Versatile and chemoselective synthesis of fluorinated methyl ethers from methoxymethyl ethers

Abstract A versatile and chemoselective route has been developed for the synthesis of aliphatic fluorinated methyl ethers (ROCH 2 R F ), specifically monofluoromethyl ethers (ROCH 2 F) and trifluoromethylthiomethyl ethers (ROCH 2 SCF 3 ), through pyridinium-type salt intermediates derived from methoxymethyl (MOM) ethers. The addition of a fluorine source (F − or SCF 3 − ) to the pyridinium-type salts afforded the corresponding fluorinated methyl ethers in good yields under mild conditions. Notably, the synthesis of monofluoromethyl ethers proceeded within just 5 min.