Asymmetric Organocatalyzed Intermolecular Dearomatization Reaction Of Both ?-and ?-naphthols

Aromatic compounds are important fossil resources found in coal and raw petrol,providing a foundation for the polymers,paints,cosmetics and pharmaceuticals that we use in our daily life.So far,substantial efficient synthetic strategies have been developed by organic chemists,which enabled access to various multi-functional scaffolds or molecules from the readily available aromatic compounds.For example,dearomatization reaction of aromatic compounds as an appealing strategy have been utilized to achieve assembly of complex polycyclic structures,and especially for the construction of chiral all-carbon quaternary centers,which naturally occurred in a variety of natural products and drug molecular skeletons.Despite great progress has been made on the asymmetric catalytic dearomatization reaction recently,most successful reports were focused on the transition metal-ligand catalysis of ?-naphthols,the development of directly asymmetric catalytic dearomatization of both ?-and?-naphthol by organocatalyst was still remained elusive.Allenamides featuring with a conjugated system and multiple potential reactive sites are always served as a unique and charming electrophilic reagent.Generally,to introduce an electron-withdrawing group(EWG)on the N atom of allylamine would improve the electrophilicity of the olefin unit,and increase the stability of the allenes.By employing the hydrogen-bond activation of the chiral phosphoric acid catalysts,the electrophile dearomatization of both ?-and ?-naphthols and allenamides have been developed to deliver the corresponding naphthone products with an all-carbon quaternary centers,along with up to 98%yield and 97:3 e.r.Our strategy is the first organocatalytic asymmetric dearomatization reaction of naphthol promoted by carbon-based electrophiles.Meanwhile,this strategy has validated the compatibility of the hydrogen-bond activation for ?-naphthol compounds,which significantly expand the substrate scope of the dearomatization reaction from the previous well-studied?-naphthols.Additionally,it provides a new and efficient method to construct the?-naphthone products with achiral all-carbon quaternary center.