Reactions of fluorinated silanes with 2-nitrocinnamates

Zemtsov, Artem A.; Levin, Vitalij V.; Dilman, Alexander D.; Стручкова, Марина И.; Tartakovsky, Vladimir A.

doi:10.1016/j.jfluchem.2011.03.015

Cited by 19 publications

(10 citation statements)

References 23 publications

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“…[20][21][22] метод нуклеофильного сопряженного трифторметилирования с использова-нием реагента Рупперта в присутствии основных активаторов получил дальней-шее развитие. Так, начиная с 2008 года, в орбиту этой реакции удалось вовлечь различные электронодефицитные ал-кены, такие как арилиденовые произ-водные малононитрила, кислоты Мель-друма и нитроуксусного эфира.…”

Section: схема 7 схемаunclassified

“…Описано взаимодействие 2-нитро-циннаматов 31 с кремниевыми реа-гентами R F SiMe 3 (R F = CF 3 , C 2 F 5 , C 6 F 5 ) в присутствии ацетата натрия в ДМФА Схема 10 (метод А) или ацетата тетрабутиламмо-ния в дихлорметане (метод В) [22]. Реак-ция протекает как сопряженное присо-единение фторированного карбаниона по связи С=С и с хорошими выходами приводит к получению 3-арил-2-нитро-алканоатов 32 с перфторированными заместителями.…”

Section: схема 7 схемаunclassified

“…In the works of Dilman with coworkers [20][21][22], the method of nucleophilic conjugated trifl uoromethylation using the Ruppert's reagent in the presence of basic activators was further developed. Since 2008, in the orbit of this reaction the various electron defi cient alkenes, such as arylidene derivatives of malononitrile, Meldrum's acid and nitroacetic ester, were involved.…”

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“…In the work [22] the interaction of 2-nitrocinnamates 31 with the silicon reagents R F SiMe 3 (R F = CF 3 , C 2 F 5 , C 6 F 5 ) in the presence of sodium acetate in DMF (method A) or tetrabutylammonium acetate in dichloromethane (method B) was described. Th e reaction proceeds as the conjugated addition of fl uorinated carbanion on the С=С bond and with good yields leads to obtaining of 3-aryl-2-nitroalkanoates with perfl uorinated substituents.…”

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Nucleophilic conjugate trifluoromethylation of chromones and activated alkenes under the action of Ruppert’s reagent

Sosnovskikh

Roshentaler

2017

Chim.Tech.Acta

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Nucleophilic conjugate tri uoromethylation of chromones and activated alkenes under the action of Ruppert's reagentThis review summarizes data on the reactions of chromones and activated alkenes with trimethyl(tri uoromethyl)silane (Ruppert's reagent), which occures as a nucleophilic 1,4-tri uoromethylation with high regioselectivity and good yields. The most important chemical properties of the formed products are also considered.Key words: chromones; activated alkenes; nucleophilic 1,4-trifluoromethylation; trimethyl(tri uoromethyl)silane. Received: 28.02 .2017; accepted: 03.03.2017; published: 14.04 Sosnovskikh V. Ya., Roschenthaler G.-V. Chimica Techno Acta. 2017. Vol. 4, No. 1. P. 29-44. ISSN 2409-5613 DOI: 10.15826/chimtech.2017 30 Th e nucleophilic trifl uoromethylation of organic compounds is complicated by the instability of free trifl uoromethyl anion, which easily breaks down into the fl uoride anion and difl uorocarbene [1]. Th e use of trimethyl(trifl uoromethyl)silane (Ruppert's reagent) in the presence of fl uoride anion as an initiator allows to avoid this unwanted reaction and to realize the direct introduction of the CF 3 group to organic substrates. It is well known that the Ruppert's reagent interacts easily with both saturated and α, β-unsaturated carbonyl compounds via 1,2-nucleophilic addition with formation of the corresponding trifl uoromethyl carbinols [2][3][4]. It is important to note that in the case of α, β-unsaturated ketones, the formation of products of nucleophilic 1,4-trifl uoromethylation (Michael addition) was not observed (Scheme 1).Th e fi rst example of the conjugate trifl uoromethylation of α, β-enone system was discovered by us on the example of the reaction R F SiMe 3 (R F = CF 3 , C 2 F 5 ) with 2-trifl uoromethylchromones 1 [5,6]. Monitoring using 19 F NMR spectroscopy showed that chromones 1 in the presence of the nucleophilic initiator Me 4 NF (THF, 0 °C, 4 h) almost quantitatively and with high regioselectively react with CF 3 SiMe 3 towards the way of 1,4-addition, giving trimethylsilyl ethers 2 (the content in the reaction mixture of 1,2-addition products 3 does not exceed 5-10 %). When processing of the reaction mixture with diluted HCl only the products of 1,4-addition 2 are subjected to hydrolysis to give 2-trifl uoromethyl-2-perfl uoroalkylchroman-4-ones 4. As expected, when increasing of the length of the R F group to C 2 F 5 the regioselectivity of the reaction is reduced to 80-85 % (Scheme 2).Th e optimal conditions of 1,4-trifl uoromethylation (Me 4 NF, THF, 0 °C, 24 h) were used by us for the preparative synthesis of chromanones 4a-f, the yields of which ranged 50-86 % (Scheme 3) [6].Currently, this reaction represents the shortest and most eff ective way of synthesis of partially fl uorinated analogues of natural chromanones, chromanes and chromenes 31with gem-dimethyl group at the atom C(2). Th us, 4-oxo-2,2-bis(trifl uoromethyl)chroman-6-carbaldehyde 5a, an analogue of natural lactarochromal, metabolite of Lactarius deliciosus mushrooms [7], in wh...

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Section: схема 7 схемаunclassified

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Nucleophilic conjugate trifluoromethylation of chromones and activated alkenes under the action of Ruppert’s reagent

Sosnovskikh

Roshentaler

2017

Chim.Tech.Acta

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“…Finally, Dilman and co--trifluoromethylation of 2-nitrocinnamates using either NaOAc or (nBu) 4 NOAc as an activator of the Ruppert-Prakash reagent. 15 The reaction was performed on several 2-nitrocinnamate derivatives 15a-f giving the corresponding products 16a-h in moderate to good yields (Scheme 5c). The reaction proved to be no selective since the products were obtained as an almost 1:1 mixture of diastereoisomeres, whatever the diastereoisomeric ratio of M a n u s c r i p t 7 the starting 2-nitrocinnamate compounds.…”

Section: 4-addition Of a Cf 3 Group Or A C N F 2n+1 Groupmentioning

confidence: 99%

1,4-Addition of the CF3 group, perfluoroalkyl groups and functionalized difluoromethylated moieties: An overview

Besset

Poisson

Pannecoucke

2015

Journal of Fluorine Chemistry

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Nucleophilic Additions of Perfluoroalkyl Groups

Beier

Zibinsky²,

Prakash

2016

Organic Reactions

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The trifluoromethyl and perfluoroalkyl functional groups possess significant thermal, chemical, and metabolic stability, as well as high lipophilicity and electronegativity. These physicochemical properties render fluorinated carbon residues indispensable in diverse applications, such as agrochemistry, drug design, and material chemistry. The generation and properties of nucleophilic perfluoroalkyl reagents as well as the scope and limitations of their additions to various electrophilic partners is described in this chapter.

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Reactions of fluorinated silanes with 2-nitrocinnamates

Cited by 19 publications

References 23 publications

Nucleophilic conjugate trifluoromethylation of chromones and activated alkenes under the action of Ruppert’s reagent

Nucleophilic conjugate trifluoromethylation of chromones and activated alkenes under the action of Ruppert’s reagent

1,4-Addition of the CF3 group, perfluoroalkyl groups and functionalized difluoromethylated moieties: An overview

Nucleophilic Additions of Perfluoroalkyl Groups

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