Three-component synthesis ofN-naphthyl pyrazolesviaRh(iii)-catalyzed cascade pyrazole annulation and Satoh–Miura benzannulation

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(27), P. 4036 - 4039

Published: Jan. 1, 2023

The synthesis of N-naphthyl pyrazoles has been realized by the direct three-component reactions enaminones, aryl hydrazine hydrochlorides and internal alkynes via Rh(III) catalysis. synthetic employing simple substrates lead to simultaneous construction dual cyclic moieties, including a pyrazole ring phenyl ring, sequential formation two C-N three C-C bonds.

Language: Английский

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Condition-Controlled Selective Synthesis of Pyranone-Tethered Indazoles or Carbazoles through the Cascade Reactions of N-Nitrosoanilines with Iodonium Ylides

Organic Letters, Journal Year: 2023, Volume and Issue: 25(24), P. 4422 - 4428

Published: June 8, 2023

Presented herein is a condition-controlled selective synthesis of pyranone-tethered indazoles or carbazole derivatives via the cascade reactions N-nitrosoanilines with iodonium ylides. Mechanistically, formation former involves an unprecedented process including nitroso group-directed C(sp2)–H bond alkylation N-nitrosoaniline ylide followed by intramolecular C-nucleophilic addition to moiety, solvent-assisted cyclohexanedione ring opening, and transesterification/annulation. On contrary, latter initial annulation denitrosation. These developed protocols feature easily controllable selectivity, mild reaction conditions, clean sustainable oxidant (air), valuable products that are structurally diverse. In addition, utility was showcased their facile diverse transformations into synthetically biologically interesting compounds.

Language: Английский

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Towards bioresource-based aggregation-induced emission luminogens from lignin β-O-4 motifs as renewable resources

Nature Communications, Journal Year: 2023, Volume and Issue: 14(1)

Published: Sept. 28, 2023

One-pot synthesis of heterocyclic aromatics with good optical properties from phenolic β-O-4 lignin segments is high importance to meet value added biorefinery demands. However, executing this process remains a huge challenge due the incompatible reaction conditions depolymerization containing γ-OH functionalities and bioresource-based aggregation-induced emission luminogens (BioAIEgens) formation desired properties. In work, benzannulation reactions starting moieties 3-alkenylated indoles catalyzed by vanadium-based complexes have been successfully developed, affording wide range functionalized carbazoles up 92% yield. Experiments density functional theory calculations suggest that pathway involves selective cleavage double C-O bonds/Diels-Alder cycloaddition/dehydrogenative aromatization. Photophysical investigations show these carbazole products represent class BioAIEgens twisted intramolecular charge transfer. Distinctions behavior were revealed based on unique acceptor-donor-acceptor-type molecular conformations as well packings. This work features motifs renewable substrates, without need apply external oxidant/reductant systems. Here, we concise sustainable route AIE properties, building bridge between BioAIE materials.

Language: Английский

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Benzannulation of Functionally Enhanced Indole-3-carbaldehydes with Ynones and Alkynoates: A Domino Approach to Bioactive Carbazoles─Synthesis of Clauolenzole A, Calothrixin A & B, Methyl Carbazole-3-carboxylate, and Quinocarbazole

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

Published: Feb. 5, 2025

A flexible, regioselective, benzannulation strategy toward multifunctional carbazoles from 2-(2-oxo-2-arylethyl)indole-3-carbaldehydes, employing either ynones or alkynoates as reaction partners, has been envisaged and implemented. This enabling access to variegated in one-flask operation leads strategic substituent diversification via partner variation. The efficacy applications of this methodology are demonstrated through 23 examples concise syntheses bioactive clauolenzole A, calothrixin & B, methyl carbazole-3-carboxylate, pharmacophoric quinocarbazole.

Language: Английский

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The solvent-controlled Rh(iii)-catalyzed switchable [4+2] annulation of 2-arylIndoles with iodonium ylides

Chemical Communications, Journal Year: 2022, Volume and Issue: 58(41), P. 6140 - 6143

Published: Jan. 1, 2022

Highly selective and switchable [4+2] annulations of 2-arylindoles with iodonium ylides were achieved by performing solvent-controlled Rh(III)-catalyzed C-H activations. When using DCM as a solvent, the functionalization selectively delivered indolo[2,1-a]isoquinoline derivatives. In contrast, same catalytic system polar HFIP solvent predominately provided benzo[a]carbazole moieties.

Language: Английский

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Cu(OTf)₂/HFIP catalyzed regioselective cycloisomerization of indole-C3-functionalized alkynols to carbazoles

Organic & Biomolecular Chemistry, Journal Year: 2024, Volume and Issue: 22(18), P. 3622 - 3629

Published: Jan. 1, 2024

We report here a simple and atom economic cycloisomerization reaction of indole-tethered alkynols for constructing diverse carbazoles using Cu(OTf)

Language: Английский

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Synthesis of functionalized indoles via cascade benzannulation strategies: a decade's overview

Organic & Biomolecular Chemistry, Journal Year: 2022, Volume and Issue: 20(15), P. 3029 - 3042

Published: Jan. 1, 2022

Indoles are one of the most prominent aromatic heterocycles in organic chemistry field. Due to their widespread presence various natural products, alkaloids, drugs, approved medicines, etc. synthesis and functionalization indoles great interest. This review emphasizes recent developments techniques domino cascade cyclization process last decade starting from building blocks. In particular, this depicts several intriguing benzannulation methods creating a benzene ring on pre-existing pyrrole nucleus an inter/intramolecular fashion under metal-catalyzed/metal-free approaches. Different subsections focus gradual timely complementary area detailed analysis mechanisms reactivity patterns. As method, gives significant incentive annulation strategies also overview remaining challenges upcoming possibilities.

Language: Английский

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N-heterocyclic carbene and photocatalyst-catalyzed rapid access to indole ketones via radical C(sp³)–H acylation

Green Chemistry, Journal Year: 2024, Volume and Issue: 26(9), P. 5397 - 5408

Published: Jan. 1, 2024

Carbene and photocatalyst-catalyzed rapid access to indole ketones via radical C(sp 3 )–H acylation.

Language: Английский

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Natural and synthetic β-carboline as a privileged antifungal scaffolds

European Journal of Medicinal Chemistry, Journal Year: 2021, Volume and Issue: 229, P. 114057 - 114057

Published: Dec. 17, 2021

Language: Английский

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Development of Carbazole-Cored Organo-Photocatalyst for Visible Light-Driven Reductive Pinacol/Imino-Pinacol Coupling

Organic Letters, Journal Year: 2022, Volume and Issue: 24(49), P. 9001 - 9006

Published: Dec. 5, 2022

Benzoperylenocarbazole (BPC), a unique carbazole-based organophotocatalyst, is reported herein as potent organo-photoreductant. Lower excited state oxidation potential (−2.0 V vs SCE) and reasonable lifetime (4.61 ns) render BPC an effective photosensitizer. Under irradiation of blue light employing low catalyst loading (0.5 mol %), plethora vicinal diols diamines were synthesized in excellent yields through reductive coupling carbonyls imines, respectively. Insight about the electronic structure was obtained by DFT calculations.

Language: Английский

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