Topic summary
Lithiation

Extracted from the Wikipedia article Organolithium reagent.
Carbolithiation reactions
As nucleophiles, organolithium reagents undergo carbolithiation reactions, whereby the carbon–lithium bond adds across a carbon–carbon double or triple bond, forming new organolithium species. This reaction is the most widely employed reaction of organolithium compounds. Carbolithiation is key in anionic polymerization processes, and n-butyllithium is used as a catalyst to initiate the polymerization of styrene, butadiene, or isoprene or mixtures thereof.