- Pd(II)-catalyzed acetalization of terminal olefins with electron-withdrawing groups in supercritical carbon dioxide: selective control and mechanism
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Pd(II)-catalyzed acetalization of terminal olefins with electron-withdrawing groups was carried out smoothly in supercritical carbon dioxide under oxygen atmosphere when polystyrene-supported benzoquinone (PS-BQ) or CuII (CuI) chloride was employed as cocatalyst. The higher selectivity was achieved, without any chlorinated by-product detected, when using PS-BQ instead of CuII (or CuI) chloride. PS-BQ could be recycled with excellent catalytic activity remaining after each simple filtration. Chlorine ion was demonstrated to be a promoter. The different acetalization mechanisms were revealed by the subtle relationship of chlorine ion and benzoquinone (BQ) to the catalytic activity of PdCl2/PS-BQ, PdII-CuCl2 or Pd(OAc)2/PS-BQ.
- Wang, Zhao-Yang,Jiang, Huan-Feng,Ouyang, Xiao-Yue,Qi, Chao-Rong,Yang, Shao-Rong
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Read Online
- Practical preparation of esters and thioacetates from alkyl halides and carboxylates or thioacetate catalyzed by PEG400 without solvent
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Carboxylic esters and thioacetates were conveniently prepared in good to excellent yields under mild conditions by the reaction of alkyl halides with sodium carboxylates or sodium thioacetate catalyzed by PEG400 in the absence of solvents. Copyright Taylor & Francis Group, LLC.
- Cao, Yu-Qing,Wu, Guo-Qiang,Li, Ya-Bin,Dai, Zhi,Chen, Bao-Hua
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Read Online
- Preparation method of ethyl 3-ethoxyacrylate
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The invention discloses a preparation method of ethyl 3-ethoxyacrylate. The preparation method comprises the following steps: (1) dropwise adding a certain amount of vinyl ethyl ether into trichloro-acetic chloride, controlling the temperature at 20 to 40 DEG C, and preserving heat for reacting for 1 to 10 hours; (2) evaporating low-boiling-point by-products under reduced pressure at the temperature of 40 DEG C; (3) adding organic alkali and ethanol, and preserving heat at 20 to 50 DEG C for reacting for 1 to 10 hours; (4) filtering, recovering a filter cake, and evaporating ethanol out of thefiltrate under reduced pressure at a temperature of 50 DEG C; (5) adding a certain amount of acid catalyst, heating to 50 to 100 DEG C, introducing nitrogen, and preserving heat for reacting for 1 to10 hours; (6) distilling under reduced pressure to obtain ethyl 3-ethoxyacrylate. The preparation method has the advantages of cheap and readily available raw materials, mild reaction conditions, easiness and convenience in operation, high yield, high product purity, few three wastes (waste gas, waste water and industrial residue), recovery of organic alkali from the generated solid waste, recyclability of the solvent and environmental friendliness, is a low-cost green synthesis technology, and is suitable for industrial production.
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Paragraph 0038-0049
(2019/03/30)
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- Catalytic Enantioselective Nazarov Cyclization
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A detailed account of an asymmetric Nazarov cyclization that leads to α-hydroxycyclopentenones bearing either vicinal, all-carbon quaternary centers, or vicinal quaternary and tertiary centers is given. The all-aliphatic examples represent the greatest challenge, as the dienone starting materials are not activated toward cyclization by an aryl group. The rational design and optimization of the substrates in parallel with optimization of the chiral Br?nsted acid catalyst is also described, as well as a series of diastereoselective transformations of a fully substituted cyclopentenone product.
- Jolit, Anais,Dickinson, Cody F.,Kitamura, Kei,Walleser, Patrick M.,Yap, Glenn P. A.,Tius, Marcus A.
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supporting information
p. 6067 - 6076
(2017/11/14)
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- A kind of 3,4-dichloro-thiazole derivatives and process for their preparation and use
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The invention provides 3,4-dichloro isothiazole derivatives, their preparation method and application. The invention relates to a heterocyclic compound containing 3,4-dichloro isothiazol, and the compound is represented by the following chemical structural general formula. The invention discloses the structural general formula of the compound, a synthetic method of the compound and applications of the compound as pesticide, bactericide, anti-plant virus agent, and plant activator, and a technology of mixing the compound with agriculturally acceptable auxiliary agents or synergists for preparing pesticide, bactericide, anti-plant virus agent, and plant activator. The invention further discloses the combined application of the compound and the commercial pesticide, bactericide, anti-plant virus agent, and plant activator in controlling diseases, insect pests, and virus diseases in agriculture, forestry and gardening, and a preparation method of the compound and the commercial pesticide, bactericide, anti-plant virus agent, and plant activator.
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Paragraph 0038-0039; 0091-0092
(2016/10/08)
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- A novel and facile method for the synthesis of 2,3-disubstituted quinolines by a three-component coupling reaction
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A Lewis acid effectively catalyzed the three-component coupling reaction of an aromatic amine and aldehyde with ethyl propiolate, and the 2,3-disubstituted quinoline was regioselectively obtained in a good yield (up to 83% GC yield). Georg Thieme Verlag Stuttgart.
- Kikuchi, Satoshi,Iwai, Masahiro,Fukuzawa, Shin-Ichi
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p. 2639 - 2642
(2008/02/12)
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- Process for preparing substituted acetals of malondialdehyde
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A process directed to the preparation of 2-substituted and 2,2-disubstituted acetals of malondialdehyde from ortho formates and substituted vinyl ethers in the presence of an acidic catalyst.
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Page column 8
(2008/06/13)
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- PALLADIUM-CATALYZED CROSS-COUPLING OF ARYL IODIDES WITH ETHYL 2-ETHOXY- AND 3-ETHOXYACRYLATE
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The cross-coupling of iodobenzenes with ethyl 2-ethoxy- and 3-ethoxyacrylate in the presence of palladium-charcoal gave ethyl α-ethoxy- and β-ethoxycinnamates in moderate yields.The cross-coupling of N-heteroaryl iodides with the same acrylates was also d
- Sakamoto, Takao,Kondo, Yoshinori,Kashiwagi, Yoshitomo,Yamanaka, Hiroshi
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p. 257 - 260
(2007/10/02)
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- Action de l'hydroxyuree sur les esters α-acetyleniques
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Hydroxyurea, in its oxanion form NH2-CO-NHO(1-), reacts in basic medium by a 1,4-addition to α-acetylenic esters leading to the E and Z ethylenic β-ureidoxy esters isomers.The E isomer can be isolated and identified from reaction with ethyl tetrolate and ethyl propiolate.The Z isomer undergoes cyclisation in situ to give the 2-carboxamido-5-methyl-3-isoxazolone.With phenyl propiolate, the 3-hydroxy-5-phenyl isoxazole is directly obtained without isolation of the intermediate N-carboxamido derivative.In the case of ethyl propiolate two cyclic compounds are obtained: 3-hydroxyisoxazole and 2-N-carboxamido-5-ethoxy-3-isoxazolidinone.The formation of the former is due to the in situ cyclisation of the Z isomer.The isolation of the latter compound can be explained by solvent addition to the E β-ureidoxyacrylate intermadiate in a Michael addition followed by cyclisation.
- Lassalvy, Christiane,Petrus, Clement,Petrus, Francoise
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p. 175 - 180
(2007/10/02)
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