Chiral ionic Bronsted acid-achiral Bronsted base synergistic catalysis for asymmetric sulfa-Michael addition to nitroolefins

摘要

A highly enantioselective sulfa-Miehael addition to aromatic and aliphatic nitroolefins is achieved under the synergistic catalysis of chiral, ionic Bronsted acid homo-1b·HBArF and 2,6-lutidine. The potential utility of this new method is clearly demonstrated by its application to the syntheses of a novel, optically active taurine derivative and β-sultam.