Trifluoromethoxy group

The trifluoromethoxy group is the chemical group –O–CF
₃. It can be seen as a methoxy group –O–CH
₃ whose hydrogen atoms are replaced by fluorine atoms or as a trifluoromethyl group attached to the rest of the molecule by a bridging oxygen atom. Either leads to viable syntheses,^[1] but in 2022 "the synthesis of CF₃O^- compounds suffer[ed] from restricted methods and remain[ed] difficult. In particular, the direct introduction of the CF₃O motif onto organic substrates [was] still poorly described," partly because trifluoromethoxide easily decomposes to difluorophosgene.^[2]

Compounds having this functional group are of some relevance as pharmaceuticals, because it is a much more hydrophobic analogue of chlorine. One example is riluzole.^[3]