Selective production of difluoromethyl methyl ether from chlorodifluoromethane using alkali metal carbonates
CHF2OCH3 (HFE-152a), an important starting material for synthesizing various C2 hydrofluoroethers and a prospective alternative to CH3CF2Cl (HCFC-142b), has been found to be effectively produced from the reaction of CHF2Cl (HCFC-22) with alkali metal carbonates in methanol. Some alkali metal carbonates induce selective production of CHF2OCH3 with a small amount of CH(OCH3)3, a major side product. Activities of alkali metal carbonates for producing CHF2OCH3 are in the order of K2CO3 > Na2CO3 > Li2CO3, suggesting that the solubility and ionization tendency of alkali metal carbonate in methanol play important roles in the reaction.
Lee,Hoon Sik Kim,Sang Deuk Lee,Won Koo Lee,Kim
p. 133 - 136
(2007/10/03)
Potassium 3-oxa-ω-fluorosulfonylperfluoropentanoate (FO2SCF2CF2OCF2CO2K), a low-temperature trifluoromethylating agent for organic halides; its α-carbon-oxygen bond fragmentation
The trifluoromethylation of organic halides with FO2SCF2CF2OCF2CO2K (1) in DMF can be accomplished at 45 °C which is advantageous for thermally sensitive substrates. α-Carbon-oxygen bond fragmentation of 1 and the related β-carbon-oxygen bond scission are discussed.
Difluormethylchalkogenide: eine NMR-Studie der Reaktionen von Cd(CF3)2*2MeCN und ZnBr(CF3)*2MeCN mit Dialkylchalkogeniden und Bortrifluorid
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Naumann, Dieter,Moeckel, Regina,Tyrra, Wieland
p. 325 - 326
(2007/10/02)
A SIMPLE CONVENIENT METHOD FOR PREPARATION OF DIFLUOROMETHYL ETHERS USING FLUOROSULFONYLDIFLUOROACETIC ACID AS A DIFLUOROCARBENE PRECURSOR
In the presence of catalytic amounts of sodium sulfate or cuprous iodide, a variety of alkyl and aryl difluoromethyl ethers were synthesized in moderate yields by the reaction of the corresponding alcohols and phenols with fluorosulfonyldifluoroacetic acid (1) in acetonitrile under mild conditions.Fluorosulfonyldifluoroacetate anion (5) is believed to readily eliminate SO2, CO2 and F(1-), thus liberating CF2:; insertion of difluorocarbene into O-H bonds and its capture by fluorode ion then result in the formation of ethers and by-product CF3H, respectively.