Organocatalytic Enantioselective Friedel-Crafts Alkylation Reactions of Pyrroles

Substituted and annulated pyrroles containing chiral centers are potentially accessible by means of an organocatalytic enantioselective Friedel-Crafts alkylation (FCA) reaction. They are interesting compounds because of their abundant natural occurrence and their different biological activities. In comparison to indoles, for which a myriad of asymmetric procedures involving the FCA have been developed, pyrroles have been relatively less used as nucleophilic counterparts in this reaction. However, in the last two decades, huge synthetic efforts have been performed around this interesting asymmetric transformation and several methodologies have been devised. In this context, this review article provides a general overview of the organocatalytic enantioselective FCA chemistry of pyrroles, which has not been revised to date.