Enantioselective Copper-Catalyzed Dearomative Spiroannulation of β-Naphthols or Indoles with Yne-Allylic Esters
Ruinan Zhao, Shuang Deng, Rongkang Huang, Han‐Han Kong, Yuepeng Lu, Tingrui Yin, Jiaqiang Wang, Ying Li, Cuiju Zhu, Fangfang Pan, Xiaotian Qi, Hao Xu
Abstract
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.