Fluorination tertiary

Fluorinated tertiary selenoetheis are prepared by reaction of branched per-fluoroolefins with an alkali metal fluoride and phenylselenenyl chloride 1S2] (equation 31)... 

Fluoroxytiifluorouiethane ettectively fluorinates tertiary carbon-hydrogen bonds in materials with biologieal applications [2 3] (equations 23 and 24)... 

Highly fluorinated tertiary alcohols usually give olefins on iluormation with sulfur tetrafluoride [759/, but in certain cases, replacement of the hydroxyl group with fluorine occurs under mild conditions Hexafluoro-2-arylpropan-2-ols react with sulfur tetrafluoride at low temperatures to give high yields of heptafluoro-isopropylarenes [766] (equation 77), and similarly, 3,8 dihydroxy 9,9,9,10,10,10-hexafluoro-p-menthane affords 3,8,9,9,9,10,10,10-octafluoromenthane [766] (equation 78)... 

While aromatic amines are discussed in Section 5.2.14., various data for aliphatic amines are listed in Table 20. It is worthwhile remembering that tertiary perfluorinated amines, such as perfluorotributylamine. are completely stable, inert and nontoxic compounds, while some partially fluorinated tertiary amines tend to be unstable, eliminating hydrogen fluoride even at low temperature and are therefore toxie. Primary and secondary aliphatic fluorinated amines carrying CF,N groups have not, so far, been isolated due to their instability. 

The generation of highly fluorinated tertiary alkoxides and alcohols by the use of triniethyl-(trifluoromcthyl)silane and its analogs is most important.A simple, high-yield synthesis of perfluoro(l,l-diniethylethanol) from either hexafluoroacetone or difluorophosgene with trimcthyl(trinuoroniethyl)silaiie probably represents the best overall route to this alcohol to date.""- - " ... 

Coordination chemistry of fluorinated tertiary phosphines and catalytic applications 277... 

The above strategies have also been used in the preparation of a wide range of other fluorinated tertiary phosphines.282-288... 

Fluorine and fluoroxytrifluoromethane were found to fluorinate tertiary carbon atoms in the liquid phase in halogenated solvents (CH2CI2, CHCI3,... 

Even electrophilic fluorination of alkanes has been reported. F2 and fluoroxytrifluoro-methane have been used to fluorinate tertiary centers in steroids and adamantanes by Barton and coworkers ". The electrophilic nature of a reaction involving polarized but not cationic fluorine species has been invoked. Gal and Rozen have carried out direct electrophilic fluorination of hydrocarbons in the presence of chloroform. F2 appears to be strongly polarized in chloroform (hydrogen bonding with the acidic proton of CHCI3). However, so far no positively charged fluorine species (fluoronium ion) is known in solution chemistry. 

Current density (mA cm" ) Cleavage compounds Fluorinated tertiary amines ... 

The ratios of all constituents in the anode gas to overall anode gas in electrolysis of the mixed melt of (CH3)3N-5.0HF- -70wt% CsF-2.3HF at various current densities of 20-200 mA cm for 200hours with a BDD anode are summarized in Table 5.2.4. The viscosity of (CH3)3N-5.0HF-l-CsF-2.3HF melt increased with increasing ratio of CsF-2.3HF in the mixed melt [9], In the mixed melt of (CH3)3N-5.0HF-l-70 wt% CsF-2.3HF, the yield of (CF3)3N became higher than that in electrolysis of only the (CHjljN-wHF melt. This may be caused by an increase in the viscosity due to an increase in electrostatic interaction between species such as HF, anion, a partially fluorinated tertiary ammonium cation, and a partially fluorinated compound by adding CsF-2.3HF to a (CH3)3N-5.0HF melt, resulting in an increase in retention time of partially fluorinated tertiary amines with polarity in the mixed melt. 

Carboxybetaines have been prepared by reacting a fluorinated tertiary amine with /3-propiolactone [182-186], chloroacetic acid or its sodium salt [185-194] or acrylic acid [182,185,186]. j8-Propiolactone is a suspected carcinogen and is probably no longer used commercially as a quaternizing agent. 

Fluorinated tertiary amines with a sulfonamide linkage are obtained by a reaction with a fluorinated alkanesulfonyl chloride and a primary or a secondary amine. For example, l-amino-3-dimethylaminopropane reacts with perfluo-roalkylethanesulfonyl chloride to give a fluorinated tertiary amine which is quat-emized to yield a betaine [196] ... 

A highly enantioselective synthesis of cyclopropanes containing fluorinated tertiary stereogenic carbon centres has been accomplished using a chiral a-fluoro carbanion... 

---