Enantioselective Copper-Catalyzed Dearomative Spiroannulation of β-Naphthols or Indoles with Yne-Allylic Esters

Catalytic asymmetric dearomatization reactions of α-unsubstituted β-naphthols are very challenging due to the high energy barrier resulting from the loss of aromaticity. Herein, we describe an example of enantioselective catalytic dearomative spiroannulation with yne-allylic esters. The success of this reaction relied on the copper-catalyzed remote asymmetric strategy using yne-allylic esters as the bis-electrophilic reagents. This transformation features mild reaction conditions, broad functional group tolerance, and an extensive substrate scope, thereby facilitating the efficient construction of an array of enantioenriched naphthalene-2-one and spiroindolenine derivatives. Experimental studies and density functional theory calculations establish the reaction pathway and origin of stereoselectivity.