Trimethylsilyl trifluoromethanesulfonate (TMSOTf) is an
organosilicon compound with the formula . It is a colorless moisture-sensitive liquid. It is the
trifluoromethanesulfonate derivative of
trimethylsilyl
A trimethylsilyl group (abbreviated TMS) is a functional group in organic chemistry. This group consists of three methyl groups bonded to a silicon atom minus;Si(CH3)3 which is in turn bonded to the rest of a molecule. This structural group i ...
. It is mainly used to activate ketones and aldehydes in
organic synthesis
Organic synthesis is a branch of chemical synthesis concerned with the construction of organic compounds. Organic compounds are molecules consisting of combinations of covalently-linked hydrogen, carbon, oxygen, and nitrogen atoms. Within the gen ...
.
Reactions
TMSOTf is quite sensitive toward hydrolysis:
:
It is far more electrophilic than
trimethylsilyl chloride.
Related to its tendency to hydrolyze, TMSOTf is effective for silylation of
alcohol
Alcohol may refer to:
Common uses
* Alcohol (chemistry), a class of compounds
* Ethanol, one of several alcohols, commonly known as alcohol in everyday life
** Alcohol (drug), intoxicant found in alcoholic beverages
** Alcoholic beverage, an alco ...
s:
:
A common use of is for the preparation of
silyl enol ethers. One example involves the synthesis of the silyl enol ether of
camphor
Camphor () is a waxy, colorless solid with a strong aroma. It is classified as a terpenoid and a cyclic ketone. It is found in the wood of the camphor laurel (''Cinnamomum camphora''), a large evergreen tree found in East Asia; and in the kapu ...
:
:

It was also used in
Takahashi Taxol total synthesis and in
chemical glycosylation reactions.
Trimethylsilyl trifluoromethanesulfonate has a variety of other specialized uses. It has been used to install tert-alkyl groups on phosphine (R = alkyl):
:PH
3 + R
3C–OAc + Me
3SiOTf →
3C)2PH2">R3C)2PH2Tf
Deprotection of
Boc-protected amines can be achieved using trimethylsilyl trifluoromethanesulfonate and
triethylamine
Triethylamine is the chemical compound with the formula N(CH2CH3)3, commonly abbreviated Et3N. Like triethanolamine and the tetraethylammonium ion, it is often abbreviated TEA. It is a colourless volatile liquid with a strong fishy odor remini ...
or
2,6-lutidine.
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.
References
{{reflist
Trimethylsilyl compounds
Triflate esters