A Cu-electrocatalytic azidation of -aryl enamines and subsequent denitrogenative annulation for the construction of quinoxaline frameworks is reported. Only 0.5 mol % of copper(II) chloride was employed for this cascade transformation displaying excellent functional-group compatibility even with complex bioactive scaffolds. The efficient electro-oxidative protocol enables the use of NaN as the cheapest azide source. Detailed mechanistic experiments, cyclic voltammetry, and spectroscopic studies provided strong evidence for a dual role of the Cu catalyst in azidyl and iminyl radical generation steps.

Download full-text PDF

Source
http://dx.doi.org/10.1021/acs.orglett.3c02186DOI Listing

Publication Analysis

Top Keywords

synthesis quinoxalines
4
quinoxalines cu-electrocatalytic
4
cu-electrocatalytic azidation/annulation
4
azidation/annulation cascade
4
cascade low
4
low catalyst
4
catalyst loading
4
loading cu-electrocatalytic
4
cu-electrocatalytic azidation
4
azidation -aryl
4

Similar Publications

The synthetic approach based on a sequence of Buchwald-Hartwig cross-coupling and annulation through intramolecular oxidative cyclodehydrogenation has been used for the construction of novel 4-alkyl-4-thieno[2',3':4,5]pyrrolo[2,3-]quinoxaline derivatives. For the first time, these polycyclic compounds were evaluated for antimycobacterial activity, including extensively drug-resistant strains. A reasonable bacteriostatic effect against HRv was demonstrated.

View Article and Find Full Text PDF

Capturing CO is highly valued in the field of organic synthesis, especially underdeveloped dual-CO conversion. In this study, we detail a novel reductive cyclization of 2-indolylanilines with dual CO as a difunctional reagent in the presence of PMHS [poly(methylhydrosiloxane)], delivering methyl-substituted quinoxalines. Furthermore, another chemoselective cyclization with 2-pyrrolylanilines is also realized by converting mono-CO.

View Article and Find Full Text PDF

Late-stage C-H trifluoroacetylation of quinoxaline-2(1)-ones using masked trifluoroacyl reagents.

Org Biomol Chem

January 2025

Jiangsu Key Laboratory of Pesticide Science and Department of Chemistry, College of Sciences, Nanjing Agricultural University, Nanjing 210095, P. R. China.

A strategy for trifluoroacetylation of quinoxaline-2(1)-ones has been investigated. This strategy employs masked trifluoroacyl reagents to obtain trifluoroacetylated quinoxaline-2(1)-ones under metal-, catalyst-, and light-free conditions. This approach is distinguished by its functional group compatibility and tolerance, as well as the simplicity of the experimental process, making it suitable for gram-scale synthesis.

View Article and Find Full Text PDF

Non-fused electron acceptors have obtained increasing curiosity in organic solar cells (OSCs) thanks to simple synthetic route and versatile chemical modification capabilities. However, non-fused acceptors with varying quinoxaline core and as-cast device have rarely been explored, and the molecular structure-photovoltaic performance relationship of such acceptors remains unclear. Herein, two non-fused acceptors L19 and L21 with thienyl substituted non-fluorinated/fluorinated quinoxaline core were developed via five-step synthesis.

View Article and Find Full Text PDF

Benzylic C-H Oxidation: Recent Advances and Applications in Heterocyclic Synthesis.

Molecules

December 2024

School of Chemistry and Physics, University of KwaZulu-Natal, Scottsville, Pietermaritzburg 3209, South Africa.

Benzylic C-H oxidation to form carbonyl compounds, such as ketones, is a fundamental transformation in organic synthesis as it allows for the preparation of versatile intermediates. In this review, we highlight the synthesis of aromatic ketones via catalytic, electrochemical, and photochemical oxidation of alkylarenes using different catalysts and oxidants in the past 5 years. Additionally, we also discuss the synthesis of heterocyclic molecules using benzylic C-H oxidation as a key step.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!