Catalytic C3 aza-alkylation of Indoles

Aza-alkylation reaction at indole C3 position allows the introduction of a differently substituted aminomethyl group, with the formation of a new stereogenic centre. The reaction involves essentially three different partners: indole, aldehyde and an amine. The formation of the reactive iminium specie can be catalyzed by metals, Brønsted acids, Lewis acids or by organocatalysts. The stereoselective reaction is feasible with satisfactory outcomes. This review summarizes the recent (2000-2019) meaningful papers in which the in-depht study and the exploitation of this reactivity are reported.