Gold-Catalyzed Intermolecular Formal [4 + 2 + 2]-Cycloaddition of Anthranils with Allenamides

Organic Letters, Journal Year: 2020, Volume and Issue: 22(15), P. 5990 - 5994

Published: July 17, 2020

The construction of eight-membered rings is a challenging issue due to unfavorable transannular strain and entropic barriers. We report herein gold-catalyzed formal [4 + 2 2] cycloaddition reaction anthranils with allenamides deliver oxa-bridged heterocycles in accepted yields unique E/Z configuration. Moreover, the asymmetric by using chiral phosphoramidite gold catalyst has also been conducted.

Language: Английский

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HFIP‐Mediated Decarboxylative [4+3]‐Annulation of Azaoxyallyl Cations with Isatoic Anhydride

Advanced Synthesis & Catalysis, Journal Year: 2020, Volume and Issue: 362(17), P. 3594 - 3603

Published: May 15, 2020

Abstract The first example of a [4+3]‐annulation reaction between in situ‐generated azaoxyallyl cations and isatoic anhydride has been developed for the construction seven‐membered 1,4‐benzodiazepinediones moderate to good yields (up 91% yield). This annulation involves cascade decarboxylative addition hexafluoroisopropanol anhydride, cation, intramolecular substitution yield 1,4‐benzodiazepinediones. magnified image

Language: Английский

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Base-Promoted Formal [3 + 2] Cycloaddition of α-Halohydroxamates with Carbon Disulfide to Synthesize Polysubstituted Rhodanines

Organic Letters, Journal Year: 2022, Volume and Issue: 24(15), P. 2837 - 2841

Published: April 8, 2022

A concise and practical strategy via potassium-carbonate-mediated [3 + 2]-cycloaddition reaction of α-halohydroxamates with the common solvent carbon disulfide for synthesis functionalized rhodanine derivatives in good to excellent yields is developed. The present methodology features a wide substrate scope as well functional group tolerance. potential synthetic utility this protocol demonstrated by series natural product containing rhodamine skeletons.

Language: Английский

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Synthesis of 1,4-diazepinone derivatives via a domino aza-Michael/S_N2 cyclization of 1-azadienes with α-halogenoacetamides

Organic & Biomolecular Chemistry, Journal Year: 2020, Volume and Issue: 18(6), P. 1082 - 1086

Published: Jan. 1, 2020

A novel cyclization of N-alkoxy α-halogenoacetamides with N-sulfonyl-1-aza-1,3-butadienes has been developed for the efficient preparation 1,4-diazepinones in one step under transition metal-free conditions.

Language: Английский

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[8+3]‐Cycloaddition of Tropones with Azaoxyallyl Cations

Chemistry - An Asian Journal, Journal Year: 2019, Volume and Issue: 14(24), P. 4748 - 4753

Published: Sept. 17, 2019

Although azaoxyallyl cations are widely used as 1,3-dipoles for various cycloaddition reactions leading to nitrogen-containing heterocycles, their application in higher-order reaction remains scarce. Herein, we present the [8+3]-cycloaddition of tropones with situ generated allowing one-step construction cycloheptatriene-fused 1,4-oxazinones moderate good yields. This base-promoted new carbon-oxygen and carbon-nitrogen bond-forming takes place under mild conditions absence transition metal catalysts.

Language: Английский

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Practical synthesis of 3-aryl anthranils via an electrophilic aromatic substitution strategy

Chemical Science, Journal Year: 2022, Volume and Issue: 13(7), P. 2105 - 2114

Published: Jan. 1, 2022

A practical route for the synthesis of valuable 3-aryl anthranils from readily available and simple arenes has been achieved through an electrophilic substitution rearomatization sequence by employing Tf 2 O as effective activator.

Language: Английский

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Base‐Promoted Cycloaddition of γ‐Hydroxy‐ and δ‐Hydroxy‐α,β‐Unsaturated Carbonyls with Azaoxyallyl Cations: Rapid Synthesis of N,O‐Heterocycles

European Journal of Organic Chemistry, Journal Year: 2020, Volume and Issue: 2020(20), P. 3090 - 3100

Published: April 9, 2020

Metal‐free and environmentally friendly synthesis of morpholin‐3‐one 1,4‐oxazepan‐3‐one skeletons was achieved by the cycloaddition reaction alcohol‐tethered enones α‐halohydroxamates. This transformation proposed to proceed through addition hydroxyl group in enone an in‐situ generated azaoxyallyl cation followed intramolecular aza‐Michael‐type trapping. Accordingly, morpholin‐3‐ones 1,4‐oxazepan‐3‐ones could be from γ‐hydroxy δ‐hydroxy enones, respectively, a highly diastereoselective manner.

Language: Английский

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Metal free amination of congested and functionalized alkyl bromides at room temperature

Chemical Communications, Journal Year: 2020, Volume and Issue: 56(35), P. 4804 - 4807

Published: Jan. 1, 2020

Herein, we report a highly facile and unprecedented approach to synthesize congested N-(hetero)aryl amines en route α-amino acid amides using α-bromoamides as alkylating agents under mild reaction conditions (room temperature). The involvement of aza-oxyallyl cations is the hallmark this reaction. method was readily adapted for rapid synthesis coveted 1,4-benzodiazepine-3,5-diones.

Language: Английский

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Diastereoselective synthesis of tetrahydrobenzo[b]azocines by Lu(OTf)₃-catalyzed [4+4] cycloaddition of donor–acceptor cyclobutanes with anthranils

Chemical Communications, Journal Year: 2022, Volume and Issue: 58(39), P. 5865 - 5868

Published: Jan. 1, 2022

A Lewis acid-catalyzed [4+4] cycloaddition reaction from D–A cyclobutanes and anthranils, providing the corresponding oxa-bridged eight-membered heterocycles under mild conditions.

Language: Английский

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Synthesis of Five-Membered Cyclic Guanidines via Cascade [3 + 2] Cycloaddition of α-Haloamides with Organo-cyanamides

The Journal of Organic Chemistry, Journal Year: 2021, Volume and Issue: 86(4), P. 3546 - 3554

Published: Feb. 4, 2021

The convenient preparation of N2-unprotected five-membered cyclic guanidines was achieved through a cascade [3 + 2] cycloaddition between organo-cyanamides and α-haloamides under mild conditions in good to excellent yields (up 99%). corresponding could be easily transformed into hydantoins via hydrolysis.

Language: Английский

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