Asymmetric Homoenolate Additions to Acyl Phosphonates through Rational Design of a TailoredN-Heterocyclic Carbene Catalyst

A highly selective NHC-catalyzed synthesis of γ-butyrolactones from the fusion of enals and α-ketophosphonates has been developed. Computational modeling of competing transition states guided a rational design strategy to achieve enhanced levels of enantioselectivity with a new tailored C1-symmetric biaryl-saturated imidazolium-derived NHC catalyst.