Organoalkali compounds metallation with

Base catalysis is most effective with alkali metals dispersed on solid supports or in the homogeneous form as aldoxides, amides, and so on. Small amounts of promoters may be added to form organoalkali compounds that really have the catalytic power. Basic ion exchange resins also are useful. Some base-catalyzed processes are isomerization and oligomerization of olefins, reaction of olefins with aromatics, and hydrogenation of polynuclear aromatics. 

Organoalkali metal compounds of the heavier alkah metals with more highly substituted alkyl groups can be formed from the reaction of an alkane with the appropriate methyl derivative (MMe M = Na, K, Rb, and Cs ) (equation 18). 

The preparation of adducts of conjugated hydrocarbons by reaction with alkali metals demands absence of Oj, HjO or solvent impurities that can combine with the organometallic product or the alkali metal. The T must be below the decomposition point of the organoalkali compound in the particular solvent. Adequate contact between the alkali metal and the hydrocarbon must be established. In small-scale preparations the alkali metal is deposited as a mirror on the walls of the reaction vessel, where it can come in contact with solvent. In larger scale or synthetic preparations the alkali metal is in the form of a sand or dispersion (see 5.5.3.2.1), and good stirring may be helpful. 

Some other contributions of organometallic compounds to fundamental research are (a) the detection of free alkyl radicals by the pyrolysis of lead alkyls (b) the classification of hydrocarbon acidity via organoalkali compounds (c) the study of Lewis acid-base interactions with Group III alkyls (d) the development of the concept of electron-deficient compounds by the study of metal alkyls (e) the discovery of stereospecific olefin polymerization and (f) the investigation of nucleophilic additions to unsaturated organic compounds via reactive metal alkyls. 

The direct reaction of an organic halide with an alkali metal is one of the most important methods for synthesizing organolithium compounds. The reaction of two equivalents of the alkali metal with one equivalent of the organohalide produces the organoalkali metal compound and metal halide... 

The reactivity of hydrocarbon anion or dianion compounds of the alkali metals with respect to alkylation, electron transfer, and protonation has been studied. These species have also been used as reagents in the preparation of organoalkali metal compounds. 

In another study (SO) l-chloro-2-p-biphenylylethane-l,l-d2 was allowed to react with various alkali metals in tetrahydrofuran (organoalkali compounds appear to have longer lifetimes in tetrahydrofuran than in 1,2-dimethoxyethane). Reaction with lithium at -70°C gave a good yield of 2-/7-biphenylyllithium-l,l-d2 (35) however on warming to Ot this... 

S.3.2.2 Reactions with Organoalkali Metal Compounds or with Alkali Metals... 

Reactions with organoalkali metal compounds or with Grignard reagents... 

REACTIONS WITH ORGANOALKALI METAL COMPOUNDS OR WITH GRIGNARD REAGENTS... 

Organolithium compounds have been more widely used than compounds of the heavier alkali metals. Smith has pubhshed an extensive review that focuses on the organometallic chemistry of sodium, potassium, mbidium, and cesium. An important textbook that covers the general aspects of organoalkali metal chemistry was written by Elschenbroich and Salzer. These publications, along with this article in the first edition of this encyclopedia, were used as foundational sources for this overview of the organometallic chemistry of the alkali metals. 

The direct reaction of an organic molecule with an alkali metal produces an organoalkali metal compound and hydrogen gas (equation 5). 

The reaction of an organo- or amido-alkah metal reagent with an acidic organic molecule produces an organoalkali metal compound and the amine or organic compound (equation 7). 

Methyl lithium and butyl lithium are widely used for the synthesis of other organolithium compounds. For example, lithium cyclopentadienides are generally prepared by the reaction of the cyclopentadiene with butyl lithium. In contrast, the amido-alkali metal compounds are becoming increasingly important in the synthesis of organoalkali metal compounds with the heavier alkali metals. For example, l,2,4-tris(trimethylsilyl)-l,3-cyclopentadiene reacts with potassium bis(trimethylsilyl)amide to form potassium l,2,4-tris(trimethylsilyl)cyclopentadienide. ... 

By reacting directly with the alkali metal, organomercury compounds are commonly used to synthesize organoalkali metal compounds of the heavier alkali metals. This route has been used to make various alkyl compounds, such as butyl and trimethylsilylmethyl derivatives (equation 10). 

The compositions RjPbM are deduced by conversion to benzyltriorganoleads on addition of benzylchloride to RjPbM solns . They are complexes "" of a diorgano-lead(II) compound with an organoalkali metal derivative, analogous to alkali halo-plumbates(II). 

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