Asymmetric Dearomatization of Phenols via Ligand‐Enabled Cooperative Gold Catalysis

Abstract

AbstractBy employing a chiral bifunctional phosphine ligand, a gold(I)‐catalyzed efficient and highly enantioselective dearomatization of phenols is achieved via versatile metal‐ligand cooperation. The reaction is proven to be remarkably general in scope, permitting substitutions at all four remaining benzene positions, accommodating electron‐withdrawing groups including strongly deactivating nitro, and allowing carbon‐based groups of varying steric bulk including tert‐butyl at the alkyne terminus. Moreover, besides N‐(o‐hydroxyphenyl)alkynamides, the corresponding ynoates and ynones are all suitable substrates. Spirocyclohexadienone‐pyrrol‐2‐ones, spirocyclohexadienone‐butenolides, and spirocyclohexadenone‐cyclopentenones are formed in yields up to 99 % and with ee up to 99 %.