Identifiers | |
---|---|
3D model (JSmol) | |
3587231 | |
ChEBI | |
ChemSpider | |
EC Number |
|
723 | |
PubChem CID | |
| |
| |
Properties | |
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). |
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]
Solutions of vinyllithium are prepared by lithium-halogen exchange reactions. A halide-free route entails reaction of tetravinyltin with butyllithium:
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]
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]
Vinyl magnesium bromide, a Grignard reagent, is in many ways easier to generate in the laboratory and behaves similarly to vinyllithium. [5]
A Gilman reagent is a lithium and copper (diorganocopper) reagent compound, R2CuLi, where R is an alkyl or aryl. These reagents are useful because, unlike related Grignard reagents and organolithium reagents, they react with organic halides to replace the halide group with an R group (the Corey–House reaction). Such displacement reactions allow for the synthesis of complex products from simple building blocks.
In organometallic chemistry, organolithium reagents are chemical compounds that contain carbon–lithium (C–Li) bonds. These reagents are important in organic synthesis, and are frequently used to transfer the organic group or the lithium atom to the substrates in synthetic steps, through nucleophilic addition or simple deprotonation. Organolithium reagents are used in industry as an initiator for anionic polymerization, which leads to the production of various elastomers. They have also been applied in asymmetric synthesis in the pharmaceutical industry. Due to the large difference in electronegativity between the carbon atom and the lithium atom, the C−Li bond is highly ionic. Owing to the polar nature of the C−Li bond, organolithium reagents are good nucleophiles and strong bases. For laboratory organic synthesis, many organolithium reagents are commercially available in solution form. These reagents are highly reactive, and are sometimes pyrophoric.
In organometallic chemistry, acetylide refers to chemical compounds with the chemical formulas MC≡CH and MC≡CM, where M is a metal. The term is used loosely and can refer to substituted acetylides having the general structure RC≡CM. Acetylides are reagents in organic synthesis. The calcium acetylide commonly called calcium carbide is a major compound of commerce.
Organotin chemistry is the scientific study of the synthesis and properties of organotin compounds or stannanes, which are organometallic compounds containing tin carbon bonds. The first organotin compound was diethyltin diiodide, discovered by Edward Frankland in 1849. The area grew rapidly in the 1900s, especially after the discovery of the Grignard reagents, which are useful for producing Sn–C bonds. The area remains rich with many applications in industry and continuing activity in the research laboratory.
n-Butyllithium C4H9Li (abbreviated n-BuLi) is an organolithium reagent. It is widely used as a polymerization initiator in the production of elastomers such as polybutadiene or styrene-butadiene-styrene (SBS). Also, it is broadly employed as a strong base (superbase) in the synthesis of organic compounds as in the pharmaceutical industry.
1-Bromobutane is the organobromine compound with the formula CH3(CH2)3Br. It is a colorless liquid, although impure samples appear yellowish. It is insoluble in water, but soluble in organic solvents. It is primarily used as a source of the butyl group in organic synthesis. It is one of several isomers of butyl bromide.
The Trapp mixture is a specific mixture of organic solvents that allows chemical reactions to take place at very low temperatures. It is made up of THF:diethyl ether:pentane in a 4:4:1 ratio which remains liquid down to −110 °C and the same solvents in a 4:1:1 ratio remain a liquid down to −120 °C. This solvent system retains a low viscosity until just before freezing and it allows a lower temperature reaction than pure THF, which melts at −108.4 °C. An illustrative application of Trapp solvent is the preparation of vinyllithium by lithium halogen exchange from vinyl bromide and tert-butyllithium. The low temperatures suppress the reaction of the strongly basic organolithium reagent with the THF.
Hydroperoxides or peroxols are compounds of the form ROOH, which contain the hydroperoxy functional group (–OOH). The hydroperoxide anion and the neutral hydroperoxyl radical (HOO·) consist of an unbond hydroperoxy group. When R is organic, the compounds are called organic hydroperoxides. Such compounds are a subset of organic peroxides, which have the formula ROOR. Organic hydroperoxides can either intentionally or unintentionally initiate explosive polymerisation in materials with unsaturated chemical bonds.
tert-Butyllithium is a chemical compound with the formula (CH3)3CLi. As an organolithium compound, it has applications in organic synthesis since it is a strong base, capable of deprotonating many carbon molecules, including benzene. tert-Butyllithium is available commercially as hydrocarbon solutions; it is not usually prepared in the laboratory.
A Grignard reagent or Grignard compound is a chemical compound with the general formula R−Mg−X, where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride Cl−Mg−CH3 and phenylmagnesium bromide (C6H5)−Mg−Br. They are a subclass of the organomagnesium compounds.
The Finkelstein reaction named after the German chemist Hans Finkelstein, is an SN2 reaction that involves the exchange of one halogen atom for another. It is an equilibrium reaction, but the reaction can be driven to completion by exploiting the differential solubility of halide salts, or by using a large excess of the halide salt.
Organocopper chemistry is the study of the physical properties, reactions, and synthesis of organocopper compounds, which are organometallic compounds containing a carbon to copper chemical bond. They are reagents in organic chemistry.
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.
Group 2 organometallic chemistry refers to the chemistry of compounds containing carbon bonded to any group 2 element. By far the most common group 2 organometallic compounds are the magnesium-containing Grignard reagents which are widely used in organic chemistry. Other organmetallic group 2 compounds are rare and are typically limited to academic interests.
Trimethyltin chloride is an organotin compound with the formula (CH3)3SnCl. It is a white solid that is highly toxic and malodorous. It is susceptible to hydrolysis.
Organomanganese chemistry is the chemistry of organometallic compounds containing a carbon to manganese chemical bond. In a 2009 review, Cahiez et al. argued that as manganese is cheap and benign, organomanganese compounds have potential as chemical reagents, although currently they are not widely used as such despite extensive research.
Propynyllithium is an organolithium compound with the chemical formula LiC
2CH
3. It is a white solid that is soluble in 1,2-dimethoxyethane, and tetrahydrofuran. To preclude its degradation by oxygen and water, propynyllithium and its solutions are handled under inert gas. Although commonly depicted as a monomer, propynyllithium adopts a more complicated cluster structure as seen for many other organolithium compounds.
In organic chemistry, vinylation is the process of attaching a vinyl group to a substrate. Many organic compounds contain vinyl groups, so the process has attracted significant interest, especially since the reaction scope includes substituted vinyl groups. The reactions can be classified according to the source of the vinyl group.
Vinyl tributyltin is an organotin compound with the formula Bu3SnCH=CH2 (Bu = butyl). It is a white, air-stable solid. It is used as a source of vinyl anion equivalent in Stille coupling reactions. As a source of vinyltin reagents, early work used vinyl trimethyltin, but trimethyltin compounds are avoided nowadays owing to their toxicity.
In organometallic chemistry, metal–halogen exchange is a fundamental reaction that converts an organic halide into an organometallic product. The reaction commonly involves the use of electropositive metals and organochlorides, bromides, and iodides. Particularly well-developed is the use of metal–halogen exchange for the preparation of organolithium compounds.
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