Enantioselective β‑Protonation by a Cooperative Catalysis Strategy

An enantioselective N-heterocyclic carbene (NHC)-catalyzed β-protonation through the orchestration of three distinct organocatalysts has been developed. This cooperative catalyst system enhances both yield and selectivity, compared to only the NHC-catalyzed process. This new method allows for the efficient conversion of a large scope of aryl-oxobutenoates to highly enantioenriched succinate derivatives and demonstrates the benefits of combining different activation modes in organocatalysis.