- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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- 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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