Metalations with organolithium compounds

Metalations with organolithium compounds, 8, 6 26, 1 27, 1 Methylenation of carbonyl groups, 43, 1 Methylenecyclopropane, in cycloaddition reactions, 61, 1... 

In general, polymeric materials that contain either side groups or main-chain allylic or acidic hydrogens can be metallated with organolithium compounds in the presence of chelating diamines. They can also be grafted with ionically polymerizable monomers to produce comblike materials (Halasa et al., 1976). 

The terminal methyl group of unsymmetrical ketone dimethylhydrazone is reactive, and is easily metalated with organolithium compounds. Subsequently, the substituted products are produced by reaction with halides as shown in eq. (3.25). These reactions are applied for the synthesis of dihydrojasmone [73]. 

Metalation of Thiophenes with Organolithium Compounds (Nucleophilic Substitution on Hydrogen)... 

Deprotonation of very weakly acidic C—H acids is accomplished by metallation with organolithium and organosodium compounds. 

THF is used as solvent for this reaction (Scheme 156). Indeed, THF is the solvent of choice for the alkylation of N- oxides by Grignard reagents. The following references (B-71MI20500, 74HC(14-S2)i) should be consulted for a more comprehensive coverage of these reactions. Reactions of the above type with organolithium compounds are less successful as metallation becomes a major pathway (vide infra). 

Another very important ring substitution reaction of ferrocene is its ability to undergo metalation with organolithium and organosodium compounds. Metalation with n-butyllithium in ethyl ether, first reported by Nesmeyanov and coworkers (63) and independently by Benkeser, Goggin, and Schroll (3),"leads to rather low yields of ferrocenyllithium (XXXI, M = Li) and l,l -ferrocenylenedi-lithium (XXXII, M = Li). It was subsequently shown by Mayo, Shaw, and... 

H. Gilman, The Metalation Reaction with Organolithium Compounds," Organic Reactions 8, 258 (1954) 6, 339 (1951). 

The metalation of benzylamines is similarly interesting, because slight variations of the reaction conditions can significantly alter the regioselectivity of proton removal. Treatment of N,N-dimethylbenzylamine with organolithium compounds leads to dean ortho-metalation of the phenyl group [418, 431], If, however, phenyl-sodium [432] or mixtures of organolithium compounds and KOfBu [193, 209, 433]... 

The reaction of transition-metal carbonyls with organolithium compounds to give metal carbene complexes is now well known it can also take place when the metal is linked to a group IV atom, as in the following series of reactions (426). 

R. G. Jones, H. Gilman, The Halogen-Metal Interconversion Reaction with Organolithium Compounds, ... 

The halogen-metal interconversion reaction with organolithium compounds... 

Atmosphere. Reactions with organolithium compounds must be carried out in an inert atmosphere (Ar and He are best Nj tarnishes lithium metal by forming lithium nitride). 

Gilman, H., Morton, J. W., Jr. The metalation reaction with organolithium compounds. Org. React. 1954, 258-304. 

The detailed discussion of transmetallation reactions with organolithium compounds (1, XM = RLi), and coupling reactions (5) in the presence of transition metal catalysts (particularly the Stille reactions) is deferred until Sections 22.1 and 22.2. 

This report is limited to the most recent work on chelating diamines with organolithium compounds and their application to metalation and grafting. 

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