Organocatalytic Enantioselective Cycloaddition of o ‐Quinone Methides with Oxazolones: Asymmetric Synthesis of Dihydrocoumarins

Abstract The organocatalytic enantioselective cycloaddition of ortho ‐quinone methides with oxazolones promoted by a chiral binaphthyl‐modified squaramide bifunctional organocatalyst was developed, allowing an efficient synthesis of chiral dihydrocoumarins with excellent enantioselectivity (up to 97 % ee). This approach represents a practical method for the preparation of chiral 3,4‐dihydrocoumarin derivatives.