Palladium-Catalyzed [3 + 2] Annulation of Aromatic Amides with Maleimides through Dual C–H Activation

Organic Letters, Journal Year: 2023, Volume and Issue: 25(13), P. 2190 - 2195

Published: March 26, 2023

A palladium-catalyzed [3 + 2] annulation of substituted aromatic amides with maleimides providing tricyclic heterocyclic molecules in good to moderate yields through weak carbonyl chelation is reported. The reaction proceeds via a dual C-H bond activation where the first takes place selectively at benzylic position followed by second meta afford five-membered cyclic ring. An external ligand Ac-Gly-OH has been used succeed this protocol. plausible mechanism proposed for reaction.

Language: Английский

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Recent Advances in N-Heterocyclic Small Molecules for Synthesis and Application in Direct Fluorescence Cell Imaging

Molecules, Journal Year: 2023, Volume and Issue: 28(2), P. 733 - 733

Published: Jan. 11, 2023

Nitrogen-containing heterocycles are ubiquitous in natural products and drugs. Various organic small molecules with nitrogen-containing heterocycles, such as boron compounds, cyanine, pyridine derivatives, indole quinoline maleimide etc., have unique biological features, which could be applied various fields, including imaging. Fluorescence cell imaging is a significant effective modality This review focuses on the synthesis applications direct fluorescence of N-heterocyclic last five years, to provide useful information enlightenment for researchers this field.

Language: Английский

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Mn(I)-Catalyzed Preferential Electrophilic C3-Maleimidation in Quinoxaline Leading to Spirocyclization and Dehydrogenation of Succinimides

Organic Letters, Journal Year: 2023, Volume and Issue: 25(20), P. 3806 - 3811

Published: May 17, 2023

A Mn(I)-catalyzed site-selective nondirected C3-maleimidation of quinoxaline is established. Herein, the electrophilic C3-metalation precedes over o-directed strategy to access diversely substituted quinoxaline-appended succinimides. The products undergo PIFA-promoted C(sp2)-C(sp3) spirocyclization via π-electrons drifting from aryls and Selectfluor-mediated dehydrogenation succinimide at room temperature.

Language: Английский

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Pd-Catalyzed Sequential Electrophilic Cyclization/Selective C–H Annulation Cascade: Synthesis of Isoxazole-Phthalimide-Fused Poly-Heterocyclics

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(5), P. 3214 - 3225

Published: Feb. 21, 2024

Harnessing the organo-palladium intermediates generated from electrophilic cyclizations for tandem C–C bond construction is a challenging task but constitutes an excellent tool constructing complex motifs simpler substrates. We realize herein such cyclative annulation of alkynyl-oxime ethers with maleimides facile isoxazole-phthalimide hybrid through Pd(II) catalysis. This protocol features regio-selectivity in C–H selection, broad substrate scope, good functional group tolerance, and scalability. Necessary KIE & labeling studies give insight into reaction mechanism.

Language: Английский

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Synthesis of 2-Formyl Carbazoles via Tandem Reaction of Indolyl Nitrones with 2-Methylidene Cyclic Carbonate

Organic Letters, Journal Year: 2023, Volume and Issue: 25(23), P. 4298 - 4302

Published: June 7, 2023

The synthesis of functionalized carbazoles as privileged nitrogen heterocycles has emerged a central topic in drug discovery and material science. We herein disclose the rhodium(III)-catalyzed cross-coupling reaction between indolyl nitrones 2-methylidene cyclic carbonate an allylating surrogate, resulting formation C2-formylated via tandem C–H allylation, [3 + 2] cycloaddition, aromatization, benzylic oxidation. synthetic utility this protocol is highlighted by variety post-transformations carbazoles.

Language: Английский

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Dearomative bis-functionalization of quinoxalines and bis-N-arylation of (benz)imidazoles via Cu(ii)-mediated addition of boronic acids

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(15), P. 2118 - 2121

Published: Jan. 1, 2023

A Cu(OTf) 2 -mediated regioselective dearomative aryl-hydroxylation across the C(sp )N bond of 2-aryl quinoxalines and bis- N -arylation (benz)imidazoles were developed using aryl boronic acids.

Language: Английский

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Photo-induced 1,2-thiohydroxylation of maleimide involving disulfide and singlet oxygen

Chemical Communications, Journal Year: 2023, Volume and Issue: 59(75), P. 11196 - 11199

Published: Jan. 1, 2023

A visible light-driven di-functionalization of maleimide with disulfide and in situ -generated singlet oxygen offers selective 1,2-thiohydroxylation under additive-free conditions.

Language: Английский

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Synthesis of Highly Fluorescent Thiazole Fused Benzo[a] Carbazoles by Sunlight Driven Photocyclization of Indolylthiazoles

European Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 19, 2024

Abstract Herein we report for the first time a sunlight‐driven, irreversible photocyclization reaction of indole‐linked trisubstituted thiazoles, synthesis highly fluorescent thiazole‐fused benzo[ ]carbazoles using mixture solvents (CH 3 CN: DMSO; : 1). Ring opening indole moiety was observed in case thiazole derivatives having 2‐methyl substituents. Under similar conditions, thiazoles cyclic 1,3‐dicarbonyls place also worked. This provides products two medicinally important moieties and benzocarbazoles. We have studied photophysical properties all found that most synthesized very good fluorescence quantum yields.

Language: Английский

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C3-Heteroarylation of Indoles via Cu(II)-Catalyzed Aminocupration and Subsequent Nucleophilic Addition of o-Alkynylanilines

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

Published: Feb. 23, 2025

Transition-metal-catalyzed aminometalation of o-alkynylanilines is a promising pathway for the synthesis C3-functionalized indoles. Herein, we describe Cu(II)-catalyzed site-selective C3-heteroarylation indoles from and quinoline N-oxides. A plausible reaction mechanism involving aminocupration followed by nucleophilic addition Cu(II)-indolyl complexes to N-oxides was proposed. Post-transformations generated C3-heteroarylated demonstrated broad applicability developed method.

Language: Английский

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Transition-metal-catalyzed straightforward synthesis of N-trifluoromethyl indoles from 2-alkynylaryl isothiocyanates or 2-alkynylanilines

Organic Chemistry Frontiers, Journal Year: 2024, Volume and Issue: 11(6), P. 1720 - 1728

Published: Jan. 1, 2024

Two new cascade approaches for N -CF 3 indoles via transition-metal-catalyzed reactions from 2-alkynylaryl isothiocyanates or 2-alkynylanilines have been demonstrated, featuring mild conditions, a broad substrate scope and moderate to high yields.

Language: Английский

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