C2-Symmetric Chiral Sulfoxide-Mediated Intermolecular Interrupted Pummerer Reaction for Enantioselective Construction of C3a-Substituted Pyrroloindolines

The first example of an enantioselective intermolecular interrupted Pummerer reaction has been developed by the utilization of a C-2-symmetric chiral sulfoxide. The reaction was used for the enantioselective synthesis of C3a-substituted pyrroloindolines in a one-pot procedure starting from tryptamine. The synthetic utility of the reaction was further demonstrated by its application to the highly concise total synthesis of (+)-psychotriasine.