- Evidence for the involvement of silver nanoclusters during the wolff rearrangement of α-diazoketones
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(Matrix presented) In situ-generated silver nanoclusters(Agn) during the reduction of either silver(I) oxide or other salts presumably catalyze the Wolff rearrangement of α-diazoketones. Their optical, physical, and catalytic properties depend
- Sudrik, Surendra G.,Maddanimath, Trupti,Chaki, Nirmalya K.,Chavan, Sambhaji P.,Chavan, Subhash P.,Sonawane, Harikisan R.,Vijayamohanan
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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 0028-0032; 0049
(2020/08/25)
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- Site-Selective, Remote sp3 C?H Carboxylation Enabled by the Merger of Photoredox and Nickel Catalysis
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A photoinduced carboxylation of alkyl halides with CO2 at remote sp3 C?H sites enabled by the merger of photoredox and Ni catalysis is described. This protocol features a predictable reactivity and site selectivity that can be modulated by the ligand backbone. Preliminary studies reinforce a rationale based on a dynamic displacement of the catalyst throughout the alkyl side chain.
- Sahoo, Basudev,Bellotti, Peter,Juliá-Hernández, Francisco,Meng, Qing-Yuan,Crespi, Stefano,K?nig, Burkhard,Martin, Ruben
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supporting information
p. 9001 - 9005
(2019/06/24)
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- Synthesis of Elongated Esters from Alkenes
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A convenient method for synthesizing elongated aliphatic esters from alkenes is reported. An (alkoxycarbonyl)methyl radical species is generated upon visible-light irradiation of an ester-stabilized phosphorus ylide in the presence of a photoredox catalyst. This radical species adds onto the carbon–carbon double bond of an alkene to produce an elongated aliphatic ester.
- Miura, Tomoya,Funakoshi, Yuuta,Nakahashi, Junki,Moriyama, Daisuke,Murakami, Masahiro
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supporting information
p. 15455 - 15459
(2018/10/31)
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- CARBOXAMIDE INHIBITORS
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The present invention provides a compound of formula I The compounds of formula I demonstrate properties as Smurf-1 inhibitors and are thus useful in the treatment of a range of disorders, particularly pulmonary arterial hypertension.
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- Synthetic Applications and Mechanistic Studies of the Hydroxide-Mediated Cleavage of Carbon-Carbon Bonds in Ketones
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The hydroxide-mediated cleavage of ketones into alkanes and carboxylic acids has been reinvestigated and the substrate scope extended to benzyl carbonyl compounds. The transformation is performed with a 0.05 M ketone solution in refluxing xylene in the presence of 10 equiv of potassium hydroxide. The reaction constitutes a straightforward protocol for the synthesis of certain phenyl-substituted carboxylic acids from 2-phenylcycloalkanones. The mechanism was investigated by kinetic experiments which indicated a first order reaction in hydroxide and a full negative charge in the rate-determining step. The studies were complemented by a theoretical investigation where two possible pathways were characterized by DFT/M06-2X. The calculations showed that the scission takes place by nucleophilic attack of hydroxide on the ketone followed by fragmentation of the resulting oxyanion into the carboxylic acid and a benzyl anion.
- Mazziotta, Andrea,Makarov, Ilya S.,Fristrup, Peter,Madsen, Robert
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p. 5890 - 5897
(2017/06/07)
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- Palladium on carbon-catalyzed aqueous transformation of primary alcohols to carboxylic acids based on dehydrogenation under mildly reduced pressure
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The catalytic dehydrogenation of alcohols to carbonyl products is a green sustainable oxidation with no production of waste except for hydrogen, which can be an energy source. Additionally, a reusable heterogeneous catalyst is valuable from the viewpoint of process chemistry and water is a green solvent. We have accomplished the palladium on carbon (Pd/C)-catalyzed dehydrogenation of primary alcohols to carboxylic acids in water under a mildly reduced pressure (800 hPa). The reduced pressure can be easily controlled by the vacuum controller of the rotary evaporator to remove the excess of generated hydrogen, which causes the reduction (reverse reaction) of aldehydes to alcohols (starting materials) and other undesirable side reactions. The present method is applicable to the reaction of various aliphatic and benzylic alcohols to the corresponding carboxylic acids, and the Pd/C could be reused at least 5 times.
- Sawama, Yoshinari,Morita, Kosuke,Asai, Shota,Kozawa, Masami,Tadokoro, Shinsuke,Nakajima, Junichi,Monguchi, Yasunari,Sajiki, Hironao
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supporting information
p. 1205 - 1210
(2015/04/22)
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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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- Rhodium-on-carbon catalyzed hydrogen scavenger- and oxidant-free dehydrogenation of alcohols in aqueous media
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The efficient and catalytic dehydrogenation of alcohols is a clean approach for preparing carbonyl compounds accompanied only by the generation of hydrogen gas. We have accomplished the heterogeneous rhodium-on-carbon catalyzed dehydrogenation of secondary, as well as primary, alcohols to the corresponding ketones and carboxylic acids in water under basic conditions. This journal is the Partner Organisations 2014.
- Sawama, Yoshinari,Morita, Kosuke,Yamada, Tsuyoshi,Nagata, Saori,Yabe, Yuki,Monguchi, Yasunari,Sajiki, Hironao
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supporting information
p. 3439 - 3443
(2014/07/08)
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- Indium-mediated chemoselective deprotection and demonochlorination of 2,2,2-trichloroethyl esters
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On treatment with indium metal, the 2,2,2-trichloroethyl carboxylates smoothly undergo deprotection to carboxylic acids and reductive demonochlorination to 2,2-dichloroethyl esters, sharply depending on their structures.
- Mineno, Tomoko,Kansui, Hisao,Kunieda, Takehisa
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p. 5027 - 5030
(2008/02/10)
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- Development of an enzyme-linked immunosorbent assay for the determination of the linear alkylbenzene sulfonates and long-chain sulfophenyl carboxylates using antibodies generated by pseudoheterologous immunization
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ELISA methods have been developed for screening contamination of water resources by linear alkyl benzene sulfonates (LAS) or the most immediate degradation products, the long chain sulfophenyl carboxylates, SPCs. The assay uses antibodies raised through pseudoheterologous immunization strategies using an equimolar mixture of two immunogens (SFA-KLH and 13C13-SPC-KLH) prepared by coupling N-(4-alkylpnenyl)sulfonyl-3-aminopropanoic acid (SFA) andp-(1-carboxy-13-tridecyl)-phenylsulfonic acid (13C13-SPC) to keyhole limpet hemocyanin (KLH). The immunizing haptens have been designed to address recognition versus two different epitopes of the molecule. The SFA hapten maximizes recognition of the alkyl moiety while preserving the complexity of the different alkyl chains present in the LAS technical mixture. The 13C13-SPC hapten addresses recognition of the common and highly antigenic phenylsulfonic group. The antisera raised using this strategy have been shown to be superior to those obtained through homologous immunization procedures using a single substance. By using an indirect ELISA format, LAS and long-chain SPCs can be detected down to 1.8 and 0.2 μg L-1, respectively. Coefficients of variation of 6 and 12% within and between assays, respectively, demonstrate immunoassay reproducibility. The assay can be used in media with a wide range of pH and ionic strength values. Preliminary experiments performed to assess matrix effects have demonstrated the potential applicability of the method as a screening tool to assess contamination by these types of surfactants in natural water samples.
- Ramon-Azcon, Javier,Galve, Roger,Sanchez-Baeza, Francisco,Marco, M.-Pilar
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- Silver nanocluster redox-couple-promoted nonclassical electron transfer: An efficient electrochemical wolff rearrangement of α-diazoketones
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In this work we report the unique electrocatalytic role of benzoic acid protected silver nanoclusters (Agn, mean core diameter 2.5 nm) in the Wolff rearrangement (Scheme 1) of α-diazoketones. More specifically, the presence of a Agn0/Agn+ redox couple facilitates a nonclassical electron-transfer process, involving chemical reaction(s) interposed between two electron-transfer steps occurring in opposite directions. Consequently, the net electron transfer between the electron mediator (Agn) and α-diazoketone is zero. In-situ UV-visible studies using pyridine as a nucleophilic probe indicate the participation of α-ketocarbene/ketene as important reaction intermediates. Controlled potential coulometry of α-diazoketones using Agn as the anode results in the formation of Wolff rearranged carboxylic acids in excellent yield, without sacrificing the electrocatalyst.
- Sudrik, Surendra G.,Chaki, Nirmalya K.,Chavan, Vilas B.,Chavan, Sambhaji P.,Chavan, Subhash P.,Sonawane, Harikisan R.,Vijayamohanan
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p. 859 - 864
(2007/10/03)
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- METHOD FOR PRODUCING CARBOXYLIC ACID AND METHOD FOR CLEAVING BOND OF CARBONYL COMPOUND
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PROBLEM TO BE SOLVED: To provide a method for producing a carboxylic acid, capable of reducing the generation of by-products and environment-polluting substances in the production of the carboxylic acid, and a method for cleaving the bond of a carbonyl compound. SOLUTION: This method for generating the carboxylic acid and/or a ketone is provided by performing the reaction of the carbonyl compound with a vanadium-based catalyst in a carboxylic acid solvent under oxygen atmosphere to cleave the bond of the carbonyl compound.
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Page/Page column 5
(2008/06/13)
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- Orientation of the benzophenone group at various depths in bilayers
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The hydrophobic core of biological membranes is primarily composed of fatty acyl chains of lipids and side chains of nonpolar amino acids belonging to membrane-spanning domains of transmembrane proteins. Electron transport across the 35-40-? membrane dielectric takes place via suitably oriented electron-transfer groups associated with transmembrane domains of membrane-bound proteins. We propose here that the design of lipids bearing electron-transport groups oriented at different depths can provide the necessary supramolecular assembly in the form of a monolayer or a bilayer to carry out electron transfer. The design of these modified lipids is crucial to the success of such a molecular device. We report here the design and synthesis of three benzophenone-based phospholipids capable of orienting the benzophenone group at different depths in a bilayer. The orientation of the benzophenone group was determined by photochemical cross-linking of these lipids with dimyristoylphosphatidylcholine in single bilayer vesicles followed by mass spectral analyses of the cross-linked products. The actual site of cross-linking on the myristoyl chain was determined, and it was observed that a range of carbon atoms are functionalized. The range of carbon atoms functionalized was found to be centered around the position expected from the transverse location of the benzophenone-based phospholipid in the bilayer. The data could be best interpreted in terms of zones of carbon atoms functionalized rather than any discreet site. This is in keeping with the current models of membranes which suggest the presence of a fluid gradient as one goes down the fatty acyl chain in the membrane. However, the range of carbon atoms functionalized was narrowed with probes reported here. The use of a hydrophobic tail attached to the benzophenone group assisted in directing the orientation of the photoactive group at different depths. Besides providing an effective design strategy for the orientation of electron-transfer groups at different depths in a bilayer, the high insertion yield and the depth-dependent labeling observed in artificial membranes suggest that the benzophenone-based phospholipids reported here could also prove useful for studying the structure of single and multiple spanning transmembrane proteins.
- Lala, Anil K.,Ravi Kumar
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p. 3982 - 3988
(2007/10/02)
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- Antiinflammatory leukotriene B4 analogs
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This invention encompasses novel analogs of Leukotriene B4 which are selected from a compound of formula I, B--C~C--CH2 C(M2)--C~C--Y--C(M1)--A, or formula II, B--C~C--CH2 C(M2)--C~C--P--R5 --A: wherein Y is: STR1 wherein P is: STR2 Patentable intermediates, process for making the novel analogs and intermediates and preparation of useful pharmacological agents comprising the analogs and intermediates are part of this invention.
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- Benzophenone Dicarboxylic Acid Antagonists of Leukotriene B4. 2. Structure-Activity Relationships of the Lipophilic Side Chain
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A series of lipophilic benzophenone dicarboxylic acid derivatives were found to inhibit the binding of the potent chemotoxin leukotriene B4 (LTB4) to its receptor on intact human neutrophils.Activity at the LTB4 receptor was determined by using a 3H>LTB4-binding assay.The structure-activity relationship for the lipophilic side chain was systematically investigated.Compounds with n-alkyl side chains of varying lengths were prepared and tested.Best inhibition of 3H>LTB4 binding was observed with the n-decyl derivative.Analogues with alkyl chains terminated with an aromatic ring showed improved activity.The 6-phenylhexyl side chain was optimal.Substitution on the terminal aromatic ring was also evaluated.Methoxyl, methylsulfinyl, and methyl substituents greatly enhanced the activity of the compound.For a given substituent, the para isomer had the best activity.Thus the nature of the lipophilic side chain can greatly influence the ability of the compounds to inhibit the binding of LTB4 to its receptor on intact human neutrophils.The most active compound from this series, 84 (LY223982), bound to the LTB4 receptor with the affinity approaching that of the agonist.
- Gapinski, D. Mark,Mallett, Barbara E.,Froelich, Larry L.,Jackson, William T.
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p. 2807 - 2813
(2007/10/02)
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- SYNTHESIS OF 16-(4-IODOPHENYL)HEXADECANOIC ACID
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16-(4-Iodophenyl)hexadecanoic acid was prepared in six steps by two methods: from 6-(2-thienyl)hexanoic acid and 6-phenylhexanoyl chloride or by alkylation, or acylation, of 2-thienylthiophene.Mass and 1H NMR spectra of some prepared compounds are discussed.The synthesis is suitable for preparation of radioactively labelled acids used as myocardial imaging agents.
- Protiva, Jiri,Pecka, Jaroslav,Klinotova, Eva,Prochazka, Milos
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p. 872 - 878
(2007/10/02)
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- Aspects of Tautomerism. 13. Alkaline Hydrolysis of γ-, δ-, and ε-Keto Esters and their Desoxy Analogues. Geometrical Constraints on Keto Participation
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The rates of alkaline hydrolysis of methyl β-benzoylpropionate (I), methyl γ-benzoylbutyrate (II) and methyl δ-benzoylvalerate (III) decrease in the order I>II>III.Keto participation is the predominant pathway in the case of γ-keto esters.Evidence has also been obtained for keto participation in the case of δ-keto esters, whereas no such evidence is available in the case of ε-keto esters studied.
- Bhatt, M. Vivekananda,Ravindranathan, M.,Somayaji, Viswanatha,Rao, G. Venkoba
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p. 3170 - 3173
(2007/10/02)
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- EFFETS POLAIRES DANS LES REACTIONS DE TRANSFERT HOMOLYTIQUE INTRAMOLECULAIRE D'HYDROGENE
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In this paper we analyse the influence of a phenyl substituent on the relative rates of the 1-5 and 1-6 intramolecular hydrogen transfers.Compared to the abstraction of an aliphatic H atom, the activation energy for the abstraction of a benzylic H atom is smaller.The effect is nevertheless more important with a primary alkyl radical (1,3 kcal/mole) than with an alkoxy radical (0,9 kcal/mole).This can be analysed in terms of a polar effect.In addition, the size of the effect is too small to make a short distance transfer of a H atom feasible; this is in keeping with the statement that H atom migration requires a linear transition state.
- Lefort, D.,Nedelec, J. Y.
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p. 2681 - 2686
(2007/10/02)
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