Developing NHC-Iridium Catalysts for the Highly Efficient Enantioselective Intramolecular Hydroamination Reaction

Chiral, cationic NHC-iridium complexes are introduced as catalysts for the intramolecular hydroamination reaction of unactivated aminoalkenes. The catalysts show high activity in the construction of pyrrolidines, which are accessed with excellent optical purity. Enantiomerically enriched piperidines and indolines are also produced, and various functional groups are tolerated with this LTM system. A reaction mechanism is proposed, and a major deactivation pathway of these catalysts is presented and discussed.