Chiral primary amine mediated conjugate addition of branched aldehydes to vinyl sulfone: asymmetric generation of quaternary carbon centers

Novel L-threonine-derived bifunctional organic catalysts containing primary amine and sulfonamide groups were utilized to promote asymmetric conjugate addition of alpha,alpha-disubstituted aldehydes to 1,1-bis(benzenesulfonyl)ethylene. The adducts with quaternary stereogenic centers adjacent to an aldehyde group were obtained in high yield and with good enantioselectivity.