Lewis Acid Promoted Dearomatization of Naphthols

Two‐step dearomative functionalization of naphthols promoted by Lewis acids and copper(I) catalysis was developed. Initially, Lewis acid complexation inverted the electronic properties of the ring and established an equilibrium with the dearomatized counterpart. Subsequent trapping of the dearomatized intermediate with organometallics as well as organophosphines was demonstrated and provided the corresponding dearomatized products. A method to activate naphthols with Lewis acids (LA) is developed, stabilizing the non‐aromatic tautomer and leading to the formation of α,β‐unsaturated ketones. Organometallic addition catalyzed by CuI as well as addition of phosphines and hydrides are compatible with the presence of LA, yielding the corresponding dearomatized products. The procedure requires very mild reaction conditions and can be an important tool for organic synthesis.