- HPLC and GC-MS identification of the major organic constituents in New Zealand propolis
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The major organic constituents of New Zealand sourced propolis have been identified and quantified in tincture solutions by a combination of HPLC and GC-mass spectrometry (MS). HPLC was the preferred method for the analysis of flavonoids because of their very low response factors in GC-MS. Flavonoid levels ranged from 30-40 mg ml-1. A distinctive characteristic of the flavonoids in New Zealand propolis is the unusually high proportion (ca 70%) of dihydroflavonoids, e.g. pinocembrin, pinobanksin and pinobanksin 3-acetate. Non-flavonoid components analysed by GC-MS comprised a range of aromatic compounds (3-7.5 mg ml-1), together with low levels (0.25-0.78 mg ml-1) of fatty acids. The former comprised mainly cinnamic acids and their esters, but also included the rare 5-phenyl-trans-trans-2,4-pentadienoic acid and the new natural product, 5-phenyl-trans-3-pentenoic acid. Both were synthesized to confirm their identity. Copyright
- Markham, Kenneth R.,Mitchell, Kevin A.,Wilkins, Alistair L.,Daldy, Julia A.,Lu, Yinrong
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- Electrophilic Activation of α,β-Unsaturated Amides: Catalytic Asymmetric Vinylogous Conjugate Addition of Unsaturated γ-Butyrolactones
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Although catalytic asymmetric conjugate addition reactions have remarkably advanced over the last two decades, the application of less electrophilic α,β-unsaturated carboxylic acid derivatives in this useful reaction manifold remains challenging. Herein, we report that α,β-unsaturated 7-azaindoline amides act as reactive electrophiles to participate in catalytic diastereo- and enantioselective vinylogous conjugate addition of γ-butyrolactones in the presence of a cooperative catalyst comprising of a soft Lewis acid and a Br?nsted base. Reactions mostly reached completion with as little as 1 mol % of catalyst loading to give the desired conjugate adducts in a highly stereoselective manner.
- Zhang, Ming,Kumagai, Naoya,Shibasaki, Masakatsu
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- Stereoregular two-dimensional polymers constructed by topochemical polymerization
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Two stereoregular 2D polyesters were synthesized by using topochemical polymerization of symmetric four-armed monomers. The monomers contain reactive carbon-carbon double bond(s) on each arm. The critical assemblies with multiple preorganized reactive centers were characterized by powder and single crystal X-ray diffraction. The solvent-free polymerization could be carried out with sunlight or UV irradiation. The locally confined photopolymerization process dimerized all of the olefins within the 2D bricklayer packing, which led to the formation of 2D polymers in the solid state. The process was monitored by FT-IR, and the products were confirmed by solid state NMR. After hydrolysis of the 2D polyester, the newly formed carbon-carbon single bonds during the [2 + 2] photocyclization were directly revealed by the single crystal structure of the hydrolysis product. Ultrathin sheets of the 2D polymer were observed under SEM and TEM after exfoliation.
- Wang, Zhihan,Randazzo, Katelyn,Hou, Xiaodong,Simpson, Jeffrey,Struppe, Jochem,Ugrinov, Angel,Kastern, Brent,Wysocki, Erin,Chu, Qianli R.
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Read Online
- Amino Group Functionalized Hf-Based Metal-Organic Framework for Knoevenagel-Doebner Condensation
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A Hf(IV) metal-organic framework (MOF) with di-amino functionalized linker was obtained as a crystalline solid with UiO-67 topology under solvothermal reaction conditions. The guest free form of Hf(IV) MOF (1′) was efficiently employed as a heterogeneous catalyst to synthesize cinnamic acid derivatives via Knoevenagel-Doebner reaction for the first time. The catalyst (1′) was efficiently active to directly achieve cinnamic acid from benzaldehyde and malonic acid. The solid retained its activity up to 6th cycle with no decay in its activity. The noticeable advantages of the catalyst are its milder reaction conditions, high yield, high stability, recyclable nature towards catalysis and wide substrate scope as well as shape-selective behaviour. The possible mechanism of the reaction was also studied thoroughly with suitable control experiments.
- Das, Aniruddha,Anbu, Nagaraj,Gogoi, Chiranjib,Dhakshinamoorthy, Amarajothi,Biswas, Shyam
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p. 3396 - 3403
(2021/08/20)
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- Photo-Promoted Decarboxylative Alkylation of α, β-Unsaturated Carboxylic Acids with ICH2CN for the Synthesis of β, γ-Unsaturated Nitriles
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An efficient, catalyst/photocatalyst-free, and cost-effective methodology for the decarboxylative alkylation of α,β-unsaturated carboxylic acids to synthesize β,γ-unsaturated nitriles has been developed. The reaction proceeded in an environmentally benign atmosphere of blue light-emitting diode irradiation with K2CO3 and water at room temperature. The methodology worked for a wide range of substrates (22 examples) with up to 83% yield. The protocol is also compatible for gram-scale synthesis.
- Pan, Chunxiang,Yang, Chunhui,Li, Kangkui,Zhang, Keyang,Zhu, Yuanbin,Wu, Shiyuan,Zhou, Yongyun,Fan, Baomin
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supporting information
p. 7188 - 7193
(2021/10/01)
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- Enantioselective Redox-Divergent Chiral Phosphoric Acid Catalyzed Quinone Diels–Alder Reactions
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An efficient enantioselective construction of tetrahydronaphthalene-1,4-diones as well as dihydronaphthalene-1,4-diols by a chiral phosphoric acid catalyzed quinone Diels–Alder reaction with dienecarbamates is reported. The nature of the protecting group on the diene is key to the success of achieving high enantioselectivity. The divergent “redox” selectivity is controlled by using an adequate amount of quinones. Reversible redox switching without erosion of enantioselectivity was possible from individual redox isomers.
- Bernadat, Guillaume,Gelis, Coralie,Masson, Géraldine,Neuville, Luc,Retailleau, Pascal,Varlet, Thomas
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supporting information
p. 8491 - 8496
(2020/04/10)
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- Reaction of 5-phenylpenta-2,4-dienoic acid with benzene in trifluoromethanesulfonic acid
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The reaction of 5-phenylpenta-2,4-dienoic acid with benzene in CF3SO3H, depending on the reaction conditions, gives three products, namely, 5,5-diphenylpent-2-enoic acid and tetralone and indanone derivatives. These carbocyclic compo
- Ismagilova, A. R.,Osetrova, L. V.,Vasilyev, A. V.,Zakusilo, D. N.
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p. 1928 - 1932
(2020/11/05)
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- Synthesis and characterization of unsaturated diacyl and alkyl-acyl piperazine derivatives
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The aim of this study is to obtain new unsaturated piperazine compounds by the reactions of piperazine (1a) and piperazine derivatives (1b–1d) with acylation reactive groups (2a–2j). Methacryloyl piperazine (1b) was synthesized from the reaction of methacrylic anhydride with piperazine (1a). Acyl chlorides (2b–2d) were prepared from the reaction of thionyl chloride with carboxylic acids (3a–3c) obtained as a result of the reaction with malonic acid and suitable aldehyde (5-methylfuran-2-carbaldehyde for 3a, cinnamaldehyde for 3b, and thiophene-2-carbaldehyde for 3c), respectively, by literature methods. Acyl chlorides 2e and 2f were obtained from the reaction of commercially purchased carboxylic acids 3d and 3e with thionyl chloride. Acyl chlorides (2g–2j) were synthesized from the reaction of thionyl chloride with carboxylic acids (3d–3g) transformed from hydrolyzation of esters (4a–4d) obtained as a result of the reaction of triethyl phosphonoacetate with a suitable ketone (acetophenone for 4a, benzophenone for 4b, 1-(5-methylfuran-2-yl)ethan-1-one for 4c, and 1-(thiophen-2-yl)ethan-1-one for 4d), respectively, by literature methods. Unsaturated piperazine derivatives 5a and 5b were obtained from the reaction of 1b with 2b and 2e, respectively. In addition, from the reaction of 1b and acyl chlorides (2b–2j), unsaturated piperazines (5c–5k) were synthesized in medium to good yields (63%–84%). Also, 5l–5g and 5r–5w were obtained from the reaction of allyl piperazine (2c) and cinnamyl piperazine (2d) with acyl chlorides (2a–2f).
- Sari, Sait,ünalan, Seda,Yilmaz, Mehmet
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p. 1656 - 1671
(2020/01/03)
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- Iron-Catalyzed Reactions of 2-Pyridone Derivatives: 1,6-Addition and Formal Ring Opening/Cross Coupling
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In the presence of simple iron salts, 2-pyridone derivatives react with Grignard reagents under mild conditions to give the corresponding 1,6-addition products; if the reaction medium is supplemented with an aprotic dipolar cosolvent after the actual addition step, the intermediates primarily formed succumb to ring opening, giving rise to non-thermodynamic Z,E-configured dienoic acid amide derivatives which are difficult to make otherwise. Control experiments as well as the isolation and crystallographic characterization of a (tricarbonyl)iron pyridone complex suggest that the active iron catalyst generated in situ exhibits high affinity to the polarized diene system embedded into the heterocyclic ring system of the substrates, which likely serves as the actual recognition element.
- Huang, Lin,Gu, Yiting,Fürstner, Alois
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supporting information
p. 4017 - 4023
(2019/08/07)
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- Cis-cinnamic acid analogue, gravitropism modifier (by machine translation)
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[Problem] cinnamic acid or cinnamic acid analogue comprising adjusting agent gravitropism cis. [Solution] cinnamic acid and/or cinnamic acid as an active ingredient to adjust gravitropism cis edge agents, cinnamic acid edge is, for example obtained by reacting compounds of the following formula. (In the formula, R is a phenyl group. )Figure 6 [drawing] (by machine translation)
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Paragraph 0083-0087
(2019/11/30)
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- A Short, Efficient, and Stereoselective Synthesis of Piperine and its Analogues
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A quantitative synthesis of piperine from commercially available starting material is presented. The synthesis relies on a stereoselective nucleophilic attack of an in situ generated cuprate onto a cyclobutene lactone. The so-formed aryl-substituted cyclobutene spontaneously undergoes a conrotatory 4π-electrocyclic ring opening to form the 4-aryl pentadienoic acid as a single diastereoisomer. The high-yielding synthesis can be easily modulated on the aryl and on the amide moiety for the synthesis of a wide range of piperine analogues.
- Bauer, Adriano,Nam, Jun-Hyun,Maulide, Nuno
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p. 413 - 416
(2019/02/26)
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- Ni-Catalyzed Site-Selective Dicarboxylation of 1,3-Dienes with CO2
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A site-selective catalytic incorporation of multiple CO2 molecules into 1,3-dienes en route to adipic acids is described. This protocol is characterized by its mild conditions, excellent chemo- and regioselectivity and ease of execution under CO2 (1 atm), including the use of bulk butadiene and/or isoprene feedstocks.
- Tortajada, Andreu,Ninokata, Ryo,Martin, Ruben
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supporting information
p. 2050 - 2053
(2018/02/19)
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- Iridium-Catalyzed Aerobic α,β-Dehydrogenation of γ,δ-Unsaturated Amides and Acids: Activation of Both α- And β-C-H bonds through an Allyl-Iridium Intermediate
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Direct aerobic α,β-dehydrogenation of γ, δ-unsaturated amides and acids using a simple iridium/copper relay catalysis system is described. We developed a new strategy that overcomes the challenging issue associated with the low α-acidity of amides and acids. Instead of α-C-H metalation, this reaction proceeds by β-C-H activation, which results in enhanced α-acidity. Conjugated dienamides and dienoic acids were synthesized in excellent yield with this reaction, which uses a simple reaction protocol. Mechanistic experiments suggest a catalyst resting state mechanism in which both α-C-H and β-C-H cleavage is accelerated.
- Wang, Zhen,He, Zhiqi,Zhang, Linrui,Huang, Yong
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supporting information
p. 735 - 740
(2018/01/26)
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- Tailored Mutants of Phenylalanine Ammonia-Lyase from Petroselinum crispum for the Synthesis of Bulky l- and d-Arylalanines
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Tailored mutants of phenylalanine ammonia-lyase from Petroselinum crispum (PcPAL) were created and tested in ammonia elimination from various sterically demanding, non-natural analogues of phenylalanine and in ammonia addition reactions into the corresponding (E)-arylacrylates. The wild-type PcPAL was inert or exhibited quite poor conversions in both reactions with all members of the substrate panel. Appropriate single mutations of residue F137 and the highly conserved residue I460 resulted in PcPAL variants that were active in ammonia elimination but still had a poor activity in ammonia addition onto bulky substrates. However, combined mutations that involve I460 besides the well-studied F137 led to mutants that exhibited activity in ammonia addition as well. The synergistic multiple mutations resulted in substantial substrate scope extension of PcPAL and opened up new biocatalytic routes for the synthesis of both enantiomers of valuable phenylalanine analogues, such as (4-methoxyphenyl)-, (napthalen-2-yl)-, ([1,1′-biphenyl]-4-yl)-, (4′-fluoro-[1,1′-biphenyl]-4-yl)-, and (5-phenylthiophene-2-yl)alanines.
- Filip, Alina,Nagy, Emma Z. A.,Tork, Souad D.,Bánóczi, Gergely,To?a, Monica I.,Irimie, Florin D.,Poppe, László,Paizs, Csaba,Bencze, László C.
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p. 2627 - 2633
(2018/05/03)
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- Catalytic Regio- and Enantioselective Alkylation of Conjugated Dienyl Amides
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A method for catalytic asymmetric alkylation of conjugated dienyl amides has been developed and it allows efficient and high-yielding transformations of a wide range of polyconjugated amides into the corresponding chiral products. Smooth addition of organomagnesium reagents to relatively unreactive dienyl amides with excellent 1,6- and 1,4-selectivities, as well as enantioselectivites above 90 %, is achieved owing to the complementary action of the Lewis acid and a chiral copper-based catalyst.
- Guo, Yafei,Kootstra, Johanan,Harutyunyan, Syuzanna R.
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p. 13547 - 13550
(2018/09/25)
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- Synthesis of some monosaccharide-related ester derivatives as insecticidal and acaricidal agents
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To develop natural-product-based pesticidal agents, a series of monosaccharide-related ester derivatives (17a–q and 18a–f), glucose (xylose)-piperic acid/piperic acid-like conjugates, were synthesized. Three-dimensional structures of compounds 17b, 17g, 17h, and 17n were unambiguously determined by single-crystal X-ray diffraction. Especially compounds 18e and 18f exhibited the most potent insecticidal and acaricidal activities against Mythimna separata and Tetranychus cinnabarinus. Their structure-activity relationships were also discussed.
- Huang, Xiaobo,Zhang, Bingchuan,Xu, Hui
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supporting information
p. 4336 - 4340
(2017/09/12)
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- Enantioselective Synthesis of N?H-Free 1,5-Benzothiazepines
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An enantioselective sulfa-Michael-cyclization reaction was developed for the synthesis of 1,5-benzothiazepines with versatile pharmacological activities. The reaction between 2-aminothiophenol and α,β-unsaturated pyrazoleamides gave direct access to N?H-free 1,5-benzothiazepines in the presence of a chiral N,N′-dioxide/Yb(OTf)3complex. Excellent enantioselectivities (up to 96 % ee) and high yields (up to 99 %) were obtained for a broad range of substrates under mild reaction conditions. This method provided a facile approach to the antidepressant drug (R)-(?)-Thiazesim.
- Wang, Guojin,Tang, Yu,Zhang, Yu,Liu, Xiaohua,Lin, Lili,Feng, Xiaoming
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supporting information
p. 554 - 557
(2017/01/18)
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- Photoinduced, Copper-Promoted Regio- and Stereoselective Decarboxylative Alkylation of α,β-Unsaturated Acids with Alkyl Iodides
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The first example of UV light-induced, copper-catalyzed regio- and stereoselective decarboxylative coupling of α,β-unsaturated acids with alkyl iodides was reported. Under standard conditions, the 1°, 2°, and 3° alkyl iodides proceeded smoothly with the E-selective alkenes obtained in uniformly good yields and high stereoselectivities.
- Wang, Chao,Lei, Yingjie,Guo, Mengzhun,Shang, Qinyu,Liu, Hong,Xu, Zhaoqing,Wang, Rui
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supporting information
p. 6412 - 6415
(2017/12/08)
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- Expanding the substrate scope of phenylalanine ammonia-lyase from: Petroselinum crispum towards styrylalanines
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This study focuses on the expansion of the substrate scope of phenylalanine ammonia-lyase from Petroselinum crispum (PcPAL) towards the l-enantiomers of racemic styrylalanines rac-1a-d-which are less studied and synthetically challenging unnatural amino acids-by reshaping the aromatic binding pocket of the active site of PcPAL by point mutations. Ammonia elimination from l-styrylalanine (l-1a) catalyzed by non-mutated PcPAL (wt-PcPAL) took place with a 777-fold lower kcat/KM value than the deamination of the natural substrate, l-Phe. Computer modeling of the reactions catalyzed by wt-PcPAL indicated an unproductive and two major catalytically active conformations and detrimental interactions between the aromatic moiety of l-styrylalanine, l-1a, and the phenyl ring of the residue F137 in the aromatic binding region of the active site. Replacing the residue F137 by smaller hydrophobic residues resulted in a small mutant library (F137X-PcPAL, X being V, A, and G), from which F137V-PcPAL could transform l-styrylalanine with comparable activity to that of the wt-PcPAL with l-Phe. Furthermore, F137V-PcPAL showed superior catalytic efficiency in the ammonia elimination reaction of several racemic styrylalanine derivatives (rac-1a-d) providing access to d-1a-d by kinetic resolution, even though the d-enantiomers proved to be reversible inhibitors. The enhanced catalytic efficiency of F137V-PcPAL towards racemic styrylalanines rac-1a-d could be rationalized by molecular modeling, indicating the more relaxed enzyme-substrate complexes and the promotion of conformations with higher catalytic activities as the main reasons. Unfortunately, ammonia addition onto the corresponding styrylacrylates 2a-d failed with both wt-PcPAL and F137V-PcPAL. The low equilibrium constant of the ammonia addition, the poor ligand binding affinities of 2a-d, and the non-productive binding states of the unsaturated ligands 2a-d within the active sites of either wt-PcPAL or F137V-PcPAL-as indicated by molecular modeling-might be responsible for the inactivity of the PcPAL variants in the reverse reaction. Modeling predicted that the F137V mutation is beneficial for the KRs of 4-fluoro-, 4-cyano- and 4-bromostyrylalanines, but non-effective for the KR process of 4-trifluoromethylstyrylalanine.
- Bencze, László Csaba,Filip, Alina,Bánóczi, Gergely,To?a, Monica Ioana,Irimie, Florin Dan,Gellért, ákos,Poppe, László,Paizs, Csaba
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supporting information
p. 3717 - 3727
(2017/07/07)
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- CIS CINNAMIC ACID ANALOG AND GRAVITROPISM MODIFIER
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PROBLEM TO BE SOLVED: To provide a gravitropism modifier having effects on creeping property of plants or sugar content of fruits. SOLUTION: There is provided a gravitropism modifier containing cis cinnamic acid and/or a cinnamic acid analog represented by the formula (1) as active ingredients. (1), where A is cyclic hydrocarbon which may have a substituent, X is a bound or a C1 to 5 substituted or unsubstituted hydrocarbon chain, R1 is H, a hydroxyl group, an alkali earth metal salt or the like, R2 is a bond or a C1 to 5 substituted or unsubstituted hydrocarbon chain and R3 and R4 are H or together form C5 to 8 cyclic hydrocarbon. SELECTED DRAWING: Figure 6 COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0082; 0083; 0086
(2017/06/02)
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- Studies on [2?+?3] cycloaddition reaction of nitrile oxides to linear dipolarophiles bearing multiple double bonds
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Abstract: Site selectivity, regioselectivity, and stereoselectivity of [2?+?3] cycloaddition of benzonitrile oxides to polyunsaturated esters were examined. Site selectivity was correlated with electron charges of unsaturated carbon atoms. Structure of the products has been established by an extensive application of 1H and 13C NMR spectroscopy and electrospray ionization mass spectrometry. Graphical abstract: [Figure not available: see fulltext.]
- Gucma, Miros?aw,Go??biewski, W. Marek,Michalczyk, Alicja Katarzyna
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p. 1809 - 1818
(2016/09/28)
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- Regio- and Stereoselective Preparation of β,γ-Unsaturated Carboxylic Acids by One-Pot Sequential Double 1,6-Addition of Grignard Reagents to Methyl Coumalate
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An efficient regio- and stereoselective metal-catalyzed addition of two Grignard reagents (homo-coupling, 2 RMgX or hetero-coupling, R1MgX+R2MgX) to methyl coumalate (methyl 2-oxo-2H-pyran-5-carboxylate) is described. This synthetic approach opens the access to a wide variety of functionalized β,γ-unsaturated carboxylic acids in a modular way. Control of the chemo- and stereoselectivity of this one-pot procedure is discussed. (Figure presented.).
- Plevová, Kristína,Chang, Liang,Martin, Emmeline,Llopis, Quentin,Dechoux, Luc,Thorimbert, Serge
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supporting information
p. 3293 - 3297
(2016/10/21)
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- Novel cinnamic acid derivatives as antioxidant and anticancer agents: Design, synthesis and modeling studies
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Cinnamic acids have been identified as interesting compounds with antioxidant, anti-inflammatory and cytotoxic properties. In the present study, simple cinnamic acids were synthesized by Knoevenagel condensation reactions and evaluated for the above biological activities. Compound 4ii proved to be the most potent LOX inhibitor. Phenylsubstituted acids showed better inhibitory activity against soybean LOX, and it must be noted that compounds 4i and 3i with higher lipophilicity values resulted less active than compounds 2i and 1i. The compounds have shown very good activity in different antioxidant assays. The antitumor properties of these derivatives have been assessed by their 1/IC50 inhibitory values in the proliferation of HT-29, A-549, OAW-42, MDA-MB-231, HeLa and MRC-5 normal cell lines. The compounds presented low antitumor activity considering the IC50 values attained for the cell lines, with the exception of compound 4ii. Molecular docking studies were carried out on cinnamic acid derivative 4ii and were found to be in accordance with our experimental biological results.
- Pontiki, Eleni,Hadjipavlou-Litina, Dimitra,Litinas, Konstantinos,Geromichalos, George
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p. 9655 - 9674
(2014/08/05)
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- Identification of cinnamic acid derivatives as novel antagonists of the prokaryotic proton-gated ion channel GLIC
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Pentameric ligand gated ion channels (pLGICs) mediate signal transduction. The binding of an extracellular ligand is coupled to the transmembrane channel opening. So far, all known agonists bind at the interface between subunits in a topologically conserved "orthosteric site" whose amino acid composition defines the pharmacological specificity of pLGIC subtypes. A striking exception is the bacterial proton-activated GLIC protein, exhibiting an uncommon orthosteric binding site in terms of sequence and local architecture. Among a library of Gloeobacter violaceus metabolites, we identified a series of cinnamic acid derivatives, which antagonize the GLIC proton-elicited response. Structure-activity analysis shows a key contribution of the carboxylate moiety to GLIC inhibition. Molecular docking coupled to site-directed mutagenesis support that the binding pocket is located below the classical orthosteric site. These antagonists provide new tools to modulate conformation of GLIC, currently used as a prototypic pLGIC, and opens new avenues to study the signal transduction mechanism.
- Prevost, Marie S.,Delarue-Cochin, Sandrine,Marteaux, Justine,Colas, Claire,Van Renterghem, Catherine,Blondel, Arnaud,Malliavin, Thérèse,Corringer, Pierre-Jean,Joseph, Delphine
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p. 4619 - 4630
(2013/07/19)
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- A practical and convenient protocol for the synthesis of (E)-α,β-unsaturated acids
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α,β-Unsaturated acids are very useful and versatile reagents in organic synthesis. A novel, practical, and convenient catalytic protocol comprising FeCl3·6H2O (0.5 mol %) and H 2O (1 equiv) in CH3NO2 is described for the rapid synthesis of α,β-unsaturated acids with high E-stereoselectivity under both microwave and conventional heating conditions with high TON and TOF values. This powerful approach efficiently demonstrated the utility of biomass derived aldehydes to build chemical agents used as fuel additives. The method proved to be scalable to gram scale synthesis.
- Mohite, Amar R.,Bhat, Ramakrishna G.
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supporting information
p. 4564 - 4567
(2013/09/24)
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- Key structural features of cis-cinnamic acid as an allelochemical
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1-O-cis-cinnamoyl-β-d-glucopyranose is one of the most potent allelochemicals isolated from Spiraea thunbergii Sieb. It is suggested that it derives its strong inhibitory activity from cis-cinnamic acid, which is crucial for phytotoxicity. It was synthesized to confirm its structure and bioactivity, and also a series of cis-cinnamic acid analogues were prepared to elucidate the key features of cis-cinnamic acid for lettuce root growth inhibition. The cis-cyclopropyl analogue showed potent inhibitory activity while the saturated and alkyne analogues proved to be inactive, demonstrating the importance of the cis-double bond. Moreover, the aromatic ring could not be replaced with a saturated ring. However, the 1,3-dienylcyclohexene analogue showed strong activity. These results suggest that the geometry of the C-C double bond between the carboxyl group and the aromatic ring is essential for potent inhibitory activity. In addition, using several light sources, the photostability of the cinnamic acid derivatives and the role of the C-C double bond were also investigated.
- Abe, Masato,Nishikawa, Keisuke,Okuda, Katsuhiro,Shindo, Mitsuru,Fukuda, Hiroshi,Nakanishi, Kazunari,Tazawa, Yuta,Taniguchi, Tomoya,Park, So-Young,Hiradate, Syuntaro,Fujii, Yoshiharu
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p. 56 - 67,12
(2012/12/12)
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- One-flask tethered ring closing metathesis-electrocyclic ring opening for the highly stereoselective synthesis of conjugated Z/E-dienes
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A one-flask reaction sequence comprising ring closing metathesis (RCM) of butenoates derived from allylic alcohols and a base-mediated ring opening gives 2Z,4E-configured dienoic acids in high yields and stereoselectivities. Application of the method to the synthesis of the natural product fusanolide A suggests that the originally published structure was erroneously assigned and should be revised. Ring closing metathesis (RCM) of butenoates derived from allylic alcohols can be combined with base-induced ring opening in a one-flask sequence. In this way, dienoic acids become accessible in an operationally simple procedure in very high yields and excellent stereoselectivities, with the tether remaining in the product as a valuable functional group for further transformations. Copyright
- Schmidt, Bernd,Kunz, Oliver
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supporting information; experimental part
p. 1008 - 1018
(2012/03/27)
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- αβ-Unsaturated δ-valerolactones through RCM-isomerization sequence
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αβ-Unsaturated δ-lactones are accessible via a sequential ring-closing metathesis (RCM) double-bond migration reaction starting from butenoates of allyl alcohols. This approach proceeds efficiently with lower catalyst loadings and higher initial substrate concentrations compared to the alternative RCM of acrylates derived from homoallylic alcohols. Georg Thieme Verlag Stuttgart . New York.
- Schmidt, Bernd,Kunz, Oliver
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supporting information; scheme or table
p. 851 - 854
(2012/06/15)
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- Mechanistic, mutational, and structural evaluation of a taxus phenylalanine aminomutase
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The structure of a phenylalanine aminomutase (TcPAM) from Taxus canadensis has been determined at 2.4 A resolution. The active site of the TcPAM contains the signature 4-methylidene-1H-imidazol-5(4H)-one prosthesis, observed in all catalysts of the class I lyase-like family. This catalyst isomerizes (S)-α-phenylalanine to the (R)-β-isomer by exchange of the NH 2/H pair. The stereochemistry of the TcPAM reaction product is opposite of the (S)-β-tyrosine made by the mechanistically related tyrosine aminomutase (SgTAM) from Streptomyces globisporus. Since TcPAM and SgTAM share similar tertiary- and quaternary-structures and have several highly conserved aliphatic residues positioned analogously in their active sites for substrate recognition, the divergent product stereochemistries of these catalysts likely cannot be explained by differences in active site architecture. The active site of the TcPAM structure also is in complex with (E)-cinnamate; the latter functions as both a substrate and an intermediate. To account for the distinct (3R)-β-amino acid stereochemistry catalyzed by TcPAM, the cinnamate skeleton must rotate the C1-Cα and C ipso-β bonds 180° in the active site prior to exchange and rebinding of the NH2/H pair to the cinnamate, an event that is not required for the corresponding acrylate intermediate in the SgTAM reaction. Moreover, the aromatic ring of the intermediate makes only one direct hydrophobic interaction with Leu-104. A L104A mutant of TcPAM demonstrated an ~1.5-fold increase in kcat and a decrease in KM values for sterically demanding 3′-methyl-α-phenylalanine and styryl-α-alanine substrates, compared to the kinetic parameters for TcPAM. These parameters did not change significantly for the mutant with 4′-methyl-α-phenylalanine compared to those for TcPAM.(Figure Presented)
- Feng, Lei,Wanninayake, Udayanga,Strom, Susan,Geiger, James,Walker, Kevin D.
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experimental part
p. 2919 - 2930
(2012/07/14)
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- Contribution of cinnamic acid analogues in rosmarinic acid to inhibition of snake venom induced hemorrhage
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In our previous paper, we reported that rosmarinic acid (1) of Argusia argentea could neutralize snake venom induced hemorrhagic action. Rosmarinic acid (1) consists of two phenylpropanoids: caffeic acid (2) and 3-(3,4-dihydroxyphenyl)lactic acid (3). In this study, we investigated the structural requirements necessary for inhibition of snake venom activity through the use of compounds, which are structurally related to rosmarinic acid (1). By examining anti-hemorrhagic activity of cinnamic acid analogs against Protobothrops flavoviridis (Habu) venom, it was revealed that the presence of the E-enoic acid moiety (-CHCH-COOH) was critical. Furthermore, among the compound tested, it was concluded that rosmarinic acid (1) (IC50 0.15 μM) was the most potent inhibitor against the venom.
- Aung, Hnin Thanda,Furukawa, Tadashi,Nikai, Toshiaki,Niwa, Masatake,Takaya, Yoshiaki
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experimental part
p. 2392 - 2396
(2011/05/12)
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- A facile method for synthesis of amine-functionalized mesoporous zirconia and its catalytic evaluation in Knoevenagel condensation
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Amine-functionalized mesoporous zirconia was prepared by a co-condensation method using silane (aminopropyltrimethoxysilane, APTES) and zirconium butoxide. The materials were characterized by X-ray diffraction, BET surface area analysis, 13C magic angle spinning-nuclear magnetic resonance (NMR), Fourier-transfer infrared spectroscopy (FTIR), transmittance electron micrography (TEM), and CHN analysis. FTIR and NMR results revealed the successful grafting of organic amines onto the surface of zirconia. The catalytic activities were investigated for liquid phase Knoevenagel condensation of various aromatic aldehydes with diethyl malonate. The catalysts showed excellent yield of products at room temperature in solvent-free condition.
- Parida,Mallick, Sujata,Sahoo,Rana
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experimental part
p. 226 - 232
(2010/08/06)
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- Method for regio- and stereoselective synthesis of (E)-Β,γ- unsaturated acids from aldehydes under solvent-free conditions
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Synthesis of (E)-β,-γunsaturated acids from aldehydes with malonic acid has been explored under solvent-free conditions. The modified Knoevenagel condensation reaction with N-methyl morpholine (NMM) as catalyst exhibits highly β,-γ regioselectivity and exclusively E-stereoselectivity. A mechanism accounting for both regio- and stereoselectivity has been proposed and preliminarily studied. Copyright Taylor & Francis Group, LLC.
- Zhang, Shi-Jie,Hu, Wei-Xiao
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experimental part
p. 3093 - 3100
(2010/12/19)
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- Potent and selective fluoroketone inhibitors of group VIA calcium-independent phospholipase A2
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Group VIA calcium-independent phospholipase A2 (GVIA iPLA 2) has recently emerged as a novel pharmaceutical target. We have now explored the Structure-activity relationship between fluoroketones and GVIA iPLA2 inhibition. The presence of a naphthyl group proved to be of paramount importance. 1,1,1-Trifluoro-6-(naphthalen-2-yl)hexan-2-one (FKGK18) is the most potent inhibitor of GVIA iPLA2 (XI(50) = 0.0002) ever reported. Being 195 and >455 times more potent for GVIA iPLA 2 than for GIVA cPLA2 and GV sPLA2, respectively, makes it a valuable tool to explore the role of GVIA iPLA 2 in cells and in vivo models. 1,1,1,2,2,3,3-Heptafluoro-8- (naphthalene-2-yl)octan-4-one inhibited GVIA iPLA2 with a X I(50) value of 0.001 while inhibiting the other intracellular GIVA cPLA2 and GV sPLA2 at least 90 times less potently. Hexa- and octafluoro ketones were also found to be potent inhibitors of GVIA iPLA 2; however, they are not selective.
- Kokotos, George,Hsu, Yuan-Hao,Burke, John E.,Baskakis, Constantinos,Kokotos, Christoforos G.,Magrioti, Victoria,Dennis, Edward A.
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experimental part
p. 3602 - 3610
(2010/08/06)
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- Dual inhibition of monoamine oxidase B and antagonism of the adenosine A2A receptor by (E,E)-8-(4-phenylbutadien-1-yl)caffeine analogues
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The adenosine A2A receptor has emerged as an attractive target for the treatment of Parkinson's disease (PD). Evidence suggests that antagonists of the A2A receptor (A2A antagonists) may be neuroprotective and may help to alleviate the symptoms of PD. We have reported recently that several members of the (E)-8-styrylcaffeine class of A2A antagonists also are potent inhibitors of monoamine oxidase B (MAO-B). Since MAO-B inhibitors are known to possess anti-parkinsonian properties, dual-target-directed drugs that block both MAO-B and A2A receptors may have enhanced value in the management of PD. In an attempt to explore this concept further we have prepared three additional classes of C-8 substituted caffeinyl analogues. The 8-phenyl- and 8-benzylcaffeinyl analogues exhibited relatively weak MAO-B inhibition potencies while selected (E,E)-8-(4-phenylbutadien-1-yl)caffeinyl analogues were found to be exceptionally potent reversible MAO-B inhibitors with enzyme-inhibitor dissociation constants (Ki values) ranging from 17 to 149 nM. Furthermore, these (E,E)-8-(4-phenylbutadien-1-yl)caffeines acted as potent A2A antagonists with Ki values ranging from 59 to 153 nM. We conclude that the (E,E)-8-(4-phenylbutadien-1-yl)caffeines are a promising candidate class of dual-acting compounds.
- Pretorius, Judey,Malan, Sarel F.,Castagnoli Jr., Neal,Bergh, Jacobus J.,Petzer, Jacobus P.
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p. 8676 - 8684
(2008/12/23)
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- Tandem olefin metathesis-elimination reactions. A new route to doubly unsaturated carbonyl derivatives
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Cross-metathesis between an activated olefin and an ethereal derivative of homoallylic alcohols leads to products that are subject to facile elimination resulting in α,β,γ,δ-unsaturated esters, ketones, acids, and aldehydes in high yields.
- Lipshutz, Bruce H.,Ghorai, Subir,Bo?kovi?, ?arko V.
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p. 6949 - 6954
(2008/09/20)
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- A fast and convenient heck reaction in water under microwave irradiation
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A fast and convenient base-free Heck reaction of acrylic acid and allyl alcohol with hypervalent iodonium salts was achieved under microwave irradiation in water, providing a simple method for synthesis of trans-cinnamic acids and trans-cinnamyl alcohols in good yields in short time. Georg Thieme Verlag Stuttgart.
- Zhu, Min,Song, Yunlong,Cao, Yan
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p. 853 - 856
(2008/01/06)
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- Mild zinc-promoted Horner-Wadsworth-Emmons reactions of diprotic phosphonate reagents
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We report the development of a mild protocol for the Horner-Wadsworth- Emmons reaction of diprotic phosphonates that makes use of a zinc triflate promoter in the presence of mild ter-tiary amine bases to produce α,β-unsaturated carboxylic acids and amides. Georg Thieme Verlag Stuttgart.
- Schauer, Douglas J.,Helquist, Paul
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p. 3654 - 3660
(2008/03/13)
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- Synthesis of dihydronaphthalenes via aryne Diels-Alder reactions: Scope and diastereoselectivity
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Novel aryne Diels-Alder reactions with functionalized acyclic dienes are reported. These give useful cis-substituted dihydronaphthalene building blocks in good yield which are not easily accessible via other means, as demonstrated in the synthesis of sert
- Dockendorff, Chris,Sahli, Stefan,Olsen, Madeline,Milhau, Ludovic,Lautens, Mark
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p. 15028 - 15029
(2007/10/03)
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- Gold-catalyzed cyclization of tert-butyl allenoate: General synthesis of 2,4-functionalized butenolides
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AuCl3 efficiently catalyzes cyclization of tert-butyl allenoates into γ-butenolides. Advantage of directly using allenic ester precursor instead of corresponding acid is demonstrated in the synthesis of a variety of 2,4-disubstituted butenolides. A low catalyst loading and mild reaction condition makes this process an attractive alternative over conventional methods using strong Lewis acids.
- Kang, Ji-Eun,Lee, Eun-Sun,Park, Sang-Il,Shin, Seunghoon
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p. 7431 - 7433
(2007/10/03)
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- Effects of piperine analogues on stimulation of melanocyte proliferation and melanocyte differentiation
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A wide range of piperine analogues has been synthesised in order to undertake a structure-activity study of their ability to stimulate melanocyte proliferation. Results demonstrate that an aromatic ring containing at least one ether function and a carbonyl group containing side chain is essential for this activity. A number of highly active piperine analogues have been identified, for instance 1-(3,4-methylenedioxyphenyl)-penta-2E,4E-dienoic acid methyl ester (5a), 1-E,E-piperinoyl-isobutylamine (4f) and 1-(3,4- methylenedioxyphenyl)-pentanoic acid cyclohexyl amide (20). A selection of analogues has also been evaluated for their effect on melanocyte morphology and melanogenesis. The piperine analogues altered cell morphology by increasing dendrite formation leading to bi-, tri- and quadripolar cells. These same analogues were found to increase total melanin in cell cultures, although melanin content per cell was not significantly altered from control in the presence of these compounds.
- Venkatasamy, Radhakrishnan,Faas, Laura,Young, Antony R.,Raman, Amala,Hider, Robert C.
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p. 1905 - 1920
(2007/10/03)
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- Carbamic acid compounds comprising an amide linkage as hdac inhibitors
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This invention pertains to certain active carbamic acid compounds which inhibit HDAC activity and which have the formula (1) wherein: A is an aryl group; Q1 is an aryl leader group having a backbone of at least 2 carbon atoms; J is an amide linkage selected from: —NR1C(═O)—and —C(═O)NR1—; R1 is an amido substituent; and, Q2 is an acid leader group; and pharmaceutically acceptable salts, solvates, amides, esters, ethers, chemically protected forms, and prodrugs thereof. The present invention also pertains to pharmaceutical compositions comprising such compounds, and the use of such compounds and compositions, both in vitro and in vivo, to inhibit HDAC, and, e.g., to inhibit proliferative conditions, such as cancer and psoriasis.
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- Synthetic and spectroscopic studies of structural analogs of piper amides - The 5-aryl-2E,4E-pentadienamides
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The methyl esters and piperidides of fourteen 5-aryl-2E,4E-pentadienoic acids have been synthesized starting from the corresponding aryl aldehydes.
- Banerji, Avijit,Banerjee, Tapasri,Sengupta, Ratna,Sengupta, Piyali,Das, Chittaranjan,Sahu, Anita
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p. 876 - 883
(2007/10/03)
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- Diamide compound and drugs containing the same
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The present invention provides diamide derivatives represented by the following general formula (1): wherein A is a phenyl group or the like, which may be substituted, B is —CH═CH—, —C═C—, —(CH═CH)2—, —C≡C—CH═CH—, —CH═CH—C≡C—, phenylene or the
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Page column 6
(2010/01/30)
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- Two-carbon homologation of aldehydes via silyl ketene acetals. 2. Study of the stereochemical control in the formation of (E)-alkenoic acids
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The condensation of C,O,O-tris(trimethylsilyl)ketene acetal 1 with aldehydes 2 in the presence of catalytic amounts of mercuric iodide at room temperature affords syn and anti β-trimethylsiloxy α-trimethylsilyl alkanoic acid silyl esters 3 in good yields. These new compounds gave, under acidic or basic conditions, E and (or) Z enoic acids 4. The paths for the formation of these alkenoic acids are discussed.
- Bellassoued,Mouelhi,Lensen
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p. 5054 - 5057
(2007/10/03)
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- Two-carbon homologation of aldehydes via silyl ketene acetals: A new stereoselective approach to (E)-alkenoic acids
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Aldehydes are converted into (E)-α,β-unsaturated carboxylic acids using C,O,O-tris(trimethylsilyl)ketene acetal 1. This organosilicon reagent is easily generated from trimethylsilyl acetate, LDA, and chlorotrimethylsilane. The effectiveness of the reaction has been explored for a large variety of aldehydes with Lewis acids and fluorides as catalysts.
- Bellassoued, Moncef,Lensen, Nathalie,Bakasse, Mina,Mouelhi, Sinda
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p. 8785 - 8789
(2007/10/03)
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- Reactivity of substituted and unsubstituted diphenylphosphonium diylides towards carbonic acids derivatives
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In order to further delimit the scope of application of diphenylphosphonium diylides, their reactivity towards carbonic acid derivatives was investigated. Non-stabilized diylides react with ethyl carbonate to give new monoylide intermediates which lead, by in situ Wittig reaction with carbonyl compounds, to the synthesis of α,β-unsaturated esters or acids the double bond being di- or trisubstituted. The reaction proceeds in mild conditions and with high E stereoselectivity. Stabilized diylides are inactive towards carbonates but semi-stabilized diylides react with ethyl carbonate leading to the synthesis of non-functionalized alkenes instead of the α,β-unsaturated esters or acids.
- Cristau,Taillefer
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p. 1507 - 1522
(2007/10/03)
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- Tandem [2 + 2] cycloaddition-cycloreversion reactions in highly polar media: A convergent one-pot entry to substituted alkenes and dienes
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Reaction at room temperature between acyl chlorides and aromatic or α,β-unsaturated aldehydes in the presence of a tertiary base and in 5M lithium perchlorate-diethyl ether (5M LPDE) as solvent yields substituted alkenes in satisfactory yields. The reaction is formally conceived as a [2 + 2] cycloaddition between the aldehyde and the in situ formed ketene, followed by thermal decarboxylation of the intermediate 2 oxetanone. Ketene itself yields α,β-unsaturated acids under these reaction conditions.
- Arrastia, Iosune,Cossio, Fernando P.
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p. 7143 - 7146
(2007/10/03)
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- Organoaluminum-promoted cycloaddition of trialkylsilylketene with aldehydes: A new, stereoselectie approach to cis-2-oxetanones and 2(Z)-alkenoic acids
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The exceptionally bulky methylaluminum bis(4-bromo-2,6-di-tert-butylphenoxide) (MABR) can be successfully utilized as a highly efficient Lewis acid for achieving high stereoselectivity in the cycloaddition of trialkylsilylketene with aldehydes. This method serves as a highly effective route to the synthesis of cis-2-oxetanones from saturated aldehydes, and the synthesis of 2(Z)-alkenoic acids from aromatic and α,β-unsaturated aldehydes.
- Concepcion,Maruoka,Yamamoto
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p. 4011 - 4020
(2007/10/02)
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- Stereochemistry of Thermolytic Base-catalysed Decarboxylation to form Cojugated Diene-Acids: Synthesis using Ethylidenemalonic Ester Condensation
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The condensation of aromatic aldehydes with ethylidenemalonic ester in the presence of benzyltrimethylammonium hydroxide leads to 2(E),4(E)-half-esters, which are decarboxylated in refluxing pyridine to 2(E),4(E)-esters.When decarboxylated by thermolysis in quinoline at 130 deg C cinnamylidenemalonic acid gives almost pure 5-phenylpenta-2(Z),4(E)-dienoic acid which slowly stereomutates, but on continued heating at 170 deg C it passes over to give almost pure 2(E),4(E)-acid.In pyridine near its boiling point, however, the malonic acid is converted into a 64:36 mixture of 2(Z),4(E)-:2(E),4(E)-acids, the composition of which does not change on continued refluxing.The use of carboxy-labelled dideuteriomalonic acid in the pyridine reaction leads to 5-phenylpenta-2(Z),4(E)-dienoic acid and its 2(E),4(E)-stereoisomer, each having similar ca. 2.1 α/γ deuterium labelling.The latter stereoisomer does not arise by stereomutation, and a dual pathway originating from a common deuteriated lactone is proposed.Decarboxylation of the deuteriomalonic acid in quinoline at 130 deg C, giving almost pure 2(Z),4(E)-dienoic acid with ca. 2:1 α/γ labelling, involves only one of the pathways.The ethylidenemalonic acid method is suitable for the preparation of 2(E),4(E)-half-esters and 5-phenylpenta-2(Z),4(E)-dienoic acids having both electron-withdrawing as well as electron-releasing aryl substituents. 2(Z),4(E)-Sorbic acid can also be made from the corresponding malonic acid by quinoline-catalysed decarboxylation, whereas the classical pyridine-catalysed Doebner reaction forms almost entirely 2(E),4(E)-sorbic acid.
- Crombie, Leslie,Crombie, W. Mary L.
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p. 1267 - 1274
(2007/10/02)
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