Carbonylmetallates and carbanions in aromatic and vinylic nucleophilic substitution

Beletskaya, I. P.; Artamkina, G. A.; Mil'chenko, A. Yu.; Sazonov, P. K.; Shtern, M. M.

doi:10.1002/(sici)1099-1395(199606)9:6<319::aid-poc786>3.0.co;2-7

Cited by 19 publications

(15 citation statements)

References 32 publications

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“…In principle, the extent of substitution can be ordered by careful control of the reagents nucleophilicity and the reaction conditions and is summarized in Figure 1. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20] In general, there are few approaches reported to selectively afford mono-substitution of HFB, while disubstitution is generally obtained under mild conditions at room temperature. Stronger bases, longer reaction times, higher temperatures and a greater concentration of thiols can orient the reaction toward tetrasubstitution while hexa-substitution can be achieved with even harsher conditions and a larger excess of thiols.…”

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confidence: 99%

Using ¹⁹F NMR and two‐level factorial design to explore thiol‐fluoride substitution in hexafluorobenzene and its application in peptide stapling and cyclisation

et al. 2020

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Hexafluorobenzene undergoes 1,4‐selective thiol‐fluoride disubstitution and is an attractive disulfide crosslinking reagent for peptide cyclisation and stapling. Little attention has been directed toward understanding the scope of this reaction. Traditional reaction optimisation relies on a one‐variable‐at‐a‐time approach, which can exclude important combined effects of reaction variables. This study initially explored base and solvent effects to inform a subsequent two‐level factorial design approach to understand how to control the reactivity and product selectivity in a model reaction of hexafluorobenzene. We describe new conditions that selectively afford higher order substitution products for example, 1,2,4,5‐tetrasubstitution, making hexafluorobenzene a possible suitable scaffold for future branched or multicyclic peptide systems. Moreover, our new conditions provide an improved rapid (<1 minute) and selective peptide disulfide stapling and cyclisation approach under peptide‐compatible conditions.

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confidence: 99%

Using ¹⁹F NMR and two‐level factorial design to explore thiol‐fluoride substitution in hexafluorobenzene and its application in peptide stapling and cyclisation

et al. 2020

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“…For instance, Ir(ppy) 3 and Cat A could proceed through an oxidative quenching path, 30 despite a slight underpotential (C 5 F 5 N –2.17 vs. Ir(ppy) 3 – 2.01 and Cat A –1.94, E 1/2 vs. SCE). 31 While a reductive quenching of these photocatalysts by the amine is possible (EtNiPr 2 + 0.68 vs. 0.51 (Ir(ppy) 3 ), 0.27 ( Cat A ), E 1/2 vs. SCE) 32 this process is even more endothermic. The photoexcited state of Cat B is less reducing (–1.70 V vs. SCE) and less likely to undergo reductive quenching but is more oxidizing (0.58 V vs. SCE) and still undergoes efficient coupling.…”

Section: Resultsmentioning

confidence: 99%

Photocatalytic C–F alkylation; facile access to multifluorinated arenes

2015

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“…Aromatic nucleophilic substitution in polyfluoroarenes is known to proceed in a step-wise addition-elimination process; addition of the nucleophile is usually a rate-determine stage. 17,18 The regioselectivity of substitution of fluorine in monosubstituted pentafluorobenzenes (C 6 F 5 X) is governed mainly by the other fluorine atoms rather that the group X, with the exception of powerful electron-donating groups. 6 Probably for similar reasons, the starting sulfoxide (1 or 2) and phenoxyderivative (4 or 6, respectively) demonstrated very similar reaction capabilities.…”

Section: Mechanistic Rationalementioning

confidence: 99%

Reactions of 4-substituted 1-[(difluoromethyl)sulfinyl]polyfluorobenzenes with phenolate anion

Koshcheev¹,

Bredikhin²,

Maksimov³

et al. 2020

Arkivoc

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The reactions of 4-substituted-polyfluorinated-[(difluoromethyl)sulfinyl]benzenes ([4-X-C 6 F 4 S(O)CHF 2 [X = H, CF 3 and C 6 F 5 S(O)]) with phenolate anion in benzene, Et 2 O and CH 3 CN have been investigated. The reactions of the substrate (X = H, CF 3 ) and sodium phenolate in equal amounts resulted in the formation of mixtures of the starting compound, 2-phenoxyderivative and disubstituted products. The two-fold amount of the phenolate afforded the 2,6-disubstituted products for X = H in MeCN and for X = CF 3 in Et 2 O. At the same time, 4-CF 3 -C 6 F 4 S(O)CHF 2 in CH 3 CN gave a mixture of the 2,6-and 2,5-bis(phenoxy) derivatives. Quantum chemical calculations have been performed to explain this phenomenon. For X = C 6 F 5 S(O) in MeCN, the reaction was accompanied by sulfinyl moiety ipso-substitution.

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Carbonylmetallates and carbanions in aromatic and vinylic nucleophilic substitution

Cited by 19 publications

References 32 publications

Using ¹⁹F NMR and two‐level factorial design to explore thiol‐fluoride substitution in hexafluorobenzene and its application in peptide stapling and cyclisation

Using ¹⁹F NMR and two‐level factorial design to explore thiol‐fluoride substitution in hexafluorobenzene and its application in peptide stapling and cyclisation

Photocatalytic C–F alkylation; facile access to multifluorinated arenes

Reactions of 4-substituted 1-[(difluoromethyl)sulfinyl]polyfluorobenzenes with phenolate anion

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Carbonylmetallates and carbanions in aromatic and vinylic nucleophilic substitution

Cited by 19 publications

References 32 publications

Using 19F NMR and two‐level factorial design to explore thiol‐fluoride substitution in hexafluorobenzene and its application in peptide stapling and cyclisation

Using 19F NMR and two‐level factorial design to explore thiol‐fluoride substitution in hexafluorobenzene and its application in peptide stapling and cyclisation

Photocatalytic C–F alkylation; facile access to multifluorinated arenes

Reactions of 4-substituted 1-[(difluoromethyl)sulfinyl]polyfluorobenzenes with phenolate anion

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Using ¹⁹F NMR and two‐level factorial design to explore thiol‐fluoride substitution in hexafluorobenzene and its application in peptide stapling and cyclisation

Using ¹⁹F NMR and two‐level factorial design to explore thiol‐fluoride substitution in hexafluorobenzene and its application in peptide stapling and cyclisation