- Jalapinoside, a macrocyclic bisdesmoside from the resin glycosides of ipomea purga, as a modulator of multidrug resistance in human cancer cells
-
The first macrocyclic bisdesmoside resin glycoside, jalapinoside (4), was purified by preparative-scale recycling HPLC from the MeOH-soluble extracts of Ipomoea purga roots, the officinal jalap. Purgic acid C (3), a new glycosidic acid of ipurolic acid, was identified as 3-O-β-d-quinovopyranoside, 11-O-β-d-quinovopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→3)-O-[β-d-fucopyranosyl-(1→4)]-O-α-l-rhamnopyranosyl-(1→2)-O-β-d-glucopyranosyl-(1→2)-O-β-d-quinovopyranoside (3S,11S)-dihydroxytetradecanoic acid. The acylating residues of this core were acetic, (+)-(2S)-methylbutanoic, and dodecanoic acids. The site of lactonization was defined as C-3 of the second saccharide moiety. Reversal of multidrug resistance by this noncytotoxic compound was evaluated in vinblastine-resistant human breast carcinoma cells.
- Bautista, Elihü,Fragoso-Serrano, Mabel,Pereda-Miranda, Rogelio
-
-
Read Online
- Batatins III-VI, glycolipid ester-type dimers from Ipomoea batatas
-
Batatins III-VI (1-4), glycolipid ester-type dimers, were isolated from the tuberous roots of sweet potato (Ipomoea batatas) using recycle high performance liquid chromatography. Their structures were characterized by means of several high-resolution NMR and mass spectrometry techniques. These compounds are the first examples of ester-type dimers which consist of two units of the heterotetrasaccharide operculinic acid C. Each unit was esterified by a different amount and type of acid residues: (2S)-methylbutanoic, cinnamic, decanoic (capric) and dodecanoic (lauric) acids. Batatins III-VI (1-4) are an example of the presence of a large number of resin glycoside congeners in each morning glory species caused by partial acylation of their constitutive saccharide cores.
- Rosas-Ramírez, Daniel,Escalante-Sánchez, Edgar,Pereda-Miranda, Rogelio
-
-
Read Online
- Characterization of a xylose containing oligosaccharide, an inhibitor of multidrug resistance in Staphylococcus aureus, from Ipomoea pes-caprae
-
Pescaprein XVIII (1), a type of bacterial efflux pump inhibitor, was obtained from the CHCl3-soluble resin glycosides of beach morning glory (Ipomoea pes-caprae). The glycosidation sequence for pescaproside C, the glycosidic acid core of the lipophilic macrolactone 1 containing d-xylose and l-rhamnose, was characterized by means of several NMR techniques and FAB mass spectrometry. Recycling HPLC also yielded eight non-cytotoxic bacterial resistance modifiers, the two pescapreins XIX (2) and XX (3) as well as the known murucoidin VI (4), pecapreins II (6) and III (7), and stoloniferins III (5), IX (8) and X (9), all of which contain simonic acid B as their oligosaccharide core. Compounds 1-9 were tested for in vitro antibacterial and resistance-modifying activity against strains of Staphylococcus aureus possessing multidrug resistance efflux mechanisms. All of the pescapreins potentiated the action of norfloxacin against the NorA over-expressing strain by 4-fold (8 μg/mL from 32 μg/mL) at a concentration of 25 μg/mL.
- Escobedo-Martínez, Carolina,Cruz-Morales, Sara,Fragoso-Serrano, Mabel,Mukhlesur Rahman,Gibbons, Simon,Pereda-Miranda, Rogelio
-
-
Read Online
- Carbon-dot-hydrogel for enzyme-mediated bacterial detection
-
A hybrid carbon-dot (C-dot)-hydrogel matrix was constructed and employed for detection of bacteria. The transduction mechanism is novel, based upon cleavage of ester bonds within the hydrogel scaffold by bacterially-secreted esterases; the ensuing fluidization of the hydrogel resulted in aggregation of the embedded C-dots and consequent quenching of their fluorescence. We show that the C-dot-hydrogel exhibits high sensitivity and can distinguish among bacterial species through modulation of the emitted fluorescence, depending upon their esterase secretions.
- Bhattacharya, Sagarika,Nandi, Sukhendu,Jelinek, Raz
-
-
Read Online
- Epo-C12 inhibits peroxiredoxin 1 peroxidase activity
-
Epo-C12 is a synthetic derivative of epolactaene, isolated from Penicillium sp. BM 1689-P. Epo-C12 induces apoptosis in human acute lymphoblastoid leukemia BALL-1 cells. In our previous studies, seven proteins that bind to Epo-C12 were identified by a combination of pull-down experiments using biotinylated Epo-C12 (Bio-Epo-C12) and mass spectrometry. In the present study, the effect of Epo-C12 on peroxiredoxin 1 (Prx 1), one of the proteins that binds to Epo-C12, was investigated. Epo-C12 inhibited Prx 1 peroxidase activity. However, it did not suppress its chaperone activity. Binding experiments between Bio-Epo-C12 and point-mutated Prx 1s suggest that Epo-C12 binds to Cys52 and Cys83 in Prx 1. The present study revealed that Prx 1 is one of the target proteins through which Epo-C12 exerts an apoptotic effect in BALL-1 cells.
- Yoda, Tomoka,Furuta, Masateru,Tsutsumi, Tomohiko,Ikeda, Seiki,Yukizawa, Shunsuke,Arai, Satoshi,Morita, Akinori,Yamatoya, Kenji,Nakata, Kazuya,Tomoshige, Shusuke,Ohgane, Kenji,Furuyama, Yuuki,Sakaguchi, Kengo,Sugawara, Fumio,Kobayashi, Susumu,Ikekita, Masahiko,Kuramochi, Kouji
-
-
Read Online
- Resin glycosides from Ipomoea pes-caprae
-
Ipomoea pes-caprae (beach morning-glory; "rinonina" for the herbal drug in Mexico) is prescribed by traditional healers to moderate "heat" in an infected kidney. The hexane-soluble extract from the aerial parts of this medicinal plant, through preparative-scale recycling HPLC, yielded six new lipophilic oligosaccharides of jalapinolic acid: pescaproside B (1) and pescapreins V-IX (2-6). The previously known pescaproside A (7), pescapreins I-IV (8-11), and stoloniferin III (12) were also identified in the analyzed material by means of HPLC comparison with authentic samples. The glycosidic acid structure for all pentasaccharides was confirmed as simonic acid B. Pescaproside B (1), an acylated glycosidic acid methyl ester, is structurally related to pescaprein III (10). Pescapreins V (2) and VI (3) are diasteroisomeric tetraglycosidic lactones of operculinic acid C. Both of these compounds contain (2S)-methylbutyric and n-dodecanoic acids as their esterifying residues. Pescapreins VII (4) and IX (6) are pentasaccharides that contain an n-decanoyl group as their esterifying fatty acid residue instead of the n-dodecanoyl found in pescapreins I (8) and IV (11). Pescaprein VIII (5) represents an isomer of pescaprein II (9) containing an n-dodecanoyl unit as the esterifying residue at position C-4 of the third rhamnose moiety and a 2-methylpropanoyl at C-2 of the second rhamnose. High-field NMR spectroscopy and FAB mass spectrometry were used to characterize all new isolated compounds.
- Escobedo-Martinez, Carolina,Pereda-Miranda, Rogelio
-
-
Read Online
- α-Oxidative decarboxylation of fatty acids catalysed by cytochrome P450 peroxygenases yielding shorter-alkyl-chain fatty acids
-
Cytochrome P450 peroxygenases belonging to the CYP152 family catalyse the oxidation of fatty acids using H2O2. CYP152N1 isolated from Exiguobacterium sp. AT1b exclusively catalyses the α-selective hydroxylation of myristic acid at physiological H2O2 concentration. However, a series of shorter-alkyl-chain fatty acids such as tridecanoic acid were produced from myristic acid by increasing the concentration of H2O2 (1-10 mM). The yield of tridecanoic acid from myristic acid reached 17%. An 18O-labeled oxidant study suggested that CYP152N1 catalysed the overoxidation of α-hydroxymyristic acid to form α-ketomyristic acid, which in turn was spontaneously decomposed by H2O2 to yield tridecanoic acid. Crystal structure analysis of CYP152N1 revealed its high similarity to other CYP152 family enzymes, such as CYP152A1 and CYP152B1. MD simulations of α-hydroxymyristic acid accommodated in CYP152N1 proposed a possible pre-oxidation conformation of α-hydroxymyristic acid for the decarboxylation reaction.
- Onoda, Hiroki,Shoji, Osami,Suzuki, Kazuto,Sugimoto, Hiroshi,Shiro, Yoshitsugu,Watanabe, Yoshihito
-
-
Read Online
- A New Steroidal Alkaloid from Allium victorialis
-
Allumine C (1), a new steroidal alkaloid, has been isolated from the CHCl3-soluble fraction of the whole plant of Allium victorialis L. Its structure was elucidated by chemical and spectral studies.
- Khan, Sadia,Fatima, Itrat,Kazmi, Mehdi Hassan,Malik, Abdul
-
-
Read Online
- Aquivion Perfluorosulfonic Superacid as an Efficient Pickering Interfacial Catalyst for the Hydrolysis of Triglycerides
-
Rational design of the surface properties of heterogeneous catalysts can boost the interfacial activity in biphasic reactions through the generation of Pickering emulsions. This concept, termed Pickering interfacial catalysis (PIC), has shown promising cr
- Shi, Hui,Fan, Zhaoyu,Hong, Bing,Pera-Titus, Marc
-
-
Read Online
- Non-hydrolytic cleavage of esters with magnesium iodide in aprotic non-polar solvents
-
An efficacious procedure for the hydrolysis of primary, secondary and tertiary carboxylic esters with magnesium iodide in aprotic non-polar solvents, carbon disulphide and toluene, is reported.
- Garcia Martinez,Osio Barcinaa,Hidalgo Del Veccio,Hanack,Subramanian
-
-
Read Online
- Iron-Catalyzed Aerobic Oxidation of Aldehydes: Single Component Catalyst and Mechanistic Studies
-
An aerobic oxidation of aldehydes towards carboxylic acids in MeCN using 1 atm of pure oxygen or oxygen in air as the oxidant and a catalytic amount of single component catalyst, Fe(NO3)3·9H2O, has been developed. Carboxylic acids with different synthetically useful functional groups were obtained at room temperature. Two mechanistic pathways have been proposed based on isotopic labeling, NMR monitoring, and control experiments. The practicality of this reaction has been demonstrated by conducting several 50 mmol-scale reactions using pure oxygen or an air-flow of ~30 mL/min.
- Jiang, Xingguo,Zhai, Yizhan,Chen, Junyu,Han, Yulin,Yang, Zheng,Ma, Shengming
-
-
Read Online
- Glycerol eutectics as sustainable solvent systems
-
In this work the use of glycerol as a hydrogen bond donor in Deep Eutectic Solvents is studied. The physical properties of choline chloride mixtures with glycerol are quantified and it is shown that eutectic mixtures can circumvent some of the difficulties of using glycerol as a solvent viz. high viscosity and high melting point. The solvent properties are characterised using polarity parameters and the values are similar to other ionic liquids although it is shown that this procedure is a poor method of characterising Lewis basicity. The application of these liquids to the esterification of glycerol is used as a demonstration of the ability to tune a reaction with the quaternary ammonium halide acting as a quasi-protecting group. The liquids represent a sustainable way of preparing non-toxic, tuneable solvent systems.
- Abbott, Andrew P.,Harris, Robert C.,Ryder, Karl S.,D'Agostino, Carmine,Gladden, Lynn F.,Mantle, Mick D.
-
-
Read Online
- Hydrodeoxygenation of non-edible bio-lipids to renewable hydrocarbons over mesoporous SiO2-TiO2 supported NiMo bimetallic catalyst
-
Ni-catalysts are promising candidate for fatty acid hydrodeoxygenation (HDO), but are limited by their quite poor HDO selectivity. Herein, a mesoporous Ni-Mo/SiO2-TiO2 catalyst was prepared by precipitation and impregnation method and used for methyl laurate HDO, yielding 96.3% n-dodecane yield at full methyl laurate conversion. Non-edible bio-lipids such as jatropha oil and waste cooking oil also converted to n-C14+16+18 hydrocarbons with yields of 94.3% and 92.4%, respectively. Besides, Ni-Mo/SiO2-TiO2 shows strong chemoselectivity towards the HDO of ester groups. Experimental results showed that Mo-addition and Ti/Si molar ratio strongly influenced HDO selectivity. Oxygen vacancies formed on partial reduced TiO2 surface securely bond Ni NPs and activate C[dbnd]O/C–O bonds, improving Ni NPs dispersion and promoting R–COOCH3→R–CHO reduction. Additional, Mo-addition switches reactant adsorption configuration from η1(C)-acyl to η2(C,O)-aldehyde, promoting the formation of R–CH2OH intermediate. Moreover, abundant Br?nsted acidic sites (Mo4+–OH, Mo6+–OH, hydroxy groups) facilitate the HDO of R-CH2OH to R-CH3.
- Ba, Wenxia,Fu, Lin,Li, Xin,Li, Yongfei,Liu, Yuejin,Zhang, Simiao,Zhao, Jingxuan
-
-
- Biochemical and biophysical characterisation of a small purified lipase from Rhizopus oryzae ZAC3
-
The characteristics of a purified lipase from Rhizopus oryzae ZAC3 (RoL-ZAC3) were investigated. RoL-ZAC3, a 15.8 kDa protein, which was optimally active at pH 8 and 55 °C had a half-life of 126 min at 60 °C. The kinetic parameters using p-nitrophenylbuty
- Ayinla, Zainab A.,Ademakinwa, Adedeji N.,Gross, Richard A.,Agboola, Femi K.
-
-
- Efficient Assay for the Detection of Hydrogen Peroxide by Estimating Enzyme Promiscuous Activity in the Perhydrolysis Reaction
-
Hydrogen peroxide is an ideal oxidant in view of its availability, atom economy, or green aspects. Furthermore, it is produced by the cell mitochondria and plays a meaningful role in controlling physiological processes, but its unregulated production leads to the destruction of organs. Due to its diverse roles, a fast and selective method for hydrogen peroxide detection is the major limitation to preventing the negative effects caused by its excess. Therefore, we aimed to develop an efficient assay for the detection of H2O2. For this purpose, we combined the enzymatic method for the detection of hydrogen peroxide with the estimation of the promiscuity of various enzymes. We estimated the activity of an enzyme in the reaction of p-nitrophenyl esters with hydrogen peroxide resulting in the formation of peracid. To our knowledge, there is no example of a simple, multi-sensor demonstrating the promiscuous activity of an enzyme and detecting hydrogen peroxide in aqueous media.
- Wilk, Monika,Ostaszewski, Ryszard
-
p. 1464 - 1469
(2021/02/01)
-
- Cleavage of Carboxylic Esters by Aluminum and Iodine
-
A one-pot procedure for deprotecting carboxylic esters under nonhydrolytic conditions is described. Typical alkyl carboxylates are readily deblocked to the carboxylic acids by the action of aluminum powder and iodine in anhydrous acetonitrile. Cleavage of lactones affords the corresponding ω-iodoalkylcarboxylic acids. Aryl acetylates undergo deacetylation with the participation of the neighboring group. This method enables the selective cleavage of alkyl carboxylic esters in the presence of aryl esters.
- Sang, Dayong,Yue, Huaxin,Fu, Yang,Tian, Juan
-
p. 4254 - 4261
(2021/03/09)
-
- Scalable, sustainable and catalyst-free continuous flow ozonolysis of fatty acids
-
A simple and efficient catalyst-free protocol for continuous flow synthesis of azelaic acid is developed from the renewable feedstock oleic acid. An ozone and oxygen mixture was used as the reagent for oxidative cleavage of double bond without using any metal catalyst or terminal oxidant. The target product was scaled up to more than 100 g with 86% yield in a white powder form. Complete recycling and reuse of the solvent were established making it a green method. The approach is significantly energy efficient and also has a very small chemical footprint. The methodology has been successfully tested with four fatty acids making it a versatile platform that gives value addition from renewable resources.
- Atapalkar, Ranjit S.,Athawale, Paresh R.,Srinivasa Reddy,Kulkarni, Amol A.
-
supporting information
p. 2391 - 2396
(2021/04/07)
-
- Synergistic Catalytic?Effect?of N-Hydroxyphthalimide/Cobalt Tetraamide Phthalocyanine and Its Application for Aerobic Oxidation of Hydrocarbons and Alcohols
-
Abstract: The activation of oxygen?for?selective?oxidation?of?organic molecules, such as hydrocarbons and alcohols, remains a major catalytic?challenge. We have developed a catalytic system combining N-hydroxyphthalimide (NHPI) with cobalt tetraamide phthalocyanine [CoPc(CONH2)4] for the oxidation of hydrocarbons and alcohols at 75?°C under an oxygen atmosphere. CoPc(CONH2)4 was synthesized by trimellitic anhydride-urea method, and its structure was confirmed by FT-IR, UV–Vis and XRD. This catalyst, in synergy with NHPI/O2 system, exhibited excellent catalytic ability and high selectivity in the oxidation of hydrocarbons and alcohols. Based on the experimental results, a reasonable reaction mechanism was proposed for the oxidation of alkanes and alcohols, respectively. Graphic Abstract: Cobalt tetraamide phthalocyanine (CoPc(CONH2)4) was synthesized by a simple solid-thermal method, and the synergistic catalysis oxidation of NHPI and CoPc(CONH2)4 was studied. A synergistic catalysis system for the aerobic oxidation of hydrocarbons and alcohols by N-hydroxyphthalimide combined with cobalt tetraamide phthalocyanine has been developed.[Figure not available: see fulltext.]
- Li, Fei,Tang, Shuo,Tang, Zhilin,Ye, Lingjun,Li, Hehua,Niu, Fanfan,Sun, Xiaoling
-
-
- Atomically Dispersed Co Clusters Anchored on N-doped Carbon Nanotubes for Efficient Dehydrogenation of Alcohols and Subsequent Conversion to Carboxylic Acids
-
The catalytic dehydrogenation of readily available alcohols to high value-added carbonyl compounds is a research hotspot with scientific significance. Most of the current research about this reaction is performed with noble metal-based homogeneous catalysts of high price and poor reusability. Herein, highly dispersed Co-cluster-decorated N-doped carbon nanotubes (Co/N-CNTs) were fabricated via a facile strategy and used for the dehydrogenation of alcohols with high efficiency. Various characterization techniques confirmed the presence of metallic Co clusters with almost atomic dispersion, and the N-doped carbon supports also enhanced the catalytic activity of Co clusters in the dehydrogenation reaction. Aldehydes as dehydrogenation products were further transformed in situ to carboxylic acids through a Cannizzaro-type pathway under alkaline conditions. The reaction pathway of the dehydrogenation of alcohols was clearly confirmed by theoretical calculations. This work should provide an effective and simple approach for the accurate design and synthesis of small Co-clusters catalysts for the efficient dehydrogenation-based transformation of alcohols to carboxylic acids under mild reaction conditions.
- Dong, Zhengping,Fang, Jian,Li, Boyang,Xu, Dan,Zhang, Fengwei,Zhao, Hong,Zhu, Hanghang
-
p. 4536 - 4545
(2021/09/22)
-
- Aerobic oxidation of aldehydes to acids with N-hydroxyphthalimide derivatives
-
The N-hydroxyphthalimide derivative-mediated aerobic oxidation of a selection of aldehydes to the corresponding carboxylic acids in air is described. This reaction proceeds via rearrangement of the Creigee (carboxylic peracid) intermediate and/or by the treatment of H2O and/or sulfides. Optimization of reaction conditions established NHNPI (14) as a mild catalyst for the oxidation reaction in MeCN under an atmosphere of air.
- Takamatsu, Keigo,Kasai, Miku,Nishizawa, Hinaru,Suzuki, Rio,Konno, Hiroyuki
-
-
- Cobalt-Catalyzed Deprotection of Allyl Carboxylic Esters Induced by Hydrogen Atom Transfer
-
A brief, efficient method has been developed for the removal of the allyl protecting group from allyl carboxylic esters using a Co(II)/TBHP/(Me2SiH)2O catalytic system. This facile strategy displays excellent chemoselectivity, functional group tolerance, and high yields. This transformation probably occurs through the hydrogen atom transfer process, and a Co(III)-six-membered cyclic intermediate is recommended.
- Li, Nan,Gui, Yizhen,Chu, Mengqi,You, Mengdi,Qiu, Xiaohan,Liu, Hejia,Wang, Shiang,Deng, Meng,Ji, Baoming
-
supporting information
p. 8460 - 8464
(2021/11/13)
-
- Aggregation properties of cold-active lipase produced by a psychrotolerant strain of Pseudomonas palleroniana (GBPI_508)
-
The present study aims to exploit microbial potential from colder region to produce lipase enzyme stable at low temperatures. A newly isolated bacterium GBPI_508 from Himalayan environment, was investigated for the production of cold-active lipase emphasi
- Jain, Rahul,Pandey, Neha,Pandey, Anita
-
p. 263 - 273
(2019/11/03)
-
- Substrate hydrophobicity and enzyme modifiers play a major role in the activity of lipase from: Thermomyces lanuginosus
-
Lipase from Thermomyces lanuginosus (TL) displays high affinity for long-chain substrates, such as triolein and other long-chain triacylglycerols. Aiming to broaden the substrate chain-length specificity, different aldehydes (naphthaldehyde, butyraldehyde, hexyl aldehyde and dodecyl aldehyde) and naphthyl isothiocyanate were grafted onto lipase TL through lysine coupling. The catalytic activity of the modified lipases was investigated by reaction with substrates differing in the aliphatic chain size (p-nitrophenyl benzoate, p-nitrophenyl acetate, p-nitrophenyl butyrate, p-nitrophenyl hexanoate, p-nitrophenyl octanoate, p-nitrophenyl laurate and p-nitrophenyl palmitate). The enzymes modified with aldehydes revealed higher activity than the enzymes modified with the isothiocyanate. The most notable results were achieved for lipase TL grafted with 4 units of a dodecyl chain (TL5), which revealed the highest activity against all the tested substrates, being 10-fold more active than the native enzyme for smaller substrates (acetate and butyrate chains) and 2-fold for longer substrates (laurate and palmitate chains). The kinetic parameters evaluated (Vmax, KM and kcat/KM) also confirmed the significant catalytic performance of TL5 compared to the native enzyme. The increase in activity revealed by the modified lipases was directly proportional to the size and hydrophobicity of the linkers' aliphatic chain. Small conformational changes, either on the enzyme's lid or on the cavity of the active site were suggested by molecular dynamics simulations, circular dichroism and fluorescence spectroscopy. Moreover, the grafting with aldehydes or with the isothiocyanate conferred higher thermostability to the lipase. The chemical surface modification developed efficiently improved the activity of lipase TL, broadening the substrate's chain-length specificity, increasing thereafter the substrate possibilities for industrial reactions. This journal is
- Castro, Tarsila G.,Cavaco-Paulo, Artur,Noro, Jennifer,Silva, Carla
-
p. 5913 - 5924
(2020/10/08)
-
- PROCESS FOR THE PREPARATION OF A FATTY ALDEHYDE
-
The present invention relates to a process for the preparation of a fatty aldehyde which process comprises (a) providing a fatty acid, and (b) contacting the fatty acid with a zerovalent metal catalyst to reduce the fatty acid to the fatty aldehyde, wherein the zerovalent metal catalyst is in the form of solid particles.
- -
-
Page/Page column 8
(2021/01/23)
-
- Preparation method of bimetallic catalyst oxidation aldehyde synthetic carboxylic acid (by machine translation)
-
The method is, in a reaction solvent: under normal pressure oxygen condition, under the action of a bimetallic catalyst under the action of a bimetallic catalyst under the action of a bimetallic catalyst under the action of a bimetallic catalyst, at, DEG, under stirring . under a stirring condition with an aldehyde compound as a substrate 10-90 °C in a reaction solvent under, a stirring condition under the action of a bimetallic catalyst . The reaction solution is stirred, for. 1-12h, hours at; room temperature, under, the action, of a bimetallic 1:1 catalyst Cu(OAc) under the action of a bimetallic catalyst under the action of a bimetallic catalyst under the action of a double-metal catalyst. 2 · H2 O And Co(OAc)2 · 44H2 O As the bimetallic catalyst, can achieve the highest yield of the carboxylic acid product, in high yield, by adjusting the reaction temperature, solvent, catalyst amount, for different types of the raw material aldehyde 98%. (by machine translation)
- -
-
Paragraph 0054-0055
(2020/05/30)
-
- Method for preparing carboxylic acid by catalyzing aldehyde oxidation with N-heterocyclic carbene
-
The invention discloses a method for preparing carboxylic acid by catalyzing aldehyde oxidation with N-heterocyclic carbene, and relates to the field of catalytic technology. The method comprises thefollowing steps: taking deionized water as a solvent and aldehyde as a reaction substrate, adding alkali into a reaction system, taking air as an oxidant and N-heterocyclic carbene as a catalyst required by the reaction, and carrying out catalytic oxidation on aldehyde at room temperature to 80 DEG C to generate a corresponding reaction product. The method has the beneficial effects that the N-heterocyclic carbene is used as the catalyst, no organic solvent is needed in the reaction process, the reaction process is green and safe, and the reaction yield is high.
- -
-
Paragraph 0043; 0064-0067; 0129-0132
(2020/11/25)
-
- Sequential Connection of Mutually Exclusive Catalytic Reactions by a Method Controlling the Presence of an MOF Catalyst: One-Pot Oxidation of Alcohols to Carboxylic Acids
-
A functionalized metal-organic framework (MOF) catalyst applied to the sequential one-pot oxidation of alcohols to carboxylic acids controls the presence of a heterogeneous catalyst. The conversion of alcohols to aldehydes was acquired through aerobic oxidation using a well-known amino-oxy radical-functionalized MOF. In the same flask, a simple filtration of the radical MOF with mild heating of the solution completely altered the reaction media, providing radical scavenger-free conditions suitable for the autoxidation of the aldehydes formed in the first step to carboxylic acids. The mutually exclusive radical-catalyzed aerobic oxidation (the first step with MOF) and radical-inhibited autoxidation (the second step without MOF) are sequentially achieved in a one-pot manner. Overall, we demonstrate a powerful and efficient method for the sequential oxidation of alcohols to carboxylic acids by employing a readily functionalizable heterogeneous MOF. In addition, our MOF in-and-out method can be utilized in an environmentally friendly way for the oxidation of alcohols to carboxylic acids of industrial and economic value with broad functional group tolerance, including 2,5-furandicarboxylic acid and 1,4-benzenedicarboxylic acid, with good yield and reusability. Furthermore, MOF-TEMPO, as an antioxidative stabilizer, prevents the undesired oxidation of aldehydes, and the perfect "recoverability"of such a reactive MOF requires a re-evaluation of the advantages of MOFs from heterogeneity in catalytic and related applications.
- Kim, Seongwoo,Lee, Ha-Eun,Suh, Jong-Min,Lim, Mi Hee,Kim, Min
-
supporting information
p. 17573 - 17582
(2020/12/22)
-
- PRODUCTION METHOD OF AMIDE COMPOUND
-
PROBLEM TO BE SOLVED: To provide a production method of an amide compound, which can use a variety of carboxylic acid halides and can produce a desired amide compound at a yield higher than a batch process by suppressing a side reaction. SOLUTION: Provided is a production method of an amide compound using a flow type reactor, in which the flow type reactor includes: a first flow path; a second flow path; a first mixing means provided at a confluent part of the first flow path and the second flow path; and a third flow path that is connected to the first mixing means and arranged on a down stream side of the first mixing means, the production method comprising: a mixing step of obtaining a mixed liquid by circulating a first liquid containing the carboxylic acid halide in the first flow path, circulating a second liquid containing an amine compound having a molecular weight of 1,000 or less, an inorganic alkali and water in the second flow path, and mixing the first liquid and the second liquid by the first mixing means to obtain a mixture; and a reaction step of obtaining an amide compound by circulating the mixed liquid in the third flow path and reacting the carboxylic acid halide and the amine compound in the third flow path. SELECTED DRAWING: Figure 1 COPYRIGHT: (C)2020,JPO&INPIT
- -
-
Paragraph 0134-0137
(2020/10/08)
-
- Method for continuously preparing carboxylic acid by primary alcohol oxidation
-
The invention discloses a method for continuously preparing carboxylic acid by primary alcohol oxidation. The method comprises the following steps: cooling a first inorganic salt aqueous solution introduced into a low-temperature reaction module of a continuous flow reactor to a first set temperature; mixing the low-molecular-weight primary alcohol and oxidant mixed solution with a second inorganic salt aqueous solution, introducing the mixed solution into the low-temperature reaction module of the continuous flow reactor, and cooling to the first set temperature; converging the two strands ofmaterials and reacting in the main tube pass of the low-temperature reaction module and then introducing into the tube pass of the high-temperature reaction module of the continuous flow reactor; carrying out oxidation reaction at a second set temperature, introducing a product into the pipe cavity of an online separator, extracting by using an extracting agent D, and separating out a water phaseE and an oil phase F; distilling the oil phase F under reduced pressure to obtain an extracting agent D and high-purity carboxylic acid G; the extracting agent D is introduced into the pressure balancer and then is repeatedly used; and the water phase E is sent to the downstream for metal salt recovery treatment. The method is low in reaction temperature, short in reaction time, controllable in reaction condition, safe, environmentally friendly and high in conversion efficiency.
- -
-
Paragraph 0028-0032
(2020/07/21)
-
- A sodium trifluoromethanesulfinate-mediated photocatalytic strategy for aerobic oxidation of alcohols
-
A sodium trifluoromethanesulfinate-mediated photocatalytic strategy for the aerobic oxidation of alcohols has been developed for the first time, and the photoredox aerobic oxidation of secondary and primary alcohols provided the corresponding ketones and carboxylic acids, respectively, in high to excellent yields.
- Zhu, Xianjin,Liu, Can,Liu, Yong,Yang, Haijun,Fu, Hua
-
p. 12443 - 12446
(2020/10/30)
-
- A recyclable, metal-free mechanochemical approach for the oxidation of alcohols to carboxylic acids
-
The oxidation of primary alcohols under mechanochemical conditions in a Spex8000M Mixer/Mill was investigated. To facilitate ease of separation and recyclability, a polystyrene-bound version of a TEMPO catalyst was employed. When paired with Oxone in a stainless-steel vial with a stainless-steel ball, several primary alcohols were successfully oxidized to the corresponding carboxylic acids. The product was isolated using gravity filtration, which also allowed for the polystyrene-bound TEMPO catalyst to be recovered and reused in subsequent oxidation reactions. Furthermore, it was demonstrated that the size and steric hindrance of the primary alcohol does not hinder the rate of the reaction. Finally, the aldehyde was selectively obtained from a primary alcohol under ball milling conditions by using a combination of non-supported TEMPO with a copper vial and copper ball.
- Carr, Preston,Denlinger, Kendra Leahy,Mack, James,Waddell, Daniel C.
-
-
- Method for preparing carboxylic acid by green catalytic oxidation of aliphatic primary alcohol
-
The invention relates to a method for preparing carboxylic acid by green catalytic oxidation of aliphatic primary alcohol. The method comprises the following steps of: adding aliphatic primary alcoholinto a reaction solvent, adding an N-hydroxyphthalimide-copper oxide catalyst, introducing oxygen during reaction, and carrying out reaction at 50-80DEG C under normal pressure for 6-24h to obtain carboxylic acid with high yield. Compared with the prior art, the method has the advantages that the oxidizing agent is green and environment-friendly, the catalyst is cheap and easy to prepare, easy toseparate from the product, convenient to recycle, the reaction conditions are mild and the like, therefore the method is a green oxidation method of aliphatic primary alcohol.
- -
-
Paragraph 0063-0066
(2020/12/30)
-
- METHOD FOR PRODUCING CARBONYL COMPOUND
-
PROBLEM TO BE SOLVED: To allow a method that oxidizes a first or second alcohol compound to obtain a carbonyl compound to be conducted with a higher yield than that of a method that uses sodium hypochlorite as an oxidizer. SOLUTION: A first or second alcohol compound is oxidized, in the presence of tetraalkylammonium hypochlorite and, preferably, in coexistence with a nitroxy radical catalyst and a metal halide cocatalyst, to produce a carbonyl compound composed of an aldehyde compound, a carboxylic acid compound, and a ketone compound. SELECTED DRAWING: None COPYRIGHT: (C)2021,JPO&INPIT
- -
-
Paragraph 0066; 0069
(2021/02/04)
-
- Synthetic method of acid compound
-
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.
- -
-
Paragraph 0028-0032; 0044
(2020/08/25)
-
- Iron-Catalyzed Aerobic Oxidation of Alcohols: Lower Cost and Improved Selectivity
-
An aerobic oxidation reaction of alcohols toward aldehydes or ketones using catalytic amounts of Fe(NO3)3·9H2O, 4-OH-TEMPO, and NaCl has been developed. Compared with the former catalytic system with TEMPO developed in this group, the new protocol using 4-OH-TEMPO, which is much cheaper on an industrial scale, accomplished the transformation with a higher selectivity, especially for aliphatic alcohols toward aldehydes. α,β-Unsaturated alkynals or alkynones can be efficiently synthesized from propargyl alcohols, which has been much less studied in the literature.
- Jiang, Xingguo,Liu, Jinxian,Ma, Shengming
-
p. 825 - 835
(2019/05/02)
-
- Organocatalyzed Aerobic Oxidation of Aldehydes to Acids
-
The first example organocatalyzed aerobic oxidation of aldehydes to carboxylic acids in both organic solvent and water under mild conditions is developed. As low as 5 mol % N-hydroxyphthalimide was used as the organocatalyst, and molecular O2 was used as the sole oxidant. No transition metals or hazardous oxidants or cocatalysts were involved. A wide range of carboxylic acids bearing diverse functional groups were obtained from aldehydes, even from alcohols, in high yields.
- Dai, Peng-Fei,Qu, Jian-Ping,Kang, Yan-Biao
-
supporting information
p. 1393 - 1396
(2019/02/26)
-
- Dehydrogenation of Alcohols to Carboxylic Acid Catalyzed by in Situ-Generated Facial Ruthenium- CPP Complex
-
A selective catalytic system for the dehydrogenation of primary alcohols to carboxylic acids using a facial ruthenium complex generated in situ from the [Ru(COD)Cl2]n and a hybrid N-heterocyclic carbene (NHC)-phosphine-phosphine ligand (CPP) has been first reported. The facial coordination model was unveiled by NMR analysis of the reaction mixture. Such a fac-ruthenium catalyst system exhibited high catalytic activity and stability, and a high turnover number of 20 000 could be achieved with catalyst loading as low as 0.002 mol %. The exceedingly high catalyst stability was tentatively attributed to both the anchoring role of NHC and the hemi-lability of phosphines. The catalytic system also features a wide substrate scope. In particular, the facial coordination of CPP ligands was found to be beneficial for sterically hindered alcohols, and ortho-substituted benzylic alcohols and bulky adamantanyl methanol as well as cholesterol were all found to be viable dehydrogenation substrates.
- Liu, Hui-Min,Jian, Lei,Li, Chao,Zhang, Chun-Chun,Fu, Hai-Yan,Zheng, Xue-Li,Chen, Hua,Li, Rui-Xiang
-
p. 9151 - 9160
(2019/08/12)
-
- Method for preparing ketone or carboxylic acid through catalytic oxidation of secondary alcohol or primary alcohol
-
The invention relates to a method for preparing ketone or carboxylic acid through catalytic oxidation of alcohol. The method specifically comprises the following steps: adding secondary alcohol or primary alcohol into a certain amount of organic solvent to serve as a raw material, forming an N-hydroxyphthalimide (NHPI)-phthalocyanine catalytic system and taking oxygen as an oxidant, and reacting for 9-36 hours at the reaction temperature of 60-120 DEG C under the condition of normal pressure to obtain the ketone or carboxylic acid with higher yield. Compared with the prior art, the method hasthe advantages of green and environment-friendly oxidant, cheap and easily-prepared catalyst, easiness in separation from the product, mild reaction conditions and the like, and is a green alcohol oxidation method.
- -
-
Paragraph 0062-0065
(2019/12/02)
-
- Well-dispersed nickel nanoparticles on the external and internal surfaces of SBA-15 for hydrocracking of pyrolyzed α-cellulose
-
Catalysts comprising nickel supported on SBA-15 were prepared by wet impregnation and co-impregnation methods. Wet impregnation was performed by directly dispersing an Ni(NO3)2·6H2O aqueous solution into SBA-15, whereas in co-impregnation, ethylene glycol (EG) was added to nickel nitrate aqueous solution prior to dispersion into SBA-15. After drying and calcination, NiO/SBA-15w and NiO/SBA-15c were produced. Later, after the reduction process, Ni/SBA-15w and Ni/SBA-15c were obtained. The prepared catalysts were evaluated for the hydrocracking of pyrolyzed α-cellulose. The TEM images revealed that the catalysts prepared by wet impregnation showed inhomogeneous distribution of nickel loading, whereas catalysts prepared by co-impregnation using EG exhibited homogeneous distribution and formed no nickel aggregates. During hydrocracking of pyrolyzed α-cellulose, Ni/SBA-15c with total acidity, nickel loading, particle size, and specific surface area of 7.27 m mol g?1, 5.20 wt%, 3.17 nm, and 310.0 m2 g?1, respectively, exhibited the best catalytic performance compared to other prepared catalysts with 67.35 wt% conversion of liquid product with maximum selectivity in producing 13.09 wt% of 3-methyl-pentane. Moreover, Ni/SBA-15w with total acidity, nickel loading, particle size, and specific surface area of 10.87 m mol g?1, 8.15 wt%, 7.01 nm, and 628.0 m2 g?1, respectively, produced 69.89 wt% liquid product without hydrocarbons. Study of selectivity towards the formation of liquid hydrocarbons was carried out via double step hydrocracking using Ni/SBA-15w, and 18.55 wt% of n-hexane was produced in the liquid product.
- Trisunaryanti, Wega,Suarsih, Endah,Triyono,Falah, Iip Izul
-
p. 1230 - 1237
(2019/01/23)
-
- Highly practical and efficient preparation of aldehydes and ketones from aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst
-
Herein, we divulge an efficient protocol for aerobic oxidation of alcohols with an inorganic-ligand supported iodine catalyst, (NH4)5[IMo6O24]. The catalyst system is compatible with a wide range of groups and exhibits high selectivity, and shows excellent stability and reusability, thus serving as a potentially greener alternative to the classical transformations.
- Zhang, Mengqi,Zhai, Yongyan,Ru, Shi,Zang, Dejin,Han, Sheng,Yu, Han,Wei, Yongge
-
supporting information
p. 10164 - 10167
(2018/09/13)
-
- A aldehyde or mellow directly converted into the carboxylic acid (by machine translation)
-
The invention discloses a aldehyde or mellow oxidation can be directly transformed into carboxylic acid, is characterized in that the pure oxygen environment, in N - hydroxy imide compound under the catalysis of the imide compound or N - hydroxy and nitrous acid ester compound common under the catalysis, the CH2 OH and CHO oxidation directly converted into the carboxylic acid compounds. The invention using oxygen as the oxidizing agent, does not add any metal catalyst, environment-friendly, high catalytic efficiency, simple and convenient operation. With the previous metal catalytic system complex and different catalytic system, has some metal catalytic system in the process, the use of transition metal will cause the transition metal of the residual, the invention adopts the non-metallic catalytic system, environmental protection, preventing the metal residue problem, this to the solution of the drug in the synthesis of transition metal residue problem and provides a new method of thinking. (by machine translation)
- -
-
Paragraph 0021; 0022
(2018/08/03)
-
- Arylruthenium(III) Porphyrin-Catalyzed C-H Oxidation and Epoxidation at Room Temperature and [RuV(Por)(O)(Ph)] Intermediate by Spectroscopic Analysis and Density Functional Theory Calculations
-
The development of highly active and selective metal catalysts for efficient oxidation of hydrocarbons and identification of the reactive intermediates in the oxidation catalysis are long-standing challenges. In the rapid hydrocarbon oxidation catalyzed by ruthenium(IV) and -(III) porphyrins, the putative Ru(V)-oxo intermediates remain elusive. Herein we report that arylruthenium(III) porphyrins are highly active catalysts for hydrocarbon oxidation. Using catalyst [RuIII(TDCPP)(Ph)(OEt2)] (H2TDCPP = 5,10,15,20-tetrakis(2,6-dichlorophenyl)porphyrin), the oxidation of C-H bonds of various hydrocarbons with oxidant m-CPBA at room temperature gave alcohols/ketones in up to 99% yield within 1 h; use of [nBu4N]IO4 as a mild alternative oxidant avoided formation of lactone from cyclic ketone in C-H oxidation, and the catalytic epoxidation with up to 99% yield and high selectivity (no aldehydes as side product) was accomplished within 5 min. UV-vis, electrospray ionization-mass spectrometry, resonance Raman, electron paramagnetic resonance, and kinetic measurements and density functional theory calculations lend evidence for the formation of Ru(V)-oxo intermediate [RuV(TDCPP)(O)(Ph)].
- Shing, Ka-Pan,Cao, Bei,Liu, Yungen,Lee, Hung Kay,Li, Ming-De,Phillips, David Lee,Chang, Xiao-Yong,Che, Chi-Ming
-
supporting information
p. 7032 - 7042
(2018/06/12)
-
- Hydrofunctionalization of olefins to value-added chemicals: Via photocatalytic coupling
-
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
-
supporting information
p. 3450 - 3456
(2018/08/06)
-
- Synthesis of α,β-unsaturated aldehydes as potential substrates for bacterial luciferases
-
Bacterial luciferase catalyzes the monooxygenation of long-chain aldehydes such as tetradecanal to the corresponding acid accompanied by light emission with a maximum at 490?nm. In this study even numbered aldehydes with eight, ten, twelve and fourteen carbon atoms were compared with analogs having a double bond at the α,β-position. These α,β-unsaturated aldehydes were synthesized in three steps and were examined as potential substrates in vitro. The luciferase of Photobacterium leiognathi was found to convert these analogs and showed a reduced but significant bioluminescence activity compared to tetradecanal. This study showed the trend that aldehydes, both saturated and unsaturated, with longer chain lengths had higher activity in terms of bioluminescence than shorter chain lengths. The maximal light intensity of (E)-tetradec-2-enal was approximately half with luciferase of P. leiognathi, compared to tetradecanal. Luciferases of Vibrio harveyi and Aliivibrio fisheri accepted these newly synthesized substrates but light emission dropped drastically compared to saturated aldehydes. The onset and the decay rate of bioluminescence were much slower, when using unsaturated substrates, indicating a kinetic effect. As a result the duration of the light emission is doubled. These results suggest that the substrate scope of bacterial luciferases is broader than previously reported.
- Brodl, Eveline,Ivkovic, Jakov,Tabib, Chaitanya R.,Breinbauer, Rolf,Macheroux, Peter
-
p. 1487 - 1495
(2017/02/18)
-
- Three new resin glycosides compounds from Argyreia acuta and their α-glucosidase inhibitory activity
-
Three new phenolic compounds, acutacoside C (1), acutacoside D (2) and acutacoside E (3) were isolated from the aerial part of Argyreia acuta. The oligosaccharide chain was composed of two glucoses and three rhamnoses, and the aglycone was (11S)-hydroxyhexadecanoic acid (jalapinolic acid). The core of the three compounds was operculinic acid B, which was rare in resin glycosides. Their structures were established by a combination of spectroscopic and chemical methods. Compounds 1-3 have been evaluated for inhibitory activity against α-glucosidase, which all showed weak inhibitory activities.
- Wang, Li,Yan, You-Shao,Cui, Hong-Hua,Yin, Yong-Qin,Pan, Jie-Tao,Yu, Bang-Wei
-
supporting information
p. 537 - 542
(2017/01/13)
-
- Method for preparing acid through oxidating alcohols or aldehydes by oxygen
-
The invention provides a method for preparing acid through oxidating alcohols or aldehydes by using oxygen or oxygen in air as an oxidant. The method comprises the steps: oxidating the alcohols or aldehydes to produce the acid at room temperature in an organic solvent in a manner of taking ferric nitrate (Fe(NO3)3.9H2O), 2,2,6,6-tetramethylpiperidyl nitrogen oxide (TEMPO) and an inorganic halide as catalysts and taking the oxygen or air as an oxidant, and oxidating diols to produce lactone; or, carrying out a reaction on the aldehydes, which serve as a raw material, under neutral conditions by taking ferric nitrate as a catalyst, and oxidating the aldehydes to produce the acid and peroxy acid. The method has the advantages that the method is environmentally friendly, the cost is low, the yield is high, the atomic economical efficiency is high, the compatibility of substrate functional groups is good, the reaction conditions are mild, a reaction scale can be enlarged, and the like, so that the method is suitable for being applied to industrial production.
- -
-
Paragraph 0051; 0052; 0053; 0054; 0109-0111; 0187-0189
(2017/09/29)
-
- Tert-Butyl Nitrite-Mediated Synthesis of N-Nitrosoamides, Carboxylic Acids, Benzocoumarins, and Isocoumarins from Amides
-
This work reports tert-butyl nitrite (TBN) as a multitask reagent for (1) the controlled synthesis of N-nitrosoamide from N-alkyl amides, (2) hydrolysis of N-methoxyamides to carboxylic acids, (3) metal- and oxidant-free benzocoumarin synthesis from ortho-aryl-N-methoxyamides via N-H, C-N, and C-H bond activation, and (4) isocoumarin synthesis using Ru(II)/PEG as a recyclable catalytic system via ortho-C-H activation and TBN as an oxygen source. The sequential functional group interconversion of amide to acid has also been examined using IR spectroscopic analysis. Additionally, this methodology is highly advantageous due to short reaction time, gram scale synthesis, and broad substrate scope.
- Yedage, Subhash L.,Bhanage, Bhalchandra M.
-
p. 5769 - 5781
(2017/06/07)
-
- Iron-Catalyzed Radical Decarboxylative Oxyalkylation of Terminal Alkynes with Alkyl Peroxides
-
An iron-catalyzed oxyalkylation of alkynes with alkyl peroxides as the alkylating reagents has been investigated. Alkyl peroxides are readily available from aliphatic acids and serve simultaneously as the alkylating reagents and internal oxidants. Primary, secondary, and tertiary alkyl groups of aliphatic acids were readily incorporated into C?C triple bonds and diverse α-alkylated ketones were synthesized. Mechanism studies revealed that this reaction involves highly reactive alkyl free radicals. A unique equilibrium between lauric acid and water catalyzed by the iron(III) catalyst was observed.
- Zhu, Xiaotao,Ye, Changqing,Li, Yajun,Bao, Hongli
-
supporting information
p. 10254 - 10258
(2017/08/07)
-
- Preparation method of carboxylic acid compound
-
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.
- -
-
Paragraph 0113; 0171-0173
(2017/08/29)
-
- A Comprehensive Study on Metal Triflate-Promoted Hydrogenolysis of Lactones to Carboxylic Acids: From Synthetic and Mechanistic Perspectives
-
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
-
p. 7520 - 7528
(2017/11/10)
-
- Hydrodeoxygenation of Fatty Acids, Triglycerides, and Ketones to Liquid Alkanes by a Pt–MoOx/TiO2 Catalyst
-
Various supported metal catalysts are screened for hydrogenation of lauric acid and 2-octanone as model reactions for the transformation of biomass-derived oxygenates to liquid alkanes (biofuels) in a batch reactor under solvent-free conditions. Among the catalysts tested, Pt and MoOx co-loaded on TiO2 (Pt–MoOx/TiO2) shows the highest yields of n-alkanes for both of the reactions. Pt–MoOx/TiO2 selectively catalyzes the hydrodeoxygenation of various fatty acids and triglycerides to n-alkanes without C?C bond cleavage under 50 bar H2 and shows higher turnover numbers than the catalysts in the literature. Pt–MoOx/TiO2 is effective also for the hydrodeoxygenation of various ketones to the corresponding alkanes. In situ IR study of the reaction of adsorbed acetone under H2 suggests that the high activity of Pt–MoOx/TiO2 is attributed to the cooperation between Pt and Lewis acid sites of the MoOx/TiO2 support.
- Kon, Kenichi,Toyao, Takashi,Onodera, Wataru,Siddiki,Shimizu, Ken-Ichi
-
p. 2822 - 2827
(2017/07/28)
-
- A glucose-activatable trimodal glucometer self-assembled from glucose oxidase and MnO2 nanosheets for diabetes monitoring
-
Daily monitoring of blood glucose is of great importance for the treatment of diabetes mellitus. Herein, we present an ensemble glucometer with a sandwich structure formed by the spontaneous entrapment of glucose oxidase (GOD) onto manganese dioxide nanosheets (MnO2 NSs) via the hydrophobic effect and hydrogen bond interaction. Within the hybrid glucometer, the ultrathin MnO2 NSs act as an enzyme nanosupport and target-activated signal transducer. Trimodal self-indication by fluorescence (FL) and UV-absorbance (UV) and magnetic resonance signal (MRS) activation with glucose-specificity provides multiple response signals to glucose. Taking account of its operational simplicity and convenience, even being observable by the naked eye, a detection limit as low as 0.1 ;M was obtained by using the ensemble glucometer in a colorimetric assay, whilst the precision for 11 replicated detections of 10 M glucose was 3.5% (relative standard deviation, RSD). Notably, the value of the Michaelis-Menton constant of GOD involved the presented glucometer is estimated to be 0.051 mM, showing an exceptional enhanced enzymatic activity of free GOD measured by far. The designed glucometer, with its high sensitivity and simplicity highlighted, was capable of routine blood glucose monitoring for type-I diabetes mellitus in rats. Furthermore, the fully integrated platform can be readily generalized in principle for a number of biomarkers for point of care diagnostics in the future.
- Chen, Jin-Long,Li, Li,Wang, Shuo,Sun, Xiao-Yan,Xiao, Lu,Ren, Jia-Shu,Di, Bin,Gu, Ning
-
supporting information
p. 5336 - 5344
(2017/07/22)
-
- Catalytic hydrolysis of hydrophobic esters on/in water by high-silica large pore zeolites
-
Hydrolysis of water-insoluble esters is an industrially important but challenging reaction, because the esters are mostly present in oil droplets on water during the reaction. On the basis of the screening results for hydrolysis of a water-insoluble ester, 3-phenylpropionate, on/in water by 25 types of heterogeneous and homogenous catalysts, we have found that Hβ zeolite with a moderate Si/Al ratio (Si/Al = 75), Hβ-75, is an effective and reusable catalyst for hydrolysis of hydrophobic esters. The hydrolysis of esters with different sizes is studied by Hβ and HZSM5 zeolites with different Si/Al ratios, and the results show the hydrophobicity, pore size and number of Br?nsted acid sites are critical factors affecting the catalytic activity for this system. Kinetic and adsorption studies show that the high yields by Hβ-75 are due to preferential interaction of the hydrophobic zeolite pore with hydrophobic esters over polar molecules (carboxylic acids, water, alcohols) and transfer of the carboxylic acids to the oil droplets on water, both of which inhibit the reverse reaction (esterification of the carboxylic acids).
- Siddiki,Toyao, Takashi,Kon, Kenichi,Touchy, Abeda S.,Shimizu, Ken-ichi
-
p. 741 - 748
(2016/12/09)
-
- Transformation of methyl laurate into lauryl alcohol over a Ru-Sn-Mo/C catalyst by using zerovalent iron and water as an in situ hydrogen source
-
Hydrogenation and hydrogenolysis reactions, which are used in the chemical industry for the synthesis of organic compounds, are very expensive operations because of the need for facilities that can liquefy, transport, and store the hydrogen produced through steam reforming of natural gas. We have therefore developed a novel approach for hydrogenation that does not require the use of high-cost facilities. Using this, zerovalent iron (Fe) and water (H2O) are introduced as an in situ hydrogen donor system for the transformation of methyl laurate into lauryl alcohol over a Ru-based catalyst. This combination of a Ru-Sn-Mo/C catalyst with a Fe/H2O system showed significantly higher transformation rates for the conversion of methyl laurate into lauryl alcohol than a conventional reaction system that uses pressurized hydrogen. The reason for this is that the new system produces lauric acid as an intermediate during the reaction, which is more efficiently hydrogenized into lauryl alcohol over the Ru-Sn-Mo/C catalyst. The Fe/H2O system played two important roles: a hydrogen source for the hydrogenation reaction and a catalyst for the generation of lauric acid by methyl laurate hydrolysis.
- Sagata, Kunimasa,Hirose, Mina,Hirano, Yoshiaki,Kita, Yuichi
-
-
- Iron Catalysis for Room-Temperature Aerobic Oxidation of Alcohols to Carboxylic Acids
-
Oxidation from alcohols to carboxylic acids, a class of essential chemicals in daily life, academic laboratories, and industry, is a fundamental reaction, usually using at least a stoichiometric amount of an expensive and toxic oxidant. Here, an efficient and practical sustainable oxidation technology of alcohols to carboxylic acids using pure O2 or even O2 in air as the oxidant has been developed: utilizing a catalytic amount each of Fe(NO3)3·9H2O/TEMPO/MCl, a series of carboxylic acids were obtained from alcohols (also aldehydes) in high yields at room temperature. A 55 g-scale reaction was demonstrated using air. As a synthetic application, the first total synthesis of a naturally occurring allene, i.e., phlomic acid, was accomplished.
- Jiang, Xingguo,Zhang, Jiasheng,Ma, Shengming
-
supporting information
p. 8344 - 8347
(2016/07/26)
-
- An Unusual Iron-Dependent Oxidative Deformylation Reaction Providing Insight into Hydrocarbon Biosynthesis in Nature
-
The development of new pathways for next-generation biofuel production has spurred recent investigations into the mechanisms of enzymes that biosynthesize hydrocarbons. One widely distributed group of enzymes, aldehyde decarbonylases, catalyze unusual deformylation reactions in which long-chain fatty aldehydes are converted to alkanes. These enzymes are all iron-dependent and in insects are represented by a cytochrome P450 enzyme that releases the aldehyde carbon as CO2. Here we describe a novel nonenzymatic reaction of an α-cyclopropyl-substituted aldehyde that mimics the enzyme reaction. This aldehyde is oxidatively deformylated in the presence of aqueous iron(II) salts and oxygen to yield an alkyl-substituted cyclopropane and CO2, in a reaction that competes with the more conventional oxidation of the aldehyde to the carboxylic acid. Like the enzymatic reaction, the reaction occurs with retention of the aldehyde proton in the alkane product and probably proceeds through an iron-peroxo species. Computational reaction discovery tools were used to search for potential reaction pathways and investigate their energetic feasibility. These identified a plausible reaction pathway leading to the experimentally observed products and reproduced the transfer of the aldehyde proton to the cyclopropane product. These studies provide further insight into how enzymes may control reactive iron-oxo species to catalyze the diverse range of iron-dependent oxidative transformations observed in biology.
- Ellington, Benjamin R.,Paul, Bishwajit,Das, Debasis,Vitek, Andrew K.,Zimmerman, Paul M.,Marsh, E. Neil G.
-
p. 3293 - 3300
(2016/07/06)
-
- NOVEL GENE DERIVED FROM MUD FLAT METAGENOME AND NOVEL PROTEIN OBTAINED THEREFROM SHOWING COACTIVITY OF PHOSPHOLIPASE AND LIPASE
-
The present invention relates to a novel gene derived from a tidal flat metagenome, and a novel protein obtained therefrom showing the coactivity of phospholipase and lipase. Specifically, the novel gene isolated from the metagenome library of tidal flat sedimentsand the protein having phospholipase and lipase activities encoded from the novel gene: are expressed in a water-soluble form to be mass-producible; enable ultra high-purity protein to be obtained through single step purification using an Ni-NTA column; show good activity in the pH range of 5 ?? 10; maintain good low temperature activity and stability up to a temperature of 3°C to 40°C; and have high resistance against various organic solvents. Therefore, the novel gene and the protein can be usefully used for various industrial fields such as the purification and conversion of oil and fat, bio-medicine, and fine chemistry.
- -
-
Paragraph 0083-0084
(2016/03/14)
-
