Trifluoromethyl ethers R-OCF3 are easily synthesized from the corresponding dithiocarbonates R-OCS2Me (R = aryl or primary alkyl) by a reagent system consisting of 70% HF/pyridine and an N-halo imide. When the reaction is applied to R-OCS2Me wherein R = secondary alkyl, tertiary alkyl, or benzylic group, fluorination leading to the corresponding alkyl fluorides R-F is achieved, whereas a combination
Treatment of xanthates R-OC(S)SMe with (HF)9/Py and 1,3-dibromo-5,5-dimethylhydantoin gives trifluoromethyl ethers R-OCF3 through intermediates R-OCF2SMe, which could be isolated upon treatment of xanthates with n-Bu4N+H2F3− and N-bromosuccinimide.