Alkyl halides, reaction with indole Grignard reagents

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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