Journal of Fluorine Chemistry最新文献

Organofluorine compounds have proven to play an important role in pharmaceutical, agrochemical, and functional materials owing to their unique properties. However, the synthesis of these compounds is often challenging due to the difficulties in handling fluorinating agents and controlling their reactivity precisely. Recently, flow microreactor systems have attracted significant attention from chemists as a highly efficient synthetic methodology. In this review, we summarize recent advances in fluorine chemistry facilitated by continuous flow technology, highlighting its advantages and potential applications in streamlined synthesis of organofluorine compounds.

In order to synthesize new nanocrystalline compounds of cerium fluorides, the transformations of hydrated cerium(IV) fluoride with the composition CeF₄⋅H₂O under mild hydrothermal conditions were studied, in aqueous alkaline (1 M NaOH) or acidic (1 M HF) media. In alkaline medium, at 130 °С and 220 °C, hydrated cerium(IV) fluoride hydrolyses to form CeO₂, while in 1 M hydrofluoric acid at 130 °C, a mixture of crystalline Ce₃F₁₀⋅3H₂O and CeF₃ is formed. Hydrothermal treatment of cerium(IV) fluoride hydrate in 1 M HF at 220 °C yielded a new cerium(IV) fluoride hydrate (CeF₄)₃^.H₂O (Ce₃F₁₂^.H₂O). The new compound was studied by chemical analysis, powder and single crystal X-ray diffraction, scanning electron microscopy, ¹⁹F{¹H} and ¹H NMR, IR- and Raman spectroscopy. The noncentrosymmetric crystal structure of Ce₃F₁₂^.H₂O was found to be monoclinic (sp. gr. Cm, Z = 4) being isomorphic to uranium or neptunium tetrafluoride hydrates (U₃F₁₂^.H₂O or Np₃F₁₂^.H₂O). The structure of this compound exhibits a three-dimensional network of corner- and edge-shared [CeF₉], [CeF₇(OH₂)], [CeF₈(OH₂)] and [CeF₈] polyhedra. The influence of the cerium(IV) cations coordination sphere composition on the relative lengths of Ce-O bonds and F…HO hydrogen bonds discussed. The temperature behavior of the Ce₃F₁₂^.H₂O powder up to 500 °C was studied by thermogravimetry and differential scanning calorimetry.

In this paper, we report the deoxyfluorination of tertiary alcohol using a simple combination of potassium fluoride and sulfuric acid. These cheap and widely available reagents allow for the synthesis of tertiary fluorides in good to excellent yields. Extension of the reaction to other functional groups such as alkenes, acetates and ethers have also been studied.

A substitution reaction of O-, S-, or N-nucleophiles onto fluorinated isoxazolines via carbon–fluorine (C-F) bond cleavage was achieved. The C-F bond at the C5 position of fluorinated isoxazolines was dissociated by using SnCl₄ for the generation of a carbocation intermediate in this reaction. Subsequently, various nucleophiles such as alcohols, thiols, and amines were introduced, enabling the conversion to CO, C-S, or CN bonds and the formation of a new quaternary carbon center.

A method for the oxidative dibromination of gem-difluoroalkenes has been devised, employing HBr as the brominating agent and utilizing DMSO as both a mild oxidant and solvent. These uncomplicated conditions provide a high bromide atom economy, coupled with the accessibility and cost-effectiveness of DMSO and HBr. This approach notably expands the scope of gem-difluoroalkenes amenable to dibromination and furnishes a valuable precursor for ¹⁸F radiolabeling applications.

In recent years, C₆F₁₂O gas mixtures has shown extensive prospects for application in medium and low-voltage gas-insulated equipment due to its superior electrical performance and environmental friendliness. The presence of trace water may promote overheating decomposition of gas mixtures_. Therefore, studying the thermal decomposition characteristics of C₆F₁₂O in a trace water condition is of significant importance for the industrial application, operation, and maintenance of gas equipment. In this paper, the thermal decomposition characteristics of C₆F₁₂O/CO₂ gas mixtures under trace water conditions are investigated both experimentally and theoretically. The analysis of decomposition products is conducted using gas chromatography-mass spectrometry (GC–MS) on a constructed experimental platform for C₆F₁₂O/CO₂ gas mixtures overheating. Based on ReaxFF molecular dynamics (ReaxFF-MD), the decomposition characteristics of the gas mixtures over time and the concentration of trace water are observed. The main decomposition reaction paths of C₆F₁₂O/CO₂ gas mixtures under trace water conditions are analyzed at a microscopic level. Experiment results indicate that the main thermal decomposition products include CF₄, C₂F₆, C₃F₆, C₃F₈, CF₂O, C₃F₇H, C₄F₁₀, C₆F₁₄, C₅F₁₂, and CF₃H. Additionally, trace water facilitates the thermal decomposition of the C₆F₁₂O/CO₂ gas mixtures. Theoretical results indicate that multi-step decomposition occurs in the C₆F₁₂O component of the gas mixtures, with main generated intermediates including CO, F, CF₃, C₂F₅, C₃F₇, CFO₂, CF₂, C₂, CF, C₄F₇O, CF₃O, CFO, O, C₃F₅O, CF₂O, C, C₂O, H, and OH. The findings of this study provide a foundation for further exploration of trace water content values in C₆F₁₂O gas mixtures at a microscopic level in subsequent research.

On a laboratory scale, a complete technological extractive distillation cycle of an industrial azeotropic mixture of 2,2,2-trifluoroethanol (TFE) – isopropanol (IPA) of equimolar composition using N-methyl-2-pyrrolidone (NMP) as a separation agent (SA) was implemented. All technological stages (extractive distillation, target component separation and SA regeneration) were carried out in one apparatus – a batch distillation column. It was shown that this approach makes it possible to separate the TFE – IPA mixture into individual components, as well as to regenerate NMP. The proposed method is an alternative to traditional chemical methods and allows to eliminate the use of aggressive auxiliary reagents and the formation of by-products, to reduce the number of stages and apparatuses from 5 to 1.