Copper-Catalyzed Formal [3 + 3] Annulations of Arylketoximes and o-Fluorobenzaldehydes: An Entry to Quinoline Compounds

Organic Letters, Journal Year: 2021, Volume and Issue: 23(3), P. 936 - 942

Published: Jan. 14, 2021

A copper-based catalytic system has been developed to enable efficient cyclization of ketoxime acetates with o-fluorobenzaldehydes. This protocol offers an method for the synthesis substituted quinoline derivatives a broad range compatible functionalities. The present also provides rapid access synthetically and pharmaceutically useful quinoline-fused polycycles such as benzo[c]acridines.

Language: Английский

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Recent Advances in N-O Bond Cleavage of Oximes and Hydroxylamines to Construct N-Heterocycle

Molecules, Journal Year: 2023, Volume and Issue: 28(4), P. 1775 - 1775

Published: Feb. 13, 2023

Oximes and hydroxylamines are a very important class of skeletons that not only widely exist in natural products drug molecules, but also synthon, which have been used industrial production. Due to weak N-O σ bonds oximes hydroxylamines, they can be easily transformed into other functional groups by bond cleavage. Therefore, the synthesis N-heterocycle using as nitrogen sources has attracted wide attention. Recent advances for through transition-metal-catalyzed radical-mediated cyclization classified type rings summarized. In this paper, recent cleavage reviewed. We hope review provides new perspective on field, reference develop environmentally friendly sustainable methods.

Language: Английский

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Transition-Metal-Free Cascade Approach toward 2-Alkoxy/2-Sulfenylpyridines and Dihydrofuro[2,3-b]pyridines by Trapping In Situ Generated 1,4-Oxazepine

The Journal of Organic Chemistry, Journal Year: 2017, Volume and Issue: 82(18), P. 9515 - 9524

Published: Aug. 21, 2017

An efficient cascade reaction via trapping in situ generated active intermediate 1,4-oxazepine, formed from base-promoted 7-exo-dig cyclization of N-propargyl enaminone, has been developed. Alcohols/thiols and aldehydes were used as agents, providing 2-alkoxy/2-sulfenylpyridines dihydrofuro[2,3-b]pyridines moderate to high yields. This was completed within 30 min at room temperature, generating 1 equiv H2O the sole byproduct.

Language: Английский

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N-Silylenamines as Reactive Intermediates: Hydroamination for the Modular Synthesis of Selectively Substituted Pyridines

Organic Letters, Journal Year: 2018, Volume and Issue: 20(21), P. 6663 - 6667

Published: Oct. 23, 2018

A modular and selective synthesis of mono-, di-, tri-, tetra-, pentasubstituted pyridines is reported. Hydroamination alkynes with N-silylamine using a bis(amidate)bis(amido)titanium(IV) precatalyst furnishes the regioselective formation N-silylenamines. Addition α,β-unsaturated carbonyls to crude mixtures followed by oxidation affords 47 examples in yields up 96%. This synthetic route allows for diverse containing variable substitution patterns, including pharmaceutically relevant 2,4,5-trisubstituted pyridines, this one-pot protocol.

Language: Английский

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Regioselectivity Control in the Oxidative Formal [3 + 2] Annulations of Ketoxime Acetates and Tetrohydroisoquinolines

Organic Letters, Journal Year: 2019, Volume and Issue: 21(20), P. 8239 - 8243

Published: Oct. 3, 2019

A novel copper-catalyzed oxidative formal [3 + 2] annulations of ketoxime acetates and tetrohydroisoquinolines for the synthesis fused pyrazoles imidazoles has been developed. broad range important isoquinoline-fused pyrazole imidazole products were selectively generated by key control oxidant.

Language: Английский

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