Alküülliitium

Alküülliitium refers to organolithium compounds where an alkyl group is directly bonded to a lithium atom. These are highly reactive and versatile reagents commonly used in organic synthesis. The general formula for an alkyl lithium compound is R-Li, where R represents an alkyl group such as methyl, ethyl, n-butyl, or tert-butyl.

The carbon-lithium bond in alkyl lithiums is highly polar, with a significant partial negative charge on the carbon atom and a partial positive charge on the lithium atom. This polarity makes the carbon atom nucleophilic and basic, enabling alkyl lithiums to participate in a wide range of chemical reactions. They are particularly effective in forming new carbon-carbon bonds through reactions like nucleophilic addition to carbonyl compounds, SN2 reactions with alkyl halides, and deprotonation of acidic protons.

Due to their high reactivity, alkyl lithiums are sensitive to air and moisture and are typically handled under an inert atmosphere, such as nitrogen or argon, and in anhydrous solvents like diethyl ether or tetrahydrofuran. They are often sold as solutions in hydrocarbon solvents. Common examples include n-butyllithium (n-BuLi), sec-butyllithium (sec-BuLi), and tert-butyllithium (t-BuLi). The reactivity and selectivity of these reagents can be tuned by varying the alkyl group and reaction conditions.