Fluoroalkyl sulfides

Fig. 1. Relationship between oxidation peak potentials (Ep) of fluoroalkyl sulfides and Taft s substituent constants (

Table 9. Fluoride ion promoted anodic methoxylation of fluoroalkyl sulfides...

The treatment of sulfoxides with DAST in the presence of a Lewis acid, e.g. antimony(III) chloride or zinc(II) iodide, results in the formation of a-fluoroalkyl sulfides (see Table 9).65 69 Sulfides are also converted to the corresponding a-fluoroalkyl sulfides upon treatment with DAST or DAST antimony(III) chloride (see Table 9).70... 

Fuchigami and coworkers have proposed a Pummerer-type mechanism via the fluor-osulfonium cation for the anodic fluorination of sulfides [Eq. (14)], based on the comparative study of anodic methoxylation and fluorination of fluoroalkyl sulfides [43,45]. 

Table 10. Fluoride Ion Promoted Anodic Methoxylation of Fluoroalkyl Sulfides...

Anodic fluorinations of fluoroalkyl sulfides 37 also appear to proceed by a similar mechanism. However, the effects of both substituents (X and Rf groups in Scheme 32) on this process are totally different from those observed for anodic methoxylation. Therefore, the mechanism for anodic fluorination could very well differ from that for anodic methoxylation. 

Reaction with Sulfoxides. DAST reacts with a-hydrogen containing dialkyl and aralkyl sulfoxides to form a-fluoroalkyl sulfides in high yields (eq 17). This reaction can be extended to less reactive sulfoxides by catalysis with certain Lewis acids, e.g. Antimony(IU) Chloride (eq 18) and Zinc IodideP... 

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