Trimethylsilyl iodide (iodotrimethylsilane or TMSI) is an

organosilicon compound Organosilicon compounds are organometallic compounds containing carbon–silicon bonds. Organosilicon chemistry is the corresponding science of their preparation and properties. Most organosilicon compounds are similar to the ordinary organic co ...

with the chemical formula (CH₃)₃SiI. It is a colorless, volatile liquid at room temperature.

Preparation

Trimethylsilyl iodide may be prepared by the oxidative cleavage of

hexamethyldisilane Hexamethyldisilane ( TMS2) is the organosilicon compound with the formula Si2(CH3)6, abbreviated Si2Me6. It is a colourless liquid, soluble in organic solvents. Synthesis and reactions Hexamethyldisilane can be produced by Wurtz-like coupling o ...

iodine Iodine is a chemical element with the Symbol (chemistry), symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , ...

or by the cleavage of hexamethyldisiloxane with aluminium triiodide. : TMS-TMS + I₂ → 2 TMSI (TMS = (CH₃)₃Si) : 3 TMS-O-TMS + 2 AlI₃ → 6 TMSI + Al₂O₃

Applications

Trimethylsilyl iodide is used to introduce the

trimethylsilyl A trimethylsilyl group (abbreviated TMS) is a functional group in organic chemistry. This group consists of three methyl groups bonded to a silicon atom minus;Si(CH3)3 which is in turn bonded to the rest of a molecule. This structural group is c ...

group onto

alcohol Alcohol most commonly refers to: * Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom * Alcohol (drug), an intoxicant found in alcoholic drinks Alcohol may also refer to: Chemicals * Ethanol, one of sev ...

s (ROH): :R-OH + TMSI → R-OTMS + HI This type of reaction may be useful for

gas chromatography Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, ...

analysis; the resultant

silyl ether Silyl ethers are a group of chemical compounds which contain a silicon atom covalently bonded to an alkoxy group. The general structure is R1R2R3Si−O−R4 where R4 is an alkyl group or an aryl group. Silyl ethers are usually used as protectin ...

is more volatile than the underivatized original materials. However, for the preparation of bulk trimethylsilylated material,

trimethylsilyl chloride Trimethylsilyl chloride, also known as chlorotrimethylsilane is an organosilicon compound (silyl halide), with the formula (CH3)3SiCl, often abbreviated Me3SiCl or TMSCl. It is a colourless volatile liquid that is stable in the absence of water. I ...

may be preferred due to its lower cost. TMSI reacts with alkyl

ether In organic chemistry, ethers are a class of compounds that contain an ether group—an oxygen atom connected to two alkyl or aryl groups. They have the general formula , where R and R′ represent the alkyl or aryl groups. Ethers can again b ...

s (ROR′), forming silyl ethers (ROSiMe₃) and iodoalkanes (RI) that can be hydrolyzed to alcohols (ROH). Trimethylsilyl iodide is also used for the removing of the Boc protecting group, especially where other deprotection methods are too harsh for the substrate.{{cite journal , author1=Zhijian Liu , author2=Nobuyoshi Yasuda , author3=Michael Simeone , author4=Robert A. Reamer , title = ''N''-Boc Deprotection and Isolation Method for Water-Soluble Zwitterionic Compounds , journal = J. Org. Chem. , year = 2014 , volume = 79 , issue=23 , pages = 11792–11796 , doi = 10.1021/jo502319z, pmid=25376704

References

Iodides Reagents for organic chemistry Trimethylsilyl compounds