Enantioselective Synthesis of Tetrahydroanthraquinones via Pd-Catalyzed Asymmetric [2 + 4] Annulation

An efficient asymmetric [2 + 4] annulation of 2-alkyl-3-hydroxynaphthalene-1,4-diones with electron-deficient allylic carbonates, promoted by a chiral bisphosphino-naphthamide/palladium complex, has been developed for the first time. This method accommodates a broad range of substrates, enabling the synthesis of tetrahydroanthraquinones bearing two contiguous quaternary stereocenters with high stereoselectivity.