- Design, synthesis, and insecticidal activities of novel monohalovinylated pyrethroids
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A series of novel monohalovinylated pyrethroids are designed and synthesized to replace one halo atom with a hydrogen atom on the double bond of dihalopyrethroids. Bioassays indicate that some of the synthesized compounds, such as 3j and 1j, exhibit high insecticidal activities against mosquitoes (Culex pipiens pallens), oriental armyworms (Mythimna separata), alfalfa aphids (Aphis medicagini), and carmine spider mites (Tetranychus cinnabarinus). Photolytic results of E-cis-1j suggest that monohalovinylated pyrethroids are photodegraded more easily than compound 12.
- Zheng, Zubiao,Wang, Jing,Zhang, Deyan,Guan, Xixia,Gao, Shuxu,Chen, Zizhan,Zou, Xinzhuo
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Read Online
- β,β-DIMETHYLACRYLIC ACID
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A method has been developed for obtaining β,β-dimethylacrylic acid from 3-methylbut-3-en-1-ol - a multitonnage product of the production of isoprene by the Prins method.
- Sargsyan, M. S.,Mkrtumyan, S. A.,Avakyan, O. V.,Manukyan, A. T.,Gevorkyan, A. A.
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Read Online
- MANUFACTURING METHOD OF PENTYL ALCOHOL
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A method for preparing methyl butenoic acid using (A) acetone is provided to economically mass-produce a pentyl alcohol economically. Reducing a (B)-methyl butenoic acid with a reducing agent. The present invention relates to a method for producing a pentyl alcohol comprising.
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Paragraph 0068-0069
(2021/08/05)
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- Masked Amino Trimethyl Lock (H2N-TML) Systems: New Molecular Entities for the Development of Turn-On Fluorophores and Their Application in Hydrogen Sulfide (H2S) Imaging in Human Cells
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Masked trimethyl lock (TML) systems as molecular moieties enabling the bioresponsive release of compounds or dyes in a controlled temporal and spatial manner have been widely applied for the development of drug conjugates, prodrugs or molecular imaging tools. Herein, we report the development of a novel amino trimethyl lock (H2N-TML) system as an auto-immolative molecular entity for the release of fluorophores. We designed Cou-TML-N3 and MURh-TML-N3, two azide-masked turn-on fluorophores. The latter was demonstrated to selectively release fluorescent MURh in the presence of physiological concentrations of the redox-signaling molecule H2S in vitro and was successfully applied to image H2S in human cells.
- Br?nstrup, Mark,Fuchs, Hazel Leanne Sarah,Grunenberg, J?rg,Jimidar, Claire Cheyenne,Karge, Bianka,Klahn, Philipp
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- Direct 3-Acylation of Indolizines by Carboxylic Acids for the Practical Synthesis of Red Light-Releasable Caged Carboxylic Acids
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To enhance the practicality of photouncaging system using 3-acyl-2-methoxyindolizines, direct acylation of indolizines with carboxylic acids was developed using condensation reagents, generally used for peptide coupling. This method allowed for caging a broad range of carboxylic acids with indolizines. The method enabled a facile synthesis of water-soluble caged bioactive carboxylic acids having an intramolecular photosensitizer. The efficient release of carboxylic acids from the synthesized caged compounds upon red light irradiation was confirmed in neutral buffered solutions.
- Watanabe, Kenji,Terao, Nodoka,Niwa, Takashi,Hosoya, Takamitsu
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p. 11822 - 11834
(2021/07/31)
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- Synthesis and Exploration of Abscisic Acid Receptor Agonists Against Dought Stress by Adding Constraint to a Tetrahydroquinoline-Based Lead Structure
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New oxotetrahydroquinolinyl- and oxindolinyl sulfonamides interacting with RCAR/(PYR/PYL) receptor proteins were identified as lead structures against drought stress in crops starting from protein docking studies of a sulfonamide lead structure, followed by in-depth SAR studies. Optimized five to six step synthetic approaches via substituted amino oxo-tetrahydro-quinolines and amino oxo-indolines as essential intermediates gave access to the envisaged oxo-tetrahydroquinolinyl and oxindolinyl sulfonamides. Whilst oxo-tetrahydroquinolinyl sulfonamides with additional carbon substituents or spiro-cycloalkyl groups exhibited only low to moderate target affinities, the corresponding spiro-oxindolinyl and oxo-tetrahydroquinolinyl sulfonamides carrying optimized N-substituents revealed strong interactions with RCAR/(PYR/PYL) receptor proteins in Arabidopsis thaliana. Remarkably, the in vitro activity observed for these new compounds was on the same level as observed for the naturally occurring plant hormone in line with strong efficacy against drought stress in-vivo (canola and wheat as broad-acre crops).
- Baltz, Rachel,Bojack, Guido,Dittgen, Jan,Fischer, Christian,Frackenpohl, Jens,Freigang, J?rg,Getachew, Rahel,Grill, Erwin,Helmke, Hendrik,Hohmann, Sabine,Lange, Gudrun,Lehr, Stefan,Porée, Fabien,Schmidt, Jana,Schmutzler, Dirk,Yang, Zhenyu
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p. 3442 - 3457
(2021/06/25)
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- Quantitative production of butenes from biomass-derived γ-valerolactone catalysed by hetero-atomic MFI zeolite
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The efficient production of light olefins from renewable biomass is a vital and challenging target to achieve future sustainable chemical processes. Here we report a hetero-atomic MFI-type zeolite (NbAlS-1), over which aqueous solutions of γ-valerolactone (GVL), obtained from biomass-derived carbohydrates, can be quantitatively converted into butenes with a yield of >99% at ambient pressure under continuous flow conditions. NbAlS-1 incorporates simultaneously niobium(v) and aluminium(iii) centres into the framework and thus has a desirable distribution of Lewis and Br?nsted acid sites with optimal strength. Synchrotron X-ray diffraction and absorption spectroscopy show that there is cooperativity between Nb(v) and the Br?nsted acid sites on the confined adsorption of GVL, whereas the catalytic mechanism for the conversion of the confined GVL into butenes is revealed by in situ inelastic neutron scattering, coupled with modelling. This study offers a prospect for the sustainable production of butene as a platform chemical for the manufacture of renewable materials.
- Lin, Longfei,Sheveleva, Alena M.,da Silva, Ivan,Parlett, Christopher M. A.,Tang, Zhimou,Liu, Yueming,Fan, Mengtian,Han, Xue,Carter, Joseph H.,Tuna, Floriana,McInnes, Eric J. L.,Cheng, Yongqiang,Daemen, Luke L.,Rudi?, Svemir,Ramirez-Cuesta, Anibal J.,Tang, Chiu C.,Yang, Sihai
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- Synergistic N-Heterocyclic Carbene/Palladium-Catalyzed [3 + 2] Annulation of Vinyl Enolates with 1-Tosyl-2-vinylaziridine
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The synergistic combination of N-heterocyclic carbene organocatalysis and transition-metal catalysis for a formal [3 + 2] annulation between 3-substituted but-2-enoates and 1-tosyl-2-vinylaziridine was developed. This cooperative strategy provides a facile and efficient access to various functionalized (E)-3-ethylidene-4-vinylpyrrolidin-2-ones in a regioselective and stereoselective manner. The preliminary asymmetric studies were also performed, which indicated a potential for enantioselective annulation of vinyl enolate intermediates with transition-metal-π-allyl species.
- Gao, Jian,Zhang, Jianming,Fang, Shuaishuai,Feng, Jie,Lu, Tao,Du, Ding
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supporting information
p. 7725 - 7729
(2020/10/09)
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- Highly efficient oxidation of alcohols to carboxylic acids using a polyoxometalate-supported chromium(iii) catalyst and CO2
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Direct catalytic oxidation of alcohols to carboxylic acids is very attractive, but economical catalysis systems have not yet been well established. Here, we show that a pure inorganic ligand-supported chromium compound, (NH4)3[CrMo6O18(OH)6] (simplified as CrMo6), could be used to effectively promote this type of reaction in the presence of CO2. In almost all cases, oxidation of various alcohols (aromatic and aliphatic) could be achieved under mild conditions, and the corresponding carboxylic acids can be achieved in high yield. The chromium catalyst 1 can be reused several times with little loss of activity. Mechanism study and control reactions demonstrate that the acidification proceeds via the key oxidative immediate of aldehydes.
- Han, Sheng,Wang, Ying,Wei, Yongge,Wu, Zhikang,Yu, Han
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p. 3150 - 3154
(2020/06/19)
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- Supramolecular photochemistry of encapsulated caged: Ortho -nitrobenzyl triggers
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ortho-Nitrobenzyl (oNB) triggers have been extensively used to release various molecules of interest. However, the toxicity and reactivity of the spent chromophore, o-nitrosobenzaldehyde, remains an unaddressed difficulty. In this study we have applied the well-established supramolecular photochemical concepts to retain the spent trigger o-nitrosobenzaldehyde within the organic capsule after release of water-soluble acids and alcohols. The sequestering power of organic capsules for spent chromophores during photorelease from ortho-nitrobenzyl esters, ethers and alcohols is demonstrated with several examples.
- Kamatham, Nareshbabu,Raj, A. Mohan,Givens, Richard S.,Da Silva, José P.,Ramamurthy
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p. 2411 - 2420
(2019/10/21)
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- An Efficient Aerobic Oxidation Protocol of Aldehydes to Carboxylic Acids in Water Catalyzed by an Inorganic-Ligand-Supported Copper Catalyst
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A method for the aerobic oxidation of aldehydes to carboxylic acids in water by using an inorganic-ligand-supported copper catalyst was developed. This method was performed with the use of atmospheric oxygen as the sole oxidant under extremely mild aqueous conditions, and furthermore, a wide range of aldehydes with various functional groups were tolerated. The copper catalyst could be recycled and used in successive reactions at least six times without any appreciable degradation in performance. This method is operationally simple and avoids the use of high-costing, toxic, air/moisture-sensitive, and commercially unavailable organic ligands. The generality of this method gives it potential to be used on the industrial scale.
- Yu, Han,Ru, Shi,Zhai, Yongyan,Dai, Guoyong,Han, Sheng,Wei, Yongge
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p. 1253 - 1257
(2018/02/16)
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- DMAP-Catalyzed [4 + 2] Cycloaddition of α,β-Unsaturated Carboxylic Acids with Ketones for Synthesis of α,β-Unsaturated δ-Lactones
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The DMAP-catalyzed [4 + 2] cycloaddition of α,β-unsaturated carboxylic acids with ketones furnishing α,β-unsaturated δ-lactones in good yields (up to 80%) is described, which is the first example of remote γ-C(sp3)-H activation of α,β-unsaturated carboxylic acids facilitated by DMAP, a pyridine-based catalyst. Copyright
- Jin, Jinghai,Xu, Qinchang,Deng, Weiping
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supporting information
p. 397 - 400
(2017/04/27)
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- Formation of 2,2-dimethylchroman-4-ones during the photoinduced rearrangement of some aryl 3-methyl-2-butenoate esters. A mechanistic insight
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Several aryl 3-methyl-2-butenoate esters upon irradiation lead to the formation of [1,3]-migrated photoproducts, phenol and, surprisingly 2,2-dimethylchroman-4-one derivatives. The starting photochemical reaction takes place from the singlet excited state of the ester and as a total mechanism two consecutive reaction pathways are proposed. The former involves the photo-Fries rearrangement of the esters in all the solvents studied and, depending on the proticity of the solvent, the latter involves an ESIPT process followed by thermal 6π-electrocyclic reaction and/or thermal (intramolecular oxa-Michael addition) cyclization of the ortho regioisomers photoformed. This second pathway is responsible of the formation of the 2,2-dimethylchroman-4-one derivatives.
- Iguchi, Daniela,Erra-Balsells, Rosa,Bonesi, Sergio M.
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p. 1903 - 1910
(2016/04/05)
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- METHODS FOR PRODUCING 3-HYDROXY-3-METHYLBUTYRIC ACID
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Described is a method for the conversion of 3-methylcrotonyl-CoA into 3-hydroxy-3- methylbutyric acid comprising the steps of: (a) enzymatically converting 3-methylcrotonyl-CoA into 3-hydroxy-3-methylbutyryl-CoA; and (b) further enzymatically converting the thus produced 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyric acid wherein the enzymatic conversion of 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyric acid according to step (b) is achieved by first converting 3-hydroxy-3-methylbutyryl-CoA into 3-hydroxy-3-methylbutyryl phosphate and then subsequently converting the thus produced 3-hydroxy-3-methylbutyryl phosphate into 3-hydroxy-3-methylbutyric acid.
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- Catalytic Fehling's Reaction: An Efficient Aerobic Oxidation of Aldehyde Catalyzed by Copper in Water
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The first example of homogeneous copper-catalyzed aerobic oxidation of aldehydes is reported. This method utilizes atmospheric oxygen as the sole oxidant, proceeds under extremely mild aqueous conditions, and covers a wide range of various functionalized aldehydes. Chromatography is generally not necessary for product purification.
- Liu, Mingxin,Li, Chao-Jun
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supporting information
p. 10806 - 10810
(2016/09/03)
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- Iron-catalyzed selective oxidation of α,β-unsaturated aldehydes to α,β-unsaturated carboxylic acids by molecular oxygen
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Selective oxidation of α,β-unsaturated aldehydes to α,β-unsaturated carboxylic acids was performed using O2 as the oxidant in the presence of a simple iron catalyst. The addition of an alkali metal carboxylate as a cocatalyst enhanced the selectivity for the desired product. Redox tuning of the iron catalyst via association with the alkali metal led to a controlled radical generation during the catalytic O2 oxidation.
- Tanaka, Shinji,Kon, Yoshihiro,Uesaka, Yumiko,Morioka, Ryo,Tamura, Masanori,Sato, Kazuhiko
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supporting information
p. 188 - 190
(2016/03/01)
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- MANUFACTURING METHOD OF α,β-UNSATURATED CARBOXYLIC ACID
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PROBLEM TO BE SOLVED: To provide a manufacturing method which can get α,β-unsaturated carboxylic acid at a high yield by liquid phase oxidation of α,β-unsaturated aldehyde by oxygen or air with a handy metal catalyst under a mild reaction condition. SOLUTION: Preferably under a presence of organic solvent, α,β-unsaturated carboxylic acid is manufactured by oxidation of α,β-unsaturated aldehydes and oxygen or air under a presence of an iron salt catalyst and a catalyst of alkali metal salt of carboxylic acid. SELECTED DRAWING: None COPYRIGHT: (C)2017,JPOandINPIT
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Paragraph 0050-0052
(2018/10/16)
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- Photorelease of incarcerated guests in aqueous solution with phenacyl esters as the trigger
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We report the clean, efficient photorelease of a series of carboxylic acids embedded in octa acid (OA) host and protected by a p-hydroxyphenacyl cage. A key role is played by the cage by providing hydrophobicity for entry into the OA enclosure and yet readily removable as a photoactivated protecting group for release from the host. The rapid photo-Favorskii rearrangement of the departing chromophore does not react with the host OA but diminishes hydrophobicity of the OA contents, leading to their facile release into the solvent.
- Jagadesan, Pradeepkumar,Da Silva, José P.,Givens, Richard S.,Ramamurthy
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p. 1276 - 1279
(2015/05/20)
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- Release of guests from encapsulated masked hydrophobic precursors by a phototrigger
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Examples of release of organic acids from encapsulated p-methoxyphenacyl esters provided here demonstrate the value of a phototrigger strategy to release chemicals of interest in water from hydrophobic precursors. In this study, a photochemical β-cleavage process centered on the p-methoxyphenacyl group is exploited to release the acid of interest from a water-soluble capsule made up of octa acid.
- Jayaraj, Nithyanandhan,Jagadesan, Pradeepkumar,Samanta, Shampa R.,Da Silva, Jose P.,Ramamurthy
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supporting information
p. 4374 - 4377
(2013/09/24)
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- Epoxidation of olefins with O2 and isobutyraldehyde catalyzed by cobalt (II)-containing zeolitic imidazolate framework material
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Co-containing zeolitic imidazolate framework material (Co-ZIF) was prepared and its catalytic performance in the aerobic epoxidation of olefins using isobutyraldehyde as reductant under mild conditions was first studied. Co-ZIF was characterized by XRD, FT-IR and X-ray single-crystal diffraction. It showed good performance in the epoxidation of olefins, with 100% conversion, 98.5% selectivity and 638.3 turnover frequency for the epoxidation of cyclooctene. Co-ZIF could be reused for 5 times without loss of its catalytic activity and the structure of the recovered catalyst was almost unchanged compared to that of the fresh one.
- Zhang, Aiping,Li, Linqing,Li, Jun,Zhang, Yi,Gao, Shuang
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experimental part
p. 1183 - 1187
(2012/05/20)
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- Photolysis of Regioisomeric α,α-Diphenyl-Substituted Diazotetrahydrofuranones: Primary and Secondary Photochemical Processes
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The formation of C-H insertion products in the course of direct photolysis of α,α-diphenylsubstituted diazo ketones of the tetrahydrofuran series was rationalized by secondary photochemical processes which give rise to benzophenone acting as a sensitizer. Triplet excited states of diazo ketones generated by the action of benzophenone are capable of undergoing bimolecular transformations.
- Rodina,Galkina,Supurgibekov,Grigor'Ev, Ya. M.,Utsal'
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experimental part
p. 1542 - 1545
(2011/02/26)
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- Surprising secondary photochemical reactions observed on conventional photolysis of diazotetrahydrofuranones
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The formation of C-H insertion products of the terminal N-atom of a diazo group into the α-S{cyrillic}N{cyrillic}-bond of tetrahydrofuran during direct photolysis of regioisomeric 2,2-dimethyl-5,5-diphenyl and 5,5-dimethyl-2,2-diphenyl-substituted 3-diazotetrahydrofuran-4-ones in THF is dictated by photochemical cycloelimination of the originally formed (1,1-dimethyl-2-oxa-3,3-diphenyl-propano)ketene and oxetanecarboxylic acid derivatives to yield benzophenone. The latter, under subsequent UV irradiation of the reaction mixture, initiates sensitized photolysis of the starting diazoketones resulting in the appearance of the insertion products with the solvent.
- Nikolaev, Valerij A.,Galkina, Olesja S.,Sieler, Jochim,Rodina, Ludmila L.
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experimental part
p. 2713 - 2716
(2010/06/19)
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- Catalytic aerobic oxidation of allylic alcohols to carbonyl compounds under mild conditions
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A new catalytic aerobic oxidation of alcohols to aldehydes under green conditions was developed (room temperature and pressure, water solution, open vials). The water-soluble platinum(II) tetrasulfophthalocyanine (PtPcS) catalyst showed the best selectivity for carbonyl derivatives, and in particular for α,β-unsaturated alcohols; the reactions are slow.
- Tonucci, Lucia,Nicastro, Marco,D'Alessandro, Nicola,Bressan, Mario,D'Ambrosio, Primiano,Morvillo, Antonino
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experimental part
p. 816 - 820
(2010/04/23)
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- Exploration of the molecular origin of the azinomycin epoxide: Timing of the biosynthesis revealed
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(Equation Presented) Streptomyces sahachiroi whole cell feeding experiments, utilizing putative precursors labeled with stable isotopes, established that the epoxide unit of the DNA cross-linked agents, azinomycin A and B, proceeds via a valine-dependent pathway and that hydroxylation and dehydration precedes formation of the terminal epoxide. Sodium 3-methyl-2-oxobutenoate, formed through a transimination reaction, was shown to be the penultimate precursor incorporated into the azinomycin epoxide.
- Sharma, Vasudha,Kelly, Gilbert T.,Watanabe, Coran M. H.
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supporting information; experimental part
p. 4815 - 4818
(2009/05/31)
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- Structure activity studies with xenobiotic substrates using carboxylesterases isolated from Arabidopsis thaliana
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Carboxylesterases (CXEs) catalyse the hydrolysis of xenobiotics and natural products radically altering their biological activities. Whereas the substrate selectivity of animal CXEs, such as porcine liver esterase (PLE) have been well studied, the respective enzymes in plants have yet to be defined and their activities determined. Using Arabidopsis thaliana (At) as a source, five representative members of the α/β hydrolase AtCXE family of proteins have been cloned, expressed and the purified recombinant proteins assayed for esterase activity with xenobiotic substrates. Two members, AtCXE5 and AtCXE18 were found to be active carboxylesterases, though AtCXE5 proved to be highly unstable as a soluble protein. AtCXE18 and the previously characterised S-formylglutathione hydrolase from Arabidopsis (AtSFGH) were assayed against a series of esters based on methylumbelliferone in which the acyl moiety was varied with respect to size and conformation. The same series was used to assay crude esterase preparation from Arabidopsis plants and the results compared with those obtained with the commonly used PLE. With straight chain esters, AtCXE18 behaved like PLE, but the Arabidopsis hydrolases proved less tolerant of branched chain acyl components than the mammalian enzyme. While none of the enzyme preparations accurately reflected all the activities determined with crude Arabidopsis protein extracts, the plant enzymes proved more useful than PLE in predicting the hydrolysis of the more sterically constrained esters.
- Cummins, Ian,Landrum, Marie,Steel, Patrick G.,Edwards, Robert
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p. 811 - 818
(2008/03/13)
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- Stereoselective hydroxycarbonylation of vinyl bromides to α,β-unsaturated carboxylic acids in the ionic liquid [BMIM]PF 6
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(E/Z)-Isomers containing vinyl bromides were stereoselectively carbonylated to the corresponding (E)-α,β-ethylenic carboxylic acids in the ionic liquid [BMIM]PF6. Vinyl dibromides also underwent hydroxycarbonylation to give monoacids. The products are pure by proton NMR spectroscopic determination without purification by silica gel column chromatograghy or recrystallization.
- Zhao, Xiaodan,Alper, Howard,Yu, Zhengkun
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p. 3988 - 3990
(2007/10/03)
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- Unusual fragmentation of fulvene endoperoxides with phenyliodosyl bis(trifluoroacetate) (PIFA)
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Reaction of unsaturated fulvene endoperoxides with dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate gave saturated fulvene endoperoxides containing the 1,2-dihydropyridazine ring. Treatment of dihydropyridazine endoperoxides with water followed by phenyliodosyl bis(trifluoroacetate) oxidation provided acrylic acid derivatives and dimethyl pyridazine-3,6-dicarboxylate.
- Oezer, Galip,Saracoglu, Nurullah,Balci, Metin
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p. 529 - 533
(2007/10/03)
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- IBX-mediated oxidation of primary alcohols and aldehydes to form carboxylic acids
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Under mild conditions and without the use of toxic metals, the oxidation of primary alcohols and aldehydes to the corresponding carboxylic acids with 1-hydroxy-1,2-benziodoxole-3(1H)-one-1-oxide (IBX) proceeds in the presence of 1-hydroxypyridine or N-hydroxysuccinimide (see scheme). The reaction tolerates a wide variety of functional groups.
- Mazitschek, Ralph,Muelbaier, Marcel,Giannis, Athanassios
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p. 4059 - 4061
(2007/10/03)
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- Catalytic Conversions in Water. Part 21: Mechanistic Investigations on the Palladium-Catalysed Aerobic Oxidation of Alcohols in Water
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Water-soluble complexes of palladium(II) with phenanthroline-derivatives are stable, recyclable catalysts for the selective aerobic oxidation of a wide range of alcohols to aldehydes, ketones, and carboxylic acids in a biphasic liquid-liquid system. The active catalyst is a dihydroxy-bridged palladium dimer. Kinetics of the reaction, ligand and anion effects are discussed.
- Ten Brink, Gerd-Jan,Arends, Isabel W. C. E.,Sheldon, Roger A.
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p. 355 - 369
(2007/10/03)
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- Palladium-catalysed cross-coupling of iodovinylic acids with organometallic reagents. Selective synthesis of 3,3-disubstituted prop-2-enoic acids
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3,3-Disubstituted prop-2-enoic acids were selectively prepared in good yields under mild experimental conditions via palladium-catalysed cross-coupling of 3-substituted 3-iodobut-2-enoic acids with miscellaneous organometallic reagents using dichlorobis(acetonitrile)palladium(II) as catalyst and DMF as solvent.
- Abarbri, Mohamed,Thibonnet, Jér?me,Parrain, Jean-Luc,Duchêne, Alain
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p. 543 - 551
(2007/10/03)
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- Palladium-catalyzed cross-coupling of 3-iodobut-3-enoic acid with organometallic reagents. Synthesis of 3-substituted but-3-enoic acids
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3-Substituted but-3-enoic acids were obtained in good yields under mild experimental conditions by palladium-catalyzed cross-coupling of 3-iodobut-3-enoic acid with organozinc or organotin compounds using PdCl2(MeCN)2 as catalyst and DMF as solvent.
- Abarbri,Parrain,Kitamura,Noyori,Duchene
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p. 7475 - 7478
(2007/10/03)
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- Composition for enhancing lipid production, barrier function, hydrogen peroxide neutralization, and moisturization of the skin
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Increased production of skin lipids, increased barrier function, hydrogen peroxide neutralization, prevention of loss of the natural moisturizing factor from the stratum corneum and moisturization of the skin is provided by a topically applicable composition which includes one or more components selected from the group consisting of branched chain amino acids, derivatives of branched chain amino acids and mixtures thereof, which one or more components are capable of being catabolized in epidermal cells to form lipid precursors for epidermal lipid synthesis. The composition can also include one or more enzyme activators which increase the rate of catabolism of the one or more components.
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- Synthesis of α,β-unsaturated carboxylic acids by nickel(II)-catalyzed electrochemical carboxylation of vinyl bromides
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Electrochemical carboxylation of alkyl-substituted vinyl bromides (1a-1g) in the presence of 20 mol% of NiBr2?bpy under an atmospheric pressure of carbon dioxide with a platinum cathode and a magnesium anode gave the corresponding α,β-unsaturated carboxylic acids (2a-2g) in yields of 53-82%.
- Kamekawa, Hisato,Kudoh, Hiroki,Senboku, Hisanori,Tokuda, Masao
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p. 917 - 918
(2007/10/03)
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- Activation of C-O and C-N Bonds in Allylic Alcohols and Amines by Palladium Complexes Promoted by CO2. Synthetic Applications to Allylation of Nucleophiles, Carbonylation, and Allylamine Disproportionation
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The direct activation of the C-O bonds in allylic alcohols catalyzed by palladium complexes has been accelerated by carrying out the reactions under CO2. On reaction with diethylamine, allyl alcohol can be converted into N,N-diethylallylamine in the presence of palladium complexes at room temperature under normal pressure of carbon dioxide. Allylation of various carbon nucleophiles such as β-keto esters and β-diketones can be achieved by using allylic alcohols directly in the presence of palladium complexes and CO2. Direct carbonylation of allylic alcohols into unsaturated carboxylic acids can be catalyzed by palladium complexes under the pressure of CO and CO2. Disproportionation of diallylamine into triallylamine and allylamine is also catalyzed by palladium complexes in the presence of CO2. On the basis of studies on the behavior of η3-allylpalladium hydrogencarbonate complexes with the nucleophiles, mechanisms are proposed to account for the palladium-catalyzed allylation processes influenced by CO2.
- Sakamoto, Masato,Shimizu, Isao,Yamamoto, Akio
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p. 1065 - 1078
(2007/10/03)
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- Rapid dehydrosulfenylation of sulfoxides under microwave irradiation
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Pyrolytic β-elimination of sulfoxides has been promoted by microwave irradiation. The reaction is very fast and yields are almost quantitative.
- Matloubi Moghaddam, Firouz,Ghaffarzadeh, Mohammad
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p. 1855 - 1858
(2007/10/03)
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- Stereospecific synthesis of (Z) or (E)-3-methylalk-2-enoic acids
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The palladium catalysed coupling of organozinc or organotin reagents with 3-iodobut-2(or 3)-enoic acid is stereoselective and affords Z (or E)-3-methylalk-2-enoic acids. The method was applied to the synthesis of the E and Z stereoisomers of ocimenones and pseudo-tagetones.
- Abarbri,Parrain,Duchene
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p. 2469 - 2472
(2007/10/02)
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- DIHYDROPYRANOCOUMARINS FROM PEUCEDANUM JAPONICUM
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Two new angular-type dihydropyranocoumarins, peujaponisinol A and B, were isolated from the roots of Peucedanum japonicum and the structures determined as 3'(S)-senecioyloxy-4'(S)-hydroxy-3',4'-dihydroseselin and 3'(S)-hydroxy-4'(S)-senecioyloxy-3',4'-dihydroseselin, respectively, by spectroscopic and chemical methods.
- Ikeshiro, Yasumasa,Mase, Izumi,Tomita, Yutaka
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p. 1543 - 1545
(2007/10/02)
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- Lactonization of Unsaturated Alcohols Catalyzed by Palladium Complexes under Neutral Conditions
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Secondary and tertiary allylic alcohols react with carbon monoxide in the presence of catalytic quantities of bis(dibenzylideneacetone)palladium (0) and 1,4-bis(diphenylphosphino)butane affording lactones in 45-92percent isolated yields. α,β-Unsaturated acids are formed by isomerization and carbonylation of primary allylic alcohols. 2-(5H)-Furanones were isolated in yields of 60-80percent when alkynols were employed as substrates for the cyclocarbonylation process.
- El Ali, Bassam,Alper, Howard
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p. 5357 - 5360
(2007/10/02)
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- Electrochemical Oxidation of Primary Alcohols to Aldehydes at the Nickel Hydroxide Electrode
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Primary alcohols were oxidized to aldehydes at the nickel hydroxide electrode in an emulsion of water and a nonpolar organic solvent.Benzylic and allylic primary alcohols afforded good yields, whereas the oxidation of saturated primary alcohols was less satisfactory.
- Schneider, Roy,Schaefer, Hans-J.
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p. 742 - 743
(2007/10/02)
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- Straightforward Synthesis of 2-Alkenoic Acids from the Corresponding Saturated Aldehydes
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2-Alkenoic acids may be prepared in good yields from saturated aldehydes via α-selenenylation with 4-(phenylseleno)morpholine formed in situ, followed by hydrogen peroxide oxidation.The actual oxidizing agent is benzeneperseleninic acid which is formed in the reaction medium.
- Outurquin, Francis,Paulmier, Claude
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p. 690 - 691
(2007/10/02)
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- STEREOSPECIFIC NICKEL AND PHASE TRANSFER CATALYZED CARBONYLATION OF VINYL BROMIDES AND CHLORIDES
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Nickel cyanide catalyzes the carbonylation of vinyl bromides and chlorides to α,β-unsaturated acids.
- Alper, Howard,Amer, Ibrahim,Vasapollo, Giuseppe
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p. 2615 - 2616
(2007/10/02)
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- Co-ordination of Highly Substituted Alkenes to Transition-metal Complexes: Preparation and Crystal and Molecular Structures of the Complexes 2> and 2>
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Reaction of Ph2PCl with RR'C=CR"C(X)OH in the presence of triethylamine produces Ph2POC(X)CR"=CRR' (X = O; R = R' = Me, R" = H; R = R" = H, R' = Me; R = R" = H, R' = CH=CHMe; R = Ph, R' = H, R" = Me; X = H2, R = R' = Me, R" = H) in high yield.These ligands react with 2)2> (L = C2H4 or cyclo-octene) to give high yields of 2> in which the ligands are bound through phosphorus and the double bond.The new compounds have been fully characterised by spectroscopic means, as well as by the crystal structures of 2> and 2>.Crystal data: for 2>, monoclinic, a = 8.485(!), b = 28.070(3), c = 14.253(1) Angstroem, β = 93.96(1) deg, space group P21/n; for 2>, monoclinic, a = 17.372(2), b = 22.070(1), c = 9.986(2) Angstroem, β = 104.51(1) deg, space group P21/a.Both complexes contain dimeric structures with bridging chlorine atoms.Each rhodium atom is in an approximately square-planar configuration, and is bonded to two chlorine, one phosphorus atom, and one ?-bonded C=C double bond, the phosphorus and ? system being part of a chelate ring structure.In 2> the α,β unsaturated linkage is bonded to the rhodium only, the γ,δ double bond being free.
- Cupertino, Domenico C.,Cole-Hamilton David J.
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p. 443 - 450
(2007/10/02)
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- An Uniformly Occuring Aliphatic Benzil-Benzilic-Acid-Type Rearrangement
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Treatment of 6-bromo-2,2,5,5-tetramethylcyclohex-3-enone (2) with aqueous alkaline and air affords 1-hydroxy-2,2,5,5-tetramethylcyclopent-3-enecarboxylic acid (8) as the major product of a benzil-benzilic-acid-type rearrangement.The key compound is 2,2,5,5-tetramethylcyclohex-3-ene-1,2-dione (11).The by-product of the reaction is (E)-2,2,5,5-tetramethylhex-3-enedioic acid (9) as the result of an oxidative cleavage of the 6-membered ring and the isomerization of the double bond.
- Schaltegger, Alexander,Bigler, Peter
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p. 1666 - 1670
(2007/10/02)
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- The Structure and Stereochemistry of Lantanilic Acid. A New Triterpene Isolated from Lantana camara
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The structure of lantanilic acid, a new triterpene isolated from the leaves of Lantana camara, has been finally established as 22β-β,β-dimethylacryloyloxy-3,25-epoxy-3α-hydroxy-olean-12-ene-28-oic acid (1a).
- Barua, A. K.,Chakrabarti, P.,Chowdhury, M. K.,Basak, A.,Basu, K.,et al.
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p. 298 - 305
(2007/10/02)
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- SUR LA REGIO SELECTIVITE DE LA REACTION DU BENZALDEHYDE AVEC LES ORGANOZINQUES ISSUS DU γ-BROMOCROTONATE ET DU γ-BROMOSENECIOATE DE TRIMETHYLSILYLE
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The regioselectivity of the reaction of organozinc compounds derived from γ-bromocrotonic and γ-bromosenecioic trimethylsilyl esters, with benzaldehyde is discussed.One-step reactions lead to a majority of α-substituted derivatives, while in two-step reactions, γ-substituted products are exclusively obtained.
- Bellassoued, M.,Gaudemar, M.,Borgi, A. El.,Baccar, B.
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p. 165 - 172
(2007/10/02)
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