Regioselectivity Umpolung In Asymmetric Diels-Alder Reaction Of Ortho-Formyl-Substituted Cinnamates And Dienals Via Double Aminocatalysis

The cinnamates having an ortho-formyl group can potentially form vinylogous iminium ion species under the catalysis of chiral amines, which facilitates the Diels-Alder cycloaddition reaction with the concurrently generated trienamines between dienals and amine catalysts in a regioselectivity umpolung manner. A cascade intramolecular aldol reaction was followed, finally furnishing polyhydrophenanthrene frameworks with excellent diastereo- and enantioselectivity.