| Identification | Back Directory | [Name]
VINYL LITHIUM | [CAS]
917-57-7 | [Synonyms]
VINYL LITHIUM
Ethenyllithium | [EINECS(EC#)]
213-028-5 | [Molecular Formula]
C2H3Li | [MDL Number]
MFCD00080700 | [MOL File]
917-57-7.mol | [Molecular Weight]
33.99 |
| Hazard Information | Back Directory | [Uses]
Vinyl lithium is a reactive intermediate for the formation of vinyl alcohols from aldehydes, vinyl ketones from organic acids, vinyl sulfides from disulfides, and monosubstituted alkenes from organic halides. | [Definition]
ChEBI: Vinyllithium is a vinyllithium compound and an alkenyllithium compound. | [Preparation]
Vinyllithium is prepared by a variety of methods. Direct metalation of Ethylene with Lithium metal in
dimethoxymethane yields vinyllithium contaminated with lithium hydride, and other organolithio species, such as butyllithium
and 1,4-dilithiobutane. Direct formation from ethylene can also be accomplished using Potassium t-Butoxide, n-Butyllithium, and TMEDA (N,N,N′,N′-Tetramethylethylenediamine) in hexane at -40 °C, followed by treatment of the
vinylpotassium with Lithium Bromide. The lithium-halogen exchange reaction has been used, starting from vinyl chloride
and lithium/sodium dispersions, or from vinyl bromide with 2 equiv of t-Butyllithium in either a Trapp solvent mixture at -
120 °C or ether at -78 °C. This is the most convenient procedure, but lithium halide is formed during the reaction and is
present as a contaminant. Halide-free vinyllithium can be prepared by transmetalation of Tetravinylstannane with phenyl- or
butyllithium, of tetravinyllead with either lithium metal or Phenyllithium, or of divinylmercury with lithium dispersion in
pentane. | [storage]
As with most alkyllithium reagents, vinyllithium reacts readily with moisture. Solid
vinyllithium should be maintained at -25 °C or below, under an inert atmosphere. The solid suffers a loss in activity with time
and should be used immediately upon preparation. Solutions of the reagent in ether or THF, under an inert atmosphere, are
stable for up to 1 week at rt. Solid vinyllithium is violently pyrophoric, yielding a brilliant red flash on contact with air. | [Purification Methods]
Purification of Vinyllithium: ether solutions can be evaporated under an inert atmosphere and the resulting solid washed with anhydrous
pentane or hexane. |
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