Trifluoromethanesulfonic anhydride

Trifluoromethanesulfonic anhydride (CAS 358-23-6), commercially known as triflic anhydride or Tf₂O, is one of the most powerful electrophilic triflating agents available for synthetic chemistry.

It activates hydroxyl groups and other nucleophilic sites for downstream coupling and functionalization steps that milder reagents cannot achieve efficiently. In pharmaceutical synthesis, Tf₂O converts phenols and enols into vinyl triflates.

These are key intermediates in palladium-catalyzed cross-coupling reactions used to build complex active pharmaceutical ingredients. Polymer chemists use it to initiate cationic polymerization of cyclic monomers.

This enables precise molecular weight control in specialty polymer production. It also functions as an activating agent in the synthesis of glycosyl triflates, supporting carbohydrate-based drug and excipient manufacturing.

In fine chemical production, Tf₂O generates highly reactive triflate intermediates that allow selective C–O and C–N bond formation under conditions where conventional sulfonating agents fail.

Triflic anhydride is supplied as a colorless to pale yellow liquid, typically in sealed, moisture-protected packaging due to its reactivity with atmospheric moisture.

It is available in research quantities through to multi-kilogram lots for process-scale synthesis. Standard commercial offerings are high-purity technical and synthesis grades.

Purity specifications are commonly at 99% or above as confirmed by GC or titration methods, ensuring reliability for sensitive industrial applications and laboratory research.