Chemistry of ß-Carbolines as Synthetic Intermediates

beta-Carbolines are present in a wide variety of indole alkaloids that display important biological activities. Here we review the most recent aspects of the chemistry of beta-carbolines with a focus on functionalization of the beta-carboline system and transformations into other interesting compounds. Aromatizations, reductions and alkylations of the heterocyclic system are thus summarized first, followed by methodologies directed towards the formation of additional fused rings. Finally, rearrangements that transform beta-carbolines into other heterocyclic systems are covered.