- Silver-catalyzed decarboxylative radical allylation of α,α-difluoroarylacetic acids for the construction of CF2-allyl bonds
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An efficient silver-catalyzed method of decarboxylative radical allylation of α,α-difluoroarylacetic acids to build CF2-allyl bonds has been developed. Using allylsulfone as an allyl donor, α,α-difluorine substituted arylacetic acids bearing various functional groups are successfully allylated to access a series of 3-(α,α-difluorobenzyl)-1-propylene compounds in moderate to excellent yields in aqueous CH3CN solution under the mild conditions. Experimental studies disclosed that the α-fluorine substitution of arylacetic acid has a great influence on free radical activity and reactivity.
- Wang, Pingyang,Du, Pengcheng,Sun, Qianqian,Zhang, Jianhua,Deng, Hongmei,Jiang, Haizhen
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supporting information
p. 2023 - 2029
(2021/03/16)
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- Synthetic method of aromatic ring group or aromatic heterocyclic tetrazole
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The synthetic method comprises the following steps: (1) reacting 1.0 eq of ArI or HArI with 1.2 eq of ethyl 2, 2-difluoroacetate in the presence of DMSO as a solvent and 4.0 eq of Cu under the protection of nitrogen at 30 DEG C and 50 DEG C, and purifying to obtain a first intermediate compound; (2) dissolving 1.0 eq of the first intermediate compound in a mixed solvent of THF and water, adding 2.0 eq of LiOH, reacting at room temperature for 2 hours, spin-drying the solvent, adding HCl until the pH value is equal to 3, and filtering to obtain a second intermediate compound; and (3) reacting 1.0 eq of the second intermediate compound with 2.0 eq of diphenyl azide phosphate in the presence of 2.5 eq of triethylamine by taking tert-butyl alcohol as a solvent to generate aromatic ring group or aromatic heterocyclic tetrazole. The invention provides a novel synthetic method of aromatic ring group or aromatic heterocyclic tetrazole, wherein a target compound can be more conveniently obtained, and reagents participating in the reaction are low in toxicity, mild in reaction condition, simple and safe in aftertreatment, good in product quality and suitable for large-scale production.
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Paragraph 0055-0062; 0069
(2020/12/30)
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- Controlling the cleavage of carbon-carbon bonds to generate α,α-difluorobenzyl carbanions for the construction of difluoromethylbenzenes
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Controlling the cleavage of carbon-carbon bonds during a chemical reaction is a substantial challenge; however, synthetic methods that accomplish this objective produce valuable and often unexplored reactivity. We have designed a mild process to generate α,α-difluorobenzyl carbanions in the presence of potassium carbonate by exploiting the cleavage of C-C bonds during the release of trifluoroacetate. The initiating reagent is potassium carbonate, which represents an improvement over existing protocols that require a strong base. Fragmentation studies across substituted arenes and heteroarenes were conducted along with computational analyses to elucidate reactivity trends. Furthermore, the mildly generated α,α-difluorobenzyl carbanions from electron-deficient aromatics and heteroaromatic rings can react with aldehydes to create derivatives of difluoromethylbenzenes, which are valuable synthetic targets.
- Khatri, Hari R.,Han, Changho,Luong, Erica,Pan, Xiaoliang,Adam, Amna T.,Alshammari, Maali D.,Shao, Yihan,Colby, David A.
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p. 11665 - 11675
(2019/10/02)
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- Silver-Catalyzed Decarboxylative Alkynylation of α,α-Difluoroarylacetic Acids with Ethynylbenziodoxolone Reagents
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A decarboxylating alkynylation of α,α-difluoroarylacetic acids with ethynylbenziodoxolone reagents is reported. AgNO3 serves as the catalyst and K2S2O8 as the oxidant. A series of functional groups were tolerated, and moderate to good yields were obtained.
- Chen, Fei,Hashmi, A. Stephen K.
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supporting information
p. 2880 - 2882
(2016/07/06)
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- Method of manufacturing arom. defluoromethyl compd.
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PROBLEM TO BE SOLVED: To provide a method for easily producing an aromatic compound having a difluoromethyl group in high yield while using a reagent having low toxicity. SOLUTION: The method for producing the aromatic difluoromethyl compound includes reacting an aromatic difluoroacetic acid in the presence of a metal halide (especially potassium fluoride). COPYRIGHT: (C)2011,JPOandINPIT
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Paragraph 0051; 0054; 0055
(2018/11/22)
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- Catalytic decarboxylative fluorination for the synthesis of Tri- and difluoromethyl arenes
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Treatment of readily available α,α-difluoro- and α-fluoroarylacetic acids with Selectfluor under Ag(I) catalysis led to decarboxylative fluorination. This operationally simple reaction gave access to tri- and difluoromethylarenes applying a late-stage fluorination strategy. Translation to [18F]labeling is demonstrated using [ 18F]Selectfluor bis(triflate), a reagent affording [ 18F]tri- and [18F]difluoromethylarenes not within reach with [18F]F2.
- Mizuta, Satoshi,Stenhagen, Ida S.R.,O'Duill, Miriam,Wolstenhulme, Jamie,Kirjavainen, Anna K.,Forsback, Sarita J.,Tredwell, Matthew,Sandford, Graham,Moore, Peter R.,Huiban, Mickael,Luthra, Sajinder K.,Passchier, Jan,Solin, Olof,Gouverneur, Véronique
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supporting information
p. 2648 - 2651
(2013/07/11)
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- METHOD FOR PRODUCING AROMATIC DIFLUOROACETIC ACID ESTER
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Disclosed is a method for producing a compound having a difluoromethylene group at an even lower cost and with excellent yield. The production method of the present invention is a method for producing an aromatic difluoroacetic acid ester, which comprises reacting an iodobenzene containing an electro attracting group and an α-silyl difluoroacetic acid ester in the presence of a metal halide.
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Page/Page column 6
(2012/09/10)
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- A new method for aromatic difluoromethylation: Copper-catalyzed cross-coupling and decarboxylation sequence from aryl iodides
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A new methodology for aromatic difluoromethylation is described. Aryl iodides reacted with α-silyldifluoroacetates upon treatment with copper catalyst in DMSO or DME to give the corresponding aryldifluoroacetates in moderate to good yields. The subsequent hydrolysis of aryldifluoroacetates and KF-promoted decarboxylation afforded a variety of difluoromethyl aromatics.
- Fujikawa, Kenichi,Fujioka, Yasutaka,Kobayashi, Akira,Amii, Hideki
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supporting information; experimental part
p. 5560 - 5563
(2011/12/05)
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- Synthesis of 4-[4′-bis(2″-chloroethyl)aminophenyl]-3,3,4,4-tetrafluorobutanoic acid [3,3,4,4-tetrafluorochlorambucil]
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Reaction of 2,2-dichloro-2-(4′-nitrophenyl)acetonitrile with mercury(II) oxide/pyridiniumpoly(hydrogen fluoride), (aqueous work-up), gave 2,2-difluoro-2-(4′-nitrophenyl)acetamide, from which were made the parent acid and thence its acid chloride. This and
- Buss, Christopher W.,Coe, Paul L.,Tatlow, John Colin
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p. 111 - 116
(2007/10/03)
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