Co-Catalyzed Hydrofluorination of Alkenes: Photocatalytic Method Development and Electroanalytical Mechanistic Investigation

Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(7), P. 4380 - 4392

Published: Feb. 1, 2024

The hydrofluorination of alkenes represents an attractive strategy for the synthesis aliphatic fluorides. This approach provides a direct means to form C(sp3)–F bonds selectively from readily available alkenes. Nonetheless, conducting using nucleophilic fluorine sources poses significant challenges due low acidity and high toxicity associated with HF poor nucleophilicity fluoride. In this study, we present new Co(salen)-catalyzed simple utilizing Et3N·3HF as sole source both hydrogen fluorine. process operates via photoredox-mediated polar-radical-polar crossover mechanism. We also demonstrated versatility method by effectively converting diverse array activated varying degrees substitution into hydrofluorinated products. Furthermore, successfully applied methodology 18F-hydrofluorination reactions, enabling introduction 18F potential radiopharmaceuticals. Our mechanistic investigations, conducted rotating disk electrode voltammetry DFT calculations, unveiled involvement carbocation CoIV–alkyl species viable intermediates during fluorination step, contribution each pathway depends on structure starting alkene.

Language: Английский

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Direct electrochemical synthesis of arenesulfonyl fluorides from nitroarenes: a dramatic ionic liquid effect

Green Chemistry, Journal Year: 2024, Volume and Issue: 26(6), P. 3435 - 3440

Published: Jan. 1, 2024

A practical electrosynthesis of aryl sulfonyl fluorides from nitroarenes is described. Cheap N -methylimidazolium p -toluenesulfonate has been found to be an effective additive, promoting the desired fluorosulfonylation under very mild conditions.

Language: Английский

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Review and Theoretical Analysis of Fluorinated Radicals in Direct C_Ar−H Functionalization of (Hetero)arenes

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(16)

Published: Jan. 29, 2024

Abstract We highlight key contributions in the field of direct radical C Ar − H (hetero)aromatic functionalization involving fluorinated radicals. A compilation Functional Group Transfer Reagents and their diverse activation mechanisms leading to release radicals are discussed. The substrate scope for each is analyzed classified into three categories according electronic properties substrates. Density functional theory computational analysis provides insights chemical reactivity several through electrophilicity nucleophilicity parameters. Theoretical reduction potentials also highlights remarkable correlation between oxidizing ability. It established that highly (e.g. ⋅OCF 3 ) capable engaging single‐electron transfer (SET) processes rather than addition, which good agreement with experimental literature data. scale, based on barrier addition these benzene elaborated using high accuracy DLPNO‐(U)CCSD(T) method.

Language: Английский

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Substitution–Leaching–Deposition (SLD) Processes Drive Reversible Surface Layer Reconstruction of Metal Oxides for Fluoride Adsorption

Environmental Science & Technology, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 10, 2025

Surface complexation has long been recognized as the basic mode involved in fluoride adsorption onto metal oxides. However, such general recognition is challenged by unusual pH dependence observed adsorption. Here, we selected hydrated zirconium oxide (HZO) a representative to revisit mechanism. Multiple situ microscopic analyses and thermodynamic simulations suggest that, unlike of other anions that proceed exclusively via substituting protonated terminal hydroxyl (η-OH2+) groups oxides, can displace both η-OH2+ bridging (μ-OH+) HZO (i.e., Substitution). This distinctive displacement drives leaching Zr from HZO, generating aqueous polyfluorozirconium complexes Leaching) which subsequently deposit outer-sphere Deposition). The adsorbed gradually converts into fluorozirconate (Na5Zr2F13) coating, resulting surface layer reconstruction up 100 nm depth. atypical dependency be explained processes Substitution, Leaching, Deposition SLD processes). More attractively, SLD-driven reversible nature, ensuring constant defluoridation capability during cyclic adsorption-desorption assays. study advances our understanding at water-metal interfaces.

Language: Английский

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Copper-Mediated Radical Fluorine-Atom Transfer to Sulfonyl Radical: A Dramatic 4-Methoxypyridine 1-Oxide Ligand Effect

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(5), P. 3115 - 3127

Published: Feb. 13, 2024

Although the transition metal-catalyzed radical fluorine atom transfer (FAT) strategy has emerged as a powerful tool for construction of C–F bonds, to our knowledge, this approach rarely been applied formation S–F bonds. Here, we report that 4-methoxypyridine 1-oxide can serve an inexpensive and simple yet effective ligand thus promote transformation copper-mediated challengeable FAT sulfonyl radicals, paving way assembly FSO2 group. Based on concept, three Cu(I)-catalyzed protocols involving site-selective intra- intermolecular fluorosulfonylation inert C(sp3)–H bonds 1,2-aminofluorosulfonylation inactivated alkenes have developed, enabling preparation C(sp3)-rich aliphatic fluorides cannot be easily synthesized by known methods. These practical operationally methods result in high functional group tolerance under mild conditions modification bioactive derivatives highly valued molecules. Detailed mechanistic studies indicate unique role facilitating such rare FATs via outer-sphere pathway.

Language: Английский

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Mechanochemical-assisted decarboxylative sulfonylation of α,β-unsaturated carboxylic acids with sodium sulfinate salts

Green Chemistry, Journal Year: 2024, Volume and Issue: 26(5), P. 2721 - 2729

Published: Jan. 1, 2024

Herein, we report a mechanochemical-assisted decarboxylative sulfonylation of α,β-unsaturated carboxylic acids with sodium sulfinate salts using potassium iodide as an activator under water-assisted grinding conditions.

Language: Английский

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Navigating Ball Mill Specifications for Theory‐to‐Practice Reproducibility in Mechanochemistry

Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(48)

Published: Aug. 16, 2024

Abstract The rising prospects of mechanochemically assisted syntheses hold promise for both academia and industry, yet they face challenges in understanding and, therefore, anticipating respective reaction kinetics. Particularly, dependencies based on variations milling equipment remain little understood globally overlooked. This study aims to address this issue by identifying critical parameters through kinematic models, facilitating the reproducibility mechanochemical reactions across most prominent mills laboratory settings, namely planetary mixer mills. Through a series selected experiments replicating major classes organic, organometallic, transition metal‐catalyzed, inorganic from literature, we rationalize independence kinetics when accumulated energy criterion is met. As step forward facilitate practicability our findings, provide freely accessible online tool [†] that allows calculation different Our work advances current mechanochemistry lays foundation future rational exploration rapidly evolving field.

Language: Английский

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Mechanochemical Deoxyfluorination of Carboxylic Acids to Acyl Fluorides and Successive Mechanochemical Amide Bond Formation

ACS Sustainable Chemistry & Engineering, Journal Year: 2024, Volume and Issue: 12(9), P. 3565 - 3574

Published: Feb. 16, 2024

Diverse methods have been reported for the synthesis of acyl fluorides; however, an environmentally benign method fluorides remains underdeveloped. In this study, we developed solvent-free mechanochemical deoxyfluorination carboxylic acids to mediated by 1,1,2,2-tetrafluoroethyl-N,N-dimethylamine (TFEDMA) using a ball mill. This facilitated high product yields in short reaction times even sterically challenged acids. We also realized coupling and amines as well TFEDMA-mediated direct with via sequential one-pot deoxyfluorination/coupling pathway. Furthermore, protocol was expanded include peptide synthesis. The efficiency protocol, terms speed, characteristics, favorable E-factor, aligns requirements current environmental policies.

Language: Английский

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Enabling nucleophilic reactivity in molecular calcium fluoride complexes

Nature Chemistry, Journal Year: 2024, Volume and Issue: 16(9), P. 1473 - 1480

Published: May 14, 2024

Abstract Calcium fluoride is the ultimate source of all fluorochemicals. Current synthetic approaches rely on use HF, generated from naturally occurring fluorspar and sulfuric acid. Methods for constructing E–F bonds directly CaF 2 have long been frustrated by its high lattice energy, low solubility impaired ion nucleophilicity. Little fundamental understanding reactivity Ca–F moieties available to guide methodology development; well-defined molecular species containing are extremely rare, existing examples strongly aggregated evidence no nucleophilic delivery. Here, contrast, we show that targeting anionic systems type [L n (X) CaF] − , monomeric calcium complexes single can be synthesized, including via routes involving abstraction C–F bonds. Comparative structural spectroscopic studies mono- dinuclear allow us define structure–activity relationships bond formation fluorides.

Language: Английский

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Mechano-photoexcitation for organic synthesis using mechanoluminescent materials as photon sources

Nature Synthesis, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 14, 2024

Language: Английский

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