Triflic anhydride with the chemical formula (CF3SO2)2O is a colorless liquid. Also known trifluoromethanesulfonic anhydride or TFSA, this highly reactive organic compound also has strong acidic properties. It is generally referred to as triflic anhydride as it is derived from triflic acid (CF3SO3H). This chemical compound is utilized in organic synthesis as a powerful acylation reagent. It reacts with alcohol to form esters. Similarly, when it reacts with amines and thiols, it forms amides, and thioesters, respectively. These reactions are performed under anhydrous and inert conditions. This chemical compound has the ability to activate and promote reactions that are otherwise difficult or slow.