Amine‐Free Approach toward <i>N</i>‐Toluenesulfonyl Amidine Construction: A Phosphite‐Mediated Beckmann‐Like Coupling of Oximes and <i>p</i>‐Toluenesulfonyl Azide

Fleury, Lauren M.; Wilson, Erin E.; Vogt, Monika; Fan, Tiffany J.; Oliver, Allen G.; Ashfeld, Brandon L.

doi:10.1002/anie.201305141

Cited by 33 publications

(19 citation statements)

References 47 publications

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“…Multiple methods exist for the synthesis of amidines in general, including the Pinner reaction, 13 substitution of phenoxyimidates, 14 Beckman-type rearrangements, 15 and dehydrogenative coupling reactions, 16,17 or by catalysis with palladium 14,18−21 or nickel, 22 as well as some multicomponent reactions. 23−33 Chang developed strategies for the synthesis of sulfonated and phosphorylated amidines via traditional click chemistry with azides, followed by a thermal N 2 exclusion, resulting in a net coupling of a nitrene to an alkyne.…”

Section: Introductionmentioning

confidence: 99%

Efficient Copper-Catalyzed Multicomponent Synthesis of N-Acyl Amidines via Acyl Nitrenes

Vliet

Polak

Siegler³

et al. 2019

J. Am. Chem. Soc.

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Direct synthetic routes to amidines are desired, as they are widely present in many biologically active compounds and organometallic complexes. N-Acyl amidines in particular can be used as a starting material for the synthesis of heterocycles and have several other applications. Here, we describe a fast and practical copper-catalyzed three-component reaction of aryl acetylenes, amines, and easily accessible 1,4,2-dioxazol-5-ones to N-acyl amidines, generating CO2 as the only byproduct. Transformation of the dioxazolones on the Cu catalyst generates acyl nitrenes that rapidly insert into the copper acetylide Cu–C bond rather than undergoing an undesired Curtius rearrangement. For nonaromatic dioxazolones, [Cu(OAc)(Xantphos)] is a superior catalyst for this transformation, leading to full substrate conversion within 10 min. For the direct synthesis of N-benzoyl amidine derivatives from aromatic dioxazolones, [Cu(OAc)(Xantphos)] proved to be inactive, but moderate to good yields were obtained when using simple copper(I) iodide (CuI) as the catalyst. Mechanistic studies revealed the aerobic instability of one of the intermediates at low catalyst loadings, but the reaction could still be performed in air for most substrates when using catalyst loadings of 5 mol %. The herein reported procedure not only provides a new, practical, and direct route to N-acyl amidines but also represents a new type of C–N bond formation.

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Section: Introductionmentioning

confidence: 99%

Efficient Copper-Catalyzed Multicomponent Synthesis of N-Acyl Amidines via Acyl Nitrenes

Vliet

Polak

Siegler³

et al. 2019

J. Am. Chem. Soc.

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“…Based on previous reports– and control experiments, a tentative mechanism for the zinc‐promoted Beckmann‐type rearrangement of oxime acetates with arylamines was proposed (Scheme ). First, with the assistance of Zn(OTf) 2 , the aryl group migrates to the nitrogen atom in a concerted pathway and the acetyl group is expulsed.…”

Section: Resultsmentioning

confidence: 99%

“…For example, Ashfeld etc . reported an effective method for the synthesis of N ‐toluenesulfonyl amidines via nitrilium ions intermediate . Zhang and co‐workers achieved the preparation of common amidines by carbodiimides intermediates .…”

Section: Introductionmentioning

confidence: 99%

Access to Amidines and Arylbenzimidazoles: Zinc‐Promoted Rearrangement of Oxime Acetates

et al. 2018

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An efficient and straightforward zinc-promoted rearrangement of oxime acetates with arylamines for the synthesis of amidines has been developed under mild conditions. This process involves NÀO/CÀC bond cleavages and CÀC/CÀN bond formations. Various oxime acetates and arylamines are suitable for this transformation. Furthermore, diverse arylbenzimidazoles could also be prepared through simple one-pot procedure.1-(3,4-Dihydroquinolin-1(2H)-yl)-N-phenylethan-1-imine (3 bs): as a yellow oil (58.5 mg, 78%); R f = 0.55 (petroleum

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“…A variety of methods have been developed for the synthesis of N-sulfonyl amidines. The most commonly used methods to prepare these compounds include the Cu-catalyzed multicomponent reaction of alkynes, sulfonyl azides and amines [23][24][25][26][27][28][29][30][31], the reaction of thioacetamide derivatives and cyclic thioamides with sulfonyl azides [22,32,33], the chlorophosphite-mediated Beckmann reaction of oximes with p-toluenesulfonyl azide [34], the sulfonyl ynamide rearrangement by treatment with amines [35], the sodium iodide catalyzed reaction of sulfonamide with formamide [36], and the condensation of sulfonamide derivatives with DMF-DMA [37].…”

Section: Introductionmentioning

confidence: 99%

Regioselective synthesis of heterocyclic N-sulfonyl amidines from heteroaromatic thioamides and sulfonyl azides

Ilkin¹,

Berseneva²,

Beryozkina³

et al. 2020

Beilstein J. Org. Chem.

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N-Sulfonyl amidines bearing 1,2,3-triazole, isoxazole, thiazole and pyridine substituents were successfully prepared for the first time by reactions of primary, secondary and tertiary heterocyclic thioamides with alkyl- and arylsulfonyl azides. For each type of thioamides a reliable procedure to prepare N-sulfonyl amidines in good yields was found. Reactions of 1-aryl-1,2,3-triazole-4-carbothioamides with azides were shown to be accompanied with a Dimroth rearrangement to form 1-unsubstituted 5-arylamino-1,2,3-triazole-4-N-sulfonylcarbimidamides. 2,5-Dithiocarbamoylpyridine reacts with sulfonyl azides to form a pyridine bearing two sulfonyl amidine groups.

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Amine‐Free Approach toward N‐Toluenesulfonyl Amidine Construction: A Phosphite‐Mediated Beckmann‐Like Coupling of Oximes and p‐Toluenesulfonyl Azide

Cited by 33 publications

References 47 publications

Efficient Copper-Catalyzed Multicomponent Synthesis of N-Acyl Amidines via Acyl Nitrenes

Efficient Copper-Catalyzed Multicomponent Synthesis of N-Acyl Amidines via Acyl Nitrenes

Access to Amidines and Arylbenzimidazoles: Zinc‐Promoted Rearrangement of Oxime Acetates

Regioselective synthesis of heterocyclic N-sulfonyl amidines from heteroaromatic thioamides and sulfonyl azides

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