silylklorider

Silyl chlorides, or silylklorider, are a family of organosilicon compounds characterized by a silicon atom bearing three substituents and a chlorine substituent (R3SiCl). They are moisture-sensitive chlorosilanes used extensively in organic synthesis as silylating reagents.

Common members include trimethylsilyl chloride (TMSCl), tert-butyldimethylsilyl chloride (TBDMSCl, also known as TBSCl), tert-butyldiphenylsilyl chloride (TBDPSCl), and triisopropylsilyl chloride (TIPSCl). The choice of silyl group affects stability toward hydrolysis and deprotection conditions.

Primary application is protection of alcohols as silyl ethers. In the presence of a base such as imidazole or pyridine, ROH reacts with R3SiCl to give RO-SiR3 and HCl or a base salt. Silyl ethers are robust to many reaction conditions but can be selectively removed later by fluoride sources (e.g., TBAF, HF-pyridine) or acid, enabling sequence control in complex syntheses. Silyl chlorides also form N-silyl derivatives with amines and serve as precursors for other silicon-containing reagents, though alcohol protection remains the dominant use.

Handling and safety: silyl chlorides are moisture-sensitive and react vigorously with water to release HCl. They are typically stored under dry conditions and used with an inert atmosphere. They can be corrosive and irritant; appropriate protective equipment and ventilation are required.

Preparation: they are typically prepared by chlorination of corresponding hydrosilanes or chlorosilyl derivates; they are widely available commercially.