Indole Grignard reagents with alkyl halides

Oddo reported that the organomagnesium derivatives of p3Trole, indole, skatole, and carbazole could be prepared in a single operation by mixing the parent heterocyclic compound with an alkyl halide and magnesium in anhydrous ether.The product formed was reported to be the same as that obtained by the more conventional procedure. However, this approach to the synthesis of the indole Grignard reagents does not seem to have been exploited in subsequent work. 

In the 19.S0 s a number of workers, including Hoshino, Oddo, and Kubota suggested that indolenine-type intermediates (cf. 431) were formed during the reaction of the indole Grignard reagents [depicted as N—MgX derivatives (cf. 432)] with alkyl and arylalkyl halides. Rather surprisingly these were the last reports dealing with... 

Some recent studies have underlined the effect that certain physical properties of the reaction medium have in governing the nature and yields of the products obtained when indole Grignard reagents react with alkyl or alkynyl halides. Such factors include the basicity and dielectric constant of the medium and its ability to solvate any of the reacting species. ... 

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