Trifluoromethanesulfonic acid difluoromethyl ester

Difluoromethyl triflate (TfO-CHF₂) can be used as a reagent:

• In difluoromethylation reaction.
• To prepare difluoromethoxylated heterocycles by reacting with hydroxylated N-based heterocycles.
• To synthesize trifluoromethylated arenes by treating with diaryliodonium salts in the presence of copper and tetrabutylammonium difluorotriphenylsilicate (TBAT).

It allows for a simple method toward the preparation of difluoromethyl ethers and thioethers under basic conditions from alcohols and thiols. Difluoromethyl phenols can also be obtained in a single pot from boronic acids and C-H activation of arenes.

Difluoromethyl triflate (HCF₂OTf) is an easy to handle, air-stable and non-ozone-depleting liquid reagent for difluoromethylation. It can be prepared by reacting trifluoromethyltrimethylsilane (TMSCF₃) and triflic acid in the presence of titanium tetrachloride (TiCl₄).