- Br?nsted Base-Catalyzed Transformation of α,β-Epoxyketones Utilizing [1,2]-Phospha-Brook Rearrangement for the Synthesis of Allylic Alcohols Having a Tetrasubstituted Alkene Moiety
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A stereoselective transformation of α,β-epoxyketones into alkenylphosphates having a hydroxymethyl group on the β-carbon was established by utilizing the [1,2]-phospha-Brook rearrangement under Br?nsted base catalysis. The reaction involves the catalytic generation of an α-oxygenated carbanion located at the α-position of an epoxide moiety through the [1,2]-phospha-Brook rearrangement and the following epoxide opening. Further transformation of the alkenylphosphates by the palladium-catalyzed cross-coupling reaction with Grignard reagents provided allylic alcohols having a stereodefined all-carbon tetrasubstituted alkene moiety.
- Kondoh, Azusa,Tasato, Naoko,Aoki, Takuma,Terada, Masahiro
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supporting information
p. 5170 - 5175
(2020/07/04)
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- Transition-Metal-Free Reductive Deoxygenative Olefination with CO2
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A new transition-metal-free reductive deoxygenative olefination of phosphorus ylides with CO2, an abundant and sustainable C1 chemical feedstock, is described. This catalytic CO2 fixation afforded β-unsubstituted acrylates and vinyl ketones in good yields with broad scope and good functional group tolerance under mild reaction conditions. Cost-effective and easily handled polymethylhydrosiloxane was used as a reductant. Bis(silyl)acetal was proved to be the key intermediate in this reductive functionalization of CO2.
- Zhu, Dao-Yong,Li, Wen-Duo,Yang, Ce,Chen, Jie,Xia, Ji-Bao
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p. 3282 - 3285
(2018/06/11)
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- Method for synthesizing alpha,beta-unsaturated ketone compounds from dimethyl sulfoxide and ketone compounds
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The invention discloses a method for synthesizing alpha,beta-unsaturated ketone compounds from dimethyl sulfoxide and ketone compounds. According to the method, dimethyl sulfoxide and ketone compoundsare subjected to a one-pot reaction in the presence of carboxylate and persulfate so as to produce the alpha,beta-unsaturated ketone compounds. The method uses dimethyl sulfoxide as a methylenation reagent and employs a one-pot process for high-selectivity high-yield synthesis of the alpha,beta-unsaturated ketone compounds from the ketone compounds; and the method is simple to operate, low in cost, friendly to environment and beneficial for industrial production.
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Paragraph 0131-0133; 0140-0143
(2018/03/24)
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- Transition Metal-Free α-Csp3-H Methylenation of Ketones to Form C=C Bond Using Dimethyl Sulfoxide as Carbon Source
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A direct α-Csp3-H methylenation of arylketones to form C=C bond using dimethyl sulfoxide as one-carbon source is achieved under transition metal-free reaction condition. Various aryl ketone derivatives react readily with DMSO, producing the α,β-unsaturated carbonyl compounds in yields of 42 to 90%. This method features a transition metal-free reaction condition, wide substrate scope and using DMSO as novel one-carbon source to form C=C bond, thus providing an efficient and expeditious approach to an important class of α,β-unsaturated carbonyl compounds. Based on the preliminary experiments, a plausible mechanism of this transformation is disclosed.
- Liu, Yu-Feng,Ji, Peng-Yi,Xu, Jing-Wen,Hu, Yu-Qun,Liu, Qiang,Luo, Wei-Ping,Guo, Can-Cheng
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p. 7159 - 7164
(2017/07/26)
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- A methylene compound of preparation method and its application (by machine translation)
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The invention discloses a methylene compound of preparation method and its application, relates to the field of organic synthesis, the process comprises: 1) in the presence of a three-valent metal salt catalyst, will arone compound and halogen methyl radical trialkyl ammonium salt dissolved in a solvent, 2) 80 - 130 °C reaction 1 - 4 hours, separated and purified α - the methyl radical is fragrant compounds, the reaction environment pollution is small, substrate and wide range of application. (by machine translation)
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Paragraph 0023-0024; 0031-0032; 0059-0060
(2017/11/16)
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- Kinetic resolution of aryl alkenylcarbinols catalyzed by Fc-PIP
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An effective kinetic resolution of a variety of aryl alkenylcarbinols catalyzed by nonenzymatic acyl transfer catalyst Fc-PIP was developed, affording corresponding unreacted alcohols in good to excellent ee value up to 99% and with selectivity factors up to 24.
- Hu, Bin,Meng, Meng,Jiang, Shanshan,Deng, Weiping
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p. 1289 - 1294
(2012/08/28)
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- UNSATURATED IMINE COMPOUND AND USE THEREOF FOR PEST CONTROL
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An α, β-unsaturated imine compound of the formula: wherein A represents a phenyl group or the like, where said aromatic hetero ring forms a carbon-to-carbon bond with a main chain of the compound, R represents a hydrogen atom or a C1 to C5 alkyl group opt
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Page/Page column 245-246
(2009/05/28)
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- Synthesis of taiwaniaquinoids via Nazarov triflation
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A unified approach toward the taiwaniaquinoids that has yielded four natural products is described. A new variant of the Nazarov reaction with concomitant formation of an enol triflate serves as one of the key steps, considerably shortening the synthetic
- Liang, Guangxin,Xu, Yue,Seiple, Ian B.,Trauner, Dirk
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p. 11022 - 11023
(2007/10/03)
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- Synthesis of 4-Benzoyl-4-methylcyclohexa-2,5-dienone and its Benzoyl Substitued Derivatives: Isolated 4-Acylcyclohexa-2,5-dienones
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The synthesis are reported of 4-benzoyl-4-methylcyclohexa-2,5-dienone, and its 4-(4-chlorobenzoyl) and 4-(4-methoxybenzoyl) analogues.These are the first isolated 4-acylcyclohexa-2,5-dienones containing the dienone function in a monocyclic ring system.All are sensitive to nucleophilic attack at the benzoyl carbonyl group, being cleaved to 4-methylphenol and its derivatives of the appropriate substitued benzoic acid.Treatment with acids failed to give the desired dienone-phenol rearrangement, with a benzoyl migration from C-4 to C-3, but instead gave 4-methylphenyl benzoate or its derivatives, by a reversal of a Fries rearrangement with C-4 to O-aroyl migration.
- Jackson, Lorraine B.,Waring, Anthony J.
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p. 1791 - 1798
(2007/10/02)
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- KINETICS AND SPECTROSCOPY OF YLIDS FROM REACTION OF p-SUBSTITUTED PHENYLCHLOROCARBENES WITH ACETONE
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Laser flash photolysis of p-CF3 and p-Cl-phenylchloro diazirines produces the corresponding carbenes which react with acetone to produce easily detected ylids.The absolute rate constants of reaction of these carbenes with acetone, and the rate constants of reaction of the ylids with diethylfumarate have been determined.No reaction was found between these carbenes and simple esters or ethylene carbonate.
- Soundararajan, N.,Jackson, James E.,Platz, Matthew S.,Liu, Michael T. H.
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p. 3419 - 3422
(2007/10/02)
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