Enantioselective Addition of Alkynyl Ketones to Nitroolefins Assisted by Bronsted Base/H-Bonding Catalysis

Various sets of enolizable alkynyl ketones (including methyl ynones with alpha-aryl, alpha-alkenyl, and alpha-alkoxy groups) were able to react smoothly with nitroolefins with the assistance of bifunctional Bronsted base/H-bond catalysts to provide adducts with two consecutive tertiary stereocenters in a highly diastereo- and enantioselective fashion. Further transformation of the obtained adducts into optically active acyclic and polycyclic molecules, including some with intricate carbon skeletons, was also demonstrated.