- Oxidation of KA oil to caprolactone with molecular oxygen using N-hydroxyphthalimide-mediated Ce(NH4)2(NO3)6 catalyst
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In traditional Baeyer-Villiger oxidation, peracids or hydrogen peroxide are usually adopted as the oxidants. When molecular oxygen is used as oxidant, the sacrificial agents are always indispensable, such as aldehydes that are transformed into cheap acids after reaction. In this work, KA oil (the industrial raw material, a mixture of cyclohexanol and cyclohexanone) has been oxidized to caprolactone by molecular oxygen using N-hydroxyphthalimide (NHPI) and cerium ammonium nitrate (CAN) as catalyst, in which the sacrificial agent is cyclohexanol, and it is converted into cyclohexanone, then into caprolactone rather than into byproducts. The selectivity of caprolactone was 98% with cyclohexanol conversion of 34% and it was still kept at 90% when the conversion reached to 46%. The mechanism investigation showed a bifunctional role of CAN, which performed both as a radical initiator for cyclohexanol oxidation and a Lewis acid for Baeyer-Villiger reaction. In the Baeyer-Villiger oxidation, a weak interaction between cerium and cyclohexanone was suggested by Fourier Transform Infrared Spectroscopy (FTIR), meanwhile, the active species generated from cerium and hydrogen peroxide was separated and characterized by FTIR. The detailed research also revealed an unusual effect between cerium and the Br?nsted acid generated as a byproduct, which was critical for caprolactone synthesis.
- Du, Renfeng,Yuan, Haoran,Yao, Jia,Li, Haoran
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- Heterogeneous catalysts hold the edge over homogeneous systems: Zeolite-Y encapsulated complexes for Baeyer-Villiger oxidation of cyclohexanone
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A series of heterogeneous catalysts [M(pamp)]-Y (Where, M = V, Mn, Fe or Cu; pamp = 2,2′-((1E,1′E)-(1,2-phenylenebis(azanylylidene))bis(methanylylidene))diphenol) was prepared by encapsulation of metal complexes within zeolite-Y. Synthesized materials were characterized by chemical, BET and thermogravimetric (TG) analysis, X-ray diffraction (XRD), UV-vis and infrared spectroscopies, and scanning electron microscopy (SEM). Zeolite-Y encapsulated complexes were tested in Baeyer-Villiger (B-V) oxidation of cyclohexanone beside neat complexes to check the aptitude of heterogeneous catalysis over the homogeneous system. The effect of experimental variables viz., solvents, catalysts amount, the mole ratio of substrate to an oxidant, temperature and reaction time on substrate conversion was also tested. Under the optimized reaction conditions, [VO(pamp)]-Y was found to be a potential candidate by providing 1500 TONs in cyclohexanone oxidation, and the selectivity towards ?-caprolactone was 85.2%.
- Mehta, Jignasu P.,Parmar, Digvijaysinh K.,Godhani, Dinesh R.,Nakum, Haresh D.,Desai, Nisheeth C.
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- Ruthenium-catalyzed highly chemoselective hydrogenation of aldehydes
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The use of a [(ethylenediamine)(dppe)Ru(OCOtBu)2] [dppe=1,2-bis(diphenylphosphino)ethane] complex under base-free conditions allowed highly efficient and selective hydrogenation of aldehydes in the presence of ketones in addition to olefins. Even in the case of highly sensitive 1,6-ketoaldehydes, the desired ketoalcohols were obtained in high yields with 94-99 % overall selectivity at complete aldehyde conversion with a TON up to 30 000. The lack of requirement for strong basic co-catalysts and polar protic solvents also allowed efficient and highly chemoselective reduction of aldehydes bearing other functional groups, such as epoxides, carboxylic acids, esters, amides, and nitriles emphasizing the potential synthetic utility of the catalyst. It's all about the aldehyde: The use of [(ethylenediamine)(dppe)Ru(OCOtBu)2] [dppe=1,2-bis(diphenylphosphino)ethane] under base-free conditions allows highly efficient and selective hydrogenation of aldehydes in the presence of ketones. Highly selective hydrogenation of additional aldehydes in the presence of other functional groups, such as epoxides, carboxylic acids, esters, amides, and nitriles emphasizes the potential synthetic utility of the catalyst.
- Bonomo, Lucia,Kermorvan, Laurent,Dupau, Philippe
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- Baeyer-Villiger oxidations with hydrogen peroxide in fluorinated alcohols: Lactone formation by a nonclassical mechanism
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What a difference the solvent makes! Unlike in conventional solvents, non-strained ketones such as cyclohexanone react smoothly with hydrogen peroxide in 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) to give lactones. The reaction proceeds via an isolatable spiro-bisperoxide, which undergoes a highly exothermic acid-catalyzed rearrangement to two equivalents of lactone (see Equation and IR thermogram).
- Berkessel, Albrecht,Andreae, Marc R. M.,Schmickler, Hans,Lex, Johann
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- New and efficient technique for the synthesis of ε-caprolactone using KHSO5 as an oxidising agent in the presence of a phase transfer catalyst
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A new method for the synthesis of ε-caprolactone based on the Baeyer-Villiger oxidation of cyclohexanone was developed. In the proposed reaction, potassium peroxomonosulphate was used as an oxidising agent under phase transfer catalysis conditions. The effects of the reaction parameters, including the type of phase transfer catalyst, the concentration of the oxidising agent, the type of organic solvent and temperature, were investigated. When dichloromethane was used as an organic solvent and an adequate amount of water was added to the reaction mixture, the highest yield and selectivity for ε-caprolactone were achieved at 40 °C.
- Baj, Stefan,Chrobok, Anna,Siewniak, Agnieszka
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- Solid-phase synthesis of a library of linear oligoester ion-channels
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A solid-phase synthesis protocol was used to prepare fifteen new linear tetra-, and penta-esters structurally related to an active lead compound. The structures were assembled from three types of hydroxyl protected building blocks: monoalkyl esters of hydroxyglutaric acid, ω-hydroxyacids, and α-hydroxymethylalkanoic acids. The standard methodology gave acceptable quantities of material free of small molecule impurities. Mass spectrometric analysis revealed the presence of deletions due to incomplete coupling, as well as additions and macrolactones due to partial acidic rearrangement on release from the solid-support. The amount of these impurities could be estimated from the 1H NMR spectra, and their implications for subsequent activity analysis are discussed.
- Fyles, Thomas Murray,Luong, Horace
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- Mesoporous core-shell fenton nanocatalyst: A mild, operationally simple approach to the synthesis of adipic acid
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Mesoporous nanoparticles composed of γ-Al2O3 cores and α-Fe2O3 shells were synthesized in aqueous medium. The surface charge of γ-Al2O3 helps to form the core-shell nanocrystals. The core-shell structure and formation mechanism have been investigated by wide-angle XRD, energy-dispersive X-ray spectroscopy, and elemental mapping by ultrahigh-resolution (UHR) TEM and X-ray photoelectron spectroscopy. The N2 adsorption-desorption isotherm of this core-shell materials, which is of type IV, is characteristic of a mesoporous material having a BET surface area of 385 m2 g-1 and an average pore size of about 3.2 nm. The SEM images revealed that the mesoporosity in this core-shell material is due to self-aggregation of tiny spherical nanocrystals with sizes of about 15-20 nm. Diffuse-reflectance UV/Vis spectra, elemental mapping by UHRTEM, and wide-angle XRD patterns indicate that the materials are composed of aluminum oxide cores and iron oxide shells. These Al2O3@Fe2O3 core-shell nanoparticles act as a heterogeneous Fenton nanocatalyst in the presence of hydrogen peroxide, and show high catalytic efficiency for the one-pot conversion of cyclohexanone to adipic acid in water. The heterogeneous nature of the catalyst was confirmed by a hot filtration test and analysis of the reaction mixture by atomic absorption spectroscopy. The kinetics of the reaction was monitored by gas chromatography and 1H NMR spectroscopy. The new core-shell catalyst remained in a separate solid phase, which could easily be removed from the reaction mixture by simple filtration and the catalyst reused efficiently. Mesoporous core-shell particles: Mesoporous nanoparticles composed of γ-Al2O3 cores and α-Fe2O 3 shells were synthesized in aqueous medium. The Al2O 3@Fe2O3 core-shell nanoparticles act as a heterogeneous Fenton nanocatalyst in the presence of hydrogen peroxide, and show high catalytic efficiency for the conversion of cyclohexanone to adipic acid in water in one step (see figure). Copyright
- Patra, Astam K.,Dutta, Arghya,Bhaumik, Asim
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- Hydrolytic degradation of poly(ethylene oxide)-block-polycaprolactone worm micelles
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Spherical micelles and nanoparticles made with degradable polymers have been of great interest for therapeutic application, but degradation-induced changes in a spherical morphology can be subtle and mechanism/kinetics appears poorly understood. Here, we report the first preparation of giant and flexible worm micelles self-assembled from degradable copolymer poly(ethylene oxide)-block-polycaprolactone. Such worm micelles spontaneously shorten to generate spherical micelles, triggered by polycaprolactone hydrolysis, with distinct mechanism and kinetics from that which occurs in bulk material. Copyright
- Geng, Yan,Discher, Dennis E.
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- Simple preparation of highly pure monomeric ω-hydroxycarboxylic acids
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Highly pure monomeric ω-hydroxycarboxylic acids (HCAs) with ≥C6 are prepared from their corresponding lactones or alkyl ω-hydroxycarboxylates through saponification followed by H 2SO4 acidification and treatment at 35-40 °C/8-12 mbar or by freeze-drying. The HCA is being formed through its sodium or potassium salt and is obtained in 80-85% yield with >99.5% purity, uncontaminated with dimers. This simple procedure excludes chromatographic purification.
- Stephan, Michel Massoud S.,Mohar, Barbara
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- Lipase-catalyzed ring-opening polymerizations of 4-substituted ε-caprolactones: Mechanistic considerations
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Lipase-catalyzed ring-opening polymerizations of 4-substituted ε-caprolactones employing Novozym 435 as the biocatalyst demonstrate dramatic differences in polymerization rates and selectivity depending on the size of the substituent. Quantification of the reaction rates shows that the polymerization rate decreases by a factor of 2 upon the introduction of a Me substituent at the 4-position. Moreover, 4-EtCL polymerizes 5 times slower than 4-MeCl and 4-PrCL is even 70 times slower. The decrease in polymerization rate is accompanied by a strong decrease in enantioselectivity: while the E-ratio of 4-MeCL polymerization is 16.9, the E-ratios of 4-EtCL and 4-PrCL are 7.1 and 2.0, respectively. Interestingly, Novozym 435 displays S-selectivity for 4-MeCL and 4-EtCL in the polymerization reaction, but the enantioselectivity is changed to the (R)-enantiomer in the case of the 4-PrCL. The nature of these differences was investigated by hydrolyzing all monomers in water/diisopropyl ether mixtures employing Novozym 435 as the catalyst. In the hydrolysis reactions, the rates are only moderately affected upon increasing the substituent size, and the enantioselectivity is S in all cases, also for 4-PrCL. Again, a steady decrease of the U-ratio was observed upon increasing the substituent size, but this was less pronounced than in the polymerization reactions: the E-ratios were 17.6, 12.4, and 4.6, going from 4-MeCL to 4-PrCL. For 4-substituted ε-caprolactones, the results obtained are a clear indication that the chirality of the propagating alcohol chain end is important in the catalytic cycle and that-in contrast to unsubstituted lactones-the rate-determining step is not necessarily the formation of the acyl-enzyme intermediate but more likely the deacylation of the acyl-enzyme intermediate by the propagating alcohol chain end.
- Peeters, Joris W.,Van Leeuwen, Oscar,Palmans, Anja R. A.,Meijer
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- Aerobic oxidation of 1,6-hexanediol to adipic acid over Au-based catalysts: The role of basic supports
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1,6-Hexanediol is one of the most relevant building blocks originating from biomass and it transforms into adipic acid for polymer synthesis. Herein, we examine the selective oxidation of 1,6-hexanediol to adipic acid over Au-based catalysts, in the aqueous phase, under base-free conditions. Particularly, the absence of a base allows the neutralization step at the end of the reaction to be avoided. The influences of various supports (MgO, BaO, NiO, and TiO2) and substrate/gold molar ratios were studied. Under the conditions used, the leaching of Mg in the mixture of MgF2 and MgO was limited by diluting the basic sites in the support. The highest selectivity to adipic acid (43%) was achieved at 110 °C under 15 bar of air in the presence of 2 wt% Au/0.6MgF2-0.4MgO.
- Capece, Noemi,Cavani, Fabrizio,Palombo Ferraz, Camila,Paul, Sébastien,Pietrowski, Mariusz,Sadier, Achraf,Thuriot-Roukos, Jo?lle,Wojcieszak, Robert,Zieliński, Micha?
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- A highly stable and active CaO/Al2O3 base catalyst in the form of calcium aluminate phase for oxidation of cyclohexanone to ε-caprolactone
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A series of CaO/Al2O3 base catalysts with different crystal phases is prepared via thermal treatment. The as-prepared base catalysts are tested through Baeyer-Villiger oxidation of cyclohexanone to ε-caprolactone in liquid-phase using a mixture of aqueous hydrogen peroxide and benzonitrile as oxidant. The corresponding results show that the CaO/Al2O3 catalysts with high thermal treatment temperature (e.g. 900 °C) exhibit excellent activity as well as stability. Upon these, the catalysts are characterized by TG-DTG, XRD, N 2-physisorption, SEM and CO2-TPD techniques. The characterization results clearly suggest that such a stable and efficient catalytic performance is beneficial from the formation of calcium aluminate phase, thus overcoming one of base catalyst application barriers, that Ca or CaO species loss (leach) from CaO-based catalysts during reactions. Correspondingly, it can be inferred that the treatment of the catalysts at different temperatures results in the diverse distribution of basic strength. Furthermore, it is also demonstrated that the suitable base strength (medium strength is good for the reaction selected in the work) plays a critically role in the improvement of catalytic performance. Finally, the effects of operation conditions on catalytic activity and product selectivity are also determined and discussed.
- Zhu, Lihua,Cao, Maohong,Zhou, Hua,Zhang, Nuowei,Zheng, Jinbao,Li, Yunhua,Chen, Bing H.
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- Synthesis of E-caprolactone with stable hydrogen peroxide adducts
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Oxidation of cyclohexanone to E-caprolactone with stable industrially manufactured hydrogen peroxide derivatives: adduct with urea (urea hydrogen peroxide), sodium perborate, sodium percarbonate (Persol), magnesium monoperphthalate (Dismozon) was studied. Oxidation with urea hydrogen peroxide is the most efficient in hexafluoroisopropanol in the case of preliminary removal of urea in the form of an oxalate. Oxidation with sodium perborate and percarbonate provides high yields in trifluoroacetic acid. The lowest cost process consists in interaction with sodium monoperphthalate (Persol and phthalic anhydride) in an aqueous medium.
- Kuznetsov,Pervova,Yatluk
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- Oxidation of cyclohexane with hydrogen peroxide over β-zeolites with various Si/Al ratios
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Selective oxidation of cyclohexanone to ε-caprolactone by H 2O2 was investigated on β-zeolites with various Si/Al ratio. The yield of ε-caprolactone was increased with decreasing Si/Al ratio. The β-zeolites in which Si/Al ratio was l
- Ohno, Ryohei,Taniya, Keita,Tsuruya, Shigeru,Ichihashi, Yuichi,Nishiyama, Satoru
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- Selective oxidation of 1,6-hexanediol to 6-hydroxycaproic acid over reusable hydrotalcite-supported au-pd bimetallic catalysts
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Selective oxidation of 1,6-hexanediol into 6-hydroxycaproic acid was achieved over hydrotalcite-supported Au-Pd bimetallic nanoparticles as heterogeneous catalyst using aqueous H2O2. N,N-dimethyldodecylamine N-oxide (DDAO) was used as an efficient capping agent. Spectroscopic analyses by UV/Vis, TEM, XPS, and X-ray absorption spectroscopy suggested that interactions between gold and palladium atoms are responsible for the high activity of the reusable Au40Pd60-DDAO/HT catalyst. Talcite assumptions: Au-Pd nanoparticles stabilized by N,N-dimethyldodecylamine N-oxide (DDAO) and on a hydrotalcite support are prepared. The supported nanoparticles are employed for the selective oxidation of 1,6-hexanediol to 6-hydroxycaproic acid in alkaline medium with 30% aq. H2O2 as oxidant. Analysis of the catalysts by a combination of spectroscopic techniques reveals electronic interactions between gold an palladium that are responsible for the catalytic performance.
- Tuteja, Jaya,Nishimura, Shun,Choudhary, Hemant,Ebitani, Kohki
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- Inclusion Complex Formation and Hydrolysis of Lactones by Cyclodextrins
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Cyclodextrins (CDs) have been found to form inclusion complexes with lactones in aqueous solutions and/or in the solid states; hydrolysis of lactones has been found to be suppressed or promoted by CDs according to the combination of lactones and CD.
- Takashima, Yoshinori,Kawaguchi, Yoshinori,Nakagawa, Shinya,Harada, Akira
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- Oxidative ring contraction of cycloalkanones: A facile metrod for synthesis of medium ring cycloalkanecarboxylic acids
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Cycloalkanones (1) oxidized with 30% hydrogen peroxide in the presence of poly(bisanthracenyl) diselenide (5b) as catalyst, produce cycloalkanecarboxylic acids (2) having one carbon atom less in the ring that the substrate. Although preparative yield of acids 2 does not exceed 60% the reaction can be applied as a simple way for synthesis of cycloalkanecarboxylic acids with five to seven-membered ring.
- Giurg, Miroslaw,Mlochowski, Jacek
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- Methodology for synthesizing crystalline metallosilicates with expanded pore windows through molecular alkoxysilylation of zeolitic lamellar precursors
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Postalkoxysilylation with diethoxydimethylsilane has been carried out on the zeolitic lamellar precursors of various topologies such as MWW, FER, CDO and MCM-47 aiming to construct new crystalline structures with expanded pore apertures between the layers. The silylation process and the crystalline and pore structures of the resulting materials have been investigated with the techniques of XRD, IR, 13C and 29Si MAS NMR, ICP, SEM, HRTEM, elemental analyses, and N2 adsorption. In contrast to forming known three-dimensional zeolite structures after direct calcination of the lamellar precursors, the silylation led to new crystalline structures with opener pores, as evidenced by the shift of layer-related diffractions to the lower-angle region in XRD patterns and the enlarged interlayer pores found by HRTEM images. After optimizing the treatment conditions, particularly the amount of silane agent, a maximum and homogeneous silylation was realized, which guaranteed the phase purity in interlayer expanded zeolites. The expanded structures were well preserved after calcination at 823 K or reflux in water for 1 to 2 weeks, indicating a high thermal stability and also a hydrothermal stability. The interlayer expanded zeolites prepared from the metallosilicate precursors of MWW topology exhibited higher catalytic activities in the redox and solid acid-catalyzed reactions of bulky molecules than that of their counterparts with conventional MWW topology.
- Wu, Peng,Ruan, Juanfang,Wang, Lingling,Wu, Leilei,Wang, Yong,Liu, Yueming,Fan, Weibin,He, Mingyuan,Terasaki, Osamu,Tatsumi, Takashi
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- Change in reactivity of differently capped AuPd bimetallic nanoparticle catalysts for selective oxidation of aliphatic diols to hydroxycarboxylic acids in basic aqueous solution
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N,N-Dimethyldodecylamine N-oxide (DDAO), PVP and PVA capped supported AuPd bimetallic nanoparticles (NPs) were prepared, and their catalytic activities were evaluated for the oxidation of 1,6-hexanediol (HDO) to 6-hydroxycaproic acid (HCA) using H2O2 in basic aqueous solution. Among three catalysts, DDAO capped AuPd bimetallic NPs catalysts exhibited superior selectivity for HCA formation than PVP and PVA capped catalysts. To explain the difference in the catalytic behavior, the catalysts were characterized thoroughly. XRD, TEM and STEM-HAADF-EDS studies were employed to identify the structure and morphology of capped AuPd-NPs, respectively. The chemical and electronic states were elucidated using XPS and XAS methods. The characterization data revealed that the capping agent significantly influences the electron density on metals and extent of alloying between Au and Pd metals. It was revealed that DDAO-capped catalyst induces appropriate negatively charged Au species with a few numbers of Au-Pd interfaces for the highly selective formation of HCA via HDO oxidation in basic aqueous media. Furthermore, other aliphatic diols, 1,7-heptanediol, 1,8-octanediol and 1,2-hexanediol, were also selectively oxidized on AuPd-DDAO catalysts toward the corresponding ω-hydroxycarboxylic acids in high yields.
- Tuteja, Jaya,Nishimura, Shun,Ebitani, Kohki
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- Selectivity and Lifetime Effects in Zeolite-Catalysed Baeyer–Villiger Oxidation Investigated in Batch and Continuous Flow
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In this manuscript, we investigate the kinetic, mechanistic and lifetime aspects of the Baeyer–Villiger oxidation of cyclohexanone with Sn-β as catalyst and H2O2 as oxidant, with the aim of: 1) elucidating the overall reaction network, 2) closing the carbon balance, particularly at high levels of conversion, and 3) examining the intensification of this process in the continuous regime. The results presented herein conclusively demonstrate that this reaction is highly selective for the desired product (?-caprolactone) only below conversions of 60 %. Above this level of conversion, unavoidable hydrolysis of ?-caprolactone to 6-hydroxyhexanoic acid is observed, which consumes the desired product and leads to a reduction in catalytic activity through poisoning. By elucidating the reaction network and working under optimised conditions, we show the potential viability of this methodology to operate continuously over a 180 h period, both at high levels of productivity (324 g (cyclohexanone converted) cm?3 (reactor volume) kg?1 (catalyst) h?1) and selectivity (70 % at 60 % conversion). Over 5000 substrate turnovers were observed during this period, an order of magnitude higher than previously noted for this particular catalyst system.
- Yakabi, Keiko,Milne, Kirstie,Buchard, Antoine,Hammond, Ceri
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- Supported sulfonic acid as green and efficient catalyst for Baeyer-Villiger oxidation with 30% aqueous hydrogen peroxide
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Silica-supported propylsulfonic acid is a very good heterogeneous catalyst for the Baeyer-Villiger oxidation of cyclic ketones to lactones with stoichiometric 30% aqueous hydrogen peroxide in 1,1,1,3,3,3-hexafluoro-2- propanol as solvent.
- Piscopo, Calogero G.,Loebbecke, Stefan,Maggi, Raimondo,Sartori, Giovanni
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- A Ru-Sn-Co/AlO(OH) as a highly efficient catalyst for hydrogenation of dimethyl adipate to 1,6-hexanodiol in aqueous phase
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A Ru-Sn-Co/AlO(OH) catalyst was prepared by co-impregnation, calcination, and hydrothermal reduction. The catalyst was well characterized by BET, XRD, SEM-EDX, XPS, H2-TPR, and M?ssbauer spectroscopy, and then it was applied in the hydrogenation of dimethyl adipate to 1,6-hexanodiol in aqueous phase. It was found that the addition of cobalt could stabilize Sn(IV) and the cooperation between tin and cobalt could promote the reduction of ruthenium oxide. The γ-Al2O3 in the catalyst Ru-Sn-Co/γ-Al2O3 was transformed to AlO(OH) by the hydrothermal reduction. It was suggested that the stabilized Sn(IV) and the interaction between the hydroxyl group on the surface of AlO(OH) and the solvent water played a key role to improve the conversion of dimethyl adipate and the selectivity to 1,6-hexanodiol. The conversion of dimethyl adipate and the selectivity to 1,6-hexanodiol were up to 98% and 95%, respectively, under 5 MPa of H2 and 493 K for 10 h.
- Jiang, Hong-Bin,Jiang, Hai-Jun,Su, Ke,Zhu, De-Ming,Zheng, Xue-Li,Fu, Hai-Yan,Chen, Hua,Li, Rui-Xiang
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- Influence of Dioxygen on the Promotional Effect of Bi during Pt-Catalyzed Oxidation of 1,6-Hexanediol
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A series of carbon-supported, Bi-promoted Pt catalysts with various Bi/Pt atomic ratios was prepared by selectively depositing Bi on Pt nanoparticles. The catalysts were evaluated for 1,6-hexanediol oxidation activity in aqueous solvent under different dioxygen pressures. The rate of diol oxidation on the basis of Pt loading over a Bi-promoted catalyst was 3 times faster than that of an unpromoted Pt catalyst under 0.02 MPa of O2, whereas the unpromoted catalyst was more active than the promoted catalyst under 1 MPa of O2. After liquid-phase catalyst pretreatment and 1,6-hexanediol oxidation, migration of Bi on the carbon support was observed. The reaction order in O2 was 0 over Bi-promoted Pt/C in comparison to 0.75 over unpromoted Pt/C in the range of 0.02-0.2 MPa of O2. Under low O2 pressure, rate measurements in D2O instead of H2O solvent revealed a moderate kinetic isotope effect (rateH2O/rateD2O) on 1,6-hexanediol oxidation over Pt/C (KIE = 1.4), whereas a negligible effect was observed on Bi-Pt/C (KIE = 0.9), indicating that the promotional effect of Bi could be related to the formation of surface hydroxyl groups from the reaction of dioxygen and water. No significant change in product distribution or catalyst stability was observed with Bi promotion, regardless of the dioxygen pressure.
- Xie, Jiahan,Huang, Benjamin,Yin, Kehua,Pham, Hien N.,Unocic, Raymond R.,Datye, Abhaya K.,Davis, Robert J.
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- Synthesis of a series of hydroxycarboxylic acids as standards for oxidation of nonanoic acid
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The synthesis of a series of nonanoic acids hydroxylated in terminal,ω-1,ω-2,ω-3 positions is described. These compounds will be employed as useful standards for the study of enzymatic and microbiological oxidation of nonanoic acid.
- Rajabi, Mehdi,Lanfranchi, Moreno,Campo, Federica,Panza, Luigi
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- Introducing an in situ capping strategy in systems biocatalysis to access 6-aminohexanoic acid
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The combination of two cofactor self-sufficient biocatalytic cascade modules allowed the successful transformation of cyclohexanol into the nylon-6 monomer 6-aminohexanoic acid at the expense of only oxygen and ammonia. A hitherto unprecedented carboxylic acid capping strategy was introduced to minimize the formation of the deadend intermediate 6-hydroxyhexanoic acid. For this purpose, the precursor ε-caprolactone was converted in aqueous medium in the presence of methanol into the corresponding methyl ester instead of the acid. Hence, it was shown for the first time that esterases-specifically horse liver esterase-can perform the selective ring-opening of ε-caprolactone with a clear preference for methanol over water as the nucleophile.
- Sattler, Johann H.,Fuchs, Michael,Mutti, Francesco G.,Grischek, Barbara,Engel, Philip,Pfeffer, Jan,Woodley, John M.,Kroutil, Wolfgang
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- A reduction-responsive drug delivery with improved stability: disulfide crosslinked micelles of small amiphiphilic molecules
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Micelles self-assembled from small amphiphilic molecules are unstable in biological fluids, and thus are poor drug carriers. In contrast, amphiphilic polymer micelles can encapsulate hydrophobic drugs in their core to greatly enhance their aqueous solubility and extend their retention time in blood circulation owing to their hydrophilic shell. However, the major disadvantages of conventional polymer micelles are the heterogeneity of the amphiphilic polymer structure and premature drug leakage. Thus, herein, to address these shortcomings, disulfide crosslinked micelles composed of a small amphiphilic molecule, di-lipoyl-glycerophosphorylcholine (di-LA-PC), were developed as redox-responsive drug carriers. Specifically, di-LA-PC was synthesized and self-assembled to form crosslinked micelles under catalysis by dithiothreitol. The disulfide crosslinked micelles maintained high stability in a simulated physiological environment, but rapidly disassembled under reductive conditions. Furthermore, paclitaxel (PTX), as a model drug, was encapsulated in the core of the crosslinked micelles with a high loading content of 8.13%. Thein vitrorelease studies indicated that over 80% of PTX was released from the micelles in the reductive environment, whereas less than 20% PTX was released without reduction in the 68 h test. Benefiting from their nanoscale characteristics, the PTX-loaded micelles showed efficient cellular internalization and effectively induced the death of cancer cells, as revealed in the MTT, apoptosis and cell cycle tests. Moreover, pharmacokinetic studies demonstrated that the crosslinked micelles prolonged the circulation of the incorporated PTX in the bloodstream and increased its accumulation in the tumor tissueviathe EPR effect. Finally, the PTX-loaded micelles displayed prominentin vivoanti-tumor activity in a 4T1 xenograft tumor model. In summary, the di-LA-PC crosslinked micelle platform possesses excellent stability, high loading capacity and reduction-responsive release profile, which may have applications in the delivery of PTX and other anti-cancer drugs.
- Li, Man,Ling, Longbing,Xia, Qing,Li, Xinsong
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- Comparative Baeyer-Villiger oxidation of cyclohexanone on Fe-pillared clays and iron tetrasulfophthalocyanine covalently supported on silica
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The Baeyer-Villiger oxidation of cyclohexanone to caprolactone has been investigated at room temperature over AlFe-pillared clays, using oxygen as oxidant in the presence of benzaldehyde. A nearly complete conversion is observed with a selectivity into ca
- Belaroui, Lala Setti,Sorokin, Alexander B.,Figueras, Fran?ois,Bengueddach, Abdelkader,Millet, Jean-Marc M.
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- Expedient synthesis of long-chain ω-substituted fatty acids and esters from cyclic ketones using iodine and hydrogen peroxide
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A simple and convenient synthesis of ω-iodoaliphatic carboxylic acids and esters by the reaction of cyclic ketones with iodine and hydrogen peroxide in the presence of catalytic CuCl has been developed. ω-Iodoaliphatic carboxylic esters were further used for the efficient preparation of di(2-pyridylmethylamino)alkanoic acids in excellent yields.
- Podrezova, Ekaterina V.,Larkina, Maria S.,Belousov, Mikhail V.,Kirschning, Andreas,Zhdankin, Viktor V.,Yusubov, Mekhman S.
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- A Fed-Batch Synthetic Strategy for a Three-Step Enzymatic Synthesis of Poly-?-caprolactone
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A three-step enzymatic reaction sequence for the synthesis of poly-?-caprolactone (PCL) was designed running in a fed-batch operation. The first part of the cascade consisted of two oxidation steps starting with alcohol dehydrogenase catalyzed oxidation from cyclohexanol to cyclohexanone and further oxidation to ?-caprolactone (ECL) by means of a Baeyer–Villiger monooxygenase. As a third step, lipase-catalyzed hydrolysis of the lactone to 6-hydroxyhexanoic acid (6-HHA) was designed. With this biocatalytic multistep process reported herein, severe substrate surplus and product inhibition could be circumvented by the fed-batch operation by adding the cyclohexanol substrate and by in situ product removal of ECL by hydrolysis, respectively. Up to 283 mm product concentration of 6-HHA was reached in the fed-batch operated process without loss in productivity within 20 h. After extraction and subsequent polymerization catalyzed by Candida antarctica lipase B, analysis of the unfractionated polymer revealed a bimodal distribution of the polymer population, which reached a mass average molar mass (Mw) value of approximately 63 000 g mol?1 and a dispersity (Mw/Mn) of 1.1 for the higher molecular weight population, which thus revealed an alternative route to the conventional synthesis of PCL.
- Scherkus, Christian,Schmidt, Sandy,Bornscheuer, Uwe T.,Gr?ger, Harald,Kara, Selin,Liese, Andreas
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- Carving the Active Site of CYP153A7 Monooxygenase for Improving Terminal Hydroxylation of Medium-Chain Fatty Acids
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The P450-mediated terminal hydroxylation of non-activated C?H bonds is a chemically challenging reaction. CYP153A7 monooxygenase, discovered in Sphingomonas sp. HXN200, belongs to the CYP153A subfamily and shows a pronounced terminal selectivity. Herein, we report the significantly improved terminal hydroxylation activity of CYP153A7 by redesign of the substrate binding pocket based on molecular docking of CYP153A7?C8:0 and sequence alignments. Some of the resultant single mutants were advantageous over the wild-type enzyme with higher reaction rates, achieving a complete conversion of n-octanoic acid (C8:0, 1 mM) in a shorter time period. Especially, a single-mutation variant, D258E, showed 3.8-fold higher catalytic efficiency than the wild type toward the terminal hydroxylation of medium-chain fatty acid C8:0 to the high value-added product 8-hydroxyoctanoic acid.
- Chen, Qi,Chong, Gang-Gang,Dong, Ya-Li,Li, Ai-Tao,Li, Chun-Xiu,Pan, Jiang,Xu, Jian-He
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- Oxidation of cyclohexanone and/or cyclohexanol catalyzed by Dawson-type polyoxometalates using hydrogen peroxide
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The oxidation of cyclohexanone, cyclohexanol or cyclohexanone/cyclohexanol mixture using as catalyst, Dawson-type polyoxometalates (POMs) of formula, α- and β-K6P2W18O62, α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62 and hydrogen peroxide, carried out at 90 °C with a reaction time of 20 h, led to a high number of mono- and di-acids which were identified by GC-MS. Levulinic, 6-hydroxyhexanoic, adipic, glutaric and succinic acids, major products were evaluated by HPLC. Regardless of the substrate nature, all POMs exhibited high catalytic activity with 94–99% of conversion, whereas the formation of the different products is sensitively related to both the composition and symmetry of the POMs and the substrate nature. The main products are adipic acid in the presence of α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62, levulinic acid in the presence of α1-K7P2Mo5VW12O62 and β-K6P2W18O62 and 6-hydroxyhexanoic acid in the presence of α- and β-K6P2W18O62. Graphical abstract: High catalytic activity was observed with?α- and?β-K6P2W18O62, α-K6P2Mo6W12O62 and α1-K7P2Mo5VW12O62 Dawson-type for the oxidation of cyclohexanone, cyclohexanol or cyclohexanone/cyclohexanol mixture, in the hydrogen peroxide presence, to several oxygenated products. Adipic, levulinic and 6-hydroxyhexanoic acids are the main products. The peroxo- species formed in situ could be the active sites.[Figure not available: see fulltext.]
- Dermeche, Leila,Idrissou, Yasmina,Mazari, Tassadit,Moudjahed, Mohammed,Rabia, Cherifa
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- Lipase catalysed oxidations in a sugar-derived natural deep eutectic solvent
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Chemoenzymatic oxidations involving the CAL-B/H2O2 system was developed in a sugar derived Natural Deep Eutectic Solvent (NaDES) composed by a mixture of glucose, fructose and sucrose. Good to excellent conversions of substrates like cyclooctene, limonene, oleic acid and stilbene to their corresponding epoxides, cyclohexanone to its corresponding lactone and 2-phenylacetophenone to its corresponding ester, demonstrate the viability of the sugar NaDES as a reaction medium for epoxidation and Baeyer-Villiger oxidation.
- Vagnoni, Martina,Samorì, Chiara,Pirini, Daniele,Vasquez De Paz, Maria Katrina,Gidey, Dawit Gebremichael,Galletti, Paola
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- A gulose moiety contributes to the belomycin (BLM) disaccharide selective targeting to lung cancer cells
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Eight mono- or disaccharide analogues derived from BLM disaccharide, along with the corresponding carbohydate-dye conjugates have been designed and synthesized in this study, aiming at exploring the effect of a gulose residue on the cellular binding/uptake of BLM disaccharide and it possible uptake mechanism. Our evidence is presented indicating that, for the cellular binding/uptake of BLM disaccharide, a gulose residue is an essential subunit but unrelated to its chemical nature. Interestingly, D-gulose-dye conjugate is able to selectively target A549 cancer cells, but L-gulose-dye conjugate fails. Further uptake mechanism studies demonstrate D-gulose-dye derivatives similar to BLM disaccharide-dye ones behave in a temperature- and ATP-dependent manner, and are partly directed by the GLUT1 receptor. Moreover, D-gulose modifying gemcitabine 53a exhibits more potent antitumor activity compared to derivatives 53b-c in which gemcitabine is decorated with other monosaccharides. Taken together, the monosacharide D-gulose conjugate offers a new strategy for solving cytotoxic drugs via the increased tumor targeting in the therapy of lung cancer.
- Cao, Yongjun,Chen, Wenming,Huang, Weiping,Li, Houkai,Liao, Guohao,Qi, Dongxia,Wang, Meizhu,Wang, Xiaoyang,Ye, Wenchong,Zhou, Cui,Zhou, Wen
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- Preparation method 6 -hydroxy caproic acid
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The invention provides a preparation method of 6 -hydroxycaproic acid. The method comprises the following steps: 1) subjecting 1 and 6 - adipic acid to intramolecular dehydration to obtain adipic anhydride. 2) The adipic acid anhydride is reacted with fatty alcohol to obtain the adipic acid monoester. 3) The adipic acid monoester was subjected to a reduction reaction under hydrogen pressure to give 6 - hydroxycaproic acid. 1-hydroxycaproic acid is prepared by taking 6 - and 6 - adipic acid cheap and easily available as raw materials through intramolecular dehydration, ring opening esterification, hydrogenation reduction and the like.
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Paragraph 0056; 0078-0089; 0093; 0102-0106; 0107; 0116-0120
(2021/11/10)
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- Method for preparing epsilon-caprolactone, 6-hydroxyhexanoic acid and esters thereof from tetrahydrofuranacetic acid and esters thereof
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The invention provides a method for preparing epsilon-caprolactone and 6-hydroxyhexanoic acid and esters thereof from tetrahydrofuranacetic acid and esters thereof, which comprises the following steps: in a solvent, in a reducing atmosphere and under the action of a catalyst, carrying out reduction reaction on tetrahydrofuranacetic acid and ester compounds thereof under the conditions that the pressure is 0.1-10MPa and the temperature is 20-200 DEG C for 0.5-48 hours, separating the catalyst, and distilling out the solvent, so that the target products epsilon-caprolactone, 6-hydroxyhexanoic acid and ester compounds of 6-hydroxyhexanoic acid are obtained. According to the method, efficient conversion of bio-based tetrahydrofuranacetic acid and esters thereof is realized under relatively mild conditions, the produced epsilon-caprolactone and 6-hydroxycaproic acid and ester compounds thereof are polymer monomers and are wide in application, and the application range of biomass is expanded; and meanwhile, the dilemma that the preparation of [epsilon]-caprolactone, 6-hydroxycaproic acid and ester thereof must depend on fossil resources is solved.
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Paragraph 0019; 0022
(2021/05/29)
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- PROCESS FOR PRODUCING HYDROXY ACID
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PROBLEM TO BE SOLVED: To provide a process for highly efficiently producing hydroxy acid from cyclic ketone. SOLUTION: Provided is a process for producing hydroxy acid, including a step in which hydrogen peroxide and cyclic ketone are reacted using water as solvent in the presence of a zeolite catalyst and a catalytic amount of organic acid. SELECTED DRAWING: None COPYRIGHT: (C)2020,JPOandINPIT
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Paragraph 0025-0027
(2020/05/13)
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- METHOD FOR PRODUCING HYDROXY ACID
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PROBLEM TO BE SOLVED: To provide a method for producing hydroxy acid with excellent yield. SOLUTION: The production of hydroxy acid by the reaction between lactone and water in the presence of acid catalysts such as zeolite, a metal sulfate catalyst, cation exchange resin. For example, ε-caprolactone is reacted with water in the presence of zeolite, allowing 6-hydroxy caproic acid to be prepared in high yield. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPO&INPIT
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Paragraph 0042-0049
(2020/12/09)
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- One-pot biosynthesis of 1,6-hexanediol from cyclohexane by: De novo designed cascade biocatalysis
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1,6-Hexanediol (HDO) is an important precursor in the polymer industry. The current industrial route to produce HDO involves energy intensive and hazardous multistage (four-pot-four-step) chemical reactions using cyclohexane (CH) as the starting material, which leads to serious environmental problems. Here, we report the development of a biocatalytic cascade process for the biotransformation of CH to HDO under mild conditions in a one-pot-one-step manner. This cascade biocatalysis operates by using a microbial consortium composed of three E. coli cell modules, each containing the necessary enzymes. The cell modules with assigned functions were engineered in parallel, followed by combination to construct E. coli consortia for use in biotransformations. The engineered E. coli consortia, which contained the corresponding cell modules, efficiently converted not only CH or cyclohexanol to HDO, but also other cycloalkanes or cycloalkanols to related dihydric alcohols. In conclusion, the newly developed biocatalytic process provides a promising alternative to the current industrial process for manufacturing HDO and related dihydric alcohols. This journal is
- Kang, Lixin,Li, Aitao,Li, Qian,Li, Renjie,Wang, Fei,Yu, Xiaojuan,Zhang, Zhongwei,Zhao, Jing
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p. 7476 - 7483
(2020/11/23)
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- A sustainable synthetic route for biobased 6-hydroxyhexanoic acid, adipic acid and ?-caprolactone by integrating bio- And chemical catalysis
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A green route for the production of 6-carbon polymer building blocks 6-hydroxyhexanoic acid, adipic acid and ?-caprolactone from 1,6-hexanediol, a hydrogenation product of biobased 5-hydroxymethylfurfural is reported. Gluconobacter oxydans oxidized 1,6-hexanediol completely to adipic acid, and selectively at pH 6-7 to 6-hydroxyhexanoic acid, which was converted to ?-caprolactone by catalytic cyclization. This journal is
- Hatti-Kaul, Rajni,Park, Ji Hoon,Pyo, Sang-Hyun,Srebny, Vanessa
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p. 4450 - 4455
(2020/08/10)
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- METHOD FOR PRODUCING ε-CAPROLACTONE
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A method for manufacturing andepsi;-caprolactone of the present invention comprises steps of converting adipic acid to 1,6-hexanediol and ring-closing 1,6-hexanediol to andepsi;-caprolactone. The method for manufacturing andepsi;-caprolactone of the present invention comprises steps of: converting adipic acid to 1,6-hexanediol; partially oxidizing the 1,6-hexanediol to 6-hydroxycaproic acid; and ring-closing 6-hydroxycaproic acid into andepsi;-caprolactone. The present process provides a novel approach for the synthesis of andepsi;-caprolactone with a high yield and selectivity.COPYRIGHT KIPO 2020
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- Routes of Formation of Bifunctional C6 Carboxylic Acids in the Cyclohexane Oxidation Process
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Abstract: The buildup kinetics of the main and side products during uncatalyzed and cobalt naphthenate-catalyzed oxidation of cyclohexane at 150°C have been studied. 6-Hydroxyhexanoic, 6-oxohexanoic, and adipic acids are accumulated in parallel during the oxidation of cyclohexane, cyclohexanone, and 2-hydroxycyclohexanone. The critical consideration of their known formation pathways and the reactivity of possible precursors gives evidence for the predominant formation of 6-hydroxyhexanoic acid at the step of cyclohexanol oxidation and adipic acid from 2-hydroxycyclohexanol.
- Perkel’,Voronina
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p. 587 - 595
(2019/06/24)
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- Aerobic oxidation of C4-C6 α,ω-diols to the diacids in base-free medium over zirconia-supported (bi)metallic catalysts
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Oxidation of aliphatic α,ω-diols is a potentially interesting route to the production of valuable α,ω-diacids or ω-hydroxy acids for various polymer synthesis. 1,4-Butanediol (BDO), 1,5-pentanediol (PDO) and 1,6-hexanediol (HDO) are particularly attractive since they may be obtained from lignocellulosic biomass. The aqueous aerobic oxidation of these diols to the corresponding diacids was investigated in water over a set of Au, Pt, Au-Pt and Au-Pd catalysts supported on zirconia at 70 °C or 90 °C under 40 bar air. The nature of the metallic catalyst influenced the distribution of products as oxidation proceeded. The longer the carbon chain linking the terminal alcohol groups, the higher the yield of the diacid. The best yields of succinic acid, glutaric acid and adipic acid reached 83, 84 and 96% from BDO, PDO and HDO, respectively, over Au-Pt/ZrO2. There was some evidence of decarbonylation of the α,ω-hydroxyaldehyde at the early stage of the reaction. The presence of the hydroxyl substituent in 1,2,6-hexanetriol significantly slowed the oxidation rates compared with HDO. Besides, oxidation of PDO or HDO was highly selective to the ω-hydroxycarboxylate in moderate alkaline medium (NaOH/diol = 2) over Au/ZrO2 (90-93%).
- Mounguengui-Diallo, Modibo,Sadier, Achraf,Da Silva Perez, Denilson,Nikitine, Clémence,Puchot, Laura,Habibi, Youssef,Pinel, Catherine,Perret, Noémie,Besson, Michèle
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p. 9873 - 9885
(2019/07/04)
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- METHOD FOR PRODUCING COMPOSITION DERIVED FROM ESTER COMPOUND USING ACID
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PROBLEM TO BE SOLVED: To provide a method for producing a composition derived from an ester compound from a ketone compound and a peroxide by an industrially suitable method. SOLUTION: There is provided an ester compound obtained by reacting a ketone compound, a peroxide and an inorganic acid in an organic solvent containing a compound in which at least one hydrogen atom in a hydrocarbon group is substituted with a fluorine atom. There is provided a method for producing a composition derived from an ester compound which is composed of carboxylic acid derived from the ester compound, an alcohol compound and an ester compound derived from the carboxylic acid and the alcohol compound. SELECTED DRAWING: None COPYRIGHT: (C)2019,JPOandINPIT
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Paragraph 0082
(2019/06/04)
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- CATIONIC LIPIDS FOR NUCLEIC ACID DELIVERY AND PREPARATION THEREOF
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The present invention provides cationic lipids and lipid nanoparticle formulations comprising these lipids, alone or in combination with other lipids. These lipid nanoparticles may be formulated with nucleic acids to facilitate their intracellular delivery both in vitro and for therapeutic applications. The present invention also provides methods of chemical synthesis of these lipids, lipid nanoparticle preparation and formulation with nucleic acids.
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Page/Page column 68; 88; 89
(2018/05/27)
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- Method for preparing 6-bromotriphenylphosphonio-n-caproic acid
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The invention relates to the field of production and preparation of compounds and particularly relates to a method for preparing 6-bromotriphenylphosphonio-n-caproic acid. The method comprises the following steps: (1) subjecting caprolactam to a hydrolysis reaction, so as to prepare 6-aminocaproic acid; (2) subjecting 6-aminocaproic acid to a diazotization reaction, so as to prepare 6-hydroxycaproic acid; (3) subjecting 6-hydroxycaproic acid to a bromization reaction, so as to prepare 6-bromocaproic acid; and (4) enabling 6-bromocaproic acid to react with triphenyl phosphine, thereby obtaining 6-bromotriphenylphosphonio-n-caproic acid.
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Paragraph 0084-0089
(2017/08/29)
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- Tin-containing catalyst is used for a method of producing a calbonyl compd.
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PROBLEM TO BE SOLVED: To provide a reaction catalyst having a high reaction selectivity and being recyclable in a peroxidation reaction using a carbonyl compound, and to provide a method for highly efficiently producing, for example, ester, lactone and formyloxy compounds or derivatives thereof by subjecting a carbonyl compound to a peroxidation reaction using the reaction catalyst.SOLUTION: A specific tin-containing catalyst can be used for a peroxidation reaction of a carbonyl compound, and a recyclable specific tin-containing catalyst is reusable for the reaction. A method for producing an oxide carries out a peroxidation reaction of a carbonyl compound in the presence of the tin-containing catalyst or the tin-containing recyclable catalyst.
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Paragraph 0138
(2017/03/25)
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- Modification of Sn-Beta zeolite: Characterization of acidic/basic properties and catalytic performance in Baeyer-Villiger oxidation
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Sn-Beta was post-synthetically modified with various cations such as Li+, Na+, K+, Cs+, and NH4+. During the modification process, the ion-exchange of the cations with silanol groups occurred along with a reversible change between "closed" and "open" Sn sites through hydrolysis of the Si-O-Sn bonds. The IR study showed that Sn-Beta had weak Br?nsted acid sites, which were passivated by the ion-exchange, in addition to the Lewis acid sites and that surprisingly, basic sites were formed on the modified zeolites. The ion-exchange with a small amount of Li+, Na+ and NH4+ was effective for suppressing side-reactions, leading to an improvement in selectivity to caprolactone in the Baeyer-Villiger oxidation of cyclohexanone with H2O2. The modification of Sn-Beta with such cations also effectively enhanced the catalytic activity in the Baeyer-Villiger oxidation of 2-adamantanone.
- Otomo, Ryoichi,Kosugi, Ryota,Kamiya, Yuichi,Tatsumi, Takashi,Yokoi, Toshiyuki
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p. 2787 - 2795
(2016/05/24)
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- Hydrogenation of dicarboxylic acids to diols over Re-Pd catalysts
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A Re-Pd/SiO2 (Re/Pd = 8) catalyst was applied to hydrogenation of dicarboxylic acids (succinic acid, glutaric acid and adipic acid) to diols. In the hydrogenation of dicarboxylic acids, ex situ liquid-phase (in only 1,4-dioxane solvent) reduced Re-Pd/SiO2 showed much higher activity than in situ liquid-phase (in the mixture of dicarboxylic acid and 1,4-dioxane) and gas-phase reduced ones, in which the in situ liquid-phase reduced catalyst has been reported to show good activity in the hydrogenation of monocarboxylic acids. High diol yields (71-89%) were achieved in the hydrogenation of dicarboxylic acids on the ex situ liquid-phase reduced catalyst at 413 K. Lactones and hydroxycarboxylic acids were first formed as intermediates in the reaction of C4-C5 and ≥C6 dicarboxylic acids, respectively. Characterization using XRD, XPS and XAS indicates that ex situ liquid-phase reduced catalysts with high activity contains comparable amounts of Re0 and Ren+ species, both of which have been reported to be necessary for good performance. The amount of Ren+ species on the in situ liquid-phase reduced catalysts is much larger than that of surface Re0 species. This result suggests that the presence of dicarboxylic acids suppresses the reduction of Re species to Re0 on the calcined catalysts while that of monocarboxylic acids does not, which leads to the low activity in the hydrogenation of dicarboxylic acids on in situ liquid-phase reduced catalysts.
- Takeda, Yasuyuki,Tamura, Masazumi,Nakagawa, Yoshinao,Okumura, Kazu,Tomishige, Keiichi
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p. 5668 - 5683
(2016/07/21)
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- OXIDATION OF KETONE TO ESTER USING TIN-SUBSTITUTED ZEOLITE BETA SUBJECTED TO POST-TREATMENT
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PROBLEM TO BE SOLVED: To provide a method of producing a lactone compound and/or a hydroxycarboxylic acid compound more selectively from a cyclic ketone compound. SOLUTION: A production method of a lactone compound and/or a hydroxycarboxylic acid compound comprises reacting a cyclic ketone compound with hydrogen peroxide and the following catalyst to produce a lactone compound and/or a hydroxycarboxylic compound. Catalyst: a compound obtained by reacting a tin-substituted zeolite of formula (4) (MwSnxSi1-x)O2 with a compound containing an alkali metal, an alkaline earth metal or ammonium under baking and anhydrous conditions. COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0064; 0067; 0068
(2017/01/05)
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- METHOD FOR PRODUCING CARBOXYLIC ACID COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for producing a carboxylic acid compound that enables the production of a carboxylic acid compound using an alcohol compound as a starting material with high yield and high selectivity without use of oxygen and a peroxide by using a solid catalyst comprising a specific constituent component and being easily recovered, has such safety and high versatility as to be applicable to industrial production and is also environmentally friendly. SOLUTION: The method for producing a carboxylic acid compound comprises bringing an alcohol compound into contact with a catalyst produced by mixing (A) at least one kind of metal compound selected from the group consisting of rhodium, iridium, platinum, ruthenium, tantalum, rhenium, palladium, lanthanum, cerium, samarium, ytterbium, lutetium, zirconium, hafnium, niobium, molybdenum, tungsten, cobalt, nickel, copper and gold with (B1) a metal oxide or (B2) a metal carbonyl compound each including a metal of Group 5, Group 6 or Group 7 of the Periodic Table and subjecting the mixture to reduction treatment in the co-existence of water. The metal compound (A) inevitably includes any one kind of metal selected among rhodium, iridium, platinum, ruthenium and palladium. COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0099-0101
(2016/12/22)
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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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- Facile organocatalytic domino oxidation of diols to lactones by in situ-generated TetMe-IBX
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The domino oxidation of diols to lactones is an important transformation, and catalytic protocols that allow this conversion smoothly are scarce. Capitalizing on the established reactivity of tetramethyl-IBX (TetMe-IBX) and its in situ generation in the presence of a co-oxidant, such as oxone, we have shown that a variety of diols can be converted to the corresponding lactones in respectable yields by employing the precursor of TetMe-IBX, namely, tetramethyl-o-iodobenzoic acid (TetMe-IA), as a catalyst in 5 mol % in the presence of 2 equiv of oxone.
- Jhulki, Samik,Seth, Saona,Mondal, Manas,Moorthy, Jarugu Narasimha
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p. 2286 - 2293
(2014/03/21)
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- Synthetic 1-deoxynojirimycin N-substituted peptides offer prolonged disruption to N-linked glycan processing
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A panel of 1-deoxynojirimycin (DNJ) N-linked peptides were synthesized. Their IC50 values were measured in vitro against a-glucosidases I and II and were found to be in the micromolar range for both isozymes, and better than that of the iminosugar NB-DNJ (miglustat, 3) against a-glucosidase II. Cell-based studies revealed that although the free iminosugar 3 is most effective at disrupting N-linked glycan processing for shortterm incubations (one day), when the cell-based studies were extended to three days, the DNJ N-linked tetrapeptide KDEL, which is an endoplasmic reticulum (ER)-retaining sequence, performed far better than 3. In low inhibitor washout studies, NB-DNJ inhibition was decreased to zero after 24 h, but DNJ- KDEL retained 13% activity. This method offers a general approach for targeting drugs to the ER and prolonging their activity. Moreover, it is modular, so as new iminosugars of increased potency are discovered, they can be added to this template for targeting.
- Aguilar, Aim Lpez,Escribano, Jaime,Wentworth, Paul,Butters, Terry D.
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supporting information
p. 2809 - 2813
(2015/02/02)
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- Efficient room temperature oxidation of cyclohexane over highly active hetero-mixed WO3/V2O5 oxide catalyst
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An efficient room temperature catalyzed oxidation of cyclohexane to cyclohexanone (K) and cyclohexanol (A) was achieved over hetero-mixed tungsten-vanadia (WO3/V2O5) using H 2O2 oxidant. WO3/V2O5 exhibited high catalytic activity to initiate the free-radical oxyfunctionalization of cyclohexane to afford up to 90% conversions within 6 h. The KA selectivity was found to depend on reaction time and the amount of catalyst. The WO3/V2O5 catalyst was highly recyclable with consistent catalytic activity.
- Makgwane,Ray
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p. 118 - 123
(2014/07/08)
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- Efficient room temperature oxidation of cyclohexane over highly active hetero-mixed WO3/V2O5 oxide catalyst
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An efficient room temperature catalyzed oxidation of cyclohexane to cyclohexanone (K) and cyclohexanol (A) was achieved over hetero-mixed tungsten-vanadia (WO3/V2O5) using H2O2 oxidant. WO3/V2O5 exhibited high catalytic activity to initiate the free-radical oxyfunctionalization of cyclohexane to afford up to 90% conversions within 6 h. The KA selectivity was found to depend on reaction time and the amount of catalyst. The WO3/V2O5 catalyst was highly recyclable with consistent catalytic activity.
- Makgwane,Ray
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p. 118 - 123
(2015/03/18)
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- METHOD FOR MANUFACTURING ESTER
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The present invention relates to a method for manufacturing an ester from a ketone or an aldehyde, which is a reactive substrate, by a Baeyer-Villiger oxidation reaction using hydrogen peroxide, and in this method, as a catalyst, M(BAr4)n, which is a metal borate, is used (M represents an alkali metal or an alkaline earth metal; Ar represents an aryl; and n is the same number as the valence of M). For example, when cyclohexanone was used as the reactive substrate, and Sr[B(3,5-CF3C6H3)4]2 was used as the catalyst, ε-caprolactone was obtained at an isolated yield of 82%.
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Paragraph 0040 - 0046
(2013/08/28)
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- Liquid crystal compositions, polymer networks derived therefrom and process for making the same
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The invention relates to compounds of Formula (I): The invention further relates to liquid crystal compositions comprising compounds of Formula (I); compositions further comprising one or more chiral compounds; and polymer networks derived from the polymerization of the liquid crystal compositions. Another embodiment relates to processes for providing compounds of Formula (I).
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Page/Page column 61
(2013/02/28)
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- Perspectives on the kinetics of diol oxidation over supported platinum catalysts in aqueous solution
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The catalytic oxidation of a variety of terminal alcohols was performed over Pt/C with 10 bar dioxygen at 343 K in aqueous solvent at low pH. The influences of Pt particle size, carbon support, alcohol structure, and start-up conditions were explored. Although the turnover frequency was not affected by particle size or the carbon support, the structure of the alcohols affected their initial rate of conversion. Both the rate of oxidation of α,ω-diols and selectivity of the diols to the diacids increased with increasing carbon chain length. The rate of 1,6-hexanediol oxidation was independent of dioxygen pressure and the order of reaction with respect to diol concentration depended on the start-up conditions. A kinetic model involving two types of metal sites was proposed to account for the experimental observations.
- Ide, Matthew S.,Davis, Robert J.
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- Baeyer-villiger oxidation and oxidative cascade reactions with aqueous hydrogen peroxide catalyzed by lipophilic Li[B(C6F5) 4] and Ca[B(C6F5)4]2
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Efficient and selective: Two lipophilic catalysts were used for Baeyer-Villiger (BV) oxidations to give lactones in high yields (see scheme). Cascade reactions involving this BV oxidation were used to selectively obtain either unsaturated carboxylic acids or hydroxylactones in high yields from β-silyl cyclohexanones. Copyright
- Uyanik, Muhammet,Nakashima, Daisuke,Ishihara, Kazuaki
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supporting information
p. 9093 - 9096
(2012/11/07)
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- Synthesis and characterization of well-defined l-lactic acid-caprolactone co-oligomers and their rhenium (I) and technetium(I) conjugates
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Staring from l-lactide and ε-caprolactone, the corresponding lactic-caprolactone cooligomer with hydroxyl and carboxylic acid groups were synthesized. These oligomers were connected with chelating groups through a long chain tether, ready for transition metal binding. Coordination of organometallic rhenium(I) and technetium(I) complexes generated the conjugates in high yield and short time, satisfying the requirements for short-lived radiopharmaceuticals in clinical applications. A reasonable pharmacophore model has been established to guide the design of well-defined lactic acid oligomer for nuclear medicine.
- Zhu, Hua,Yang, Zhi,Li, Nan,Wang, Xue-Juan,Wang, Feng,Su, Hua,Xie, Qing,Zhang, Yan,Ma, Yun-Xia,Lin, Bao-He
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- Nitroxide-mediated controlled radical polymerizations of styrene derivatives
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Several (protected) amine and alcohol functionalized styrene monomers were synthesized via readily accessible synthetic routes. The controlled radical copolymerization of these functionalized styrene monomers with styrene was performed using two alkoxyamines, namely N-(2-methylpropyl)-N-(1- diethylphosphono-2,2-dimethylpropyl)-O-(2-carboxylprop-2-yl) hydroxylamine (MAMA-SG1) and N-tert-butyl-N-(2-methyl-1-phenylpropyl)-O-(1-phenylethyl) hydroxylamine. The copolymers obtained showed low polydispersities, controlled molecular weights, and a random topology. The thermal properties of the polymers were determined with differential scanning calorimetry. All polymers were amorphous and showed glass transition temperatures between 40 and 111 °C. Deprotection of the copolymers afforded amine or alcohol pendant polystyrenes which were readily functionalized with isocyanates.
- Stals, Patrick J. M.,Phan, Trang N. T.,Gigmes, Didier,Paffen, Tim F. E.,Meijer,Palmans, Anja R. A.
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experimental part
p. 780 - 791
(2012/05/19)
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- Reaction discovery by using a sandwich immunoassay
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Mmm, a reaction sandwich Using an immunoassay-based technique able to monitor any kind of cross-coupling reaction, a systematic and rapid evaluation of a large panel of random reactions was carried out. This approach led to the discovery of two new copper-promoted reactions: a desulfurization reaction of thioureas leading to isoureas and a cyclization reaction leading to thiazole derivatives from alkynes and N-hydroxy thioureas. Copyright
- Quinton, Julia,Kolodych, Sergii,Chaumonet, Manon,Bevilacqua, Valentina,Nevers, Marie-Claire,Volland, Herve,Gabillet, Sandra,Thuery, Pierre,Creminon, Christophe,Taran, Frederic
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supporting information; experimental part
p. 6144 - 6148
(2012/07/17)
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