Me3SiCl

Trimethylsilyl chloride, Me3SiCl, is an organosilicon compound and a chlorosilane with the formula (CH3)3SiCl. It is a common silylating agent used in organic synthesis to introduce the trimethylsilyl group and to protect functionalities such as alcohols.

Preparation and properties

Me3SiCl is typically prepared by chlorination of the corresponding hydride, trimethylsilane (Me3SiH), using chlorine under radical conditions. The compound is a colorless, volatile liquid that is moisture sensitive and reacts with water and atmospheric moisture to release hydrogen chloride. It hydrolyzes to form trimethylsilanol (Me3SiOH) and HCl. Stored under dry, inert conditions, Me3SiCl is handled with appropriate protective equipment due to its corrosive and irritant nature.

Reactions and uses

The primary use of Me3SiCl is as a silylating agent. In the presence of a base, it reacts with alcohols to form trimethylsilyl ethers (ROSiMe3), a widely used protecting group for hydroxyl functionalities in organic synthesis. It can also react with amines to generate N-silylated amines, and with other nucleophiles under suitable conditions. Because the Me3Si group is relatively easy to introduce and remove, Me3SiCl serves as a convenient precursor to a variety of silyl-protected intermediates and is a key reagent in multi-step protective-group strategies and in the preparation of silyl enol ethers and related species.

Safety and handling

Me3SiCl is moisture sensitive and corrosive. It emits HCl upon hydrolysis and can cause skin and eye irritation. It is typically stored in dry, tightly closed containers under inert gas and used with appropriate ventilation and personal protective equipment.

See also

Trimethylsilyl derivatives, other silyl chlorides (e.g., TMSCl, TBDMSCl)