Base-Promoted Annulative Difluoromethylenation of Enaminones with BrCF₂CO₂Et toward 2,2-Difluorinated 2,3-Dihydrofurans

Organic Letters, Journal Year: 2022, Volume and Issue: 24(12), P. 2404 - 2408

Published: March 18, 2022

A practical method for the synthesis of 2,2-difluorinated 2,3-dihydrofurans has been established via [4 + 1] annulation enaminones and BrCF2CO2Et with Na2CO3 promotion. This new protocol does not employ any transition metal reagent enables annulative difluoromethylation by partial cleavage C═C double bond. In addition, further treatment hydrochloric acid in one pot leads to β-keto enoic acids (4-oxo-2-butenoic acids) a formal enaminone C-N carboxylation.

Language: Английский

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Copper-catalyzed C–H/N–H annulation of enaminones and alkynyl esters for densely substituted pyrrole synthesis

Chemical Communications, Journal Year: 2022, Volume and Issue: 58(11), P. 1808 - 1811

Published: Jan. 1, 2022

Herein, the copper-catalyzed annulation of enaminones with alkynyl esters for facile synthesis different pyrroles a 2,3,4,5-tetrasubstituted structure has been developed. With Cu(OAc)2 as only catalyst, tunable 2-vinyl and 2,3-dicarboxyl-functionalized achieved by using terminal internal esters, respectively. The represents first example accessing substituted via direct cascade reactions involving vinylation pyrrole ring formation.

Language: Английский

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Ultrasound-Promoted Synthesis of α-Thiocyanoketones via Enaminone C═C Bond Cleavage and Tunable One-Pot Access to 4-Aryl-2-aminothiazoles

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(12), P. 8248 - 8255

Published: May 26, 2022

Ultrasound has been successfully employed to promote the thiocyanation of C═C bond in enaminones for synthesis α-thiocyanoketones and 2-aminothiazoles. The reactions with ammonium thiocyanate provide ultrasound irradiation at room temperature. More interestingly, simply further heating vessel after ultrasonic leads selective 2-aminothiazoles an unconventional 4-aryl substructure.

Language: Английский

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Tunable Synthesis of 4-Acyl- and 4-Formyl Pyrroles by Rhodium-Catalyzed Ring-Expansion of Azirines with Enaminones

Organic Letters, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 19, 2025

A rhodium-catalyzed annulation of 2H-azirines with enaminones is presented. This protocol affords a convenient approach to the diversity-oriented synthesis 4-acyl- and 4-formyl pyrroles good functional group tolerance. The utility this reaction has been demonstrated by scale-up preparation, late-stage modification natural molecules, diverse derivatives.

Language: Английский

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Synthesis of Tetrasubstituted Pyrroles via DBU-Mediated Cyclization of Unactivated Propargyl Tertiary Amines

The Journal of Organic Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: March 10, 2025

Compared with the well-developed cyclization of functionalized propargylamines, use unactivated tertiary propargylamines to access pyrroles remains challenging. Herein, we report an efficient method for constructing tetrasubstituted via a DBU-mediated intramolecular cycloaddition N-alkyl propargylamines. This reaction employs dihydropyrrole intermediates, followed by oxidation produce in presence 2,3-dichloro-5,6-dicyano-p-benzoquinone. In addition, broad substrate scope, high atom economy, selectivity, and simple operation are also advantages this protocol.

Language: Английский

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Thiazole-5-carbaldehyde Synthesis by Cascade Annulation of Enaminones and KSCN with Dess–Martin Periodinane Reagent

The Journal of Organic Chemistry, Journal Year: 2022, Volume and Issue: 87(21), P. 14957 - 14964

Published: Oct. 19, 2022

The Dess-Martin periodinane (DMP) reagent-mediated reactions of tertiary enaminones with potassium thiocyanate for the synthesis thiazole-5-carbaldehydes are developed. product formation involves cascade hydroxyl thiocyanation C═C double bond, intramolecular hydroamination C≡N and thiazole annulation by condensation on ketone carbonyl site, representing novel reaction pathways in between salt. DMP plays dual roles mediating free radical inducing unconventional selective thiazole-5-carbaldehyde masking situ generated formyl group during process.

Language: Английский

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Tunable vicinal, geminal diphosphorylation and C–N bond phosphorylation of enaminones toward divergent phosphorylated ketone derivatives

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(42), P. 6383 - 6386

Published: Jan. 1, 2023

The tunable reactions of enaminones with phosphine oxides/phosphonates in the form vicinal- and geminal diphosphorylation, C–N bond phosphorylation have been developed, providing new methods for synthesis divergent phosphorylated molecules.

Language: Английский

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Facile synthesis of the unknown 6,7-dihydrofuro[3,4-c]pyridines and 3,4-diaryloylpyridines from N-propargyl β-enaminones

Organic & Biomolecular Chemistry, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 1, 2025

A simple methodology for the synthesis of bicyclic 6,7-dihydrofuro[3,4- c ]pyridines is reported. The skeletal diversity synthesized heterobicyclic frame may present new nitrogen- and oxygen-based hybrid systems medicinal chemistry.

Language: Английский

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I₂/FeCl₃-Catalyzed Domino Reaction of Aurones with Enamino Esters for the Synthesis of Highly Functionalized Pyrroles

Organic Letters, Journal Year: 2022, Volume and Issue: 24(45), P. 8406 - 8411

Published: Nov. 9, 2022

A novel and efficient I2/FeCl3-catalyzed domino reaction of aurones with enamino esters via Michael addition, iodination, intramolecular nucleophilic substitution, spiro ring opening processes has been developed, affording a vast variety polysubstituted pyrroles in moderate to excellent yields. This protocol features mild conditions, broad substrate scope, high atom economy efficiency, feasibility for large-scale synthesis. plausible mechanism the pyrrole synthesis is proposed.

Language: Английский

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Tandem site-selective bromination and highly regioselective Heck reaction of N-allyl enaminones: chemodivergent synthesis of polysubstituted pyrroles and pyridines

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(19), P. 5532 - 5537

Published: Jan. 1, 2024

Chemodivergent synthesis of polysubstituted pyrroles and pyridines from N -allyl enaminones via tandem site-selective bromination the highly regioselective Heck reaction.

Language: Английский

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