Trifluoromethyltrimethylsilane

Trifluoromethyltrimethylsilane, also known as trifluoromethyltrimethylsilane (CF3SiMe3 or TMSCF3), is an organosilicon compound widely used as a source of the trifluoromethyl group in organic synthesis. Its formula is C4H9F3Si and it has a molecular weight of about 142 g/mol. It is a colorless liquid that is typically moisture sensitive and stored under dry, inert conditions.

Applications and reactivity

The reagent is best known as the Ruppert–Prakash reagent, a practical source of nucleophilic CF3− generated upon fluoride activation. In the presence of a fluoride source (such as KF, CsF, or tetrabutylammonium fluoride) and a polar aprotic solvent, CF3− is released and can be transferred to electrophilic substrates. Common targets include aldehydes and ketones to form trifluoromethylated alcohols or related products, as well as imines and certain activated alkenes. The result is the introduction of the trifluoromethyl group into various frameworks, enabling access to CF3-containing building blocks for pharmaceuticals, agrochemicals, and materials.

Preparation and handling

TMSCF3 is commercially available and is routinely used under inert, dry conditions due to its moisture sensitivity. Reactions often require careful control of solvent and fluoride additive to achieve efficient CF3 transfer. It is typically handled in a fume hood with appropriate protective equipment to minimize exposure.

Safety

The compound is an irritant and reacts with water to produce potentially hazardous byproducts. Handle with adequate ventilation, use protective gloves and eye protection, and store in a dry, cool place away from moisture.