Sodium-Promoted Borylation of Polycyclic Aromatic\nHydrocarbons

Abstract

Sodium\ndispersion promotes the reductive borylation of polycyclic\naromatic hydrocarbons (PAHs) with MeOBpin. Anthracenes and phenanthrenes\nare converted to the corresponding dearomatized diborylated products.\nThe reductive diborylation of naphthalene-based small π-systems\nyields similar yet unstable products that are oxidized into formal\nC–H borylation products with unique regioselectivity. Pyrene\nis converted to 1-borylpyrene without the addition of an oxidant.\nThe latter two reactions represent a new route to useful borylated\nPAHs that rivals C–X borylation and catalytic C–H borylation.