Quinolines nucleophilic 2-alkylation/arylation

Quinoline and isoquinoline undergo a set of reactions in which, in effect, a hydride ion is replaced by a strongly nucleophilic species. With organolithium compounds the initial adduct, on hydrolysis and mild oxidation, yields the corresponding alkyl or aryl derivative, and hydroxy or amino groups can be introduced by reaction with alkali metal (or alkaline earth) hydroxides or amides. 

The same logic can be followed on the nucleophilic attack of alkyl or aryl groups on C2 position of quinoline and Cl position of isoquinoline cores by organometalic species (lithium or Grignard reagents). The reaction seems to proceed in two steps as this is demonstrated in the alkylation of isoquinolile below. Addition at the Cl position gives a dehydroisoquinoline-A-lithio derivatives, which can be hydrolyzed to furnish an isolable 1-substituted 1,2-dihydroisoquinoline. It was followed by an oxidation process to yield the full aromatized product. ... 

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