- A trehalose ester from Lancea tibetica
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A phytochemical study of the 95% ethanolic extract of the whole plant of Lancea tibetica Hook. f. et Thoms. led to the isolation of a new trehalose ester, 6-O-undecanoyl-α,β-trehalose (1), along with 23 known compounds (2-24), of which compounds 2-17 were isolated from this plant for the first time. The structures of these compounds were established on the basis of spectroscopic methods. Compound 1 was evaluated for their in vitro anti-proliferative activities against MCF-7, NCI-H460 and Hep-G2 tumour cell lines. Compound 1 exhibited potent inhibitory activity against NCI-H460 cell growth, in contrast to moderate cytotoxic activity against MCF-7 and Hep-G2 cells.
- Liu, Shi-Jun,Liao, Zhi-Xin,Liu, Chao,Qu, Yan-Bo
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Read Online
- Nanocoating of Hydrophobic Mesoporous Silica around MIL-101Cr for Enhanced Catalytic Activity and Stability
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The metal-organic framework (MOF) MIL-101Cr was readily encapsulated by a very thin shell (around 30 nm) of hydrophobic mesoporous silica, which replicates the irregular shape of the MOF nanocrystals. Such a silica shell facilitates the diffusion of hydrophobic reactants with enhancement of the catalytic activity of the MOF and significantly improved catalytic stability of the MOF in the oxidation of indene.
- Ying, Jie,Herbst, Annika,Xiao, Yu-Xuan,Wei, Hao,Tian, Ge,Li, Zhaofei,Yang, Xiao-Yu,Su, Bao-Lian,Janiak, Christoph
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- Colloidal Nobel Metal Catalysts Protected by Surfactant Micelles. Regio-Selectivity in the Hydrogenation of Unsaturated Fatty Acids in Organized Media
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Colloidal dispersions of platinum and palladium protected by nonionic surfactants were prepared by photo-irradiation.They work as active catalysts for the hydrogenation of unsaturated fatty acids and their sodium salts.The regio-selectivity was observed in the hydrogenation in the organized media which surround the colloidal particles.Thus, 10-undecenoic acid was more rapidly hydrogenated than 2-undecenoic acid
- Toshima, Naoki,Takahashi,Tadahito
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- One-pot sequences of reactions with sol-gel entrapped opposing reagents: An enzyme and metal-complex catalysts
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We extend our sol-gel methodology of one-pot sequences of reactions with opposing reagents to an enzyme/metal-complex pair. Sol-gel entrapped lipase and sol-gel entrapped RhCl[P(C6H5)3]3 or Rh2Co2(CO)12 were used for one-pot esterification and C-C double bond hydrogenation reactions, leading to saturated esters in good yields. When only the enzyme is entrapped, the homogeneous catalysts quench its activity and poison it. Thus, when 10-undecenoic acid and 1-pentanol were subjected in one pot to the entrapped lipase and to homogeneously dissolved RhCl[P(C6H5)3]3 under hydrogen pressure, only 7% of the saturated 1-pentyl undecanoate was obtained. The yield jumped 6.5-fold when both the enzyme and the catalyst were immobilized separately in silica sol-gel matrixes. Similar one-pot esterifications and hydrogenations by sol-gel entrapped lipase and heterogenized rhodium complexes were carried out successfully with the saturated nonoic, undecanoic, and lauric acids together with several saturated and unsaturated alcohols. The use of (S)-(-)-2-methylbutanol afforded an optically pure ester. The heterogenized lipase is capable of inducing asymmetry during esterification with a prochiral alcohol. Both the entrapped lipase and the immobilized rhodium catalysts can be recovered simply by filtration and recycled in further runs without loss of catalytic activity.
- Gelman, Faina,Blum, Jochanan,Avnir, David
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- Tempo-mediated oxidation of primary alcohols to carboxylic acids by exploitation of ethers inan aqueous-organicbiphase system
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Expeditious and benign methods for primary alcohol- carboxylicacid conversions with TEMPO were developed in abiphasic system composed of aslightlymiscible ether (THP) and aqueous layer. Easily available co-oxidants such as Py-HBr3, Bu4NBr3, and electrooxidation were successfully applied to generate N-oxoammonium species as a recyclable catalyst.
- Mei, Zhen-Wu,Ma, Li-Jian,Kawafuchi, Hiroyuki,Okihara, Takumi,Inokuchi, Tsutomu
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- CYCLOPHOSPHAZENIC POLYPODANTS: A NEW CLASS OF POWERFUL METAL CATION COMPLEXING AGENTS AND PHASE-TRANSFER CATALYSTS
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Cyclophosphazenic polypodants are found to be powerful complexing agents of alkali metal salts and very efficient phase-transfer catalysts in nucleophilic substitution, alkylation, reduction and oxidation reactions.
- Landini, D.,Maia, A.,Corda, L.,Maccioni, A.,Podda, G.
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Read Online
- A Mild, General, Metal-Free Method for Desulfurization of Thiols and Disulfides Induced by Visible-Light
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A visible-light-induced metal-free desulfurization method for thiols and disulfides has been explored. This radical desulfurization features mild conditions, robustness, and excellent functionality compatibility. It was successfully applied not only to the desulfurization of small molecules, but also to peptides.
- Qiu, Wenting,Shi, Shuai,Li, Ruining,Lin, Xianfeng,Rao, Liangming,Sun, Zhankui
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supporting information
p. 1255 - 1258
(2021/05/05)
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- Process for the preparation of fatty acids
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The invention discloses a method for preparing fatty acid. The method comprises the following steps: providing a first reactant which is a furan compound containing an carbonyl group; providing a second reactant which is a compound containing a carboxyl group, an ester group or an anhydride group and can participate in a condensation reaction with the carbonyl group of the first reactant; allowingthe first reactant and the second reactant to participate in a first condensation reaction, and allowing a C=O bond of the carbonyl group of the first reactant to be connected with alpha carbon of the carbonyl group of the second reactant and to be converted into a C=C bond so as to form a condensation product; and carrying out a second-step reaction under hydrogen pressure in the presence of a co-catalytic system of a hydrogenation catalyst and Lewis acid, opening a furan ring of the condensation product, carrying out hydrodeoxygenation at the same time, removing all oxygen except for oxygenin the carboxyl group, and allowing a carbon chain to be saturated so as to obtain the fatty acid.
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Paragraph 0179-0206; 0213-0215
(2020/09/04)
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- Synthetic method of acid compound
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The invention belongs to the field of organic synthesis, and particularly relates to a synthetic method of an acid compound. An acid anhydride compound and an alkyl bromide or a functionalized alkyl bromide are subjected to a cross-electrophilic coupling reaction to synthesize an acid compound, so that the application of the alkyl bromide in the cross-electrophilic coupling reaction is expanded, and a novel non-traditional method for chemically and selectively constructing a carbon-carbon bond through a decarburization process is provided. The synthesis method is simple, economic, green and environment-friendly, and has wider applicability or is suitable for large-scale production.
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Paragraph 0028-0033; 0066-0081
(2020/08/25)
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- PRODUCTION METHOD OF AMIDE COMPOUND
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PROBLEM TO BE SOLVED: To provide a production method of an amide compound, which can use a variety of carboxylic acid halides and can produce a desired amide compound at a yield higher than a batch process by suppressing a side reaction. SOLUTION: Provided is a production method of an amide compound using a flow type reactor, in which the flow type reactor includes: a first flow path; a second flow path; a first mixing means provided at a confluent part of the first flow path and the second flow path; and a third flow path that is connected to the first mixing means and arranged on a down stream side of the first mixing means, the production method comprising: a mixing step of obtaining a mixed liquid by circulating a first liquid containing the carboxylic acid halide in the first flow path, circulating a second liquid containing an amine compound having a molecular weight of 1,000 or less, an inorganic alkali and water in the second flow path, and mixing the first liquid and the second liquid by the first mixing means to obtain a mixture; and a reaction step of obtaining an amide compound by circulating the mixed liquid in the third flow path and reacting the carboxylic acid halide and the amine compound in the third flow path. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2020,JPO&INPIT
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Paragraph 0134-0137
(2020/10/08)
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- Synthesis of Carboxylic Acids by Palladium-Catalyzed Hydroxycarbonylation
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The synthesis of carboxylic acids is of fundamental importance in the chemical industry and the corresponding products find numerous applications for polymers, cosmetics, pharmaceuticals, agrochemicals, and other manufactured chemicals. Although hydroxycarbonylations of olefins have been known for more than 60 years, currently known catalyst systems for this transformation do not fulfill industrial requirements, for example, stability. Presented herein for the first time is an aqueous-phase protocol that allows conversion of various olefins, including sterically hindered and demanding tetra-, tri-, and 1,1-disubstituted systems, as well as terminal alkenes, into the corresponding carboxylic acids in excellent yields. The outstanding stability of the catalyst system (26 recycling runs in 32 days without measurable loss of activity), is showcased in the preparation of an industrially relevant fatty acid. Key-to-success is the use of a built-in-base ligand under acidic aqueous conditions. This catalytic system is expected to provide a basis for new cost-competitive processes for the industrial production of carboxylic acids.
- Sang, Rui,Kucmierczyk, Peter,Dühren, Ricarda,Razzaq, Rauf,Dong, Kaiwu,Liu, Jie,Franke, Robert,Jackstell, Ralf,Beller, Matthias
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supporting information
p. 14365 - 14373
(2019/09/06)
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- Desulfurization method of organic compounds containing mercapto or disulfide bond
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The invention relates to a desulfurization method of organic compounds, in particular, organic compounds containing mercapto or a disulfide bond. The method comprises following steps: dissolving organic compounds containing mercapto or a disulfide bond by a solvent; adding a phosphine reagent and an initiator; and carrying out reactions in the presence of light to convert the substrate into corresponding desulfurization products. The organic compounds containing mercapto or a disulfide bond is R-SH or R-S-S-R; wherein R represents a primary carbon group, a secondary carbon group, a tertiary carbon group, an aryl group, or an acyl group. The reactions do not need any metal, and the reaction conditions are mild. Moreover, the desulfurization method has the advantages of high yield, wide substrate application range, and multiple suitable solvents, and is widely suitable for multiple kinds of mercapto-removing reactions and desulfurization reactions of disulfide.
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Paragraph 0026
(2019/10/01)
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- Oxidative Cleavage of Long-Chain Terminal Alkenes to Carboxylic Acids
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Oxidation of aliphatic terminal alkenes having more than 30 carbon atoms to carboxylic acids is presented. Such long carboxylic acids are useful as waxes, lubricants, plasticizers, etc. The oxidation was conducted under solvent-free conditions or with small amounts of diluents (heptane, methylcyclohexane, and tert-butylbenzene). Hydrogen peroxide was used as the oxidant, and tungstic acid was used as the catalyst. Halogen-free quaternary ammonium salts were used as phase-transfer catalysts, and the importance of the elimination of halide ions is discussed. Purification of the crude oxidized product and tungsten removal are also presented. The products have a maximum acid number of 75 mg of KOH/g, a saponification number of 100 mg of KOH/g, and tungsten content below 400 ppm.
- Pyszny, Dariusz,Piotrowski, Tomasz,Orlińska, Beata
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- Oxidative Cleavage of Long-Chain Terminal Alkenes to Carboxylic Acids
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Oxidation of aliphatic terminal alkenes having more than 30 carbon atoms to carboxylic acids is presented. Such long carboxylic acids are useful as waxes, lubricants, plasticizers, etc. The oxidation was conducted under solvent-free conditions or with small amounts of diluents (heptane, methylcyclohexane, and tert-butylbenzene). Hydrogen peroxide was used as the oxidant, and tungstic acid was used as the catalyst. Halogen-free quaternary ammonium salts were used as phase-transfer catalysts, and the importance of the elimination of halide ions is discussed. Purification of the crude oxidized product and tungsten removal are also presented. The products have a maximum acid number of 75 mg of KOH/g, a saponification number of 100 mg of KOH/g, and tungsten content below 400 ppm.
- Pyszny, Dariusz,Piotrowski, Tomasz,Orlińska, Beata
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p. 309 - 319
(2019/03/21)
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- Strategic Approach to the Metamorphosis of γ-Lactones to NH γ-Lactams via Reductive Cleavage and C-H Amidation
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A new approach has elaborated on the conversion of γ-lactones to the corresponding NH γ-lactams that can serve as γ-lactone bioisosteres. This approach consists of reductive C-O cleavage and an Ir-catalyzed C-H amidation, offering a powerful synthetic tool for accessing a wide range of valuable NH γ-lactam building blocks starting from γ-lactones. The synthetic utility was further demonstrated by the late-stage transformation of complex bioactive molecules and the asymmetric transformation.
- Jung, Hoi-Yun,Chang, Sukbok,Hong, Sungwoo
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supporting information
p. 7099 - 7103
(2019/09/07)
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- Transfer Hydrogenation of Alkenes Using Ethanol Catalyzed by a NCP Pincer Iridium Complex: Scope and Mechanism
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The first general catalytic approach to effecting transfer hydrogenation (TH) of unactivated alkenes using ethanol as the hydrogen source is described. A new NCP-type pincer iridium complex (BQ-NCOP)IrHCl containing a rigid benzoquinoline backbone has been developed for efficient, mild TH of unactivated C-C multiple bonds with ethanol, forming ethyl acetate as the sole byproduct. A wide variety of alkenes, including multisubstituted alkyl alkenes, aryl alkenes, and heteroatom-substituted alkenes, as well as O- or N-containing heteroarenes and internal alkynes, are suitable substrates. Importantly, the (BQ-NCOP)Ir/EtOH system exhibits high chemoselectivity for alkene hydrogenation in the presence of reactive functional groups, such as ketones and carboxylic acids. Furthermore, the reaction with C2D5OD provides a convenient route to deuterium-labeled compounds. Detailed kinetic and mechanistic studies have revealed that monosubstituted alkenes (e.g., 1-octene, styrene) and multisubstituted alkenes (e.g., cyclooctene (COE)) exhibit fundamental mechanistic difference. The OH group of ethanol displays a normal kinetic isotope effect (KIE) in the reaction of styrene, but a substantial inverse KIE in the case of COE. The catalysis of styrene or 1-octene with relatively strong binding affinity to the Ir(I) center has (BQ-NCOP)IrI(alkene) adduct as an off-cycle catalyst resting state, and the rate law shows a positive order in EtOH, inverse first-order in styrene, and first-order in the catalyst. In contrast, the catalysis of COE has an off-cycle catalyst resting state of (BQ-NCOP)IrIII(H)[O(Et)···HO(Et)···HOEt] that features a six-membered iridacycle consisting of two hydrogen-bonds between one EtO ligand and two EtOH molecules, one of which is coordinated to the Ir(III) center. The rate law shows a negative order in EtOH, zeroth-order in COE, and first-order in the catalyst. The observed inverse KIE corresponds to an inverse equilibrium isotope effect for the pre-equilibrium formation of (BQ-NCOP)IrIII(H)(OEt) from the catalyst resting state via ethanol dissociation. Regardless of the substrate, ethanol dehydrogenation is the slow segment of the catalytic cycle, while alkene hydrogenation occurs readily following the rate-determining step, that is, β-hydride elimination of (BQ-NCOP)Ir(H)(OEt) to form (BQ-NCOP)Ir(H)2 and acetaldehyde. The latter is effectively converted to innocent ethyl acetate under the catalytic conditions, thus avoiding the catalyst poisoning via iridium-mediated decarbonylation of acetaldehyde.
- Wang, Yulei,Huang, Zhidao,Leng, Xuebing,Zhu, Huping,Liu, Guixia,Huang, Zheng
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supporting information
p. 4417 - 4429
(2018/04/05)
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- Hydrofunctionalization of olefins to value-added chemicals: Via photocatalytic coupling
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A green strategy was developed for the synthesis of various value-added chemicals using methanol, acetonitrile, acetic acid, acetone and ethyl acetate as the hydrogen source by coupling them with olefins over heterogeneous photocatalysts. A radical coupling mechanism was proposed for the hydrofunctionalization of olefins with methanol to higher aliphatic alcohols over the Pt/TiO2 catalyst as the model reaction. C-H bond cleavage and C-C bond formation between photogenerated radicals and terminal olefins were accomplished in a single reaction at high efficiency. Our approach is atomically economical with high anti-Markovnikov regioselectivity and promising application potential under mild reaction conditions.
- Fan, Yonghui,Li, Shenggang,Bao, Jingxian,Shi, Lei,Yang, Yanzhang,Yu, Fei,Gao, Peng,Wang, Hui,Zhong, Liangshu,Sun, Yuhan
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supporting information
p. 3450 - 3456
(2018/08/06)
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- Synthesis of medium-chain carboxylic acids or α,ω-dicarboxylic acids from cellulose-derived platform chemicals
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Medium-chain fatty acids and their derivatives have important applications in the energy and chemical industries. Thus, we have prepared a series of medium-chain fatty acids by the selective hydrodeoxygenation of the aldol condensation products derived from cellulose using a metal triflate and Pd/C catalyst system. The selective retention of the carboxyl group is a notable feature of this catalytic system.
- Li, Xing-Long,Zhang, Kun,Jiang, Ju-Long,Zhu, Rui,Wu, Wei-Peng,Deng, Jin,Fu, Yao
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p. 362 - 368
(2018/02/07)
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- Highly efficient oxidative cleavage of alkenes and cyanosilylation of aldehydes catalysed by magnetically recoverable MIL-101
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The catalytic activity of magnetically recoverable MIL-101 was investigated in the oxidation of alkenes to carboxylic acids and cyanosilylation of aldehydes. MIL-101 was treated with Fe3O4 and the prepared catalyst was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, N2 adsorption measurements, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and inductively coupled plasma analysis. The catalytic active sites in this heterogeneous catalyst are Cr3+ nodes of the MIL-101 framework. This heterogeneous catalyst has the advantages of excellent yields, short reaction times and reusability several times without significant decrease in its initial activity and stability in both oxidation and cyanosilylation reactions. Its magnetic property allows its easy separation using an external magnetic field.
- Nourian, Maryam,Zadehahmadi, Farnaz,Kardanpour, Reihaneh,Tangestaninejad, Shahram,Moghadam, Majid,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj
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- Preparation method of carboxylic acid compound
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The invention provides a preparation method of a carboxylic acid compound. The preparation method comprises the following step of taking a lactone component to react with hydrogen in the presence of a compound catalyst to obtain the carboxylic acid compound. The compound catalyst comprises a hydrogenation catalyst and Lewis acid. In the presence of the compound catalyst comprising the hydrogenation catalyst and the Lewis acid, the lactone component is subjected to hydrogenation ring-opening reaction to obtain the carboxylic acid compound. The preparation method has the advantages of moderate reaction conditions and high yield; compared with a traditional method, less byproducts are generated, green and chemical requirements are met and the industrial value is better.
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Paragraph 0113; 0141-0143
(2017/08/29)
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- A Comprehensive Study on Metal Triflate-Promoted Hydrogenolysis of Lactones to Carboxylic Acids: From Synthetic and Mechanistic Perspectives
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Direct hydrogenolysis of lactone to carboxylic acid (i.e., hydrogenolysis of the Calkoxy-O bond with the carbonyl group untouched) is generally difficult, as the current strategies employing Br?nsted acids as the catalyst usually require harsh conditions such as a high temperature and a high H2 pressure. Herein, we report a developed solvent-free catalytic transformation, in which W(OTf)6 is believed to promote the hydrogenolysis process. This strategy could efficiently hydrogenate lactones to carboxylic acids under extra mild conditions (e.g., a reaction temperature of 2) and showed a broad substrate scope. In addition, the catalytic protocol can be further applied to the hydrogenolysis of polyhydroxyalkanoate, as a renewable polymer, to the corresponding straight-chain carboxylic acids. An extensive mechanistic study was subsequently performed, and the density functional theory calculations revealed a reaction pattern, including the complete cleavage of the C=O bond with the assistance of the W(OTf)6 catalyst. Moreover, the key intermediate created in the mechanism, as an oxonium with an OTf moiety, was successfully detected by electrospray ionization mass spectra. Through a comparison with the Br?nsted acid-catalyzed system, the study confirmed that the existence of the OTf moiety can significantly lower the barriers associated with the rearrangement and elimination processes. Meanwhile, emphasis was placed on the critical role that the anion plays, as well as the fact that the anion effect is directly related to the chemoselectivity.
- Zhu, Rui,Jiang, Ju-Long,Li, Xing-Long,Deng, Jin,Fu, Yao
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p. 7520 - 7528
(2017/11/10)
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- Remote carboxylation of halogenated aliphatic hydrocarbons with carbon dioxide
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Catalytic carbon-carbon bond formation has enabled the streamlining of synthetic routes when assembling complex molecules. It is particularly important when incorporating saturated hydrocarbons, which are common motifs in petrochemicals and biologically relevant molecules. However, cross-coupling methods that involve alkyl electrophiles result in catalytic bond formation only at specific and previously functionalized sites. Here we describe a catalytic method that is capable of promoting carboxylation reactions at remote and unfunctionalized aliphatic sites with carbon dioxide at atmospheric pressure. The reaction occurs via selective migration of the catalyst along the hydrocarbon side-chain with excellent regio- and chemoselectivity, representing a remarkable reactivity relay when compared with classical cross-coupling reactions. Our results demonstrate that site-selectivity can be switched and controlled, enabling the functionalization of less-reactive positions in the presence of a priori more reactive ones. Furthermore, we show that raw materials obtained in bulk from petroleum processing, such as alkanes and unrefined mixtures of olefins, can be used as substrates. This offers an opportunity to integrate a catalytic platform en route to valuable fatty acids by transforming petroleum-derived feedstocks directly.
- Juliá-Hernández, Francisco,Moragas, Toni,Cornella, Josep,Martin, Ruben
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- Catalytic oxidation of α-alkenes with hydrogen peroxide to carboxylic acids in the presence of peroxopolyoxotungstate complexes
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Fine organic synthesis investigation has been performed, focusing on the possibility of efficient oxidation of α-alkenes by hydrogen peroxide under conditions of phase transfer catalysis using bifunctional metal complex catalysts based on peroxotungsten compounds of general formula Q3{PO4[WO(O2)2]4}, where Q is organic cation containing quaternary nitrogen atom. Catalysts screening has been done at oxidation of octene-1, decene-1 and dodecene-1 by 30% aqueous hydrogen peroxide to obtain carboxylic acids: heptanoic, nonanoic and undecanoic acids being of importance since used as precursors in the synthesis of various organic and biologically active compounds. This approach to the synthesis of carboxylic acids may be of interest for the processes of “green chemistry” occurring under mild conditions (Т??100?°С, Р – atm) in one stage without organic solvents, and providing high target product yields (86–97%).
- Pai,Selivanova,Oleneva,Berdnikova,Beskopyl'nyi
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- Allyl-Palladium-Catalyzed α,β-Dehydrogenation of Carboxylic Acids via Enediolates
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A highly practical and step-economic α,β-dehydrogenation of carboxylic acids via enediolates is reported through the use of allyl-palladium catalysis. Dianions underwent smooth dehydrogenation when generated using Zn(TMP)2?2 LiCl as a base in the presence of excess ZnCl2, thus avoiding the typical decarboxylation pathway of these substrates. Direct access to 2-enoic acids allows derivatization by numerous approaches.
- Zhao, Yizhou,Chen, Yifeng,Newhouse, Timothy R.
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supporting information
p. 13122 - 13125
(2017/09/13)
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- Determination of Key Hydrocarbon Autoxidation Products by Fluorescence
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Hydroperoxides and carboxylic acids are key primary products that arise in the autoxidation of hydrocarbons. We have developed a simple approach to rapidly and simultaneously determine both types of products using hydroperoxide- and acid-sensitive moieties conjugated to nonpolar coumarin- and BODIPY-based fluorophores. The coumarin- and BODIPY-conjugated amine probes described here undergo 38- and 8-fold enhancement, respectively, upon protonation in a solvent system compatible with heavy hydrocarbons. The latter can be used directly with our previously described hydroperoxide-sensitive coumarin-conjugated phosphine probe to enable rapid quantification of both carboxylic acids and hydroperoxides in hydrocarbon samples. The utility of the approach is illustrated by the ready determination of the differing relative rates of hydroperoxide and acid formation with changes in hydrocarbon structure (e.g., n-hexadecane vs 1-hexadecene vs a lubricant base stock). The method offers significant versatility and automation compared with common but laborious titration approaches, and greatly improves screening efficiency and accuracy for the identification of novel radical-trapping antioxidants for high temperature applications. This application was demonstrated by the automated analysis of hydroperoxides and carboxylic acids (by microplate reader) in samples from 24 inhibited autoxidations of a lubricating oil, which were carried out on a parallel synthesizer at 160 °C in triplicate in a single day.
- Shah, Ron,Pratt, Derek A.
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p. 6649 - 6656
(2016/08/16)
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- Ni-Catalyzed Carboxylation of Unactivated Alkyl Chlorides with CO2
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A catalytic carboxylation of unactivated primary, secondary, and tertiary alkyl chlorides with CO2 at atmospheric pressure is described. This protocol represents the first intermolecular cross-electrophile coupling of unactivated alkyl chlorides, thus leading to new knowledge in the cross-coupling arena.
- B?rjesson, Marino,Moragas, Toni,Martin, Ruben
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p. 7504 - 7507
(2016/07/06)
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- Iron-Catalysed Selective Aerobic Oxidation of Alcohols to Carbonyl and Carboxylic Compounds
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A method for aerobic alcohol oxidation catalysed by Fe(NO3)3/2,2’-bipyridine/TEMPO has allowed highly selective conversion of primary alcohols into either aldehydes or carboxylic acids in one-step. The oxidation of primary alcohols proceeded selectively to aldehydes, as TEMPO was present in the reaction. Nevertheless, the aldehydes were further oxidized into carboxylic acids as the reaction time was extended. Detailed investigation of the reaction suggested, that the deoxygenation of TEMPO into TMP enabled the auto-oxidation of aldehydes to carboxylic acids, which was initially inhibited in the presence of TEMPO. The procedure was also efficient in oxidation of secondary alcohols when TEMPO was replaced by the less sterically hindered ABNO.
- Lagerblom, Kalle,Wrigstedt, Pauli,Keskiv?li, Juha,Parviainen, Arno,Repo, Timo
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p. 1160 - 1165
(2016/11/23)
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- Amination of ω-Functionalized Aliphatic Primary Alcohols by a Biocatalytic Oxidation-Transamination Cascade
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Amination of non-activated aliphatic fatty alcohols to the corresponding primary amines was achieved through a five-enzyme cascade reaction by coupling a long-chain alcohol oxidase from Aspergillus fumigatus (LCAO-Af) with a ω-transaminase from Chromobacterium violaceum (ω-TA-Cv). The alcohol was oxidized at the expense of molecular oxygen to yield the corresponding aldehyde, which was subsequently aminated by the PLP-dependent ω-TA to yield the final primary amine product. The overall cascade was optimized with respect to pH, O2 pressure, substrate concentration, decomposition of H2O2 (derived from alcohol oxidation), NADH regeneration, and biocatalyst ratio. The substrate scope of this concept was investigated under optimized conditions by using terminally functionalized C4-C11 fatty primary alcohols bearing halogen, alkyne, amino, hydroxy, thiol, and nitrile groups.
- Pickl, Mathias,Fuchs, Michael,Glueck, Silvia M.,Faber, Kurt
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p. 3121 - 3124
(2015/10/19)
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- Ketyl-type radicals from cyclic and acyclic esters are stabilized by SmI2(H2O)n: the role of SmI2(H 2O)n in post-electron transfer steps
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Mechanistic details pertaining to the SmI2-H2O- mediated reduction and reductive coupling of 6-membered lactones, the first class of simple unactivated carboxylic acid derivatives that had long been thought to lie outside the reducing range of SmI2, have been elucidated. Our results provide new experimental evidence that water enables the productive electron transfer from Sm(II) by stabilization of the radical anion intermediate rather than by solely promoting the first electron transfer as originally proposed. Notably, these studies suggest that all reactions involving the generation of ketyl-type radicals with SmI2 occur under a unified mechanism based on the thermodynamic control of the second electron transfer step, thus providing a blueprint for the development of a broad range of novel chemoselective transformations via open-shell electron pathways.
- Szostak, Michal,Spain, Malcolm,Procter, David J.
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supporting information
p. 8459 - 8466
(2014/06/24)
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- Mn(ii) acetate: An efficient and versatile oxidation catalyst for alcohols
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A homogeneous catalytic system consisting of Mn(ii) acetate (18 μmol), tert-butylhydroperoxide (2.5 mmol), acetonitrile (1.5 mL) and trifluoroacetic acid (91 μmol) was developed for efficient and selective oxidation of various alcohols (1 mmol). The system yielded good to quantitative conversions (42-100%) of various secondary alcohols, such as 2-octanol, fenchyl alcohol and borneol, to their corresponding ketones. Primary alcohols, for example 1-octanol and differently substituted benzyl alcohols, were mainly converted to their corresponding carboxylic acids. Studies with a selection of hydrocarbons, tertiary amines and a cyclic ether isochroman showed that besides alcohols, other substrates can be oxidised as well.
- Raeisaenen, Minna T.,Al-Hunaiti, Afnan,Atosuo, Elisa,Kemell, Marianna,Leskelae, Markku,Repo, Timo
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p. 2564 - 2573
(2014/07/22)
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- Carbon dioxide as a C1 building block for the formation of carboxylic acids by formal catalytic hydrocarboxylation
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A happy marriage of two processes: An effective catalytic system was identified for the direct synthesis of carboxylic acids from non-activated olefins or alcohols, CO2, and H2. Detailed analysis together with labeling studies indicated that the overall hydrocarboxylation of simple olefins results from a combination of the reverse water-gas shift (rWGS) reaction and a hydroxycarbonylation step, each promoted by a rhodium catalyst (see scheme). Copyright
- Ostapowicz, Thomas G.,Schmitz, Marc,Krystof, Monika,Klankermayer, Juergen,Leitner, Walter
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p. 12119 - 12123
(2013/12/04)
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- Two new sphingolipids from the leaves of Piper betle L.
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Two new sphingolipids, pipercerebrosides A (1) and B (2), were isolated from the leaves of Piper betle L. Their structures, including absolute configurations, were determined by spectroscopic analysis and chemical degradation. These two compounds did not show significant cytotoxic activity against the cancer cell lines K562 and HL-60 in a MTT assay.
- Chen, Duo-Zhi,Xiong, Hua-Bin,Tian, Kai,Guo, Jun-Ming,Huang, Xiang-Zhong,Jiang, Zhi-Yong
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p. 11241 - 11249
(2013/10/22)
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- METHOD OF PRODUCING SATURATED ALKYL ESTERS/ACIDS
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Disclosed herein is the production of saturated alkyl esters or acids from furan materials. The starting compounds contain furan, ketone, and ester or acid functional groups and may be biologically-derived. The method includes hydrogenating the starting compound to form a reduced mixture. The method further includes hydrodeoxygenation of the reduced mixture to yield a saturated alkyl ester or acid. The saturated alkyl ester or acid can be unbranched or branched. The ester and acid products have a wide variety of applications and may be further processed into surfactants, solvents, and lubricants suitable for use in consumer products.
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- The isolation of [Pd{OC(O)H}(H)(NHC)(PR3)] (NHC = N-heterocyclic carbene) and its role in alkene and alkyne reductions using formic acid
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The [Pd(SIPr)(PCy3)] complex efficiently promotes a tandem process involving dehydrogenation of formic acid and hydrogenation of C-C multiple bonds using H2 formed in situ. The isolation of a key catalytic hydridoformatopalladium species, [Pd{OC(O)H}(H)(IPr)(PCy 3)], is reported. The complex plays a key role in the Pd(0)-mediated formation of hydrogen from formic acid. Mechanistic and computational studies delineate the operational role of the palladium complex in this efficient tandem sequence.
- Broggi, Julie,Jurcik, Vaclav,Songis, Olivier,Poater, Albert,Cavallo, Luigi,Slawin, Alexandra M. Z.,Cazin, Catherine S. J.
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supporting information
p. 4588 - 4591
(2013/05/09)
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- Raney nickel-catalyzed hydrogenation of unsaturated carboxylic acids with sodium borohydride in water
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A mild, selective, and green method for the reduction of unsaturated carboxylic acids with sodium borohydride-Raney nickel (W6) system in water is reported. This method is practical and safe and avoids use of organic solvents. Taylor & Francis Group, LLC.
- Rao, Gopal Krishna,Gowda, Narendra B.,Ramakrishna, Ramesha A.
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experimental part
p. 893 - 904
(2012/02/01)
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- Long-chain alkanoic acid esters of lupeol from Dorstenia harmsiana Engl. (Moraceae)
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In addition to lupeol (1a), three long-chain alkanoic acid esters of lupeol, in which two were new, were isolated from the hexane and ethyl acetate twigs extract of Dorstenia harmsiana Engl. (Moraceae). The structures of the new compounds were elucidated
- Poumale, Herve Martial P.,Awoussong, Kenzo Patrice,Randrianasolo, Rivoarison,Simo, Christophe Colombe F.,Ngadjui, Bonaventure Tchaleu,Shiono, Yoshihito
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experimental part
p. 749 - 755
(2012/10/08)
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- Nickel phosphide nanocatalysts for the chemoselective hydrogenation of alkynes
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Well-defined 25 nm nickel phosphide nanoparticles act as a colloidal catalyst for the chemoselective hydrogenation of terminal and internal alkynes. Cis-alkenes are obtained in mild conditions with good conversion and selectivity. The phosphorus inserted in the Ni-P nanoparticles is critical for the selectivity of the nanocatalyst. Mechanistic investigations using isotope labeling provide insight on the reactants interaction with the nanoparticles surface. They pinpoint the occurrence of CH bond cleavage in terminal alkynes during the reaction.
- Carenco, Sophie,Leyva-Pérez, Antonio,Concepción, Patricia,Boissire, Cédric,Mézailles, Nicolas,Sanchez, Clément,Corma, Avelino
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experimental part
p. 21 - 28
(2012/07/27)
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- A detailed identification study on high-temperature degradation products of oleic and linoleic acid methyl esters by GC-MS and GC-FTIR
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GC-MS and GC-FTIR were complementarily applied to identify oxidation compounds formed under frying conditions in methyl oleate and linoleate heated at 180 °C. The study was focused on the compounds that originated through hydroperoxide scission that remain attached to the glyceridic backbone in fats and oils and form part of non-volatile molecules. Twenty-one short-chain esterified compounds, consisting of 8 aldehydes, 3 methyl ketones, 4 primary alcohols, 5 alkanes and 1 furan, were identified. In addition, twenty non-esterified volatile compounds, consisting of alcohols, aldehydes and acids, were also identified as major non-esterified components. Furanoid compounds of 18 carbon atoms formed by a different route were also identified in this study. Overall, the composition of the small fraction originated from hydroperoxide scission provides a clear idea of the complexity of the new compounds formed during thermoxidation and frying.
- Berdeaux, Olivier,Fontagné, Stéphanie,Sémon, Etienne,Velasco, Joaquin,Sébédio, Jean Louis,Dobarganes, Carmen
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experimental part
p. 338 - 347
(2012/06/29)
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- The effect of encapsulated Zn-POM on the catalytic activity of MIL-101 in the oxidation of alkenes with hydrogen peroxide
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Zinc monosubstituted Keggin heteropolyanion [PZnMo2W 9O39]5- was electrostatically bound to nanocages of MIL-101 polymer matrix. The Zn-POM@MIL-101 catalyst was characterized by XRD, N2 adsorption, atomic absorption (AAS), and FT-IR spectroscopic methods. The catalytic activity of the new composite material, Zn-POM@MIL-101, was assessed in the oxidation of alkenes using aqueous hydrogen peroxide as oxidant. Zn-POM@MIL-101/H2O2 catalytic system demonstrated good catalytic activity in the oxidation reactions. Zn-POM@MIL-101 was reusable for three catalytic cycles. While the MIL-101 matrix is an active catalyst in these oxidation reactions, the presence of Zn-POM significantly changed the selectivity and reaction times. Copyright
- Saedi, Zahra,Tangestaninejad, Shaharm,Moghadam, Majid,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj
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experimental part
p. 463 - 473
(2012/05/20)
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- Aerobic photooxidative cleavage of vicinal diols to carboxylic acids using 2-chloroanthraquinone
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We developed the aerobic photooxidative cleavage of vicinal diols to carboxylic acids using 2-chloroanthraquinone in the presence of photoirradiation with a high-pressure mercury lamp. This is the first metal-free reaction using molecular oxygen as the terminal oxidant. Georg Thieme Verlag Stuttgart New York.
- Matsusaki, Yoko,Yamaguchi, Tomoaki,Tada, Norihiro,Miura, Tsuyoshi,Itoh, Akichika
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p. 2059 - 2062
(2012/11/07)
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- MIL-101 metal-organic framework: A highly efficient heterogeneous catalyst for oxidative cleavage of alkenes with H2O2
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In the present work, a new and efficient method for direct oxidation of alkenes to carboxylic acids with H2O2 catalyzed by metal-organic framework MIL-101 is reported. In this transformation, the MIL-101 catalyzes the oxidation reactions by framework nodes and acts as a heterogeneous and reusable catalyst. The structure of MIL-101 was stable after three catalytic cycles.
- Saedi, Zahra,Tangestaninejad, Shahram,Moghadam, Majid,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj
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experimental part
p. 18 - 22
(2012/03/26)
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- Isolation of the β-galactosphingolipid coniferoside using a tumor cell proteome reverse affinity protocol
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New approaches are vital to the development of marine natural products (MNP) as therapeutic leads. One of the more time consuming aspects of MNP research arises in the connection between structure and function. Here, we describe an isolation protocol that adapts tumor cell proteomes as a vehicle for MNP isolation therein uniting structural and functional analysis. Application of this method to extracts of the sponge Agelas conifera led to the isolation of a unique poly-hydroxybutyrated β-galactosphingolipid, coniferoside.
- La Clair, James J.,Rodriguez, Abimael D.
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experimental part
p. 6645 - 6653
(2011/12/21)
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- Tetrapropylammonium perruthenate catalyzed glycol cleavage to carboxylic (Di)acids
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A new method to accomplish glycol cleavage to carboxylic (di)acids in one step using catalytic amounts of tetrapropylammonium perruthenate (TPAP) together with N-methylmorpholine N-Oxide (NMO) as the stoichiometric oxidant is presented. In addition to regenerating the active catalyst, the N-oxide stabilizes intermediary carbonyl hydrates and thereby shifts a crucial equilibrium. The mild oxidation protocol is applicable to a broad range of substrates providing the respective acids, diacids, or keto acids in high yields.
- Schmidt, Andrea-Katharina C.,Stark, Christian B. W.
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supporting information; experimental part
p. 5788 - 5791
(2011/12/05)
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- Regioselective ω-hydroxylation of medium-chain n-alkanes and primary alcohols by CYP153 enzymes from Mycobacterium marinum and Polaromonas sp. strain JS666
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The oxofunctionalization of saturated hydrocarbons is an important goal in basic and applied chemistry. Biocatalysts like cytochrome P450 enzymes can introduce oxygen into a wide variety of molecules in a very selective manner, which can be used for the synthesis of fine and bulk chemicals. Cytochrome P450 enzymes from the CYP153A subfamily have been described as alkane hydroxylases with high terminal regioselectivity. Here we report the product yields resulting from C5-C12 alkane and alcohol oxidation catalyzed by CYP153A enzymes from Mycobacterium marinum (CYP153A16) and Polaromonas sp. (CYP153A P. sp.). For all reactions, byproduct formation is described in detail. Following cloning and expression in Escherichia coli, the activity of the purified monooxygenases was reconstituted with putidaredoxin (CamA) and putidaredoxin reductase (CamB). Although both enzyme systems yielded primary alcohols and α,ω-alkanediols, each one displayed a different oxidation pattern towards alkanes. For CYP153A P. sp. a predominant ω-hydroxylation activity was observed, while CYP153A16 possessed the ability to catalyze both ω-hydroxylation and α,ω- dihydroxylation reactions.
- Scheps, Daniel,Honda Malca, Sumire,Hoffmann, Helen,Nestl, Bettina M.,Hauer, Bernhard
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scheme or table
p. 6727 - 6733
(2011/11/30)
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- PROCESS FOR PRODUCTION OF OXYGEN-CONTAINING ORGANIC COMPOUND
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Disclosed is a process for the production of an oxygen-containing organic compound by oxidizing an organic compound with molecular oxygen in a liquid phase in the presence both of a catalytic nitrogen-containing cyclic compound and a catalyst including a solid superacid and, supported thereon, a transition metal compound, in which the nitrogen-containing cyclic compound contains, as a ring constituent, a skeleton represented by following Formula (1), wherein X represents an -OR group, and wherein R represents hydrogen atom or a hydroxyl-protecting group. The process gives the oxygen-containing organic compound in a high yield and enables easy recovery and reuse of the catalyst.
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Page/Page column 19
(2010/11/19)
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- Hydrocarboxylation of terminal alkenes in supercritical carbon dioxide
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The catalytic hydrocarboxylation of linear alkenes to carboxylic acids using supercritical carbon dioxide as a solvent was studied. High selectivities in acids have been obtained. The best results were achieved when adding a perfluorinated surfactant to the reaction mixture (93% conversions and ca. 80% selectivity). Comparative multinuclear high-pressure NMR spectroscopic studies in [D8]THF and in supercritical CO2 show the formation of Pd0 species. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
- Estorach, Clara Tortosa,Orejon, Arantxa,Ruiz, Nuria,Masdeu-Bulto, Anna M.,Laurenczy, Gabor
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experimental part
p. 3524 - 3531
(2009/02/07)
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- Steroid and aliphatic esters from the seeds of Nigella sativa
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Three novel compounds, one steroid and the other two aliphatic esters, have been isolated from the seeds of Nigella sativa and identified as ergosta-5,24 (28)-dien-2,3-cis-diol 1, pentyl undecanoate 2, methyloctadeca-14,16-dienoate 3, on the basis of spectral and chemical analysis. The compound 2 exhibits significant activity against Staphylococcus aureus and Shigella spp, while moderate activity against Escherichia coli has been recorded. Rest of the compounds show poor activity against all the tested bacteria.
- Mehta,Gupta, Meenal,Verma, Manjul
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p. 1567 - 1571
(2007/10/03)
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- In situ generation of o-lodoxybenzoic acid (IBX) and the catalytic use of it in oxidation reactions in the presence of oxone as a co-oxidant
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(Chemical Equation Presented) Catalytic use of o-iodoxybenzoic acid (IBX) in the presence of Oxone as a co-oxidant is demonstrated for the oxidation of primary and secondary alcohols in user- and eco-friendly solvent mixtures. Also demonstrated is the in situ (re)oxidation of 2-iodosobenzoic acid (IBA) and even commercially available 2-iodobenzoic acid (2IBAcid) by Oxone to IBX allowing one to use these less hazardous reagents, in place of potentially explosive IBX, as catalytic oxidants.
- Thottumkara, Arun P.,Bowsher, Michael S.,Vinod, Thottumkara K.
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p. 2933 - 2936
(2007/10/03)
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- The oxidation of alcohols in N-oxyl-immobilized silica gel/aqueous NaOCl disperse systems. A prominent access to a column-flow system
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The oxidation of alcohols was performed successfully in a disperse system with N-oxyl-adsorbed or immobilized silica gel as a disperse phase and aqueous NaOCl as a disperse medium. In the disperse system, the oxidation of sec-alcohols afforded the corresponding ketones, while prim-alcohols were oxidized to aldehydes and/or carboxylic acids depending on their structures and reaction conditions. The N-oxyl-immobilized silica gel was recovered and repeatedly used without a significant change in the product yields. A column-flow system was also investigated for the oxidation of alcohols by use of a newly devised column packed with the N-oxyl-immobilized silica gel.
- Tanaka, Hideo,Chou, Jingyu,Mine, Machiko,Kuroboshi, Manabu
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p. 1745 - 1755
(2007/10/03)
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- Dianion of sulfinylacetone as a synthetic equivalent of β-enolate of propionic acid: A novel synthesis of carboxylic acids from alkyl halides with three-carbon elongation
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The reaction of the dianion of phenylsulfinylacetone with alkyl halides afforded β-keto sulfoxides, which were first chlorinated with hexachloroethane and then treated successively with KH and t-BuLi to give carboxylic acids in three-steps in moderate overall yields from the alkyl halides. This procedure affords a good method for a synthesis of carboxylic acids from alkyl halides with three-carbon elongation.
- Satoh, Tsuyoshi,Imai, Kentaro
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p. 602 - 604
(2007/10/03)
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- Alkene and alkyne oxidative cleavage catalyzed by RuO4 in environmentally acceptable solvents
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The application of CCl4, C6Hl2, EtOAc, and Me2CO as solvents for biphasic systems has been compared for oxidative cleavage of alkenes and alkynes by RuO4 to carboxylic acids, using the RuCl3·nH2O-IO(OH)5 reagent for which an improved procedure is described. Cyclohexane is an effective and economic replacement for the environmentally unfriendly CCl 4; acetone and ethyl acetate are less effective.
- Griffith, William P.,Kwong, Eugene
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p. 2945 - 2951
(2007/10/03)
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