The oxidative desulfurization-fluorination of orthothioesters of type RCH2C(SMe)3 using n-Bu4NH2F3 and 1,3-dibromo-5,5-dimethylhydantoin gave bromodifluorination products RCHBrCF2SMe in good yields. The products were converted into bromodifluoro olefins RCBr=CF2 via oxidation and thermolysis. In a similar way, the orthothioesters of type RCH(OH)C(SMe)3 or RCH(OAc)C(SMe)3 were fluorinated to afford difluoro ketones RCOCF2SMe or difluoro acetates RCH(OAc)CF2SMe, respectively. The difiuoro acetates were reduced to RCH(OAc)CF2H by radical reduction. The mechanisms are discussed for difluorination accompanied by bromination or oxidation.
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