Vinyllithium

Vinyllithium
Identifiers
CAS Number	917-57-7;
3D model (JSmol)	Interactive image;
Beilstein Reference	3587231
ChEBI	CHEBI:51472;
ChemSpider	10254403;
ECHA InfoCard	100.011.844
EC Number	213-028-5;
Gmelin Reference	723
PubChem CID	637931;
CompTox Dashboard (EPA)	DTXSID10238670 ;
	InChI InChI=1S/C2H3.Li/c1-2;/h1H,2H2; Key: PGOLTJPQCISRTO-UHFFFAOYSA-N;
	SMILES [Li]C=C;
Properties
Chemical formula	C2H3Li
Molar mass	33.99 g·mol−1
Appearance	white solid
Hazards
	Occupational safety and health (OHS/OSH):
Main hazards	pyrophoric
	Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Vinyllithium is an organolithium compound with the formula LiC₂H₃. A colorless or white solid, it is encountered mainly as a solution in tetrahydrofuran (THF). It is a reagent in synthesis of organic compounds, especially for vinylations.^[1]

Preparation and structure

Solutions of vinyllithium are prepared by lithium-halogen exchange reactions. A halide-free route entails reaction of tetravinyltin with butyllithium:

Sn(CH=CH₂)₄ + 4 BuLi → SnBu₄ + 4 LiCH=CH₂

The reaction of ethylene and lithium affords vinyl lithium and lithium hydride, together with other organolithium compounds,^[1]

Like most organolithium compounds, vinyllithium crystallizes from THF as a cluster compound as a cubane-type cluster.^[2]

Reactions

Vinyllithium is used to install vinyl groups on metal-based reagents, i.e., vinylations. It is a precursor to vinylsilanes, vinylcuprates, and vinylstannanes.^[3] It adds to ketones compounds to give allylic alcohols. Vinylmagnesium bromide is often used in place of vinyllithium.^[4]

Alternative reagents

Vinyl magnesium bromide, a Grignard reagent, is in many ways easier to generate in the laboratory and behaves similarly to vinyllithium.^[5]

References

^ ^a ^b Eisenhart, Eric K.; Bessieres, Bernard (2007). "Vinyllithium". E-EROS Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rv015.pub2. ISBN 978-0-471-93623-7..
^ Walter Bauer; Frank Hampel (1992). "X-Ray crystal structure of a vinyllithium–tetrahydrofuran solvate (C2H3Li–thf)4. Quantitative estimation of Li–H distances by 6Li–1H HOESY". J. Chem. Soc., Chem. Commun. (12): 903–905. doi:10.1039/C39920000903.
^ Lipshutz, Bruce H.; Moretti, Robert; Crow, Robert (1990). "Mixed Higher-order Cyanocuprate-induced Epoxide Openings: 1-benzyloxy-4-penten-2-ol". Org. Synth. 69: 80. doi:10.15227/orgsyn.069.0080.
^ Dietmar Seyferth (1959). "Di-n-butyldivinyltin". Org. Synth. 39: 10. doi:10.15227/orgsyn.039.0010.
^ William J. Scott, G. T. Crisp, J. K. Stille (1990). "Palladium-catalyzed Coupling of Vinyl Triflates with Organostannanes: 4-tert-Butyl-1-Vinylcyclohexene and 1-(4-tert-Butylcyclohexen-1-yl)-2-propen-1-one". Organic Syntheses. 68: 116. doi:10.15227/orgsyn.068.0116.{{cite journal}}: CS1 maint: multiple names: authors list (link)