organoszilícium

Organosilicon compounds are chemical species that contain at least one carbon–silicon bond. They encompass a wide range of structures, from simple silanes to complex organosiloxanes and silicon-containing polymers. The Si–C bond is the defining feature, generally covalent, and silicon is typically tetravalent, often bound to alkyl or aryl groups, hydrogen, and sometimes other substituents.

Major classes include:

- Silanes and organosilanes: compounds with Si–C bonds such as alkyl- or aryl-substituted silanes.

- Siloxanes and silicones: polymers with repeating Si–O–Si units, commonly with organic side groups, noted for flexibility and thermal stability.

- Organosiloles and heterocyclic silicon compounds: silicon-containing rings and related structures.

- Silyl ethers and silyl protecting groups: species used to shield hydroxyl groups in organic synthesis.

Key reactions involve:

- Hydrosilylation: addition of Si–H across carbon–carbon multiple bonds, often catalyzed by transition metals.

- Silylation: formation of silyl ethers and other silyl derivatives from alcohols and other nucleophiles.

- Cross-coupling with organosilicon reagents (Hiyama coupling): silicon–carbon bonds participate in palladium- or nickel-catalyzed couplings to form C–C bonds.

Applications span silicone polymers used in sealants, lubricants, medical devices, and cosmetics; surface modification agents; and precursors for advanced materials and electronics. Organosilicon chemistry provides versatile reagents and strategies for synthesis, catalysis, and materials science, underpinning both industrial and academic research.