Polyfluorinated alcohol

Diacetato(l, 10-phenanthroline)palladium(II)-catalyzed transetheriflcation of polyfluorinated alcohols with enol ethers leads to the corresponding fluormated vinylic ethers [14] (equation 13)... 

Polyfluorinated alcohols, a,a,m-trihydryl-F-alkanols prepared by telomerization of tetrafluoro-ethcnc with methanol, are readily converted into ot,a.cu-trihydryl-F-alkanes 4.45... 

Iodine(III)-induced spiroannulation reactions of phenol derivatives have been applied widely to total syntheses of related natural products. These reactions have been usually carried out in MeCN, but recently polyfluorinated alcohols such as CF3CH2OH and (CF3)2CHOH are prefered. 

Solvolysis of S0C12 by polyfluorinated alcohols, H(CF2) CH2OH n = 2, 4, catalysed by Et3N proceeded by an 5x2 mechanism evidence for ion-pair, RO- Et3NH+, attack on S=0 was obtained.65... 

All of these synthetic signal peptides, as well as peptides resembling the signal sequences of lysozyme and lipoprotein (Reddy and Nagaraj, 1985), became partially a helical in polyfluorinated alcohols [trifluoroethanol (TFE) and hexafluoroisopropanol (HFIP)], which are more hydrophobic than water and have been used as models for the membrane interior. These solvents promote the formation of intramolecular hydrogen bonds, and consequently induce a-helix formation. In... 

H O include perfluoroheptadecan-le rnonyldibutylarsine, and HRe04-I.in oligomeric 9,10-bis(diseleno)-ig, x roxide. Polyfluorinated alcohols >g.- vroxide toward epoxidation and... 

Polyfluorinated alcohols 876 can be selectively oxidized by DMP to the respective aldehydes 877 (Scheme 3.352) without the formation of dehydrofluorinated by-products [1238,1239],... 

Alternative approaches to some fluorinated synthons were developed in 1990s by Yamanaka with co-workers starting from conunercially available polyfluorinated alcohol. The corresponding qnatemary anunoninm salt 80 was prepared in four step... 

Details have been published of the preparation and testing of esters of polyfluorinated alcohols of the type H(CFa) CHa OH as oils and greases for use as LOX (liquid oxygen)-compatible lubricants and the fluid characteristics of a number of ethers prepared via base-catalysed reactions between polyfluoroalkanols and per- and poly-fluorocycloalkenes have been compared. ... 

The polyphilic surfactant F(CF2)6(CH2)uOC6H4C6H4COOH [121] is synthesized from the poly fluorinated alcohol prepared by 1-2 addition of perfluoro-hexyl iodide on tt>-undecenol, followed by reduction. The polyfluorinated alcohol is reacted with HBr/H2S04, and the resulting bromide is etherified with 4-cyano-4 -hydroxybiphenyl to give 4-(polyfluoroalkoxy)-4 -cyanobiphenyl. Hydrolysis yields the polyphilic carboxylic acid. 

A very interesting type of POM catalyst with polyfluorinated quaternary ammonium salts as counterions for the oxidation of alkenes, alkenols and alcohols was developed by Neumann and coworkers in 2003 . This catalyst with the general composition... 

In polyfluorinated and especially perfluorinated aromatics, fluorine is hydrolyzed relatively easily. Perfluorochlorobenzene gives perfluoro-4-chlorophenol (2) on treatment with potassium hydroxide in tert-butyl alcohol.33... 

Perfluoroalkyl acids (PFAs) are synthetic, perfluorinated, straight- or bran-ched-chain organic acids characterized by a carboxylate or sulfonate moiety [1]. PFAs are manufactured directly but can also be formed through transformation of many precursor molecules containing a perfluoroalkyl moiety [2], These include fluorotelomer alcohols (FTOHs) and perfluoroalkyl-sulfonamides (Table 1, Fig. 1), however, others likely exist. Collectively, this family of chemicals including PFAs and their polyfluorinated precursors will be referred to in this document as perfluoroalkyl substances (PFSs). 

However, the low basicity of polyfluorinated materials usually limits this method to the carbocations originating from nonfluorinated compounds (some alcohols, aromatics, etc.) or such relatively basic fluorinated substrates as mono- and dihaloalkanes, and fluoroethylenes,e.g.,CH2=CF2 [21]. 

Simons process — Electrochemical polyfluorination reactions of organic compounds are the only efficient way to industrial production of perfluorinated compounds. The reaction proceeds in the solution of KF in liquid HF (b.p. 19.5 °C), where the starting substances as alcohols, amines, ethers, esters, aliphatic hydrocarbons and halo-hydrocarbons, aromatic and heterocyclic compounds, sulfo- or carboxylic acids are dissolved. During anodic oxidation, splitting of the C-H bonds and saturation of the C=C bonds occur and fluorine atoms are introduced. 

Jahnke, A., Ahrens, L., Ebinghaus, R., Temme, C. (2007) Urban versus remote air concentrations of flurotelomer alcohols and other polyfluorinated alky substances in Germany. Environ. Sci. Technol, 41 745-752. 

Polyfluorinated primary alcohols of the general formulae CF3(CF2) CH20H and CHF2(CF2) CH20H can be fluorinatcd with sulfur tetrafluoride to give products 1 in one step in good yield. 

Other functional polyfluorinated compounds are available by addition of perhaloalkyl halides to enol derivatives, e.g. formation of 1 and 2 (see also Table 4). The adducts formed from enol acetates or enol ethers are not very stable and their hydrolysis to give a-perhaloalkyl aldehydes or ketones is often rapid. However, the enol derivatives can be transformed either to give ketals using alcohols or to give various products by oxidation and reduction reactions. The peculiar perfluoroalkyl iodide addition to enamines is spontaneous at room temperature, e.g. formation of 3. ... 

The role of steric factors has been examined in the opening of polyfluorinated oxiranes. Accounts have been given of the alcoholysis of steroid oxiranes and their transformation with phenol.The kinetics of the reactions of oxiranes with alcohols and phenols have been reported in a number of publications. The catalytic influence of transition metals has been examined. A secondary deuterium isotope effect has been studied in the course of methanolysis, and the solvent effect has been considered in reactions with phenols. ... 

Curran, D. P., Dandapani, S. Fluorous nucleophilic substitution of alcohols and reagents for use therein, specifically, perfluoroalkyl-containing phosphines and azodicarboxylates as polyfluorinated reagents for the Mitsunobu reaction, 2002-US26045 2003016246, 2003 (University of Pittsburgh, USA). 

Petrov, V.A. S3mthesis of polyfluorinated tertiary alcohols using ring opening reactions of 2,2-bis(trifluoromethyl)oxirane. Synthesis 2002, 2225. 

Polyfluorinated compounds comprise hundreds of chemicals characterized by hydrophobic linear alkyl chains partially or fully fluorinated (as the perfluorinated compounds [PFCs]) and containing different functional groups. Polyfluorinated compounds include perfluoroalkyl sulfonamides (PFASAs), fluorotelomer alcohols (FTOHs), polyfluorinated alkyl phosphates (PFAPs), fluorotelomer unsaturated carboxylic acids (FTUCAs), perfluoroalkyl acids (PFAAs), and their salts. The most common PFAAs are perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFASs). In particular, PFASs contain one or more fluorinated alkyl chains bonded to a polar head, which at neutral pH can be charged (anionic, cationic, and amphiphilic surfactants) or noncharged (nonionic surfactants). 

Abstract In the past years, elucidation of transformation products of per- and polyfluorinated chemicals (PFC) has been a task frequently approached by analytical chemists. PCT, such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are persistent and thus, the analytical quest to detect transformation products has failed so far. Their prominence as contaminants is mainly due to their extreme persistence, which is linked to their perfluoroalkyl chain length. Molecules that are less heavily fluorinated can show very complex metabolic behavior, as is the case for fluorotelomer alcohols. These compounds are degraded via different but simultaneous pathways, which produce different stable metabolites. Biotransformation processes of PFC may occur when these compounds enter the environment, and thus known and unknown PFC may be generated in these compartments. Therefore, it is essential to determine metabolic pathways of such compounds in order to entirely understand their fate in the environment. This chapter summarizes methodological approaches and instmmental setups which have been implemented in biotransformation studies of PFC and focuses on mass spectrometric methods and the separation techniques coupled to the mass spectrometer (MS). Valuable MS approaches that have not been frequently used in studies on PFC are presented as well. Since compounds carrying C-F bonds exhibit unique properties, these will be initially presented to address the meaning of these properties both for analytical tasks and for the setup of biotransformation experiments. 

Carbon-fluorine couplings across one and two bonds have been reported by Marchione and Buck for a set of polyfluorinated adds and alcohols typical /cF values were about 270 Hz for the eouplings aeross one bond and 30 Hz for those across two bonds. 

Ytterbium triiodide activates the C-F bond of alkyl fluorides giving iodides in high yields (82-98%) in CH2CI2 or CHCls. The reaction is successful in the presence of ketone, ether, alcohol, ester, trialkylamine, aryl, and cyano groups in the substrate and with primary, secondary, and tertiary fluorides but does not occur with polyfluorinated compounds, or those with a CF2, CF3, or group. The reaction... 

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