Chiral Copper Complex-Catalyzed Enantioselective Oxidative Cross-Coupling of 2-Naphthols for Synthesis of C 1 -Symmetric BINOLs

An efficient Cu-Box system was developed for the oxidative cross-coupling of 2-naphthols under mild conditions. The method tolerates a broad substrate scope, and a series of C1-symmetric chiral BINOLs were obtained in excellent yields (up to 96%) and enantioselectivities (up to a 98:2 e.r.). By combining electron-rich and electron-deficient 2-naphthols to create a significant redox potential difference between the two reaction partners, the challenge of chemoselectivity was addressed, driving preferential cross-coupling over homocoupling. DFT calculations and HRMS analyses revealed a radical-mediated pathway for this transformation.