Dendritic chiral phosphine Lewis bases-catalyzed asymmetric aza-Morita-Baylis-Hillman reaction of N-sulfonated imines with activated olefins

A series of polyether dendritic chiral phosphine Lewis bases was synthesized, and successfully applied to the asymmetric aza-Morita-Baylis-Hillman reaction of N-sulfonated imines (N-arylmethylidene-4-methylbenzenesulfonamides) with methyl vinyl ketone (MVK), ethyl vinyl ketone (EVK), and acrolein to give the adducts in good to excellent yields along with up to 97 % ee, which are more effective than our previously reported original chiral phosphine Lewis bases. In addition, the dendrimer-supported chiral phosphine Lewis bases can be easily recovered and reused.