Chemical compound
Hexamethyldisilane (TMS2) is the organosilicon compound with the formula Si2(CH3)6, abbreviated Si2Me6. It is a colourless liquid, soluble in organic solvents.[1]
Synthesis and reactions
Hexamethyldisilane can be produced by Wurtz-like coupling of trimethylsilyl chloride in the presence of a reducing agent such as potassium graphite:
- 2 Me3SiCl + 2 K → Me3Si−SiMe3 + 2 KCl
With an excess of the reductant, the alkali metal silyl derivative is produced:[2]
- Me3Si−SiMe3 + 2 K → 2 Me3SiK
The Si-Si bond in hexamethyldisilane is cleaved by strong nucleophiles and electrophiles. Alkyl lithium compounds react as follows:
- Si2Me6 + RLi → RSiMe3 + LiSiMe3
Iodine gives trimethylsilyl iodide.[3]
- Me3Si−SiMe3 + I2 → 2 SiMe3I
References
- ^ Tamejiro Hiyama, Manabu Kuroboshi, "Hexamethyldisilane" Encyclopedia of Reagents for Organic Synthesis, 2001 John Wiley & Sons. doi:10.1002/047084289X.rh015
- ^ Fürstner, Alois; Weidmann, Hans (1988). "Efficient formation and cleavage of disilanes by potassium-graphite. Silylation with silyl metal reagents". Journal of Organometallic Chemistry. 354: 15–21. doi:10.1016/0022-328X(88)80634-X.
- ^ Olah, G.; Narang, S.C. (1982). "Iodotrimethylsilane—a versatile synthetic reagent". Tetrahedron. 38 (15): 2225. doi:10.1016/0040-4020(82)87002-6.
