Precise Synthesis of Chiral <i>Z</i>‐Allylamides by Cobalt‐Catalyzed Asymmetric Sequential Hydrogenations
Yanhua Hu, Yashi Zou, Huiwen Yang, Haotian Ji, Yue Jin, Zhenfeng Zhang, Yangang Liu, Wanbin Zhang
Abstract
Abstract Asymmetric sequential hydrogenations of conjugated enynes have been developed using a Ph‐BPE‐Co I catalyst for the precise synthesis of chiral Z ‐allylamides in high activity (up to 1000 substrate/catalyst (S/C)) and with excellent enantioselectivity (up to >99 % enantiomeric excess (ee)). Mechanism experiments and theoretical calculations support a cationic Co I /Co III redox catalytic cycle. The catalytic activity difference between cobalt complexes of Ph‐BPE and QuinoxP* was explained by the process decomposition of rate‐determining step in the second hydrogenation.
Topics & Concepts
CatalysisCobaltCationic polymerizationSubstrate (aquarium)Enantiomeric excessChemistryConjugated systemDecompositionEnantiomerCombinatorial chemistryCatalytic cycleRedoxEnantioselective synthesisAsymmetric hydrogenationStereochemistryOrganic chemistryPolymerGeologyOceanographyAsymmetric Hydrogenation and CatalysisSurface Chemistry and CatalysisAsymmetric Synthesis and Catalysis