Dipeptide-Derived Chiral Tri- or Diammonium Salt-Catalyzed Enantioselective 1,3-Dipolar Cycloaddition Reaction of Nitrones with a- (Acyloxy)acroleins

Organoammonium salts of dipeptide-derived chiral tri-amines or diamines with TfOH catalyzed the enantioselective 1,3-dipolar cycloaddition reactions of alpha-acyloxyacroleins with nitrones to give the corresponding adducts in good yields (up to 96%) and with high diastereo- and enantioselectivities (up to 89% ee). Although alpha-(p-methoxybenzoyloxy)acrolein is rather unstable under the reaction conditions, alpha-(3-pyrroline-1-carbonyloxy)acrolein is stable enough to be smoothly converted into the corresponding adducts with the aid of the chiral organoammonium salt catalysts.

This is an Accepted Manuscript of an article published by Georg Thieme Verlag in Synlett 2019; 30(15): 1835-1839 "Enantioselective 1,3-Dipolar Cycloaddition Reaction of Nitrones with α-(Acyloxy)acroleins Catalyzed by Dipeptide-Derived Chiral Tri- or Diammonium Salts