- Dimethyl fumarate is an allosteric covalent inhibitor of the p90 ribosomal S6 kinases
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Dimethyl fumarate (DMF)?has been applied for decades in the treatment of psoriasis and now also multiple sclerosis. However, the mechanism of action has remained obscure and involves high dose over long time of this small, reactive compound implicating many potential targets. Based on a 1.9 ? resolution crystal structure of the C-terminal kinase domain of the mouse p90 Ribosomal S6 Kinase 2 (RSK2) inhibited by DMF?we describe a central binding site in RSKs and the closely related Mitogen and Stress-activated Kinases (MSKs). DMF reacts covalently as a Michael acceptor to a conserved cysteine residue in the αF-helix of RSK/MSKs. Binding of DMF prevents the activation loop of the kinase from engaging substrate, and stabilizes an auto-inhibitory αL-helix, thus pointing to an effective, allosteric mechanism of kinase inhibition. The biochemical and cell biological characteristics of DMF inhibition of RSK/MSKs are consistent with the clinical protocols of DMF treatment.
- Andersen, Jacob Lauwring,Nielsen, Christine Juul F?lled,Gotfred-Rasmussen, Helle,Nissen, Poul,Gesser, Borbala,Rasmussen, Mads Kirchheiner,Iversen, Lars,Funder, Erik Daa,Gothelf, Kurt Vesterager,Toth, Rachel,Arthur, J. Simon C.
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- REACTIONS OF BENZYLCHLOROBIS(TRIPHENYLPHOSPHINE)PALLADIUM(II) WITH DIMETHYL ACETYLENEDICARBOXYLATE
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Benzylchlorobis(triphenylphosphine)palladium(II) reacted with dimethyl acetylenedicarboxylate to give Cl(PPh3)>2> (II) and PdCl(PPh3)> (III).Complexes II and III reacted with Tl(acac) to afford
- Hiraki, Katsuma,Itoh, Toshihiro,Eguchi, Katsuya,Onishi, Masayoshi
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- Protic, imidazolium ionic liquids as media for (Z)- to (E)-alkene isomerization
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The quantitative isomerization of (Z)- to (E-alkene in protic, imidazolium ionic liquids is demonstrated. The isomerization parameters were determined. The mechanism on the addition of the protic imidazolium species to carbon-carbon double bond is presented. Copyright
- Janus, Ewa,Lozynski, Marek,Pernak, Juliusz
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- Aminal-catalyzed isomerization of and addition to dimethyl maleate
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The amine moiety of aminals adds to dimethyl maleate via azomethine ylid intermediates. The products of this reaction, in turn, cause dimethyl maleate to isomerize to dimethyl fumarate.
- Cook,Voges, Andrea B,Kammrath, Aster E
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- Unusual formation of tetrahydropyridazine-3,4,5,6-tetracarboxylic and pyrroletetracarboxylic esters upon decomposition of methyl diazoacetate in the presence of pyridine
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Thermal, photolytic, and thermocatalytic decomposition of methyl diazoacetate (MDA) in the presence of Rh2(OAc)4 or Cu(acac)2 in refluxing pyridine afforded isomeric trans, cis- and cis, trans-3,4,5,6-tetra(methoxycarbonyl)-1,4,5,6-tetrahydropyridazines (~1 : 1) in a total yield of 30-70%. Decomposition of MDA in refluxing o-xylene in the presence of Rh2(OAc)4 and pyridine (20 mol.%) gave rise to 2,3,4,5-tetra(methoxycarbonyl)pyrrole in a yield of up to 40%. In these transformations of MDA, neither dimethyl fumarate (or dimethyl maleate) nor the corresponding 2-pyrazolines were generated as intermediates.
- Tomilov,Platonov,Averkiev,Shulishov,Nefedov
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- Generation and cycloaddition of polymer-supported azomethine ylide via a 1,2-silatropic shift of α-silylimines: Traceless synthesis of pyrrolidine derivatives
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(matrix presented) The 1,3-bipolar cycloaddition of polymer-supported azomethine ylides to dipolarophiles gave pyrrolidine derivatives in good yields. The azomethine ylides were generated from resin-bound α-silylimines via a 1,2-silatropic shift. The features of this method are not only a traceless synthesis but also a uniaue solid-phase route to pyrrolidines with extensive diversity.
- Komatsu, Mitsuo,Okada, Hirofumi,Akaki, Tatsuo,Oderaotoshi, Yoji,Minakata, Satoshi
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- Zwitterion-Catalyzed Isomerization of Maleic to Fumaric Acid Diesters
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Fumaric acid diesters are important building blocks for organic synthesis. A class of zwitterionic organocatalysts based on an amide anion/iminium cation charge pair were found to be effective in catalyzing the isomerization of maleic acid diesters to give fumaric acid diesters. Comparison of the performance of different zwitterionic organocatalysts toward the reaction revealed that nonclassical hydrogen bonding was involved in the stabilization of the Michael adduct intermediate.
- Lam, Ying-Pong,Lam, Zachary,Yeung, Ying-Yeung
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p. 1183 - 1190
(2021/01/09)
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- Small-Molecule Investigation of Diels-Alder Complexes for Thermoreversible Crosslinking in Polymeric Applications
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Combinations of dienes and dienophiles were examined in order to elicit possible combinations for thermoreversible crosslinking units. Comparison of experimental results and quantum calculations indicated that reaction kinetics and activation energy were much better prediction factors than change in enthalpy for the prediction of successful cycloaddition. Further testing on diene-dienophile pairs that underwent successful cycloaddition determined the feasibility of thermoreversibility/retro-reaction of each of the Diels-Alder compounds. Heating and testing of the compounds in the presence of a trapping agent allowed for experimental determination of reverse kinetics and activation energy for the retro-reaction. The experimental values were in good agreement with quantum calculations. The combination of chemical calculations with experimental results provided a strong insight into the structure-property relationships and how quantum calculations can be used to examine the feasibility of the thermoreversibility of new Diels-Alder complexes in potential polymer systems or to fine-tune thermoreversible Diels-Alder systems already in use.
- Rowlett, Jarrett R.,Deglmann, Peter,Sprafke, Johannes,Roy, Nabarun,Mülhaupt, Rolf,Bruchmann, Bernd
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p. 8933 - 8944
(2021/07/20)
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- A donor-acceptor complex enables the synthesis of: E -olefins from alcohols, amines and carboxylic acids
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Olefins are prevalent substrates and functionalities. The synthesis of olefins from readily available starting materials such as alcohols, amines and carboxylic acids is of great significance to address the sustainability concerns in organic synthesis. Metallaphotoredox-catalyzed defunctionalizations were reported to achieve such transformations under mild conditions. However, all these valuable strategies require a transition metal catalyst, a ligand or an expensive photocatalyst, with the challenges of controlling the region- and stereoselectivities remaining. Herein, we present a fundamentally distinct strategy enabled by electron donor-acceptor (EDA) complexes, for the selective synthesis of olefins from these simple and easily available starting materials. The conversions took place via photoactivation of the EDA complexes of the activated substrates with alkali salts, followed by hydrogen atom elimination from in situ generated alkyl radicals. This method is operationally simple and straightforward and free of photocatalysts and transition-metals, and shows high regio- and stereoselectivities.
- Chen, Kun-Quan,Shen, Jie,Wang, Zhi-Xiang,Chen, Xiang-Yu
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p. 6684 - 6690
(2021/05/31)
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- Dimethyl Fumarate: Heterogeneous Catalysis for the Development of an Innovative Flow Synthesis
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The present work describes the development of an improved synthesis of the active pharmaceutical ingredient (API) dimethyl fumarate. The use of continuous flow technology and the newly developed methylation conditions solve some of the issues of previous commercial production strategies, e.g., reaching complete conversion and avoiding the formation of toxic impurities. The optimization was carried out using the design of experiment approach and afforded a very efficient, sustainable process, suitable for the industrial application.
- Dedè, Fabiana,Piccolo, Oreste,Vigo, Daniele
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p. 292 - 299
(2021/02/20)
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- Continuous-flow synthesis of dimethyl fumarate: A powerful small molecule for the treatment of psoriasis and multiple sclerosis
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Dimethyl fumarate (DMF) is a methyl ester of fumaric acid and has recently gained attention due to its use as a pro-drug in different pharmaceutical preparations, besides the low price of the final molecule and no active patents being available for the synthesis of DMF, the prices of multiple sclerosis treatment are still high. In our continuous effort for the development of process intensification strategies towards the synthesis of active pharmaceutical ingredients, here we present our work on a cascade methodology for dimethyl fumarate synthesis in short reaction times and quantitative yields.
- Lima, Marcelo T.,Finelli, Fernanda G.,De Oliveira, Alline V. B.,Kartnaller, Vinicius,Cajaiba, Joa? F.,Lea?, Raquel A. C.,De Souza, Rodrigo O. M. A.
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p. 2490 - 2494
(2020/02/03)
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- A Br?nsted acidic, ionic liquid containing, heteropolyacid functionalized polysiloxane network as a highly selective catalyst for the esterification of dicarboxylic acids
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A Br?nsted acidic, ionic liquid containing, heteropolyanion functionalized polysiloxane network was formed by self-condensation of dodecatungstophosphoric acid and a zwitterionic organosilane precursor containing both imidazolinium and sulfonate groups. The resulting hybrid material POS-HPA-IL was investigated as a catalyst for the selective esterification of dicarboxylic acids.
- Rajabi, Fatemeh,Wilhelm, Christian,Thiel, Werner R.
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supporting information
p. 4438 - 4444
(2020/08/10)
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- Vinylphosphonium Salt-Mediated Reactions: A One-Pot Condensation Approach for the Highly cis-Selective Synthesis of N-Benzoylaziridines and the Green Synthesis of 1,4,2-Dioxazoles as Two Important Classes of Heterocyclic Compounds
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An efficient, one-pot, and convenient approach for the reaction of the same precursors, trialkyl(aryl) phosphines, acetylene diesters, and benzhydroxamic acids has been developed to produce two important classes of heterocyclic compounds: N-benzoylaziridines and 1,4,2-dioxazoles. The strategy utilizes the intermediate solvation as a key step in product selectivity. The usefulness of the developed approach has been confirmed in the unprecedented highly cis-selective formation of the N-benzoylaziridines. In addition, the procedure provides a green alternative method for the synthesis of 1,4,2-dioxazoles employing a β-cyclodextrin nanoreactor in aqueous media.
- Aghahosseini, Hamideh,Ramazani, Ali,Jalayer, Nastaran Safarvand,Ranjdoost, Zahra,Souldozi, Ali,?lepokura, Katarzyna,Lis, Tadeusz
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supporting information
p. 22 - 26
(2019/01/11)
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- Substituent Effects on Reactions of [RhCl(COD)]2 with Diazoalkanes
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The reactions of [RhCl(COD)]2 with a series of diazoalkanes with different substitutents were investigated. The outcomes of the reactions were found to be substituent-dependent via four different pathways. (1) The reactions with diazoindenes produced ??5-cyclopentadienyl complexes. (2) The reaction with diazofluorene produced a mixture of olefin and azine compounds. (3) The reactions with monosubstituted diazoalkanes RCHN2 (R = Ph, MeO2C) produced olefins RCHa?CHR. (4) The reaction with the disubstituted diazoalkane Ph2CN2 produced the azine Ph2Ca?N-Na?CPh2 only. Computational studies have been carried out to understand the interesting substituent effect by comparing the kinetics and thermodynamics of the reaction pathways. It was found that the reactions with diazocyclopentadiene, diazoindene, and Ph2CN2 are kinetically controlled, while the reactions with RCHN2 and diazofluorene are both thermodynamically and kinetically controlled.
- Cui, Mingxu,Lin, Shujuan,Sung, Herman H. Y.,Williams, Ian D.,Lin, Zhenyang,Jia, Guochen
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p. 905 - 915
(2019/03/04)
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- Palladium nanodendrites uniformly deposited on the surface of polymers as an efficient and recyclable catalyst for direct drug modification via Z-selective semihydrogenation of alkynes
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The preparation of new monodisperse polycrystalline palladium nanoparticles uniformly distributed on the surface of polymers, by simply adding a palladium(ii) solution in water to the polymers, is described. The polymer supported palladium nanoparticles material was used as an efficient portable and reusable catalyst for the stereoselective semihydrogenation reaction of internal alkynes to (Z)-alkenes in green solvents.
- García-Calvo, José,Calvo-Gredilla, Patricia,Vallejos, Saúl,García, José Miguel,Cuevas-Vicario, José Vicente,García-Herbosa, Gabriel,Avella, Manuel,Torroba, Tomás
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supporting information
p. 3875 - 3883
(2018/08/21)
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- Dimethyl fumarate preparation method
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The invention relates to the chemical field, and especially relates to a dimethyl fumarate preparation method. The method adopts a chemical way to control the crystal form and the granularity of a BG-12 raw agent in a one step manner. The method realizes re-crystallization and crushing operating processes in the prior art only through one operating process in order to obtain pharmaceutical production meeting granularity, so severe irritant reaction brought for operators is avoided, and the production safety is greatly improved. The method has the advantages of simplicity in operation, easiness in control of parameters, stable result, and suitableness for large-scale production. The raw medicine with different granularity ranges can be obtained through adjusting technological parameters in order to avoid dust pollution, difficulty cleaning and allergy brought by crushing.
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Paragraph 0068; 0091-0132
(2017/08/27)
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- PROCESS FOR THE PREPARATION OF PHARMACEUTICAL GRADE DIMETHYL FUMARATE
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The present invention relates to a process for the preparation of dimethyl fumarate of formula (1) from fumaric acid of formula (3). The present process is simple, cost effective and feasible in large scale production. Dimethyl fumarate obtained by the present process is free of geno toxic impurities.
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Page/Page column 7
(2017/02/09)
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- Round Granules of Dimethyl Fumarate by Three-in-One Intensified Process of Reaction, Crystallization, and Spherical Agglomeration in a Common Stirred Tank
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Pure, isomorphic, round, and free-flowing dimethyl fumarate granules in a size range of 250-2000 μm were successfully produced directly from esterification through the three-in-one intensified process of three distinctive steps of reaction, crystallization, and spherical agglomeration (SA) in a 0.5 L sized jacketed glass stirred tank. Dimethyl fumarate was prepared by sulfuric acid catalyzed esterification of fumaric acid with methanol. The reaction temperature was below the maximum allowable limit of 65 °C as determined by reaction kinetics to avoid the runaway situation. The dissolution rate of primary crystals of dimethyl fumarate was inversely proportional to the particle size which was strongly affected by the antisolvent addition and temperature cooling schemes during crystallization. However, the dissolution rate of the round granules was mainly dependent on the exterior dimension of the granules and not so much on the primary crystal size inside the granules. The mechanical properties such as density, porosity Carr's index, friability, and fracture force of round dimethyl fumarate granules generated in (1) three-in-one processes with the final temperatures at either 5 or 25 °C (Three-in-one I and II) and (2) SA of dimethyl fumarate, which was done separately and disconnected from the train of reaction and crystallization process at either 5 or 25 °C (SA I and II), were thoroughly studied and compared. The concept of scale-up for Three-in-one I and II was also verified in a 10 L sized jacketed glass stirred tank. Powder manufacturability such as flowability, blend uniformity, and compressibility had been substantially enhanced by spherical agglomeration. The added values of free-flowing and easy-to-pack properties to dimethyl fumarate in addition to its original intrinsic slip planes in the crystal lattice would make direct compaction into tablets feasible.
- Chen, Chih Wei,Lee, Tu
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supporting information
p. 1326 - 1339
(2017/09/23)
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- The MOF-driven synthesis of supported palladium clusters with catalytic activity for carbene-mediated chemistry
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The development of catalysts able to assist industrially important chemical processes is a topic of high importance. In view of the catalytic capabilities of small metal clusters, research efforts are being focused on the synthesis of novel catalysts bearing such active sites. Here we report a heterogeneous catalyst consisting of Pd4 clusters with mixed-valence 0/+1 oxidation states, stabilized and homogeneously organized within the walls of a metal-organic framework (MOF). The resulting solid catalyst outperforms state-of-the-art metal catalysts in carbene-mediated reactions of diazoacetates, with high yields (>90%) and turnover numbers (up to 100,000). In addition, the MOF-supported Pd4 clusters retain their catalytic activity in repeated batch and flow reactions (>20 cycles). Our findings demonstrate how this synthetic approach may now instruct the future design of heterogeneous catalysts with advantageous reaction capabilities for other important processes.
- Fortea-Pérez, Francisco R.,Mon, Marta,Ferrando-Soria, Jesús,Boronat, Mercedes,Leyva-Pérez, Antonio,Corma, Avelino,Herrera, Juan Manuel,Osadchii, Dmitrii,Gascon, Jorge,Armentano, Donatella,Pardo, Emilio
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p. 760 - 766
(2017/07/04)
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- Method of selectively catalytically oxidizing biomass-based furan compound
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The invention discloses a method of selectively catalytically oxidizing a biomass-based furan compound. The method comprises the following step of: by taking a heteropolyacid functional ionic liquid as a catalyst and an alcohol solution as a reaction medium, obtaining dicarboxylic acid or dicarboxylate in the conditions that the reaction temperature is 100-150 DEG C, the reaction time is 1-3h and the oxygen pressure is 0.5-1.0MPa, wherein over 62.35% of difumarate selectivity is obtained. The single chemical yield and selectivity for oxidizing preparation of a biomass-based furan derivative are far higher than those of the prior art. The method has the remarkable advantage that an ionic liquid catalyst can be recovered and recycled by simply adjusting the temperature. The method disclosed by the invention is mild in reaction condition, green and safe in process and simple to operate, and can realize intermittent and continuous production.
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Paragraph 0110-0113
(2017/07/19)
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- METHOD FOR PRODUCING MONOMETHYL FUMARATE COMPOUNDS
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The present invention relates to a novel method for preparing monomethyl fumarate, which can preferably be used in the treatment and/or prevention of systemic diseases, autoimmune diseases, inflammatory diseases such as multiple sclerosis and psoriasis. Further, the present invention relates to the use of specific compounds as intermediates in the process for preparing a monomethyl fumarate prodrug.
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Page/Page column 53
(2017/07/14)
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- AN IMPROVED PROCESS FOR THE SYNTHESIS OF DIMETHYL FUMARATE
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The present invention describes an improved process for the industrial scale production of dimethyl fumarate. The process involves a one-pot ring opening reaction of maleic anhydride to monomethyl maleate and isomerization into the corresponding monomethyl fumarate in presence of a Lewis acid. Finally the mono methyl fumarate was converted into the dimethyl fumarate by an acid catalyzed esterification reaction.
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Paragraph 0028
(2017/05/10)
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- Parent-amido (NH2) palladium(II) complexes: Synthesis, reactions, and catalytic hydroamination
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The treatment of [PdL3(NH3)](OTf)n (n = 1; L3 = (PEt3)2(Ph), (2,6-(Cy2PCH2)2C6H3), n = 2; L3 = (dppe)(NH3)) with NaNH2 in tetrahydrofuran at ambient temperature or -78 °C afforded the dimeric and monomeric parent-amido palladium(II) complexes anti-[Pd(PEt3)(Ph)(μ-NH2)]2 (1), [Pd(dppe)(μ-NH2)]2(OTf)2 (2), and Pd(2,6-(Cy2PCH2)2C6H3)(NH2) (3), respectively. The molecular structures of the amido-bridged (μ-NH2) dimeric complexes 1 and 2 were determined by single-crystal X-ray crystallography. The monomeric amido complex 3 reacted with trace amounts of water to give a hydroxo complex, Pd(2,6-(Cy2PCH2)2C6H3)(OH) (4). Exposing complex 3 to an excess of water resulted in the complete conversion of the complex into two species [Pd(2,6-(Cy2PCH2)2C6H3)(OH2)]+ and [Pd(2,6-(Cy2PCH2)2C6H3)(NH3)]+. Complex 3 reacted with diphenyliodonium triflate ([Ph2I]OTf) to give the aniline complex [Pd(2,6-(Cy2PCH2)2C6H3)(NH2Ph)]OTf. The reaction of 3 with phenylacetylene (HCCPh) yielded a palladium(II) acetylenide Pd(2,6-(Cy2PCH2)2C6H3)(CCPh) (5), quantitatively, along with the liberation of ammonia. The reaction of 3 with dialkyl acetylenedicarboxylate yielded diastereospecific palladium(II) vinyl derivatives (Z)-Pd(2,6-(Cy2PCH2)2C6H3)(CRCR(NH2)) (R = CO2Me (6a), CO2Et (6b)). The reaction of complexes 6a and 6b with p-nitrophenol produced Pd(2,6-(Cy2PCH2)2C6H3)(OC6H4-p-NO2) (7) and cis-CHRCR(NH2), exclusively. Reactions of 3 with either dialkyl maleate (cis-(CO2R)CHCH(CO2R)) (R = CH3, CH2CH3) or cis-stilbene (cis-CHPhCHPh) did not result in any addition product. Instead, isomerization of the cis-isomers to the trans-isomers occurred in the presence of catalytic amounts of 3. Complex 3 reacted with a stoichiometric amount of acrylonitrile (CH2CHCN) to generate a metastable insertion product, Pd(2,6-(Cy2PCH2)2C6H3)(CH(CN)CH2NH2). On the other hand, the reaction of 3 with an excess of acrylonitrile slowly produced polymeric species of acrylonitrile. The catalytic hydroamination of olefins with NH3 was examined in the presence of Pd(2,6-(Cy2PCH2)2C6H3)(OTf), producing a range of hydroaminated products of primary, secondary, and tertiary amines with different molar ratios of more than 99% overall yield. A mechanistic feature for the observed catalytic hydroamination is described with regard to the aminated derivatives of palladium(II).
- Kim, Youngwon,Park, Soonheum
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p. 614 - 629
(2016/06/01)
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- Limits in Proton Nuclear Singlet-State Lifetimes Measured with para-Hydrogen-Induced Polarization
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The synthesis of a hyperpolarized molecule was developed, where the polarization and the singlet state were preserved over two controlled chemical steps. Nuclear singlet-state lifetimes close to 6 min for protons are reported in dimethyl fumarate. Owing to the high symmetry (AA′X3X3′ and A2 systems), the singlet-state readout requires either a chemical desymmetrization or a long and repeated spin lock. Using DFT calculations and relaxation models, we further determine nuclear spin singlet lifetime limiting factors, which include the intramolecular dipolar coupling mechanism (proton–proton and proton–deuterium), the chemical shift anisotropy mechanism (symmetric and antisymmetric), and the intermolecular dipolar coupling mechanism (to oxygen and deuterium). If the limit of paramagnetic relaxation caused by residual oxygen could be lifted, the intramolecular dipolar coupling to deuterium would become the limiting relaxation mechanism and proton lifetimes upwards of 26 min could become available in the molecules considered here (dimethyl maleate and dimethyl fumarate).
- Zhang, Yuning,Duan, Xueyou,Soon, Pei Che,Canary, James W.,Jerschow, Alexej,Sychrovsky, Vladimír
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p. 2967 - 2971
(2016/10/22)
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- PROCESS FOR PREPARATION OF DIMETHYL FUMARATE
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The present invention relates to a process for the preparation of dimethyl fumarate, a compound of formula I, in a purity of at least 99.0% as determined by HPLC, containing less than 400 ppm of an anion of a mineral acid and less than 5 ppm of dimethyl maleate.
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Paragraph 0149-161; 0165-0176
(2016/09/12)
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- NOVEL ACID DIANHYDRIDE, METHOD FOR PREPARING SAME, AND POLYIMIDE PREPARED THEREFROM
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The present invention relates to a novel acid dianhydride, a method for preparing the same, and a polyimide prepared therefrom. More specifically, the acid dianhydride according to the present invention is useful as a colorless transparent polyimide unit exhibiting excellent thermal stability and a low dielectric ratio, and the polyimide of the present invention has excellent solubility to an organic solvent compared with the conventional polyimide.
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Paragraph 0058; 0059
(2016/05/19)
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- A Short Synthesis of the Mould Metabolite (R)-(+)-Carolinic Acid from (S)-Lactic Acid
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(R)-(+)-Carolinic acid was prepared in seven steps and 59% yield from inexpensive benzyl l-lactate, the configuration of which was inverted by a Mitsunobu reaction with trifluoroacetate. The resulting benzyl d-lactate was cyclised by a domino addition-Wittig alkenation reaction with Ph3PCCO. The product tetronic acid was acylated with a second equivalent of this ylide to give a 3-acylylidenetetronic acid, which was olefinated directly with tert-butyl glyoxylate. The product alkene was hydrogenated and deprotected to afford pure crystalline (R)-(+)-carolinic acid, which proved inactive against Staphylococcus aureus and Escherichia coli mutant D21f2.
- Linder, David,Schobert, Rainer
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p. 4564 - 4568
(2016/12/14)
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- Synthesis and characterization of an A2BC type phthalocyanine and its visible-light-responsive photocatalytic H2 production performance on graphitic carbon nitride
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A highly asymmetric A2BC type zinc phthalocyanine (Zn-di-PcNcTh) has been designed and synthesized. The Zn-di-PcNcTh used a π electron rich thiophene ring in place of the benzenoid rings of phthalocyanine which acted as an electron donor, diphenylphenoxy substituents to retard aggregation and a carboxyl-naphthalene unit as an electron acceptor. The asymmetric phthalocyanine shows a strongly split Q-band and wide spectral absorption in the visible/near-IR light region, which can extend the spectral response region of graphitic carbon nitride (g-C3N4) from ~450 nm to more than 800 nm. By using it as a sensitizer of 1.0 wt% Pt-loaded graphitic carbon nitride (g-C3N4), the experimental results indicate that Zn-di-PcNcTh-Pt/g-C3N4 shows a H2 production efficiency of 249 μmol h-1 with an impressive turnover number (TON) of 9960.8 h-1 under visible light (λ ≥ 420 nm) irradiation, much higher than that of pristine Pt/g-C3N4. Owing to the introduction of a highly bathochromic shift of 3,4-dicyanothiophene and the valuable "push-pull" effect from the thiophene (electron donor) to the carboxyl-naphthalene (electron acceptor) unit, Zn-di-PcNcTh/g-C3N4 gives an extremely high apparent quantum yield (AQY) of 2.44%, 3.05%, and 1.53% under 700, 730, and 800 nm monochromatic light irradiation, respectively, under optimized photocatalytic conditions.
- Guo, Yingying,Song, Shuaishuai,Zheng, Ya,Li, Renjie,Peng, Tianyou
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supporting information
p. 14071 - 14079
(2016/11/05)
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- PROCESS FOR MAKING MICROCRYSTALLINE DIMETHYL FUMARATE
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The invention relates to a process for making a microcrystalline dimethyl fumarate comprising a step of providing a solution of dimethyl fumarate in methanol and combining the solution with water under precipitation of microcrystalline dimethyl fumarate.
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Page/Page column 10
(2016/01/25)
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- PROCESS FOR PREPARATION OF DIMETHYL-(E)-BUTENEDIOATE
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The present invention relates to a process for preparation of dimethyl-(E)-butenedioate(I). The process for preparation of dimethyl-(E)-butenedioate (I), comprises reaction of Fumaric acid with methanol in the presence of C2-C4alkanoyl halideas coupling catalyst.
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Paragraph 0061; 0062; 0063; 0064
(2016/11/28)
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- Selective partial hydrogenation of alkynes to (Z)-alkenes with ionic liquid-doped nickel nanocatalysts at near ambient conditions
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A selective hydrogenation method for forming (Z)-alkenes from alkynes has been developed using a catalyst system of cheap Ni-NPs in a nitrile functionalised imidazolium based ionic liquid (IL) operating under very mild reaction conditions of 30-50 °C and 1-4 bar H2 pressure.
- Konnerth, Hannelore,Prechtl, Martin H. G.
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supporting information
p. 9129 - 9132
(2016/07/22)
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- Electroreductive hydrogenation of activated olefins using the concept of site isolation
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Electroreductive hydrogenation of activated olefins was investigated using the concept of site isolation. It was shown by electrochemical measurements as well as preparative electrolyses that the use of silica gel-supported sulfonic acid (Si-SO3H) promotes the protonation step in electroreductive hydrogenation of activated olefins without electroreductive destruction at the cathode. On the basis of the concept of site isolation, electroreductive hydrogenation of several activated olefins was successfully carried out to provide the corresponding hydrogenation products in high yields.
- Tomida, Shinsuke,Tsuda, Ryohei,Furukawa, Shiho,Saito, Marie,Tajima, Toshiki
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- First Base-Free Catalytic Wittig Reaction
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The first base-free catalytic Wittig reaction utilizing readily available Bu3P (5 mol %) as an organocatalyst is reported. The initial Michael addition of the phosphine to a suitable acceptor substituted alkene ultimately results in the formation of an ylide which is subsequently converted with an aldehyde. The presented 1H NMR studies actually reveal evidence for the Michael addition and proposed ylide formation. Under the optimized reaction conditions various maleates and fumarates were converted with aromatic, heteroaromatic, and aliphatic aldehydes to evaluate the scope and limitations of this unprecedented reaction. Notably, maleates and fumarates react in a stereoconvergent fashion. The corresponding products were obtained in up to 95% isolated yield and E/Z-selectivities up to 99:1.
- Schirmer, Marie-Luis,Adomeit, Sven,Werner, Thomas
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p. 3078 - 3081
(2015/06/30)
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- Process Research and Development of an Enantiomerically Enriched Allyic Amine, One of the Key Intermediates for the Manufacture of Synthetic Tetracyclines
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A robust, cost-effective, and high yielding manufacturing process for enantiomerically enriched (S)-allylic amine 3, a key intermediate for fully synthetic tetracyclines have been developed. Two novel and scalable asymmetric vinylations resulting in high-to-excellent stereoselectivity have been developed for the key step. The final product is purified by an efficient crystallization of a l-tartaric salt. The process described has been used to manufacture ~350 kg of the tartaric salt of 3 with 99.0% ee in 8 steps (35% overall yield) from cheap and readily available dimethyl maleate.
- Zhang, Wu-Yan,Hogan, Philip C.,Chen, Chi-Li,Niu, John,Wang, Zhimin,Lafrance, Danny,Gilicky, Olga,Dunwoody, Nicholas,Ronn, Magnus
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p. 1784 - 1795
(2015/12/01)
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- Novel Acid Dianhydride, Mehtod for Preparing the Same and Polyimides Prepared from the Same
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The present invention relates to a novel acid dianhydride, a method for preparing the same, and a polyimide prepared therefrom. More specifically, the acid dianhydride according to the present invention is useful as a colorless transparent polyimide unit exhibiting excellent thermal stability and a low dielectric ratio, and the polyimide of the present invention has excellent solubility to an organic solvent compared with the conventional polyimide.
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Paragraph 0085; 0086
(2016/12/07)
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- Domino [4 + 1]-annulation of α,β-unsaturated δ-amino esters with Rh(ii)-carbenoids-a new approach towards multi-functionalized N-aryl pyrrolidines
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Catalytic decomposition of diazomalonates and other diazoesters using Rh(ii)- and Cu(ii)-complexes in the presence of α,β-unsaturated δ-(N-aryl)amino esters gives rise to the formation of multi-functionalized pyrrolidines with yields of up to 82%. The reaction apparently occurs as a domino process involving the initial N-ylide formation followed by intramolecular Michael addition to the conjugated system of amino esters to afford the pyrrolidine heterocycle. The whole process can also be classified as a [4 + 1]-annulation of the δ-amino α,β-unsaturated ester with the carbenoid intermediate. This journal is
- Medvedev,Galkina,Klinkova,Giera,Hennig,Schneider,Nikolaev
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supporting information
p. 2640 - 2651
(2015/06/08)
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- Synthesis and characterization of fully aliphatic polyimides from an aliphatic dianhydride with piperazine spacer for enhanced solubility, transparency, and low dielectric constant
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A new series of fully aliphatic polyimide (API) based on a novel aliphatic dianhydride monomer-2,2-(1,4-piperazinediyl)-disuccinic anhydride (PDA), in which two units of succinic anhydride have been connected by an aliphatic heterocyclic piperazine spacer that possesses aminomethylene (-NCH2) moiety in the aliphatic/alicylic backbone capable of inducing charge transfer (CT) interactions in the polyimide network, was successfully synthesized. The APIs were soluble in common polar organic solvents. The polyimide films of PDA with alicyclic diamines were almost colorless. T10 (temperature of 10% weight loss) of APIs were ranged from 299-418 C and Tg of API3-API6 were in the temperature range of 170 to 237 C. The light-colored polyimide films of API3-API6 possessed good mechanical properties with tensile strength of 54-72 Mpa, tensile modulus of 1.6-2.3 Gpa and elongation at break of 4-9%. The polyimide films of API3-API6 were highly flexible and free-standing which is quite rare in fully APIs. The dielectric constant of one of the synthesized API (API4) was as low as 2.14.
- Tapaswi, Pradip Kumar,Choi, Myeon-Cheon,Jung, Young Sik,Cho, Hun Jeong,Seo, Deok Jin,Ha, Chang-Sik
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p. 2316 - 2328
(2014/07/21)
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- Promoted role of Cu(NO3)2 on aerobic oxidation of 5-hydroxymethylfurfural to 2,5-diformylfuran over VOSO4
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The promoted effect of Cu(NO3)2 on aerobic oxidation of 5-hydroxymethylfurfural (HMF) to 2,5-diformylfuran (DFF) catalyzed by VOSO4 in acetonitrile was intensively investigated. It was revealed that Cu(NO3)2 facilitated the activation of VOSO 4 to generate active V5+ species via the generation of NOx gas. The high DFF selectivity is ascribed to Cu2+ cation which can effectively prohibit oxidative CC bond cleavage reaction of HMF and prevent radical reaction of DFF to humins. In addition, the polarity of solvent plays a great role on high selectivity of DFF.
- Jia, Xiuquan,Ma, Jiping,Wang, Min,Du, Zhongtian,Lu, Fang,Wang, Feng,Xu, Jie
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p. 231 - 236
(2014/07/08)
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- New reactions of terminal hydrides on a diiron dithiolate
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Mechanisms for biological and bioinspired dihydrogen activation and production often invoke the intermediacy of diiron dithiolato dihydrides. The first example of such a Fe2(SR)2H2 species is provided by the complex [(term-H)(μ-H)Fe2(pdt)(CO)(dppv) 2] ([H1H]0). Spectroscopic and computational studies indicate that [H1H]0 contains both a bridging hydride and a terminal hydride, which, notably, occupies a basal site. The synthesis begins with [(μ-H)Fe2(pdt)(CO)2(dppv)2]+ ([H1(CO)]+), which undergoes substitution to afford [(μ-H)Fe 2(pdt)(CO)(NCMe)(dppv)2]+ ([H1(NCMe)] +). Upon treatment of [H1(NCMe)]+ with borohydride salts, the MeCN ligand is displaced to afford [H1H]0. DNMR (EXSY, SST) experiments on this complex show that the terminal and bridging hydride ligands interchange intramolecularly at a rate of 1 s-1 at -40 °C. The compound reacts with D2 to afford [D1D]0, but not mixed isotopomers such as [H1D]0. The dihydride undergoes oxidation with Fc+ under CO to give [1(CO)]+ and H2. Protonation in MeCN solution gives [H1(NCMe)]+ and H2. Carbonylation converts [H1H]0 into [1(CO)]0.
- Wang, Wenguang,Rauchfuss, Thomas B.,Zhu, Lingyang,Zampella, Giuseppe
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p. 5773 - 5782
(2014/05/06)
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- Reaction of Tri(2-pyridyl)phosphine with Electron-Deficient Alkynes in Water: Stereoselective Synthesis of Functionalized Pyridylvinylphosphine Oxides
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The reaction of tri(2-pyridyl)phosphine with electron-deficient alkynes in water proceeds under mild conditions (40-45 C, without catalyst, 4-5 h) with liberation of pyridine to give (E)-pyridylvinylphosphine oxides in 45-56 % yields, the only exception being the reaction with cyanophenylacetylene, which affords the corresponding vinylphosphine oxide of Z-configuration in 40 % yield. The reaction is likely triggered by the zwitterion, the adduct of tri(2-pyridyl)phosphine to the electrophilic acetylenes, the carbanionic center of which is then neutralized by a proton from water. The intermediate phosphonium hydroxide finally decomposes to the product.
- Arbuzova, Svetlana N.,Gusarova, Nina K.,Glotova, Tatyana E.,Ushakov, Igor A.,Verkhoturova, Svetlana I.,Korocheva, Anastasiya O.,Trofimov, Boris A.
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p. 639 - 643
(2015/10/05)
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- A facile synthesis of pechmann dyes
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A facile synthesis of Pechmann dyes has been accomplished by the reaction of substituted N-phenacyl-4-dimethylaminopyridinium halides with dimethyl maleate in the presence of DBU. Based on a related 4-DMAP elimination product and an isolated monolactone intermediate a reaction mechanism has been proposed. The scope of this synthetic method is determined by the availability of α-haloaroyl or heteroaroyl derivatives. DBU=1,8-diazabicycloundec-7-ene, DMAP=4-dimethylaminopyridine. A facile synthesis of Pechmann dyes has been accomplished by the reaction of substituted N-phenacyl-4-dimethylaminopyridinium halides with dimethyl maleate in the presence of DBU (see scheme). Based on a related 4-DMAP elimination product and an isolated monolactone intermediate a reaction mechanism has been proposed. The scope of this synthetic method is determined by the availability of α-haloaroyl or heteroaroyl derivatives. DBU=1,8-diazabicycloundec-7-ene, DMAP=4-dimethylaminopyridine.
- Hopf, Henning,Jones, Peter G.,Nicolescu, Alina,Bicu, Elena,Birsa, Lucian M.,Belei, Dalila
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supporting information
p. 5565 - 5568
(2014/05/20)
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- Rhodium-catalyzed intermolecular [2 + 2] cycloaddition of terminal alkynes with electron-deficient alkenes
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The first catalytic intermolecular [2 + 2] cycloaddition of terminal alkynes with electron-deficient alkenes is reported. The reaction proceeds with an 8-quinolinolato rhodium/phosphine catalyst system to give cyclobutenes from various substrates having polar functional groups in high yields with complete regioselectivity.
- Sakai, Kazunori,Kochi, Takuya,Kakiuchi, Fumitoshi
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supporting information
p. 1024 - 1027
(2013/04/10)
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- Liberation of methyl acrylate from metallalactone complexes via M-O ring opening (M = Ni, Pd) with methylation agents
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Ring opening of various nickela- and palladalactones induced by the cleavage of the M-O bond by methyl trifluoromethanesulfonate (MeOTf) and methyl iodide (MeI) is examined. Experimental evidence supports the mechanism of ring opening by the alkylating agent followed by β-H elimination leading to methyl acrylate and a metal-hydride species. MeOTf shows by far higher efficiency in the lactone ring opening than any other methylating agent including the previously reported methyl iodide.
- Lee, S. Y. Tina,Ghani, Amylia Abdul,D'Elia, Valerio,Cokoja, Mirza,Herrmann, Wolfgang A.,Basset, Jean-Marie,Kuehn, Fritz E.
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supporting information
p. 3512 - 3517
(2013/11/06)
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- Nickel-catalyzed intermolecular [2 + 2] cycloaddition of conjugated enynes with alkenes
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A nickel-catalyzed intermolecular [2 + 2] cycloaddition of conjugated enynes with alkenes has been developed. A variety of electron-deficient alkenes as well as electronically neutral norbornene and 1-decene were applicable to this reaction. The use of conjugated enynes circumvented possible side rections, such as oligomerizations and cyclotrimerizations. The isolation of reaction intermediate complexes revealed that the ν3-butadienyl coordination is the key for the selective formation of cyclobutene.
- Nishimura, Akira,Ohashi, Masato,Ogoshi, Sensuke
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supporting information
p. 15692 - 15695
(2012/11/07)
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- PROCESS FOR PREPARING HIGH PURITY AND CRYSTALLINE DIMETHYL FUMARATE
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The present invention describes a process for the preparation of dimethyl fumarate. The process involves the esterification of fumaric acid and methanol in the presence of sulfuric acid as an acid catalyst. The high purity dimethyl fumarate contains no more than trace amounts of dimethyl sulfate. The present invention also provides a process for the preparation of highly pure dimethyl fumarate with a particle size from 20 to 250 μπι.
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Page/Page column 20
(2013/02/27)
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- Mechanisms by which alkynes react with CpCr(CO)3H. Application to radical cyclization
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The reaction of CpCr(CO)3H with activated alkynes in benzene has been examined. The kinetics of these reactions have been studied with various alkynes, along with the stereochemistry with which the alkynes are hydrogenated. The hydrogenation of phenyl acetylene and diphenyl acetylene with CpCr(CO) 3H has been shown to occur by a hydrogen atom transfer (HAT) mechanism. The reaction of CpCr(CO)3H with dimethyl acetylenedicarboxylate (DMAD) produced hydrogenated products as well as phenyl substitution from reaction with solvent. On the basis of kinetic data, it is thought that the reaction of DMAD may proceed via a single electron transfer (SET) as the rate-determining step. The radical anion of dimethylfumarate was observed by EPR spectroscopy during the course of the reaction, supporting this claim. The aromatic 1,6 eneyne (8) gave cyclized products in 78% yield under catalytic conditions (35 psi H2), presumably by the 5-exo-trig cyclization of the vinyl radical arising from H? transfer. Using a cobaloxime catalyst (12) hydrogenation was completely eliminated to yield 100% cyclized products.
- Estes, Deven P.,Norton, Jack R.,Jockusch, Steffen,Sattler, Wesley
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p. 15512 - 15518
(2012/11/13)
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- Alkyl sulfonate functionalized ionic liquids: Synthesis, properties, and their application in esterification
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Ionic liquids based on alkyl sulfate anions and alkyl sulfonate functionalized cations were prepared from commercially available and cheap materials and their thermal-instability properties were studied in detail. These ionic liquids were active catalysts for esterification and they gave moderate to high yields. The catalytic performance was found to be much better than that of conventional non-cation functionalized ionic liquids and close to sulfonic acid functionalized ionic liquids. The catalytic process in this reaction was investigated by electrospray ionization mass spectrometry and a plausible reaction mechanism is suggested.
- Zhao, Yingwei,Li, Zhen,Xia, Chungu
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experimental part
p. 440 - 445
(2012/05/04)
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- Highly selective iron-catalyzed synthesis of alkenes by the reduction of alkynes
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Herein, the iron-catalyzed reduction of a variety of alkynes with silanes as a reductant has been examined. With a straightforward catalyst system composed of diiron nonacarbonyl and tributyl phosphane, excellent yields and chemoselectivities (>99 %) were obtained for the formation of the corresponding alkenes. After studying the reaction conditions, and the scope and limitations of the reaction, several attempts were undertaken to shed light on the reaction mechanism. Im Rahmen dieser Arbeit wird die Eisen-katalysierte Reduktion von Alkinen zu den entsprechenden Alkenen mit Hilfe von Silanen vorgestellt. Hierbei konnten exzellente Ausbeuten und Selektivitaeten (>99 %) durch die Modifikation des eingesetzten Eisenkatalysators mit Phosphanen beobachtet werden. Nach genauer Untersuchung verschiedenster Reaktionsparameter wurden die hervorragenden Eigenschaften des Katalysatorsystems in der Reduktion zahlreicher Alkine gezeigt. Zum besseren Verstaendnis der Reaktion wurden verschiedene mechanistische Experimente durchgefuehrt. Iron Made′m: In situ generated iron complexes catalyze the reduction of alkynes with silanes as a hydride source with excellent selectivity (>99 %). Copyright
- Enthaler, Stephan,Haberberger, Michael,Irran, Elisabeth
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experimental part
p. 1613 - 1623
(2012/06/04)
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- One-pot esterification and Ritter reaction: Chemo- and regioselectivity from tert-butyl methyl ether
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tert-Butyl methyl ether (TBME) has been effectively used as a reagent for esterification of carboxylic acids. By varying amounts of sulfuric acid, a remarkable regioselectivity in esterification has been demonstrated. Additionally, under the present reaction conditions, one-pot esterification and Ritter reaction are achieved in almost quantitative yield.
- Dawar, Pankaj,Bhagavan Raju,Ramakrishna, Ramesha A.
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supporting information; experimental part
p. 4262 - 4265
(2011/08/21)
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- Effect of imidazolium salts on the catalytic reaction of 1,3-dioxolanes with methyl diazoacetate
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Effect of imidazolium salts, [bmim]+Cl-, [bmim] +BF4 -, and [bmim]+PF6 -, on the reaction of 1,3-dioxolanes with methyl diazoacetate in the presence of copper-containing catalysts was studied. The product composition was found to depend on the reaction conditions and the nature and ratio of components of the catalytic system.
- Ivanova,Sultanova,Zlotskii
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experimental part
p. 106 - 108
(2011/06/18)
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- In situ generated bulky palladium hydride complexes as catalysts for the efficient isomerization of olefins. Selective transformation of terminal alkenes to 2-alkenes
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Application of an in situ generated bulky palladium(II) hydride catalyst obtained from a 1:1:1 mixture of Pd(dba)2, P(tBu)3, and isobutyryl chloride provides an efficient protocol for the isomerization and migration of a variety of olefins. In addition to the isomerization of (Z)- to (E)-olefins, the conjugative migration of allylbenzenes, allyl ethers, and amines was effectively achieved in near-quantitative yields and with excellent functional group tolerance. Catalyst loadings in the range of 0.5-1.0 mol % were typically applied, but even loadings as low as 0.25 mol % could be achieved when the reactions were performed under neat conditions. More interestingly, the investigated catalyst proved to be selective for converting terminal alkenes to 2-alkenes. This one-carbon migration process for monosubstituted olefins provides an alternative catalyst, which bridges the gap between the allylation and propenylation/vinylation protocols. Several substrates, including homoallylic alcohols and amines, were selectively transformed into their corresponding 2-alkenes, and examples using enantiomerically enriched substrates provided products without epimerization at the allylic stereogenic carbon centers. Finally, some mechanistic investigations were undertaken to understand the nature of the active in situ generated Pd-H catalyst. These studies revealed that the catalytic system is highly dependent on the large steric demand of the P(tBu)3 ligand. The use of an alternative ligand, cataCXium PinCy, also proved effective for generating an active catalyst, and it was demonstrated in some cases to display better selectivity for the one-carbon shifts of terminal olefins. A possible intermediate involved in the preparation of the active catalyst was characterized by its single-crystal X-ray structure, which revealed a monomeric tricoordinated palladium(II) acyl complex, bearing a chloride ligand.
- Gauthier, Delphine,Lindhardt, Anders T.,Olsen, Esben P. K.,Overgaard, Jacob,Skrydstrup, Troels
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supporting information; experimental part
p. 7998 - 8009
(2010/08/04)
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- Chemical synthesis of fully biomass-based poly(butylene succinate) from inedible-biomass-based furfural and evaluation of its biomass carbon ratio
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We have produced fully biomass-based poly(butylene succinate) (PBS) from furfural produced from inedible agricultural cellulosic waste. Furfural was oxidized to give fumaric acid. Fumaric acid was hydrogenated under high pressure with a palladium-rhenium/carbon catalyst to give 1,4-butanediol, and with a palladium/carbon catalyst to give succinic acid. Dimethyl succinate was synthesized from fumaric acid by esterification and hydrogenation under normal pressure. Fully biomass-based PBS was obtained by polycondensation of biomass-based 1,4-butanediol and biomass-based succinic acid or dimethyl succinate. The biomass carbon ratio calculated from 14C concentrations measured by accelerator mass spectroscopy (AMS) verified that the PBS obtained in this study contained only biomass carbon. The polycondensation of biomass-based 1,4-butanediol and petroleum-based terephthalic acid or dimethyl terephthalate gave partially biomass-based poly(butylene terephthalate), which is an engineering plastic.
- Tachibana, Yuya,Masuda, Takashi,Funabashi, Masahiro,Kunioka, Masao
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experimental part
p. 2760 - 2765
(2011/11/12)
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- Bafilomycins produced in culture by streptomyces spp. isolated from marine habitats are potent inhibitors of autophagy
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Five new bafilomycins, F (1) to J (5), have been isolated from laboratory cultures of two Streptomyces spp. obtained from marine sediments collected in British Columbia, and their structures have been elucidated by detailed analysis of spectroscopic data and the synthesis of model compounds. The new bafilomycins F (1), G (2), H (3), and J (5) along with several co-occurring known analogues showed potent inhibition of autophagy in microscopy and biochemical assays. The thiomorpholinone fragment present in bafilomycin F (1) has not previously been found in a natural product.
- Carr, Gavin,Williams, David E.,Diaz-Marrero, Ana R.,Patrick, Brian O.,Bottriell, Helen,Balgi, Aruna D.,Donohue, Elizabeth,Roberge, Michel,Andersen, Raymond J.
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experimental part
p. 422 - 427
(2010/08/05)
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- The mechanism of on-water catalysis
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Acid catalysis by interfacial water: A new mechanism is proposed for onwater catalysis, the acceleration of organic reactions when conducted in aqueous emulsions. It involves the protonation of a substrate by water, driven by the strong adsorption of hydroxide ions at aqueous interfaces with oils. This accounts for the specific role of water, and a deuterium isotope effect, at the interface, on reactions known to be acid-catalysed.
- Beattie, James K.,McErlean, Christopher S. P.,Phippen, Christopher B. W.
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supporting information; experimental part
p. 8972 - 8974
(2010/10/02)
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- Tetrahydropyran synthesis by intramolecular conjugate addition to enones: Synthesis of the clavosolide tetrahydropyran ring
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The synthesis of a tetrahydropyran intermediate for clavosolide A is reported, employing a combination of cross-metathesis and intramolecular oxa-Michael addition. The intramolecular oxa-Michael addition to ,-unsaturated esters requires the use of strong bases and can result in either modest yields or stereoisomeric mixtures, and can be highly variable according to the substrate structure. In contrast, the corresponding ketones cyclise under very mild conditions to give the 2,6-cis-isomers directly. The use of appropriately substituted ketones allows efficient conversion into esters.
- Bates, Roderick W.,Song, Ping
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experimental part
p. 2935 - 2942
(2010/10/21)
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