Reactions with Organoalkali Compounds

Metal-exchange reactions are observed, giving unexpected products as with alkali metals55  

Unexpected reaction products are also due to steric hindrance. Gilman and Smart215 found sym-tetra-o-tolyl-dihydroxydisilane after hydrolysis of a reaction product of Si2Cl6 and o-tolyl-Li. 

The Si—H bond as well as the Si-halogen bond reacts with organoalkali compounds and this fact can be used formation of new derivatives  

In certain experiments, alkali or alkaline-earth elements are used in the metallic state. With a Wurtz-like synthesis, new substituents can be inserted at the Si—Si bond  

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Reaction of Organoalkali Compounds with Carbon Disulfide... 

Reactions of Organoalkali Compounds with Halogenating Agents... 

Reactions of organoalkali compounds with disulfides and trialkylchlorosilane are often extremely fast. The usual procedure involves addition of the reagents to a... 

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... 

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. 

This is an excellent reaction for the conversion of most halides to acids containing one additional carbon atom. Carbonation of Grignard reagents and organoalkali compounds gives acids in yields of 50-85%. Ether solutions of the organometallic compounds formerly were treated with carbon dioxide gas at 10° to -10°. A more recent technique involves pouring the solution onto excess crushed Dry Ice. Carbon dioxide... 

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. 

Functional End-Group Polymers. The formation of various functional groups on the "living" ends of anionic polymer chains is based on the well-known reaction of organometallic compounds with various reagents. Thus, organoalkali compounds can react as illustrated in the following typical reactions ... 

The reaction of sp3 organoalkali compounds with carbon disulfide usually does not stop at the stage of the initial adduct, but is followed by an extremely fast conversion of the dithiocarboxylate into a geminal ene-dithiolate ... 

The process may be complicated, however, by reaction of intermediates I and II with unreacted phosphorus to gi e more complex phosphides which in turn arc broken down by the organometallic reactant. Ileac-tions of organoalkali compounds with phosphorus may also proceed tlirougli such intermediates, but the greater reactivity of the alkali derivatives evidently permits further phosphorus-phosphorus bond cleavage leading to more complex ions. 

There are three general types of metallation reactions (metal-hydrogen exchange) that are commonly used to synthesize organoalkali metal compounds from organic molecules Direct reaction with an alkali metal, reaction with an alkali metal hydride, or reaction with an organo- or amido-alkali metal. Since these reactions involve acid/base equilibria, they are dependent on both the C-H acidity of the organic molecule and the basicity of the alkali metal source. 

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... 

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