Trimethylsilyl cyanide
[CAS# 7677-24-9]

Identification

• Classification: Chemical reagent >> Organic reagent >> Silane
• Name: Trimethylsilyl cyanide
• Synonyms: Cyanotrimethylsilane; TMSCN
• Molecular Formula: C₄H₉NSi
• Molecular Weight: 99.21
• CAS Registry Number: 7677-24-9
• EC Number: 231-657-3
• SMILES: C[Si](C)(C)C#N

Properties

• Density: 0.744
• Melting point: 11 °C
• Boiling point: 114-117 °C
• Refractive index: 1.388-1.392
• Flash point: 1 °C
• Water solubility: reacts

Safety Data

• Hazard Symbols: GHS02;GHS05;GHS09 Danger
• Risk Statements: H225-H301-H310-H330-H400-H410
• Safety Statements: P210-P233-P240-P241-P242-P243-P260-P262-P264-P270-P271-P273-P280-P284-P301+P316-P302+P352-P303+P361+P353-P304+P340-P316-P320-P321-P330-P361+P364-P370+P378-P391-P403+P233-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	2	H225
Acute toxicity	Acute Tox.	1	H330
Acute toxicity	Acute Tox.	2	H300
Acute toxicity	Acute Tox.	2	H310
Chronic hazardous to the aquatic environment	Aquatic Chronic	1	H410
Acute toxicity	Acute Tox.	1	H310
Acute toxicity	Acute Tox.	1	H300
Acute hazardous to the aquatic environment	Aquatic Acute	1	H400
Acute toxicity	Acute Tox.	2	H330
Skin irritation	Skin Irrit.	2	H315
Eye irritation	Eye Irrit.	2	H319

• Transport Information: UN 3383

Discovery and Applications

Trimethylsilyl cyanide, with the chemical formula (CH₃)₃SiCN, is an organosilicon compound that has garnered attention in synthetic organic chemistry due to its utility as a versatile reagent. This compound features a cyanide group (-CN) bonded to a trimethylsilyl group (Si(CH₃)₃), which enhances its reactivity and stability.

The discovery of trimethylsilyl cyanide is linked to the broader study of organosilicon chemistry, which gained prominence in the mid-20th century. Researchers sought to explore the reactivity of silicon-based compounds, leading to the development of trimethylsilyl cyanide. The synthesis of this compound typically involves the reaction of trimethylsilyl chloride with sodium cyanide. The resulting product is a colorless liquid with a boiling point of around 70°C.

One of the primary applications of trimethylsilyl cyanide is as a reagent in organic synthesis. Its primary use is as a source of cyanide in reactions where the direct use of cyanide is not feasible due to its toxicity or volatility. The trimethylsilyl group stabilizes the cyanide ion, making it easier to handle and use in various chemical transformations. This stabilization allows trimethylsilyl cyanide to participate in nucleophilic addition reactions, where it reacts with carbonyl compounds to form cyanohydrins. Cyanohydrins are valuable intermediates in the synthesis of various pharmaceuticals and fine chemicals.

Trimethylsilyl cyanide is also used in the synthesis of heterocyclic compounds. For instance, it can be employed in the formation of nitriles and other functionalized derivatives that are important in the development of agrochemicals and medicinal compounds. Additionally, its role as a protecting group in organic synthesis is notable. The trimethylsilyl group can temporarily protect functional groups during multi-step synthesis processes, allowing for selective modifications without affecting other parts of the molecule.

In the field of polymer chemistry, trimethylsilyl cyanide has applications as a monomer in the synthesis of silicon-containing polymers. These polymers, which incorporate silicon into their backbone, exhibit unique properties such as high thermal stability and flexibility, making them useful in a range of industrial applications.

Overall, trimethylsilyl cyanide is a valuable tool in synthetic chemistry due to its ability to deliver cyanide functionality in a controlled manner and its versatility in various chemical processes.

References

2024. Photoelectrochemical asymmetric catalysis. Nature Catalysis, 7(12).
DOI: 10.1038/s41929-024-01260-y

2023. Sigmatropic rearrangements of B(MIDA)-propargylic alcohols towards the diverse synthesis of α-functionalized organoborons. Science China Chemistry, 66(12).
DOI: 10.1007/s11426-023-1722-8

1977. Cyanosilylation of 2-ethoxyacrolein. Bulletin of the Academy of Sciences of the USSR, Division of chemical science, 26(2).
DOI: 10.1007/bf00921852