Oxone® Mediated Regioselective C(sp²)−H Selenylation and Thiocyanation of Pyrazolo[1,5‐a]pyrimidines at Room Temperature

ChemistrySelect, Journal Year: 2024, Volume and Issue: 9(1)

Published: Jan. 2, 2024

Abstract A mild Oxone® mediated reaction for direct regioselective C−H selenylation and thiocyanation of pyrazolo[1,5‐ a ]pyrimidines is established at ambient temperature. This practical efficient methodology employs as user friendly, green, non‐toxic cheap reagent to facilitate room The present method offers high regioselectivity, broad substrate scope, conditions excellent yields. Further, this eco‐friendly approach could easily be extended other heterocycles. Mechanistic studies indicate that the occurs through electrophilic substitution mechanism via generation an chalcogen species.

Language: Английский

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I₂-Catalyzed Cascade Annulation/Cross-Dehydrogenative Coupling: Excellent Platform to Access 3-Sulfenyl Pyrazolo[1,5-a]pyrimidines with Potent Antibacterial Activity against Pseudomonas aeruginosa and Staphylococcus aureus

ACS Applied Bio Materials, Journal Year: 2025, Volume and Issue: unknown

Published: March 19, 2025

The increasing resistance of bacteria to antibiotics has become a serious threat existing options for treating bacterial infections. We have developed synthetic methodology 3-sulfenyl pyrazolo[1,5-a]pyrimidines with potent antibacterial activity. This iodine-catalyzed strategy been by employing amino pyrazoles, enaminones/chalcones, and thiophenols through intermolecular cyclization subsequent cross-dehydrogenative sulfenylation. highly regioselective practicable protocol utilized synthesize structurally diverse wide functionalities. is also extendable toward the synthesis bis(pyrazolo[1,5-a]pyrimidin-3-yl)sulfanes from pyrazole, enaminones/chalcone, KSCN pyrazolo[1,5-a]pyrimidine direct acetophenone. Mechanistic investigation disclosed radical pathway C-H sulfenylation involvement 3-iodo as active intermediate. biological activity sulfenyl against Pseudomonas aeruginosa Staphylococcus aureus, whereas sulfinyl no such Sulfenyl mechanistically inhibited growth accumulation ROS well induction in lipid peroxidation. Subsequently, circumstances changed membrane potential facilitated interaction membrane-associated proteins, leading loss integrity damage cell membranes. Moreover, these derivatives potentiated efficacy commercial antibiotic ciprofloxacin selected strains can be considered an alternative therapy

Language: Английский

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Exploration of Solvent‐Controlled Reactive Intermediates in the Synthesis of Aryloselenazoles: Altered Chalcogen Bonding Interactions

Chemistry - An Asian Journal, Journal Year: 2025, Volume and Issue: unknown

Published: May 29, 2025

Abstract A solvent‐controlled synthesis process has been developed for the preparation of a wide spectrum functional 2‐aryl‐aryloselenazoles. Investigation on reactive intermediates through theoretical studies helped establish possible mechanism present approach. Interestingly, current strategy allows star‐shaped benzoselenazoles, which are generally synthesized following multistep processes. Careful choice starting substrates led to organoselenium variants some metal‐coordinating ligands having structural similarities with several known in area coordination chemistry. The approach was explored further gram‐scale 2‐phenyl‐benzoselenazole. Moreover, impact aspects particularly remote functionalization altering chalcogen bonding interactions (CBIs) at molecular level solid‐state demonstrated. This established by studying crystal structures few

Language: Английский

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Electrochemical Regioselective C(sp2)-H Bond Chalcogenation of Pyrazolo[1,5-a]pyrimidines via Radical Cross Coupling at Room Temperature

Published: April 9, 2024

In this report, we disclose an electrochemical approach for the C(sp2)-H chalcogenation of pyrazolo[1,5-a]pyrimidines at room temperature via radical cross-coupling reaction. The reaction takes place within undivided cell employing graphite electrodes, with TBABF4 acting as supporting electrolyte. This technique offers a rapid, oxidant-free, and environmentally conscious protocol achieving regioselective specifically C3 position pyrazolo[1,5-a]pyrimidines. Furthermore, procedure uses only 0.5 equivalents diaryl chalcogenides which underscores atom economy protocol. Key attributes methodology include mild conditions, short time, utilization cost-effective electrode materials, reliable achievement yields ranging from good to excellent friendly conditions. Cyclic voltammetry studies quenching experiments suggest pathway mechanism.

Language: Английский

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Synthesis of organoselenium compounds using electrochemical and photochemical methods as novel approaches in organic chemistry

Tetrahedron, Journal Year: 2023, Volume and Issue: 148, P. 133667 - 133667

Published: Sept. 26, 2023

Language: Английский

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Electrochemical Regioselective C(sp²)–H Bond Chalcogenation of Pyrazolo[1,5-a]pyrimidines via Radical Cross-Coupling at Room Temperature

The Journal of Organic Chemistry, Journal Year: 2024, Volume and Issue: 89(19), P. 14496 - 14504

Published: Sept. 16, 2024

Herein, we disclose an electrochemical approach for the C(sp

Language: Английский

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