557-99-3Relevant articles and documents
Coordination modes and reaction of acetic anhydride with tantalum pentafluoride
Il'In,Kovalev
, p. 111 - 114 (2014)
The composition and structure of compounds formed upon the reaction of equimolar amounts of TaF5 and MeC(O)O(O)CMe in CH2Cl 2 and upon dissolution of the fluoride in an anhydride excess have been studied by 19F NMR (293-183 K). It has been found that, in both cases, the anhydride is fluorinated to form MeC(O)F (a quartet at 47.7 ppm, J FH = 18 Hz) and the MeC(O)O- anion. In the spectra of the reaction mixture in CH2Cl2, the signals of pentafluoro complexes are assigned to the TaF5[OC(Me)OC(O)Me] adduct and the TaF5[OC(O)Me]- anion; on the basis of the chemical shifts of the singlets, they are assigned to the TaF4[OC(Me)OC(O)Me] + and TaF2[OCOC(O)Me] 2 3+ cations in which the anhydride acts as a chelating ligand. Upon the direct reaction of the reagents in an anhydride excess, the spectra at low temperatures show, in addition to the signal of the tetrafluoride cation, the signals of the hexafluorotantalate ion TaF 6 - and four trifluoroacetate complexes. Close relative concentrations of the latter enable the suggestion that they form chain or cyclic structures. It is believed that, in these structures, the acetate group has monodentate and bridging coordination modes, while chelating coordination mode seems to be less probable.
Synthesis and characterization of fluorodinitroamine, FN(NO2)2
Christe, Karl O.,Wilson, William W.,Blanger-Chabot, Guillaume,Haiges, Ralf,Boatz, Jerry A.,Rahm, Martin,Prakash, G. K. Surya,Saal, Thomas,Hopfinger, Mathias
, p. 1316 - 1320 (2015)
NF3 and N(NO2)3 are known compounds, whereas the mixed fluoronitroamines, FN(NO2)2 and F2NNO2, have been unknown thus far. One of these, FN(NO2)2, has now been prepared and characterized by multinuclear NMR and Raman spectroscopy. FN(NO2)2 is the first known example of an inorganic fluoronitroamine. It is a thermally unstable, highly energetic material formed by the fluorination of the dinitramide anion using NF4+ salts as the preferred fluorinating agent.
Preparation of 2,3,3,3-tetrafluoropropene from trifluoroacetylacetone and sulphur tetrafluoride
Banks, R. Eric,Barlow, Michael G.,Nickkho-Amiry, Mahmood
, p. 171 - 174 (1997)
Practical details are presented for the laboratory preparation of 2,3,3,3-tetrafluoropropene in good yield from trifluoroacetylacetone and sulphur tetrafluoride in the presence of hydrogen fluoride. The gas-phase IR spectrum of the tetrafluoropropene (b.p., -28 °C) is reproduced and a detailed analysis of the olefin's nuclear magnetic resonance (NMR) spectra (1H, 13C, 19F) is provided.
Deoxyfluorination of Carboxylic Acids with KF and Highly Electron-Deficient Fluoroarenes
Mao, Siyu,Kramer, Jordan H.,Sun, Haoran
, p. 6066 - 6074 (2021/05/29)
A deoxyfluorination reaction of carboxylic acids using potassium fluoride (KF) and highly electron-deficient fluoroarenes is reported here, giving acyl fluorides in moderate to excellent yield (57-92% based on NMR integration and 34-95% for isolated examples).
METHOD AND REAGENT FOR DEOXYFLUORINATION
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Paragraph 0111-0112; 0114-0115, (2021/05/29)
A safe, simple, and selective method and reagent for deoxyfluorination is disclosed. With the method and reagent disclosed herein, organic compounds such as carboxylic acids, carboxylates, carboxylic acid anhydrides, aldehydes, and alcohols can be fluorinated by using the most common nucleophilic fluorinating reagents and electron deficient fluoroarenes as mediators under mild conditions, giving corresponding fluoroorganic compounds in excellent yield with a wide range of functional group compatibility and easy product purification. For example, directly utilizing KF for deoxyfluorination of carboxylic acids provides the most economical and the safest pathway to access acyl fluorides, key intermediates for syntheses of peptide, amide, ester, and dry fluoride salts.
Concise Modular Synthesis and NMR Structural Determination of Gallium Mycobactin T
Chan, Kiat Hwa,Groves, John T.
, p. 15453 - 15468 (2021/11/16)
A modular synthesis of mycobactin T and its N-acetyl analogue is reported in a route that facilitates permutation of the lipid tails. A key feature is the generation of N(α)-Cbz-N(?)-benzyloxy-N(?)-Boc-lysine (A4) with methyl(trifluoromethyl)dioxirane in 59% yield. Selective hydroxamate N-acylation was achieved with acyl fluorides, enabling installation of lipids tails in the final step. O-Benzyl-dehydrocobactin T (B4) was prepared by modifying a known five-step sequence with an overall yield of 49%. 2-Hydroxyphenyl-4-carboxyloxazoline (C3) was prepared from 2-hydroxybenzoic acid and l-serine methyl ester in three steps with an overall yield of 55%. Ester coupling of A4 and B4 with EDCI afforded MbI-1 in 73% yield. Catalytic hydrogenation with Pd/BaSO4 and 50 psi of H2 simultaneously effected alkene reduction and debenzylation to afford MbI-2 in 96% yield. Fragment C3 was converted into acyl fluoride C4, which coupled with MbI-2 to afford MbI-3 in 51% yield. Finally, Boc-removal with HCl/EtOAc and treatment of the resultant hydroxylamine with stearyl fluoride furnished mycobactin T in 65% yield. Overall, the yield is 4% over 14 steps. The gallium mycobactin T-N-acetyl derivative (GaMbT-NAc) structure was determined by 1H NMR. The structure shows an octahedral Ga and two internal hydrogen bonds between peptidic N-Hs and two of the oxygen atoms coordinating Ga.
C-F Bond Activation of a Perfluorinated Ligand Leading to Nucleophilic Fluorination of an Organic Electrophile
Hanson-Heine, Magnus W. D.,Licence, Peter,Marr, Andrew C.,Morgan, Patrick J.,Saunders, Graham C.,Thomas, Hayden P.
supporting information, p. 2116 - 2124 (2020/07/23)
We report a fluorine transfer reaction in which fluorine from a perfluorinated ligand undergoes C-F bond activation and transfers to an electrophile, resulting in the formation of a new fluorinated product and dimerization of the monodefluorinated complex. Treatment of [(η5,κ2C-C5Me4CH2C6F5CH2NC3H2NMe)-RhCl] with the organic electrophile, toluoyl chloride, resulted in the formation of a rhodium(III) metallocycle via C-F bond activation assisted defluorinative coupling. Fission of the C-F bond liberated nucleophilic fluoride, which converted acyl chloride to acyl fluoride. The overall reaction was monitored using a multivariate analysis approach in real time.
Organocatalyzed Fluoride Metathesis
Mulryan, Daniel,White, Andrew J. P.,Crimmin, Mark R.
supporting information, p. 9351 - 9355 (2020/11/30)
A new organocatalyzed fluoride metathesis reaction between fluoroarenes and carbonyl derivatives is reported. The reaction exchanges fluoride (F-) and alternate nucleophiles (OAc-, OCO2R-, SR-, Cl-, CN-, NCS-). The approach provides a conceptually novel route to manipulate the fluorine content of organic molecules. When the fluorination and defluorination steps are combined into a single catalytic cycle, a byproduct free and 100% atom-efficient reaction can be achieved.
METHOD FOR PRODUCING FLUORINATED HYDROCARBONS
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Paragraph 0100-0101, (2020/01/12)
Provided is a method for industrially advantageously producing a fluorinated hydrocarbon (3). The disclosed method for producing a fluorinated hydrocarbon represented by formula (3) includes bringing into contact, in a hydrocarbon-based solvent, a secondary or tertiary ether compound represented by formula (1) below with an acid fluoride represented by formula (2) in the presence of lithium salt or sodium salt (in the formulae, R1 and R2 each represent a C1-3 alkyl, and R1 and R2 may be bonded to each other to form a ring structure; R3 represents a hydrogen atom, methyl, or ethyl; and R4 and R5 each represent methyl or ethyl).
Cavity Catalysis by Cooperative Vibrational Strong Coupling of Reactant and Solvent Molecules
Lather, Jyoti,Bhatt, Pooja,Thomas, Anoop,Ebbesen, Thomas W.,George, Jino
supporting information, p. 10635 - 10638 (2019/07/12)
Here, we report the catalytic effect of vibrational strong coupling (VSC) on the solvolysis of para-nitrophenyl acetate (PNPA), which increases the reaction rate by an order of magnitude. This is observed when the microfluidic Fabry–Perot cavity in which the VSC is generated is tuned to the C=O vibrational stretching mode of both the reactant and solvent molecules. Thermodynamic experiments confirm the catalytic nature of VSC in the system. The change in the reaction rate follows an exponential relation with respect to the coupling strength of the solvent, indicating a cooperative effect between the solvent molecules and the reactant. Furthermore, the study of the solvent kinetic isotope effect clearly shows that the vibrational overlap of the C=O vibrational bands of the reactant and the strongly coupled solvent molecules is critical for the catalysis in this reaction. The combination of cooperative effects and cavity catalysis confirms the potential of VSC as a new frontier in chemistry.
