Enantioselective β-Protonation by a Cooperative Catalysis Strategy
摘要:
An enantioselective N-hetetoeyclic carbene (NHC)-catalyzed beta-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.
Construction of the ABCD ring system of (−)-FR182877 via the intramolecular Diels–Alder (IMDA) reaction and the highly diastereoselective intramolecular hetero-Diels–Alder (IMHDA) reaction is described. The IMHDA reactions of the substrates incorporating the oxabutadiene with the E- or Z-alkene were examined, revealing that the sole product was obtained from both substrates and the E-alkene geometry