The reagent consisting of 70% HFâpy (py = pyridine) and a
halonium oxidant converts RâOCS
2
Me into either
RâOCF
3
(R = primary) or RâF (R = secondary,
tertiary or benzylic) whereas the 50% HFâpy system converts
RâOCS
2
Me (R = secondary) into
RâOCF
3
.
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