Trimethylsilyl trifluoromethanesulfonate (TMSOTf) is an organosilicon compound with the formula (CH3)3SiO3SCF3.

TMSOTf is quite sensitive toward hydrolysis: It is far more electrophilic than trimethylsilyl chloride.

[3][4] One example involves the synthesis of the silyl enol ether of camphor: It was also used in Takahashi Taxol total synthesis and in chemical glycosylation reactions.

It has been used to install tert-alkyl groups on phosphine (R = alkyl):[6] Deprotection of Boc-protected amines can be achieved using trimethylsilyl trifluoromethanesulfonate and triethylamine or 2,6-lutidine.

[7][8] TMSOTf is also a useful reagent to replace metal-halogen bonds with a covalent M-O(SO2CF3) bond, the by-product being the highly volatile TMSCl which is easily removed.