrates with high chemoselectivity. Importantly, aliphatic long-chain fatty acids, including biomass-derived compounds, can efficiently be reduced. Mechanistic studies revealed that the reaction occurs through the formation of active manganese-hydride species via an insertion and bond metathesis type mechanism.
- Barman, Milan K.,Das, Kuhali,Maji, Biplab
-
p. 1570 - 1579
(2019/01/30)
-
- Mechanistic study of the selective hydrogenation of carboxylic acid derivatives over supported rhenium catalysts
-
The structure and performance of TiO2-supported Re (Re/TiO2) catalysts for selective hydrogenation of carboxylic acid derivatives have been investigated. Re/TiO2 promotes selective hydrogenation reactions of carboxylic acids and esters that form the corresponding alcohols, and of amides that generate the corresponding amines. These processes are not accompanied by reduction of aromatic moieties. A Re loading amount of 5 wt% and a catalyst pretreatment with H2 at 500 °C were identified as being optimal to obtain the highest catalytic activity for the hydrogenation processes. The results of studies using various characterization methods, including X-ray diffraction (XRD), X-ray absorption fine structure (XAFS), X-ray photoelectron spectroscopy (XPS), and scanning transmission electron microscopy (STEM), indicate that the Re species responsible for the catalytic hydrogenation processes have sub-nanometer to a few nanometer sizes and average oxidation states higher than 0 and below +4. The presence of either a carboxylic acid and/or its corresponding alcohol is critical for preventing the Re/TiO2 catalyst from promoting production of dearomatized byproducts. Although Re/TiO2 is intrinsically capable of hydrogenating aromatic rings, carboxylic acids, alcohols, amides, and amines strongly adsorb on the Re species, which leads to suppression of this process. Moreover, the developed catalytic system was applied to selective hydrogenation of triglycerides that form the corresponding alcohols.
- Toyao, Takashi,Ting, Kah Wei,Siddiki, S. M. A. Hakim,Touchy, Abeda S.,Onodera, Wataru,Maeno, Zen,Ariga-Miwa, Hiroko,Kanda, Yasuharu,Asakura, Kiyotaka,Shimizu, Ken-ichi
-
p. 5413 - 5424
(2019/10/29)
-
- Highly pH-Dependent Chemoselective Transfer Hydrogenation of α,β-Unsaturated Aldehydes in Water
-
The pH-dependent selective Ir-catalyzed hydrogenation of α,β-unsaturated aldehydes was realized in water. Using HCOOH as the hydride donor at low pH, the unsaturated alcohol products were obtained exclusively, while the saturated alcohol products were formed preferentially by employing HCOONa as the hydride donor at high pH. A wide range of functional groups including electron-rich as well as electron-poor substituents on the aryl group of α,β-unsaturated aldehydes can be tolerated, affording the corresponding products in excellent yields with high TOF values. High selectivity and yields were also observed for α,β-unsaturated aldehydes with aliphatic substituents. Our mechanistic investigations indicate that the pH value is critical to the chemoselectivity.
- Luo, Nianhua,Liao, Jianhua,Ouyang, Lu,Wen, Huiling,Liu, Jitian,Tang, Weiping,Luo, Renshi
-
p. 3025 - 3031
(2019/08/30)
-
- Iridium-promoted conversion of terminal epoxides to primary alcohols under acidic conditions using hydrogen
-
A strategy for the conversion of terminal epoxides to primary alcohols is presented. The reaction uses hydrogen as the only stoichiometric reagent and is promoted by an iridium precatalyst under acidic conditions. Selectivity for the formation of a terminal alcohol over an internal alcohol is observed for both alkyl- and aryl-substituted terminal epoxides in isolated yields of up to 50% and 72% respectively.
- Rainsberry, Alena N.,Sage, Jarrod G.,Scheuermann, Margaret L.
-
p. 3020 - 3022
(2019/06/27)
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- Quantitative Evaluation of the Effect of the Hydrophobicity of the Environment Surrounding Br?nsted Acid Sites on Their Catalytic Activity for the Hydrolysis of Organic Molecules
-
Sulfo-functionalized siloxane gels with a variety of surface hydrophobicities were fabricated to elucidate the effect of the environment surrounding the Br?nsted acid site on their catalytic activity for the hydrolysis of organic molecules. A detailed structural analysis of these siloxane gels by elemental analysis, X-ray photoelectron spectroscopy, Fourier-transformed infrared (FT-IR), and 29Si MAS NMR revealed the formation of gel catalysts with a highly condensed siloxane network, which enabled us to quantitatively evaluate the hydrophobicity of the environment surrounding the catalytically active sulfo-functionality. A sulfo group in a highly hydrophobic environment exhibited excellent catalytic turnover frequency for the hydrolysis of acetate esters with a long alkyl chain, whereas not only conventional solid acid catalysts but also liquid acids showed quite low catalytic activity. Detailed kinetic studies corroborated that the adsorption of oleophilic esters at the Br?nsted acid site was facilitated by the surrounding hydrophobic environment, thus significantly promoting hydrolysis under aqueous conditions. Furthermore, sulfo-functionalized siloxane gels with a highly hydrophobic surface showed excellent catalytic activity for the hydrolytic deprotection of silyl ethers.
- Miura, Hiroki,Kameyama, Shutaro,Komori, Daiki,Shishido, Tetsuya
-
supporting information
p. 1636 - 1645
(2019/01/21)
-
- Tandem Catalysis: Transforming Alcohols to Alkenes by Oxidative Dehydroxymethylation
-
We report a Rh-catalyst for accessing olefins from primary alcohols by a C-C bond cleavage that results in dehomologation. This functional group interconversion proceeds by an oxidation-dehydroformylation enabled by N,N-dimethylacrylamide as a sacrificial acceptor of hydrogen gas. Alcohols with diverse functionality and structure undergo oxidative dehydroxymethylation to access the corresponding olefins. Our catalyst protocol enables a two-step semisynthesis of (+)-yohimbenone and dehomologation of feedstock olefins.
- Wu, Xuesong,Cruz, Faben A.,Lu, Alexander,Dong, Vy M.
-
supporting information
p. 10126 - 10130
(2018/08/23)
-
- MOF-derived Cu@C catalyst for the liquid-phase hydrogenation of esters
-
MOF derived core-shell Cu@C was prepared by the pyrolysis of Cu-BTC and applied in the liquid-phase hydrogenation of ester. The severe aggregation of copper species was inhibited by the carbon shell. Compared with traditional Cu/AC-H2 catalyst, Cu@C-N2 displayed higher activity in the hydrogenation of butyl butyrate due to its higher Cu dispersion. Further reduction of Cu@C-N2 catalyst in H2 greatly improved the activity, as a result of the appropriate ratio of Cu+/Cu0, which can activate both ester and H2 molecules.
- Zhao, Yujun,Wu, Xiaoqian,Zhou, Jiahua,Wang, Yue,Wang, Shengping,Ma, Xinbin
-
supporting information
p. 883 - 886
(2018/06/29)
-
- Selective Hydrogenation of Carboxylic Acids to Alcohols or Alkanes Employing a Heterogeneous Catalyst
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The chemoselective hydrogenation of carboxylic acids to either alcohols or alkanes is reported, employing a heterogeneous bimetallic catalyst consisting of rhenium and palladium supported on graphite. α-Chiral carboxylic acids were hydrogenated without loss of optical purity. The catalyst displays a reverse order of reactivity upon hydrogenation of different carboxylic functions with esters being less reactive than amides and carboxylic acids. This allows for chemoselective hydrogenation of an acid in the presence of an ester or an amide function.
- Ullrich, Johannes,Breit, Bernhard
-
p. 785 - 789
(2018/02/14)
-
- Robust cobalt oxide catalysts for controllable hydrogenation of carboxylic acids to alcohols
-
The selective catalytic hydrogenation of carboxylic acids is an important process for alcohol production, while efficient heterogeneous catalyst systems are still being explored. Here, we report the selective hydrogenation of carboxylic acids using earth-abundant cobalt oxides through a reaction-controlled catalysis process. The further reaction of the alcohols is completely hindered by the presence of carboxylic acids in the reaction system. The partial reduction of cobalt oxides by hydrogen at designated temperatures can dramatically enhance the catalytic activity of pristine samples. A wide range of carboxylic acids with a variety of functional groups can be converted to the corresponding alcohols at a yield level applicable to large-scale production. Cobalt monoxide was established as the preferred active phase for the selective hydrogenation of carboxylic acids.
- Song, Song,Wang, Dong,Di, Lu,Wang, Chuanming,Dai, Weili,Wu, Guangjun,Guan, Naijia,Li, Landong
-
p. 250 - 257
(2018/02/20)
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- SALT OF ISOLATED COMPOUND CONTAINING AMIDE GROUP, METHOD FOR PRODUCING THE SAME, AND METHOD FOR SYNTHESIZING AMIDE COMPOUND USING THE SAME
-
PROBLEM TO BE SOLVED: To provide a salt of an isolated compound containing an amide group, a method for producing the same, and a method for synthesizing an amide compound using the same. SOLUTION: The present invention provides a salt of an isolated compound containing an amide group represented by formula (1) (M is an element belonging to group 1 in the periodic table; P is a first protective group of an amine represented by R1-O(C=O)-; Q is a second protective group of an amine represented by R2-(C=O)-; R1 and R2 independently represent a substituted/unsubstituted hydrocarbon group). SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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-
Paragraph 0105; 0107; 0116
(2018/08/23)
-
- Cobalt(II)-Mediated Desulfurization of Thiophenes, Sulfides, and Thiols
-
Desulfurization of organosulfur compounds is a highly important reaction because of its relevance to the hydrodesulfurization (HDS) process of fossil fuels. A reaction system involving Co(BF4)2·6H2O and the dinucleating ligands HBPMP or HPhBIMP has been developed that could desulfurize a large number of thiophenes, sulfides, and thiols to generate the complexes [Co2(BPMP)(μ2-SH)(MeCN)](BF4)2 (1a), [Co2(BPMP)(SH)2](BF4) (1b), and [Co2(PhBIMP)(μ2-SH)(X)](BF4)2 [X = DMF (2a), MeCN (2c)], while the substrates are mostly converted to the corresponding alcohols/phenols. This convenient desulfurization process has been demonstrated for 25 substrates in 6 different solvents at room temperature.
- Ganguly, Tuhin,Das, Ayan,Jana, Manish,Majumdar, Amit
-
supporting information
p. 11306 - 11309
(2018/09/12)
-
- Bipyridine ligand ruthenium complex is carried and its preparation method and application (by machine translation)
-
The invention relates to a novel bipyridine is carried ligand ruthenium complex and its preparation method and in the ester compound hydrogenation is the application of the alcohol compound in the reaction. The use of the bipyridine ligand ruthenium complex catalytic hydrogenation is carried ester compound alcohol compound method is characterized in that: in order to ester compound material in an amount of 0.001 - 0.3 μM % bipyridyl is carried ligand ruthenium complex as catalyst, adding esters compound material in an amount of 1 - 10mol % alkali, in the 25 - 100 °C and 1 - 10MPa hydrogen pressure catalytic hydrogenation under the conditions of ester compound corresponding alcohol compound. The invention of the bipyridine ligand ruthenium complex is carried is convenient to prepare, stable structure, in the ester compound in hydrogenation reaction exhibits excellent catalytic activity. This invention has overcome the ester compound or a non-homogeneous phase catalytic hydrogenation system requires high-temperature high-pressure reaction conditions and high defects of the catalyst amount, catalyst consumption is small, mild reaction conditions, the reaction selectivity is good, improves the economy and the safety of the production system. (by machine translation)
- -
-
Paragraph 0098; 0099; 0100; 0101; 0102; 0104
(2017/04/28)
-
- Electrochemical Deprotection of para-Methoxybenzyl Ethers in a Flow Electrolysis Cell
-
Electrochemical deprotection of p-methoxybenzyl (PMB) ethers was performed in an undivided electrochemical flow reactor in MeOH solution, leading to the unmasked alcohol and p-methoxybenzaldehyde dimethyl acetal as a byproduct. The electrochemical method removes the need for chemical oxidants, and added electrolyte (BF4NEt4) can be recovered and reused. The method was applied to 17 substrates with high conversions in a single pass, yields up to 92%, and up to 7.5 g h-1 productivity. The PMB protecting group was also selectively removed in the presence of some other common alcohol protecting groups.
- Green, Robert A.,Jolley, Katherine E.,Al-Hadedi, Azzam A. M.,Pletcher, Derek,Harrowven, David C.,De Frutos, Oscar,Mateos, Carlos,Klauber, David J.,Rincón, Juan A.,Brown, Richard C. D.
-
supporting information
p. 2050 - 2053
(2017/04/27)
-
- Rhenium-Loaded TiO2: A Highly Versatile and Chemoselective Catalyst for the Hydrogenation of Carboxylic Acid Derivatives and the N-Methylation of Amines Using H2 and CO2
-
Herein, we report a heterogeneous TiO2-supported Re catalyst (Re/TiO2) that promotes various selective hydrogenation reactions, which includes the hydrogenation of esters to alcohols, the hydrogenation of amides to amines, and the N-methylation of amines, by using H2 and CO2. Initially, Re/TiO2 was evaluated in the context of the selective hydrogenation of 3-phenylpropionic acid methyl ester to afford 3-phenylpropanol (pH2 =5 MPa, =5 MPa, T=180 °C), which revealed a superior performance over other catalysts that we tested in this study. In contrast to other typical heterogeneous catalysts, hydrogenation reactions with Re/TiO2 did not produce dearomatized byproducts. DFT studies suggested that the high selectivity for the formation of alcohols in favor of the hydrogenation of aromatic rings is ascribed to the higher affinity of Re towards the COOCH3 group than to the benzene ring. Moreover, Re/TiO2 showed a wide substrate scope for the hydrogenation reaction (19 examples). Subsequently, this Re/TiO2 catalyst was applied to the hydrogenation of amides, the N-methylation of amines, and the N-alkylation of amines with carboxylic acids or esters.
- Toyao, Takashi,Siddiki,Morita, Yoshitsugu,Kamachi, Takashi,Touchy, Abeda S.,Onodera, Wataru,Kon, Kenichi,Furukawa, Shinya,Ariga, Hiroko,Asakura, Kiyotaka,Yoshizawa, Kazunari,Shimizu, Ken-Ichi
-
supporting information
p. 14848 - 14859
(2017/10/27)
-
- EXTRUDED Cu-Al-Mn HYDROGENATION CATALYST
-
The invention relates to Cu—Al—Mn shaped catalyst bodies in extruded form, and to a process for their preparation. The shaped catalyst body is suitable for the hydrogenation of organic compounds containing a carbonyl function, in particular for the hydrogenation of aldehydes, ketones and carboxylic acids and/or their esters. In particular, the shaped catalyst body is suitable for the hydrogenation of fatty acids or their esters, such as fatty acid methyl esters, to form the corresponding alcohols and dicarboxylic acid anhydrides, such as maleic anhydride, or esters of di-acids and di-alcohols, such as butane diol.
- -
-
Paragraph 0117-0129
(2017/12/17)
-
- Chemoselective continuous-flow hydrogenation of aldehydes catalyzed by platinum nanoparticles dispersed in an amphiphilic resin
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A chemoselective continuous-flow hydrogenation of aldehydes catalyzed by a dispersion of platinum nanoparticles in an amphiphilic polymer (ARP-Pt) has been developed. Aromatic and aliphatic aldehydes bearing various reducible functional groups, such as keto, ester, or amide groups, readily underwent flow hydrogenation in aqueous solutions within 22 s in a continuous-flow system containing ARP-Pt to give the corresponding primary benzylic or aliphatic alcohols in ≤99% yield with excellent chemoselectivity. Moreover, the long-term continuous-flow hydrogenation of benzaldehyde for 8 days was realized, and the total turnover number of the catalyst reached 997. The flow hydrogenation system provides an efficient and practical method for the chemoselective hydrogenation of aldehydes bearing reducible functional groups.
- Osako, Takao,Torii, Kaoru,Hirata, Shuichi,Uozumi, Yasuhiro
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p. 7371 - 7377
(2017/11/09)
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- TiO2-Supported Re as a General and Chemoselective Heterogeneous Catalyst for Hydrogenation of Carboxylic Acids to Alcohols
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TiO2-supported Re, Re/TiO2, was found to promote selective hydrogenation of carboxylic acids having aromatic and aliphatic moieties to the corresponding alcohols. Re/TiO2showed superior results compared to other transition-metal-loaded TiO2and supported Re catalysts for selective hydrogenation of 3-phenylpropionic acid. 3-phenylpropanol was produced in 97 % yield under mild conditions (5 MPa H2at 140 °C). Contrary to typical heterogeneous catalysts, Re/TiO2does not lead to the formation of dearomatized byproducts. The catalyst is recyclable and shows a wide substrate scope in the synthesis of alcohols (22 examples; up to 97 % isolated yield).
- Toyao, Takashi,Siddiki, S. M. A. Hakim,Touchy, Abeda S.,Onodera, Wataru,Kon, Kenichi,Morita, Yoshitsugu,Kamachi, Takashi,Yoshizawa, Kazunari,Shimizu, Ken-Ichi
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supporting information
p. 1001 - 1006
(2017/02/05)
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- PRODUCTION METHOD OF ALIPHATIC ALCOHOL
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Provided is a method for producing an aliphatic alcohol having 8 or more and 22 or less carbon atoms through hydrogenation of a fatty acid or a fatty acid ester using a catalyst, wherein the catalyst carries a catalyst metal on a support,(a) the catalyst contains one or more elements selected from Co and Cu as the catalyst metal, (b) the total pore volume of the catalyst is 0.05 mL/g or more, and (c) the volume of pores with a pore size of 0.1 μm or more and 500 μm or less is 50% or more of the total pore volume of the catalyst.
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Paragraph 0250
(2017/10/10)
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- Direct Synthesis of Renewable Dodecanol and Dodecane with Methyl Isobutyl Ketone over Dual-Bed Catalyst Systems
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For the first time, we demonstrated two integrated processes for the direct synthesis of dodecanol or 2,4,8-trimethylnonane (a jet fuel range C12-branched alkane) using methyl isobutyl ketone (MIBK) that can be derived from lignocellulose. The reactions were carried out in dual-bed continuous flow reactors. In the first bed, MIBK was selectively converted to a mixture of C12 alcohol and ketone. Over the Pd-modified magnesium– aluminium hydrotalcite (Pd-MgAl-HT) catalyst, a high total carbon yield (73.0 %) of C12 oxygenates can be achieved under mild conditions. In the second bed, the C12 oxygenates generated in the first bed were hydrogenated to dodecanol over a Ru/C catalyst or hydrodeoxygenated to 2,4,8-trimethylnonane over a Cu/SiO2 catalyst. The as-obtained dodecanol can be used as feedstock in the production of sodium dodecylsulfate (SDS) and sodium dodecyl benzene sulfonate (SDBS), which are widely used as surfactants or detergents. The asobtained 2,4,8-trimethylnonane can be blended into conventional jet fuel without hydroisomerization.
- Sheng, Xueru,Li, Ning,Li, Guangyi,Wang, Wentao,Wang, Aiqin,Cong, Yu,Wang, Xiaodong,Zhang, Tao
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p. 825 - 829
(2017/03/17)
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- Failure and Redemption of Statistical and Nonstatistical Rate Theories in the Hydroboration of Alkenes
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Our previous work found that canonical forms of transition state theory incorrectly predict the regioselectivity of the hydroboration of propene with BH3 in solution. In response, it has been suggested that alternative statistical and nonstatistical rate theories can adequately account for the selectivity. This paper uses a combination of experimental and theoretical studies to critically evaluate the ability of these rate theories, as well as dynamic trajectories and newly developed localized statistical models, to predict quantitative selectivities and qualitative trends in hydroborations on a broader scale. The hydroboration of a series of terminally substituted alkenes with BH3 was examined experimentally, and a classically unexpected trend is that the selectivity increases as the alkyl chain is lengthened far from the reactive centers. Conventional and variational transition state theories can predict neither the selectivities nor the trends. The canonical competitive nonstatistical model makes somewhat better predictions for some alkenes but fails to predict trends, and it performs poorly with an alkene chosen to test a specific prediction of the model. Added nonstatistical corrections to this model make the predictions worse. Parametrized Rice-Ramsperger-Kassel-Marcus (RRKM)-master equation calculations correctly predict the direction of the trend in selectivity versus alkene size but overpredict its magnitude, and the selectivity with large alkenes remains unpredictable with any parametrization. Trajectory studies in explicit solvent can predict selectivities without parametrization but are impractical for predicting small changes in selectivity. From a lifetime and energy analysis of the trajectories, "localized RRKM-ME" and "competitive localized noncanonical" rate models are suggested as steps toward a general model. These provide the best predictions of the experimental observations and insight into the selectivities.
- Bailey, Johnathan O.,Singleton, Daniel A.
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supporting information
p. 15710 - 15723
(2017/11/14)
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