Catalytic Enantioselective Oxidative Dearomatization of 1‑Naphthols Using Chiral Iminium Salts

The catalytic enantioselective oxidative dearomatization of 1-naphthols is achieved using chiral iminium catalysts. The developed method yields ortho-quinols in high yields (up to 94%) and with high enantioselectivity (up to 99% enantiomeric excess (ee)) under mild conditions. The asymmetric reaction, which affords the complete regioselective hydroxylation of 1-naphthols at the ortho-position, requires a chiral iminium catalyst with a binaphthyl structure. To demonstrate applicability to wide range of substrates, we synthesized the core skeleton of vanitaracin A, which exhibits antiviral activity against hepatitis B. The developed reaction is therefore highly useful in the synthesis of natural aromatic polyketides.