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

A highly selective NHC-catalyzed synthesis of gamma-butyrolactones from the fusion of enals and alpha-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 C-1-symmetric biaryl-saturated imidazolium-derived NHC catalyst.