Organolithium reagents, reaction with nitriles

Reactions of either Grignard or organolithium reagents with most aldehydes, ketones, or esters produce alcohols. Reactions of organolithium reagents with carboxylic acids, or of Grignard reagents with nitriles, produce ketones. 

Some imidoyllithiums 52 derived from triphenylmethyl isocyanide (51) dissociate to produce nitriles, which react with an organolithium reagent to give the corresponding imines and, after their hydrolysis, ketones. The intermediate nitrile can be isolated working at —78°C, whereas for the isolation of imines or ketones, after addition of the organolithium, the reaction was allowed to warm to room temperature (Scheme 14)74. The structure of the imidoyllithium intermediate has been assigned by IR spectroscopy... 

Monoalkylation of primary amines. A two-step sequence for this reaction involves conversion of the amine to the N-(cyanomethyl)amine (2) by reaction with chloroaceto-nitrile or with formaldehyde and KCN. Reaction of 2 with an organolithium or a Grignard reagent generates an unstable formaldehyde imint (a) that reacts with a second equivalent of the organometallic reagent to form a secondary amine (3). 

C Reaction of a nitrile with a Grignard or organolithium reagent... 

The reaction of cerium reagents with imines and nitriles which possess a-hydrogens has been studied by Wada et al ° Available data indicate that the reagents do not effectively d to these substrates, although the results are better than with alkyllithiums themselves. A modification of the procedure improves the yields of addition products. Thus, addition of the organocerium or organolithium reagent to an... 

Reactions of organolithium and Grignard reagents, such as RLi, RC=CLi, RMgX, and RC=CMgX, with aldehydes, ketones, esters, epoxides, acid halides, and nitriles... 

The synthesis of symmetrical ketones noted above was developed into a practicable method by use of 2 eq. of the organolithium reagent for 1 eq. of the isocyanide. The reaction involves formation of the nitrile followed by reaction of this product with another equivalent of the lithium reagent ... 

It is worth mentioning that the substituted cyclohexanone was also formed from the iodocyanopentane when lithiated with n-butyllithium in diethyl ether. The halogen exchange reaction is obviously much faster than nitrile addition for the organolithium reagent (see also the reaction mentioned on p.96. 

The results of Li-Barbier reactions of bromobenzene and n-bromobutane with nitriles have also been compared with those from two-step procedures involving Grignard and organolithium reagents [23]. 

Grignard reagents and organolithium reagents react with nitriles to give imine anions, but aqueous acid hydrolysis usually converts the imine anion to a ketone as the final product. Peroxyacids react with ketones to give esters in the Baeyer-Villiger reaction. 

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