Journal of Fluorine Chemistry最新文献

The reaction of (2S)-2-(difluoro(methoxy)methyl)pyrrolidine-1-sulfinyl fluoride with aryl, heteryl and alkyl sulfonyl chlorides provides a convenient synthetic route to sulfonyl fluorides. DFT calculations predict negative reaction energy values for the exchange reaction. The S-F bond energy is higher in the sulfonyl fluorides than that in sulfinyl fluorides.

Readily available di(per)fluoroalkyl iodides and ethyl difluoroiodoacetate have been efficiently reacted with 5-amino-N-allyl-1,2,3-triazole-4-carboxamides in the presence of DIPEA under visible-light induction and fluorescein catalysis to produce high yields of the corresponding adducts, N-(n-propyl) carboxamides vicinally difunctionalized with the iodine atom and the di(per)fluoroalkyl or (methoxycarbonyl)difluoromethyl moiety. As shown experimentally, this regiospecific and triazole amino group tolerant reaction involves a radical process.

While 1,3-dehydro-5,7-difluoroadamantane 11 reacts with SbF₅ in super acid media (SO₂ClF) to generate the 1,3-dehydroadamant-5,7-diyl dication 1, 1,3-dehydro-5-fluoroadamantane 12 fails to react analogously to produce the 1,3-dehydroadamant-5-yl cation 9; instead, the 3,5-difluoro-1-adamantylcation 13 is formed. We present a computational study that explains this surprising behavior by the initial addition of Sb₂F₁₀ to the propellane bond present in 12. This is computed to be highly exothermic and leads to a zwitterionic (or ion-pair) species, which in turn reacts autocatalytically with HF to produce the observed fluorinated cation 13, SbF₃, and SbF₆^–.

A series of six, 4-substituted 2,3,5,6-tetrafluoropyridine (TFP) hetero ethers have been synthesized via regio-selective, nucleophilic aromatic substitution (SNAr) of pentafluoropyridine with aliphatic alcohols and phenols. Furthermore, the hexyloxy modified TFP substrate also served as a synthetic intermediate for the preparation of 3,5-difluoro-4-(hexyloxy)-2,6-di(1H-imidazol-1-yl)pyridine, as well as 4-(hexyloxy)-2,3,5,6-tetra(1H-pyrazol-1-yl)pyridine, which offers a terpyridine scaffold. This work outlines their synthetic methodology in addition to detailing the TFP intermediates’ unexpected reactivity with imidazole and pyrazole nucleophiles

A photoredox-catalyzed decarboxylative α-monofluoroalkylation of silyl enol ethers with fluoroalkyl carboxylic N-(hydroxy)phthalimide esters has been successfully developed. Diverse functionalized α-monofluoroalkyl acetophenones were produced in modest to good yields under mild and operationally simple conditions. The developed method was further applied to synthesize antalgic and ataractic activity compound containing α-monofluoroalkyl acetophenone skeleton.

A halon-free method for the synthesis of gem‑bromofluoroolefins utilizing ethyldibromofluoro-acetate is disclosed via a Wittig type reaction. The reaction system takes advantage of inexpensive and readily available reagents. The method was applied to a wide variety of aryl aldehydes. Both electron donating and electron withdrawing moieties on the aryl ring were tolerated and the desired olefin products were obtained in good to excellent yields.

By reacting CeF₃ with XeF₂ the anhydrous CeF₄ was synthesized and studied by XRD, SEM, FTIR, ¹⁹F NMR spectrometry and thermogravimetry. It was found that CeF₄ undergoes hydration upon keeping in air forming the crystalline hydrate with the approximate formula [CeF₄•0.2H₂O]*0.7H₂O. Water molecules both enter the coordination sphere of cerium and form crystalline hydrates with cerium(IV) fluoride due to OH…F hydrogen bonds in the crystal lattice.

In this work, we present a new method for the facile preparation of aryl-IF₄ compounds using KF and ex situ generated chlorine gas within a two-chamber reactor setup. Notably, the process stands out for its simplicity by omitting the use of specialized equipment and generating less chemical waste than the previously reported works. While demonstrating high efficiency at room temperature, the novel approach provides access to a diverse array of products with moderate to excellent yields.

The synthesis of (trifluoromethyl)alkenes, including fully substituted variants, was achieved from thioketones with in situ-generated (trifluoromethyl)diazoalkanes [CF₃C(R)=N₂] (the Barton–Kellogg reaction). In the presence of sodium methoxide and a catalytic amount of tetrabutylammonium chloride, trifluoromethylated N-tosylhydrazones [CF₃C(R)=NNHTs] derived from trifluoroacetaldehyde hemiacetal (R = H) or trifluoromethyl ketones (R = aryl or alkyl) were employed in the reactions with thioketones. The resulting (trifluoromethyl)diazoalkanes reacted with thioketones, forming (trifluoromethyl)thiirane intermediates. Treatment of these intermediates with trimethyl phosphite readily afforded the substituted (trifluoromethyl)alkenes. Theoretical calculations (DFT, B3LYP/6-31G*) showed that (trifluoromethyl)thiiranes, with less distortion than 2,2-difluorothiiranes, exhibited lower reactivity. Consequently, the involvement of a reducing agent was deemed necessary for the desulfurization step.