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Methyl Lithium
Methyllithium is the simplest organolithium reagent with the empirical formula CH3Li. This s-block organometallic compound adopts an oligomeric structure both in solution and in the solid state. This highly reactive compound, invariably used in solution with an ether as the solvent, is a reagent in organic synthesis as well as organometallic chemistry. Operations involving methyllithium require anhydrous conditions, because the compound is highly reactive toward water. Oxygen and carbon dioxide are also incompatible with MeLi. Methyllithium is usually not prepared, but purchased as a solution in various ethers. Synthesis In the direct synthesis, methyl bromide is treated with a suspension of lithium in diethyl ether. :2 Li + MeBr → LiMe + LiBr The lithium bromide forms a complex with the methyllithium. Most commercially available methyllithium consists of this complex. "Halide-free" methyllithium is prepared from methyl chloride. Lithium chloride precipitates from the dieth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organolithium Reagent
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. History and de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
