1,2-Dicarbofunctionalization of Trifluoromethyl Alkenes with Pyridinium Salts via a Cycloaddition/Visible-Light-Enabled Fragmentation Cascade

Chen, Shujie; Chen, Guoshu; Deng, Tao; Li, Jiahui; He, Zhiqing; Liu, Lishan; Ren, Hai; Liu, Yun‐Lin

doi:10.1021/acs.orglett.1c04148

Cited by 14 publications

(9 citation statements)

References 34 publications

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“…Moreover, the presence of the α−CF 3 group would mitigate phenonium ion rearrangement that would ultimately generate the geminal difluoride product [26k,m] . This strategy would circumvent the reactivity constraints imposed when using amines in I I /I III ‐based oxidative fluorination reactions, and mitigate fragmentation risks that are often observed in carbanionic manipulations [27] …”

Section: Introductionmentioning

confidence: 99%

Regio‐ and Enantioselective Intermolecular Aminofluorination of Alkenes via Iodine(I)/Iodine(III) Catalysis**

et al. 2022

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The regio-and enantio-selective, intermolecular vicinal fluoroamination of α-trifluoromethyl styrenes has been achieved by enantioselective I I /I III catalysis. Leveraging C 2 -symmetric resorcinol-based aryl iodide catalysts, it has been possible to intercept the transient iodonium intermediate using simple nitriles, which function as both the solvent and nucleophile. In situ Ritter reaction provides direct access to the corresponding amides (up to 89 % yield, e.r. 93 : 7). This main group catalysis paradigm inverts the intrinsic regioselectivity of the uncatalyzed process, thereby providing facile access to tertiary, benzylic stereocenters bearing both CF 3 and F groups. Privileged phenethylamine pharmacophores can be generated in which there is complete local partial charge inversion (CF 3 δÀ /F δÀ versus CH 3 δ + /H δ + ). Crystallographic analyses of representative β-fluoroamide products reveal highly pre-organized conformations that manifest the stereoelectronic gauche effect.

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Section: Introductionmentioning

confidence: 99%

Regio‐ and Enantioselective Intermolecular Aminofluorination of Alkenes via Iodine(I)/Iodine(III) Catalysis**

et al. 2022

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“…Darüber hinaus würde das Vorhandensein der α‐CF 3 ‐Gruppe die Phenonium‐Umlagerung verhindern, die in dem geminalen Difluorid resultieren würde. Mit dieser Strategie könnten die Einschränkungen in Bezug auf Rektivität umgangen werden, die bei der Verwendung von Aminen in I I/III ‐basierten oxidativen Fluorierungsreaktionen auftreten sowie die Fragmentierungsrisiken, die bei anionischen Manipulationen häufig zu beobachten sind [27] …”

Section: Introductionunclassified

Regio‐ und enantioselektive, intermolekulare Aminofluorierung von Alkenen durch Iod(I)/Iod(III)‐Katalyse**

et al. 2022

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Die regio-und enantioselektive, intermolekulare vicinale Fluoraminierung von α-CF 3 -Styrolen wurde durch enantioselektive I I /I III -Katalyse erreicht. Unter Nutzung von C 2 -symmetrischen, Resorcinol-basierten Aryl Iodid-Katalysatoren war es möglich, das kurzlebige Iodonium-Zwischenprodukt mit einfachen Nitrilen abzufangen, die sowohl als Lösungsmittel als auch als Nucleophil fungieren. Die in situ Ritter-Reaktion bietet direkten Zugang zu den entsprechenden Amiden (> 25 Beispiele, bis zu 89 % Ausbeute und 93 : 7 e.r.). Dieses Paradigma der Hauptgruppenkatalyse kehrt die intrinsische Regioselektivität des unkatalysierten Prozesses um und bietet so einen einfachen Zugang zu tertiären, benzylischen Stereozentren, die sowohl eine CF 3 -Gruppe als auch ein Fluor tragen. Es können privilegierte Phenethylamin-Pharmakophore erzeugt werden, bei denen die vollständige lokale partielle Ladungsumkehr vorliegt (CF 3 δÀ /F δÀ versus CH 3 δ + /H δ + ). Kristallographische Analysen von repräsentativen β-Fluoramid-Produkten zeigen Konformationen, die den stereoelektronischen Gauche-Effekt verdeutlichen.

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“…Yet, to date, only a handful of transformations such as the 1,4-addition to activated alkenes, the 1,6-addition to para -quinone methides, the direct nucleophilic substitution of preactivated α-trifluoromethyl alcohols, and coupling reaction with allenes have effectively used this strategy (see Scheme A) . An important limitation is that those methods often require tailored substrates that limit the scope of products that are attainable …”

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confidence: 99%

Leveraging the Hydroarylation of α-(Trifluoromethyl)styrenes to Access Trifluoromethylated All-Carbon Quaternary Centers

et al. 2022

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α- (Trifluoromethyl)styrenes are attractive olefin building blocks that have eluded hydroarylation processes. Here, we demonstrate that the use of a promoter system featuring triflic acid and hexafluoroisopropanol enables hydroarylation to directly build trifluoromethylated all-carbon quaternary centers. The observed reactivity significantly enriches the scope of hydroarylation of unactivated styrenes and provides straightforward access to trifluoromethylated diarylalkanes of interest. Gram-scale reactions and further functionalizations illustrate the synthetic potential of this approach.

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1,2-Dicarbofunctionalization of Trifluoromethyl Alkenes with Pyridinium Salts via a Cycloaddition/Visible-Light-Enabled Fragmentation Cascade

Cited by 14 publications

References 34 publications

Regio‐ and Enantioselective Intermolecular Aminofluorination of Alkenes via Iodine(I)/Iodine(III) Catalysis**

Regio‐ and Enantioselective Intermolecular Aminofluorination of Alkenes via Iodine(I)/Iodine(III) Catalysis**

Regio‐ und enantioselektive, intermolekulare Aminofluorierung von Alkenen durch Iod(I)/Iod(III)‐Katalyse**

Leveraging the Hydroarylation of α-(Trifluoromethyl)styrenes to Access Trifluoromethylated All-Carbon Quaternary Centers

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