From Wikipedia, the free encyclopedia
Jump to navigation Jump to search
Skeletal formula of sec-butyllithium
Skeletal formula of tetrameric sec-butyllithium
IUPAC name
Systematic IUPAC name
3D model (JSmol)
ECHA InfoCard 100.009.026
EC Number 209-927-7
Molar mass 64.06 g·mol−1
Acidity (pKa) 51
Safety data sheet Fisher MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☑Y verify (what is ☑Y☒N ?)
Infobox references

sec-Butyllithium is an organometallic compound with the formula CH3CHLiCH2CH3, abbreviated sec-BuLi or s-BuLi. This chiral organolithium reagent is used as a source of sec-butyl carbanion in organic synthesis.[1]


sec-BuLi can be prepared by the reaction of sec-butyl halides with lithium metal:[2]

Sec Butyllithium synthesis 01.svg

The carbon-lithium bond is highly polar, rendering the carbon basic, as in other organolithium reagents. Sec-butyllithium is more basic than the primary organolithium reagent, n-butyllithium. It is also more sterically hindered, though it is still useful for syntheses.


sec-BuLi is employed for deprotonations of particularly weak carbon acids where the more conventional reagent n-BuLi is unsatisfactory. It is, however, so basic that its use requires greater care than for n-BuLi. For example diethyl ether is attacked by sec-BuLi at room temperature in minutes, whereas ether solutions of n-BuLi are stable.[1] Many transformations involving sec-butyllithium are similar to those involving other organolithium reagents. For example, sec-BuLi react with carbonyl compounds and esters to form alcohols. With copper(I) iodide sec-BuLi forms lithium di-sec-butylcuprates. The first two reactions can also be accomplished by using sec-butylmagnesium bromide, a Grignard reagent; in fact, the latter is the typical reagent for this purpose.


  1. ^ a b Ovaska, T. V. "s-Butyllithium" in Encyclopedia of Reagents for Organic Synthesis, 2001 John Wiley & Sons: New York. doi:10.1002/047084289X.rb397.
  2. ^ Hay, D. R.; Song, Z.; Smith, S. G.; Beak, P. (1988). "Complex-induced proximity effects and dipole-stabilized carbanions: kinetic evidence for the role of complexes in the α-lithiations of carboxamides". J. Am. Chem. Soc. 110 (24): 8145–8153. doi:10.1021/ja00232a029.