Radical Addition ofN-Bromophthalimide to Linear and Cyclic Alkynes

Wille, Uta; Krüger, Oliver; Kirsch, André; Lüning, Ulrich

doi:10.1002/(sici)1099-0690(199911)1999:11<3185::aid-ejoc3185>3.0.co;2-m

Cited by 15 publications

(6 citation statements)

References 16 publications

(1 reference statement)

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“…Although intermolecular radical addition to alkynes generating reactive vinyl radicals to perform intramolecular cascade reactions have been well established, their intermolecular multi-component equivalents remain a formidable challenge ( vide infra ). It is thus not surprising in that light that even simple addition reactions of nitrogen-centred radicals to alkynes are very rare 17 18 . In fact, compared with the well-established nucleophilic and electrophilic amination reaction, the construction of C–N bonds based on nitrogen-centred radicals have not received sufficient attention.…”

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confidence: 99%

Radical cascade reaction of alkynes with N-fluoroarylsulfonimides and alcohols

et al. 2015

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Cascade reactions initiated by radical addition to alkynes are synthetically very attractive because they enable access to highly complex molecular skeletons in only few synthetic steps under usually mild conditions. Here we report a general radical cascade reaction of alkynes, N-fluoroarylsulfonimides and alcohols, enabling the efficient synthesis of important α-amino-α-aryl ketones from readily available starting materials via a single operation. During this process, the highly regioselective nitrogen-centred radical addition to internal and terminal alkynes generating vinyl radicals and the next explicit migration of aryl group from the nitrogen source lead the following efficient desulfonylation, oxygenation, and semi-pinacol rearrangement. In addition, the semi-pinacol rearrangement precursors, α-alkyloxyl-α,α-diaryl imines, could also be efficiently obtained under milder conditions. This methodology might open a new entry for designing intermolecular radical cascade reaction of alkynes.

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confidence: 99%

Radical cascade reaction of alkynes with N-fluoroarylsulfonimides and alcohols

et al. 2015

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“…On the other hand, N-X (halogen) reagents [14][15][16][17], such as NBS, NIS, or NFSI, are the most significant electrophilic halogenation reagents with extremely important applications in organic synthesis. They also serve as bifunctional reagents in addition to alkynes, delivering amino-halogenation products (Scheme 1C) [33][34][35][36]. In 1999, the Wille and Lüning group [34] achieved the radical amino-bromination of alkynes.…”

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confidence: 99%

Catalyst-Free Trans-Selective Oxyiodination and Oxychlorination of Alkynes Employing N–X (Halogen) Reagents

Sun,

Guo,

Xia

et al. 2023

Molecules

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β-halogenated enol esters and ethers are versatile building blocks in organic synthesis, which has attracted increasing attention. In this study, we report the facile trans-oxyiodination and oxychlorination of alkynes, leading to the direct construction of versatile halogenated enol esters and ethers. This transformation features an easy operation, optimal atomic economy, a strong functional group tolerance, broad substrate scope, and excellent trans-selectivity. Employing highly electrophilic bifunctional N–X (halogen) reagents was the key to achieving broad reaction generality. To our knowledge, this transformation represents the first oxyhalogenation system employing N–X (halogen) reagents as both oxylation and halogenation sources.

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“…The formation of the vinyl radical ( I ) would result from the regioselective radical addition of the phthalimidyl radical to the alkyne. The regioselectivity of this last pathway is well documented for the photochemical addition of halo‐phthalimide to alkynes involving a radical chain reaction (20, 21).…”

Section: Resultsmentioning

confidence: 99%

“…The formation of this radical might also take place via SET from the phthalimide anion to exicted phthalimide (path b). The for- photochemical addition of halo-phthalimide to alkynes involving a radical chain reaction (20,21). Back electron transfer from the anion-radical of phthalimide to I gave a vinyl anion, which was pi-otonated.…”

Section: Resultsmentioning

confidence: 99%

Photoinduced Addition of Phthalimide to Unactivated Alkynes†

Nájera

Garcı́a-Segura

Pérez‐Inestrosa

et al. 2006

Photochem Photobiol

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Photoexcited phthalimide in equilibrium with its conjugated base produces the regioselective hydrophthalimidation of conjugated alkynes. The vinylphthalimide thus obtained is hydrolyzed to the corresponding carbonyl compound. With unconjugated alkynes, the outcome is a double addition of phthalimide to the triple bond. The reaction is assumed to take place via single electron transfer from either the alkyne or the phthalimide anion to the excited phthalimide as the primary photoprocess.

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Radical Addition ofN-Bromophthalimide to Linear and Cyclic Alkynes

Cited by 15 publications

References 16 publications

Radical cascade reaction of alkynes with N-fluoroarylsulfonimides and alcohols

Radical cascade reaction of alkynes with N-fluoroarylsulfonimides and alcohols

Catalyst-Free Trans-Selective Oxyiodination and Oxychlorination of Alkynes Employing N–X (Halogen) Reagents

Photoinduced Addition of Phthalimide to Unactivated Alkynes†

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