381-73-7Relevant articles and documents
Preparation and properties of two novel selenoacetic acids: HCF 2C(O)SeH and ClCF2C(O)SeH
Gomez Castano, Jovanny A.,Romano, Rosana M.,Beckers, Helmut,Willner, Helge,Della Vedova, Carlos O.
, p. 2608 - 2615 (2012)
The novel selenocarboxylic Se-acids, HCF2C(O)SeH and ClCF 2C(O)SeH, were prepared by treating the corresponding carboxylic acids with Woollins' reagent. The boiling points were extrapolated from the vapor pressure curves to be 364 and 359 K for HCF2C(O)SeH and ClCF2C(O)SeH, respectively. Both compounds are unstable at ambient temperatures and decompose to the corresponding seleno anhydrides and release of H2Se. Hydrolysis results in formation of the carboxylic acids and hydrogen selenide, while diselenides presumably are obtained by oxidation. The conformational properties of these acids were studied by vibrational spectroscopy in combination with ab initio and DFT methods. IR vapor-phase spectra, Raman spectra of the neat liquids, and IR spectra of the Ar-matrix-isolated compounds deposited at two different nozzle temperatures were interpreted in terms of quenching conformational equilibria. The most stable structure of both acids was found to be syn-gauche in equilibrium with a second anti-syn form in HCF2C(O)SeH and with another two conformers, anti-gauche and anti-syn, in ClCF2C(O)SeH.
Decarbonylative Fluoroalkylation at Palladium(II): From Fundamental Organometallic Studies to Catalysis
Lalloo, Naish,Malapit, Christian A.,Taimoory, S. Maryamdokht,Brigham, Conor E.,Sanford, Melanie S.
supporting information, p. 18617 - 18625 (2021/11/16)
This Article describes the development of a decarbonylative Pd-catalyzed aryl-fluoroalkyl bond-forming reaction that couples fluoroalkylcarboxylic acid-derived electrophiles [RFC(O)X] with aryl organometallics (Ar-M′). This reaction was optimized by interrogating the individual steps of the catalytic cycle (oxidative addition, carbonyl de-insertion, transmetalation, and reductive elimination) to identify a compatible pair of coupling partners and an appropriate Pd catalyst. These stoichiometric organometallic studies revealed several critical elements for reaction design. First, uncatalyzed background reactions between RFC(O)X and Ar-M′ can be avoided by using M′ = boronate ester. Second, carbonyl de-insertion and Ar-RF reductive elimination are the two slowest steps of the catalytic cycle when RF = CF3. Both steps are dramatically accelerated upon changing to RF = CHF2. Computational studies reveal that a favorable F2C-H - -X interaction contributes to accelerating carbonyl de-insertion in this system. Finally, transmetalation is slow with X = difluoroacetate but fast with X = F. Ultimately, these studies enabled the development of an (SPhos)Pd-catalyzed decarbonylative difluoromethylation of aryl neopentylglycol boronate esters with difluoroacetyl fluoride.
Preparation method of difluoroacetic acid
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Paragraph 0020-0025, (2019/04/10)
The invention relates to a preparation method of difluoroacetic acid, and belongs to the technical field of fluorine chemical engineering. According to the preparation method of the difluoroacetic acid, KMnO4/C solid catalysts are added into a fixed bed reaction kettle; nitrogen gas is introduced to perform replacement on the air in the reaction kettle; the temperature is raised to a fixed temperature; then, hydrogen peroxide and 2-chlorine-1,1-difluoroethane are introduced by a voltage stabilizing pump to perform contact reaction; after a product is separated, the product of difluoroacetic acid is finally obtained. The preparation method of the difluoroacetic acid has the advantages that the process is simple; the flow process is short; the technical flow process is simplified; the energyconsumption is greatly reduced; the method is suitable for industrialized production; the used raw materials are all common reagents, the resources of the materials are wide, and the price is low; the reaction process can be easily controlled; the obtained difluoroacetic acid product has high yield and has wide application and popularization values.
