tBuLi

Tert-butyllithium (t-BuLi) is an organolithium reagent used in organic synthesis. It consists of a tert-butyl group bonded to lithium and is typically available as a solution in hydrocarbon solvents such as hexane or cyclohexane, commonly at concentrations around 1.0 M. In solution, t-BuLi behaves as a very strong base and a reactive nucleophile, although its bulky tert-butyl group makes it sterically hindered for many nucleophilic additions.

Preparation and handling of t-BuLi require strict air- and moisture-free conditions. It is usually prepared by the metallation of tert-butyl halides with lithium metal, or by other lithiation routes, under inert atmosphere and at low temperature. The reagent is highly reactive and pyrophoric, reacting violently with water and oxygen. In solution, t-BuLi exists as aggregates, with the aggregation state influenced by the solvent; coordinating solvents can alter reactivity and accessibility of the reactive carbanion.

Applications and typical reactions include deprotonation of substrates with very high pKa values to generate carbanions, formation of organolithium intermediates via halogen–lithium exchange, and nucleophilic alkylation of electrophiles such as carbonyl compounds to form tertiary alcohols after workup. It is often used for introducing the tert-butyl group or for generating reactive tert-butyl carbanions that can be transformed in subsequent steps, including transmetalation to other metal centers.

Safety and disposal considerations are critical. t-BuLi is highly reactive with air and moisture, capable of ignition. It should be handled under strictly inert conditions, typically in a well-ventilated fume hood with appropriate protective equipment, and quenched carefully according to established procedures.