- A novel and simple synthetic route to perfluoroalkylacetaldehydes using commercially available alkali halides and metal oxides
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Treatment of 1-acetoxy-1-iodo-2-perfluoroalkylethanes with aqueous alkali halides or neat metal oxides is presented as instead of via an innovative and highly accessible route to the synthesis of perfluoroalkylethanals. The reaction uses commercially available reactants and does not require the addition of any organic solvent.
- Calleja,Laurent,Blancou
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- Perfluoroalkyl ethyl alcohols via perfluoroalkyl acetaldehydes
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A new route to commercially important perfluoroalkyl ethyl alcohols (RfCH2CH2OH) is described. This route involves the addition of perfluoroalkyl iodides to alkyl vinyl ethers using sulfinatodehalogenation chemistry, followed by catalytic hydrogenation of the intermediate mixture of perfluoroalkylacetaldehyde and perfluoroalkylacetaldehyde hemiacetal to the desired alcohol.
- Peng, Sheng,Moloy, Kenneth G.
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- Degradation of fluorotelomer alcohols: A likely atmospheric source of perfluorinated carboxylic acids
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Human and animal tissues collected in urban and remote global locations contain persistent and bioaccumulative perfluorinated carboxylic acids (PFCAs). The source of PFCAs was previously unknown. Here we present smog chamber studies that indicate fluorotelomer alcohols (FTOHs) can degrade in the atmosphere to yield a homologous series of PFCAs. Atmospheric degradation of FTOHs is likely to contribute to the widespread dissemination of PFCAs. After their bioaccumulation potential is accounted for, the pattern of PFCAs yielded from FTOHs could account for the distinct contamination profile of PFCAs observed in arctic animals. Furthermore, polar bear liver was shown to contain predominately linear isomers (>99%) of perfluorononanoic acid (PFNA), while both branched and linear isomers were observed for perfluorooctanoic acid, strongly suggesting a sole input of PFNA from "telomer"-based products. The significance of the gas-phase peroxy radical cross reactions that produce PFCAs has not been recognized previously. Such reactions are expected to occur during the atmospheric degradation of all polyfluorinated materials, necessitating a reexamination of the environmental fate and impact of this important class of industrial chemicals.
- Ellis, David A.,Martin, Jonathan W.,De Silva, Amila O.,Mabury, Scott A.,Hurley, Michael D.,Sulbaek Andersen, Mads P.,Wallington, Timothy J.
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p. 3316 - 3321
(2007/10/03)
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- Synthesis of per(poly)fluoroalkyl aldehydes R(F)(CH2)(n)CHO
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We report the preparation of polyfluoroalkyl aldehydes R(F)(CH2)(n)CHO in high yields by direct oxidation of polyfluoroalkyl alcohols; the Swern oxidation, pyridinium chlorochromate and Dess-Martin periodinane are used and compared.
- Leveque, Laurence,Le Blanc, Maurice Le,Pastor, Raphael
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p. 8857 - 8860
(2007/10/03)
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- Synthesis of 5-per(poly)fluoroalkyl-2,3-dihydro-1,4-diazepines
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A series of 5-per(poly)fluoroalkyl-2,3-dihydro-1,4-diazepines were synthesized from α-per(poly)fluoroalkyl aldehydes and ethylenediamine. A possible reaction pathway was suggested.
- Wang, Quan-Fu,Hu, Bin,Luo, Bing-Hao,Hu, Chang-Ming
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p. 2377 - 2380
(2007/10/03)
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- A modified procedure for preparing perfluoroalkyl acetic acids from perfluoroalkyl iodides
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Perfluoroalkyl acetic acids, RFCH2COOH, can be prepared in several ways.Particular attention is here paid to the method starting from the azonitrile-initiated addition of the corresponding perfluoroalkyl iodide, RFI, to vinyl acetate, CH2=CHOCOCH3, with formation of the adduct RFCH2CHIOCOCH3.This method is reported as a four-step process that synthesizes perfluoroalkyl acetic acids through the conversion of the adduct into the corresponding ester RFCH2CH2OCOCH3 and alcohol RFCH2CH2OH.A simplified procedure consisting of three steps is also suggested: starting from the same reagents, perfluoroalkyl acetic acids can be easily prepared by the oxidation of the corresponding aldehyde RFCH2CHO obtained directly in good yields by acid hydrolysis of the primary adduct RFCH2CHIOCOCH3.
- Napoli, M.,Scipioni, A.,Conte, L.,Legnaro, E.,Krotz, L. N.
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p. 249 - 252
(2007/10/02)
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- Direct Synthesis of 3-(Fluoroalkyl)pyrazoles from Polyfluoroalkyl Aldehydes
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3-(Fluoroalkyl)pyrazoles 3 have been hynthesized in excellent yields by reaction of various fluoroalkyl aldehydes with NH2NH2*HOAc under mild conditions.It appears that the reaction involves the formation of a hydrazone, followed by elimination of hydrogen halide and intramolecular mucleophilic addition.A practical one-pot synthesis of 3-(fluoroalkyl)pyrazoles from polyfluoroalkyl iodides 1 has also been developed.
- Tang, Xiao-Qing,Hu, Chang-Ming
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p. 2161 - 2164
(2007/10/02)
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- Synthesis of fluoroalkyl ethanal: R(F)CH2CHO
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Aldehydes R(F)CH2CHO (R(F) is a linear perfluoroalkyl chain) have been obtained in the addition reaction of R(F)I to vinyl acetate in the presence of zinc. R(F)CH2CHIOAc is formed as an intermediate in the course of the reaction. Under appropriate conditions, R(F)CH2CHO and its acylal or acetal derivatives are obtained in good yields.
- Laurent,Blancou,Commeyras
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p. 2489 - 2492
(2007/10/02)
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- Areneselenolate-mediated perfluoroalkyl-sulfenylation of enol ethers
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Areneselenolate-mediated perfluoroalkyl-sulfenylation of enol ethers has been performed by the reaction of sodium arenethiolates, a catalytic amount of sodium areneselenolates, perfluoroalkyl iodides, and olefins where ArSeNa initiates a chain reaction vi
- Uneyama, Kenji,Kitagawa, Kouichi
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p. 3385 - 3386
(2007/10/02)
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