Tert-Butyllithium

Tert-Butyllithium (t-BuLi) is a highly reactive organolithium reagent with the chemical formula (CH₃)₃CLi. It is commonly used in organic synthesis for the deprotonation of weak acids and as a strong base in various chemical reactions.

Properties

Tert-Butyllithium is a colorless liquid that is highly flammable and pyrophoric, meaning it can ignite spontaneously upon exposure to air. It is typically handled in a hydrocarbon solvent such as hexane or pentane to mitigate its reactivity. The compound is known for its strong basicity and nucleophilicity, making it a valuable reagent in synthetic chemistry.

Synthesis

Tert-Butyllithium is synthesized by the reaction of tert-butyl chloride with lithium metal in the presence of a hydrocarbon solvent. The reaction proceeds as follows:

(CH₃)₃CCl + 2Li → (CH₃)₃CLi + LiCl

This process requires careful control of temperature and exclusion of moisture and air to prevent unwanted side reactions.

Applications

Tert-Butyllithium is widely used in organic chemistry for various applications, including:

• **Deprotonation Reactions**: It is used to deprotonate weak acids, such as alcohols, amines, and alkynes, to generate the corresponding carbanions.
• **Metalation Reactions**: t-BuLi is employed to introduce lithium into organic molecules, a process known as metalation.
• **Polymerization**: It is used as an initiator in the anionic polymerization of certain monomers, such as styrene and butadiene.

Safety and Handling

Due to its extreme reactivity, tert-butyllithium must be handled with great care. It is typically stored under an inert atmosphere, such as nitrogen or argon, to prevent contact with air and moisture. Proper personal protective equipment (PPE), including gloves and eye protection, is essential when working with this reagent.

See Also

• Organolithium reagent
• Deprotonation
• Nucleophilicity
• Anionic polymerization