Sulfides trifluoromethyl

Conversion of trifluoromethyl sulfides to the corresponding sulfoxides is accomplished by hydrogen peroxide [104 (equation 96). 

Another way to prepare fluorinated sulfides is the photochemical alkylation of sulfides or disulfides by perfluoroalkyl iodides [69, 70, 71] (equations 62-64). Reaction of trifluoromethyl bromide with alkyl or aryl disulfides in the presence of a sulfur dioxide radical anion precursor, such as sodium hydroxymethanesulfi-nate, affords trifluoromethyl sulfides [72] (equation 65). 

See Bis(trifluoromethyl) sulfide Chlorine fluorides Bis(trifluoromethyl) disulfide Chlorine fluorides... 

Bis(trifluoromethyl) stibine, 16 49 Bis(trifluoromethyl) sulfide, 2 134, 146 Bis(trifluoromethyl) sulfur tetrafluoride, 2 139,... 

In contrast to aryl trichloromethyl ethers (see Section 12.1.2.), the replacement of chlorine atoms by fluorine in aryl trichloromethyl sulfides using antimony(III) fluoride (or hydrogen fluoride) proceeds under milder conditions, without a catalyst. Various substituents in the aromatic ring have little effect on the halogen exchange. The yields of aryl trifluoromethyl sulfides are 60 to 90% (see Table 1). 

Bis(trifluoromethyl) sulfoxide has been prepared1 previously by the direct fluorination of bis(trifluoromethyl) sulfide at —78°C. in hexafluoroethane followed by hydrolysis of the bis(trifluoro-methyl)sulfur difluoride (difluorobis(trifluoromethyl)sulfur). This method suffers because elemental fluorine must be used, and the yields are low. 

Oxidation of bis(trifluoromethyl) sulfide with commercially obtainable chlorine monofluoride in the absence of solvent yields bis(trifluoromethyl)sulfur difluoride in >90% yield.2,3 Pure bis-(trifluoromethyl)sulfur difluoride is resistant to hydrolysis and is stable in Pyrex glass at 25°C. for extended periods of time. Reaction of bis(trifluoromethyl)sulfur difluoride with anhydrous... 

Ten mmoles of S-trifluoromethyl trifluoromonothioperoxyacetate are photolyzed for hour through Pyrex glass with a Hanovia Utility ultraviolet quartz lamp (140 watts), which produces bis(trifluoromethyl) sulfide and carbon dioxide quantitatively. Pure bis(trifluoromethyl) sulfide is retained in a —120°C. slush bath (diethyl ether) while carbon dioxide slowly sublimes into a —183°C. bath during trap-to-trap distillation. 

Bis(trifluoromethyl) sulfide exists as a colorless gas at room temperature and condenses to a colorless liquid. The vapor... 

A couple of additional efforts warrant comment. The reaction between trifluoromethyliodide and 2,5-dimethoxythiophcnol should have produced 2,5-dimethoxyphenyl trifluoromethyl sulfide, but it didn t produce anything. And one more. What about a bare thio group at the 4-position in this 2C-T-family Maybe... 

An oxygen bound to a trifluoromethyl group has much less effect upon its chemical shift than a chlorine substituent. Thus, the fluorines of trifluoromethyl ethers (—58 ppm) are not as deshielded as those of CF3C1 (—28 ppm). Those of CF3 sulfides and selenides are deshielded still further (—42 and -37 ppm, respectively). Also, aryl and alkyl trifluoromethyl ethers have similar fluorine chemical shifts, as do aryl and alkyl trifluoromethyl sulfides. 

Aryl trichloromethyl sulfides are readily fluorinated with antimony(Ill) fluoride or hydrogen fluoride to give the corresponding trifluoromethyl sulfides in good yield (Tabic 17) 00-zo ... 

Table 17. Aryl Trifluoromethyl Sulfides by Fluorination of Aryl Trichloromethyl Sulfides Using Antimony(lll) Fluoride...

In the reaction of a-(trihalomcthyl)sulfanyl ketones with hydrogen fluoride,, -difluoroalkyl fluoridothiocarhonates 14 are obtained instead of the expected trifluoromethyl sulfides.The reaction is thought to proceed via an initial chlorine-fluorine exchange reaction followed by rearrangement into the /i-difluorinated product. 

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