Alkyülliitiumühend

Alkyülliitiumühend is a class of organometallic compounds characterized by a direct covalent bond between a carbon atom and a lithium atom. These compounds are generally represented by the formula RLi, where R is an alkyl or aryl group. Alkyyllithium reagents are known for their strong basicity and nucleophilicity, making them highly reactive and versatile reagents in organic synthesis.

The reactivity of alkyyllithium compounds stems from the polarized nature of the carbon-lithium bond, where the carbon atom carries a significant negative charge. This polarity makes the alkyl group a potent carbanion equivalent. They are commonly used in deprotonation reactions, forming new carbon-carbon bonds through nucleophilic attack on electrophiles, and in metal-halogen exchange reactions.

Common examples of alkyyllithium compounds include n-butyllithium (n-BuLi), sec-butyllithium (sec-BuLi), and tert-butyllithium (t-BuLi). These reagents are often prepared by the reaction of an alkyl or aryl halide with lithium metal. Due to their high reactivity, alkyyllithium compounds are typically handled under an inert atmosphere, such as nitrogen or argon, and in anhydrous conditions to prevent decomposition by moisture or oxygen. They are commonly supplied as solutions in hydrocarbon solvents like hexane or heptane. Their applications span a wide range of organic transformations, including the synthesis of pharmaceuticals, polymers, and fine chemicals.