Alkylating agents, alkyl halides groups

The reaction of an alkyl halide with lithium is an oxidation-reduction reac tion Group I metals are powerful reducing agents... 

Cyclo acylations leadUy take place in intermoleculai acylations involving bifunctional acylating agents. Both functional groups may be acyl (as in the case of a,CO-diacyl halides) or one may be an alkylating group (as in unsaturated acyl halides or certain haloacyl halides) (18). 

The initial step is the coordination of the alkyl halide 2 to the Lewis acid to give a complex 4. The polar complex 4 can react as electrophilic agent. In cases where the group R can form a stable carbenium ion, e.g. a tert-buiyX cation, this may then act as the electrophile instead. The extent of polarization or even cleavage of the R-X bond depends on the structure of R as well as the Lewis acid used. The addition of carbenium ion species to the aromatic reactant, e.g. benzene 1, leads to formation of a cr-complex, e.g. the cyclohexadienyl cation 6, from which the aromatic system is reconstituted by loss of a proton ... 

The source of the alkyls is usually some main group alkylating agent, and the groups that are replaced on M to form a dialkyl complex usually are halides. When the alkyl group contains one or more (3 protons, then the predominant re-... 

From the radioactivity of the polymer and of the original methyl chloride it was found that if there was not more than one 14C atom per polymer molecule, 0.27 of the polymer molecules contained a methyl group derived from the solvent. The authors concluded that the formation of this fraction of molecules had been started by initiation according to equation 10, and that the remainder had been started by transfer with monomer. It has been admitted by the authors (private communication, and in press) that this conclusion is not warranted on this evidence, since alkyl halides such as methyl chloride, are known to act as transfer agents by a reaction which can be represented by Equation 7. At best, the evidence shows that methyl chloride was involved in starting - by initiation and/or transfer - about a quarter of the polymer molecules. The results of further studies with 14CH3C1 and CH336C1 are in process of publication [12]. 

In other reactions also the OH-group of the phenols shows itself to be more reactive than that of the aliphatic alcohols. Phenols, but not alcohols, react easily with diazomethane. With other alkylating agents also, such as alkyl halides, and dialkyl sulphates, the phenols react even in aqueous alkaline solution whilst the alcohols do not react under such conditions. Benzoyl derivatives, most of which crystallise readily, are excellently adapted for the characterisation of phenols (Schotten-Baumann reaction). 

Introduction of an alkyl group onto an aromatic substrate by treating the substrate with an alkylating agent such as alkyl halide, alkene, alkyne and alcohol in the presence of a Lewis acid. 

There has been much interest in diquaternary salts of 4,4 -bipyridine, the electrochemistry of which has recently been reviewed. l.l -Dialkyl diquaternary salts of 4,4 -bipyridines are prepared by treating 4,4 -bipyri-dines with excess of an alkyl halide or a dialkyl sulfate or other alkylating agent. This method has been used extensively and provides diquaternary salts of type 92 where both alkyl quaternizing groups are the same (i.e., 92 R = 211,467,689,962,967,968 Qf particular interest is the diquater-... 

Despite the great number of metal-carbamates isolated to date, the transfer of a carbamic group from a metal center to an alkylating agent such as an alkyl halide or diatkyl sulfate has been documented in only a few cases [1, 2]. 

Through the interaction of an alkylating agent, a hydrogen atom of the aromatic core, in the case of alkylation of arenes, is replaced by an alkyl group driven by a Friedel-Crafts catalyst. A variety of alkylating agents (e.g. alkyl halides, alcohols,... 

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