Trifluoromethyl Hypofluorite Research Articles

Oxidative fluorination with Selectfluor: A convenient procedure for preparing hypervalent iodine(V) fluorides.

The ability to investigate hypervalent iodine(V) fluorides has been limited primarily by their difficult preparation traditionally using harsh fluorinating reagents such as trifluoromethyl hypofluorite and bromine trifluoride. Here, we report a mild and efficient route using Selectfluor to deliver hypervalent iodine(V) fluorides in good isolated yields (72-90%). Stability studies revealed that bicyclic difluoro(aryl)-λ5-iodane 6 was much more stable in acetonitrile-d 3 than in chloroform-d 1, presumably due to acetonitrile coordinating to the iodine(V) centre and stabilising it via halogen bonding.

Catalytic microreactor with electrodeposited hierarchically nanostructured nickel coatings for gas-phase fluorination reactions

The fabrication of a catalytic microreactor for the reaction of undiluted carbonyl difluoride and elemental fluorine to synthesize trifluoromethyl hypofluorite, CF3OF, on CsF catalyst supported on F2-passivated nanosctructured Ni coating was studied. The nanosctructured Ni support for catalyst immobilization was electrodeposited by a two-step procedure, consisting of a low current density step followed by a brief high current density one, for a hierarchical differentiation of structural features. An aqueous solution of NiCl2 with diethanolamine, as crystal modifier, and sodium lauryl sulphate, as anti-pitting agent, was used as electrolyte. Constant-pH Ni electrocrystallization was performed on H2SO4-etched Cu substrates in a range of pH from 1 to 4 via a HCl/H3BO3 based buffer. Passivation was carried out under up to 300mbar of undiluted F2. XRD, XPS, SEM, AFM, and static contact angle measurements were performed. Ni coatings obtained from pH 3 electrolytes were selected for microreactor fabrication on the basis of characterization data, due to the reproducibility and homogeneity of the structured Ni layers. The catalytic microreactor allowed the quantitative production of CF3OF from pure reactants, on demand, and removing any criticality relative to thermal and safety control of the synthesis. The CF3O-group selective transfer ability of the synthetized hypofluorite has raised interest in pharmaceutical and agrochemical industries in recent years.

Synthesis of trifluoromethyl fluoroformate from trifluoromethyl hypofluorite and carbon monoxide: Thermal and catalyzed reaction

New and improved routes to trifluoromethyl fluoroformate were developed. Sterically hindered halogenated olefins initiated the reaction of CF 3OF and CO under mild conditions, giving yields of up to 80%. The thermal reaction of CF 3OF and CO in a flow system was highly dependent on temperature and the type of tubular reactor material. A PTFE reactor gave moderate conversion and high selectivity for the formate at 120 °C.

A novel synthesis of trifluoromethyl fluoroformate from trifluoromethyl hypofluorite and carbon monoxide in the presence of fluorine gas

Trifluoromethyl fluoroformate is prepared through a radical reaction between CF 3OF and CO initiated by elemental fluorine. The reaction could be integrated into a continuous synthesis process. This method represents a convenient synthesis of the title compound under mild condition.

The use of perfluoroalkyl hypofluorites for an efficient synthesis of perfluorinated ethers characterized by low Ostwald coefficient

In the reaction between perfluoroolefins and perfluoroalkylhypofluorites the existence of two different free radical reaction mechanisms is demonstrated by the presence of characteristic byproducts. These kinetic schemes can be experimentally controlled by tuning the hypofluorite concentration in the reaction media. In particular, in the reactions between trifluoromethyl hypofluorite and highly reactive perfluoroolefins like CF 2 CFOCF 3 and CF 2 CF 2, the free radical oligomerization and dimerization products can be suppressed by utilizing the opportune experimental conditions. The pure perfluorinated ethers obtained, having low Ostwald coefficient, can be utilized as contrast agents for diagnostic ultrasound imaging injectable microbubbles composition.

Kinetics and mechanism of the thermal gas‐phase oxidation of perfluorobutene‐2 in presence of trifluoromethyl hypofluorite

AbstractThe oxidation of perfluorobutene‐2 (C4F8) initiated by trifluoromethyl hypofluorite (CF3OF) in presence of O2 has been studied at 323.1, 332.6, 342.5, and 352.0 K, using a conventional static system. The initial pressure of CF3OF was varied between 4.8 and 23.6 Torr, that of C4F8 between 48.7 and 302.4 Torr, and that of O2 between 51.5 and 270.4 Torr. Several runs were made in presence of 325.5–451.2 Torr of N2. The main products were COF2, CF3C(O)F, and CF3OC(O)F. Small amounts of compound containing CF(CF3)OC(O)CF3 group were also formed, as detected by 13C NMR spectroscopy. The oxidation is a homogeneous short‐chain reaction, attaining, at the pressure of O2 used, the pseudo‐zero‐order condition with respect to O2 as reactant. The reaction is independent of the total pressure. Its basic steps are as follows: the thermal generation of CF3O• radicals by the abstraction of fluorine atom of CF3OF by C4F8, the addition of CF3O• to the alkene, the formation of perfluoroalkoxy radicals RO• in presence of O2, and the decomposition of these radicals via the CC bond scission, giving products containing C(O)F end group and reforming RO• and CF3O• radicals. The mechanism consistent with experimental results is postulated. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 532–541, 2003

A photoionization study of trifluoromethanol, CF3OH, trifluoromethyl hypofluorite, CF3OF, and trifluoromethyl hypochlorite, CF3OCl

CF 3 OH , an important and controversial by-product of atmospheric decomposition of CF3CFH2 (HFC-134a) and other hydrofluorocarbons, has been examined by photoionization mass spectrometry. The ionization onset is characterized by a broad Franck–Condon distribution, arising primarily from a substantial elongation of the C–O bond upon ionization. An upper limit to the adiabatic ionization potential (IP) of ⩽13.08±0.05 eV has been established. The appearance potentials (APs) of the first two fragments have been accurately determined by fitting with appropriate model functions as AP0(CF2OH+/CF3OH)⩽13.830±0.005 eV and AP0(CF3+/CF3OH)⩽13.996±0.005 eV. While the exact nature of the lowest-energy fragment (nominally CF2OH+) is not clear, the CF3+ fragment threshold leads unambiguously to ΔHf 298∘(CF3OH)⩾−217.2±0.9 kcal/mol and D298(CF3–OH)⩽115.2±0.3 kcal/mol. With previously derived ΔHf 298∘(CF3O)=−151.8−1.1+1.7 kcal/mol, this yields D298(CF3O–H)=117.5−1.4+1.9 kcal/mol, very close to, or only slightly weaker than the O–H bond energy in water: D298(CF3O–H)–D298(HO–H)=−1.8−1.4+1.9 kcal/mol≈0 kcal/mol. Similarly, with the recently redetermined value for ΔHf∘(CF2O), this implies a 298 K reaction enthalpy for the 1,2-elimination of HF from CF3OH of 2.8−1.1+1.7 kcal/mol. CF3OF and CF3OCl have also been examined by photoionization. CF3OF produces a very weak parent, with an apparent adiabatic IP(CF3OF)⩽12.710±0.007 eV. An analysis of the CF3+ and CF2O+ fragments from CF3OF, when combined with literature data, suggests ΔHf 298∘(CF3OF)=−176.9−1.3+1.8 kcal/mol. The fitted value for the appearance potential of CF3+ from CF3OCl, AP0(CF3+/CF3OCl)⩽12.85±0.01 eV, leads to ΔHf 298∘(CF3OCl)⩾−175.6±1.0 kcal/mol, D298(CF3–OCl)⩽88.4±0.3 kcal/mol, and D298(CF3O–Cl)⩽52.8−1.5+2.0 kcal/mol.

The thermal addition of trifluoromethyl hypofluorite, CF 3OF, to tetrachloroethene

The trifluoromethyl 1,1,2,2-tetrachloro-2-fluoroethyl ether, CF 3OCCl 2CCl 2F, was the major product of the thermal gas-phase reaction of CF 3OF with tetrachloroethene at 313.8–343.8 K. Other products were CCl 2FCCl 2F and CF 3O(CCl 2CCl 2) 2OCF 3. The yields of the ether, based on the sum of the products, increased from 97.7% to 99.5% when the initial ratio of CF 3OF to that of CCl 2CCl 2 increased from 1.075 to 10.08. The IR spectrum of CF 3OCCl 2CCl 2F is given.

Fluorination of Chlorinated Trifluoromethyl Ethers

Abstract Chlorine atoms in the chlorinated trifluoromethyl ether prepared from the reaction between chlorinated ethylenes and trifluoromethyl hypofluorite were fluorinated directly by fluorine gas. Tin(II) fluoride/sodium fluoride system was effective in the fluorination.

ChemInform Abstract: Synthesis of Perfluoro Ethyl Methyl Ether by Direct Fluorination.

AbstractThe ethenes (I) and (V) react with trifluoromethyl hypofluorite (II) to form the ethers (III) or a mixture of (VI) and (VII).

Synthesis of Perfluoroethylmethylether by Direct Fluorination

Abstract The direct fluorination of trifluoromethylethers prepared from ethylene or fluorinated ethylenes with trifluoromethyl hypofluorite proceeded in excellent yield to obtain perfluoroethylmethylethers.

Facile preparations of 4-fluororesorcinol

Two facile methods for preparing 4-fluororesorcinol have been developed. In the first method, the direct fluorination of 1,3-dimethoxybenzene with trifluoromethyl hypofluorite carried out in Freon 11 at −78 °C afforded 2,4-dimethoxyfluorobenzene. Demethylation by heating under reflux in 48% HBr in acetic acid gave 4-fluororesorcinol in an overall yield of 60%. The second method involved the fluorination of 2,6-dimethoxyacetophenone by trifluoromethyl hypofluorite in Freon 11 at −78 °C, leading to 2,6-dimethoxy-3-fluoroacetophenone. On heating under reflux in 48% HBr in acetic acid, 4-fluororesorcinol was obtained in an overall yield of 74%. The latter is the method of choice for preparing 4-fluororesorcinol.

Trifluoromethyl hypofluorite: a fluorine-donating radical scavenger

Trifluoromethyl hypofluorite, CH3OF, quantitatively reacts with ethyl radicals to form ethyl fluoride. The reaction rate for abstraction of F from CF3OF is 0.25 times as fast as abstraction of H from H2S, implying a room temperature rate constant for the loss of ethyl by reaction with CF3OF of greater than or equal to 10 W cm T molecule s . The experiments were carried out with CH2TCH2 radicals formed by addition of thermalized tritium atoms to C2H4. 10 references, 1 figure.

ChemInform Abstract: KINETICS AND MECHANISM OF THE THERMAL REACTION BETWEEN TRIFLUOROMETHYL HYPOFLUORITE AND HEXAFLUOROPROPENE

Chemischer InformationsdienstVolume 15, Issue 22 Preparative Organic Chemistry ChemInform Abstract: KINETICS AND MECHANISM OF THE THERMAL REACTION BETWEEN TRIFLUOROMETHYL HYPOFLUORITE AND HEXAFLUOROPROPENE M. DOS SANTOS AFONSO, M. DOS SANTOS AFONSOSearch for more papers by this authorH. J. SCHUMACHER, H. J. SCHUMACHERSearch for more papers by this author M. DOS SANTOS AFONSO, M. DOS SANTOS AFONSOSearch for more papers by this authorH. J. SCHUMACHER, H. J. SCHUMACHERSearch for more papers by this author First published: May 29, 1984 https://doi.org/10.1002/chin.198422145Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume15, Issue22May 29, 1984 RelatedInformation

Synthesis of fluorinated carbohydrates by the reaction of acetyl hypofluorite with glycals

Fluorinated carbohydrates have continued to attract much interest principally because of the use of [ 18F] 2-deoxy-2-fluoro- D -glucopyranose ([ 18F] 2FDG), a proven glucose analogue, as an imaging agent in studies of regional cerebral glucose metabolism by positron emission tomography (PET). Previous synthetic routes have included the electrophilic addition to tri- O -acetyl- D -glucal of trifluoromethyl hypofluorite (CF 3OF), of elemental fluorine or of xenon difluoride and fluoride displacement on an anhydro sugar. All of these methods have disadvantages, resulting in either low product yields, isomeric product mixtures and/or difluorinated compounds. These approaches have further disadvantages in the context of [ 18F]-radiolabelling in that, all of the above reagents, with the exception of F 2, are difficult to produce with 18F. While the use of [ 18F] F 2 has become routine in the production of [ 18F] 2FDG only about 10% of the 18F used is incorporated in the desired product. Prompted by the recent report of a simple preparation of acetyl hypofluorite (CH 3CO 2F) from F 2, we have investigated the reaction of this electrophilic fluorinating reagent with tri- O -acetyl-glucal, and also with the galacto analogue. In each case a high yield (78% and 84% respectively) of the 2-deoxy-2-fluoro products, corresponding to cis-addition of the hypofluorite to the sugar ring, has been isolated.

ChemInform Abstract: STUDIES ON FLUORINATED PYRIMIDINES. I. A NEW METHOD OF SYNTHESIZING 5‐FLUOROURACIL AND ITS DERIVATIVES

AbstractDie fluorhaltigen Dihydrouracile (II) werden durch direkte Fluorierung der Uracile (I) mit CF3‐OF oder F2 hergestellt.

Studies on fluorinated pyrimidines. I. A new method of synthesizing 5-fluorouracil and its derivatives.

A series of 5-fluoro-6-substituted-5, 6-dihydrouracil-5-carboxylic esters (13), -5-carboxamides (15, 16), and -5-carbonitriles (18, 19) was prepared by direct fluorination of the corresponding uracil-5-carboxylic esters (6), -5-carboxamide (14), and -5-carbonitrile (17) with fluorine or trifluoromethyl hypofluorite (CF3OF) in the presence of water, methanol and/or acetic acid. Hydrolysis of the above-mentioned products under mild conditions gave 5-fluorouracil (1a) in high yield. Some applications of the present method for the synthesis of 1-(2-tetrahydrofuryl)-5-fluorouracil (1b) were also described.

.alpha.-Fluorination of carbonyl compounds with trifluoromethyl hypofluorite

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXT.alpha.-Fluorination of carbonyl compounds with trifluoromethyl hypofluoriteW. J. Middleton and E. M. BinghamCite this: J. Am. Chem. Soc. 1980, 102, 14, 4845–4846Publication Date (Print):July 1, 1980Publication History Published online1 May 2002Published inissue 1 July 1980https://doi.org/10.1021/ja00534a053RIGHTS & PERMISSIONSArticle Views1690Altmetric-Citations80LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (224 KB) Get e-Alerts Get e-Alerts

Action de CF 3OF sur des aziridines N-substituees

Trifluoromethyl hypofluorite reacts with N-substituted aziridines with ring opening and 1, 3-addition of F on nitrogen and OCF 3 on carbon. Three R substituents are discussed. With R benzenesulfonyl or chlorine one mole of CF 3OF is added and N-fluorobenzenesulfonamides and N-chloro, N-fluoroamine are obtained. With R 4-nitrobenzoyl two moles of CF 3OF are added and a N, N-difluoroamine is isolated.

Action de CF 3 of sur des aziridines N-non substitutees

Aziridines I react with trifluoromethyl hypofluorite at − 40°C to produce mixtures of 1-(aziridine)carbonyl fluoride II and 1-fluoroaziridine III , the proportions of which depend on steric effects. Several compounds II react with starting materials to give 1, 1′-(carbonyl)bisaziridines IV . Most compounds II and all compounds IV are isolated. Chemical properties and ir and nmr data of II , III , IV are described; the formation of an isocyanate and a substituted urea from a compound II is observed. A mechanism for this reaction is suggested.