Novel Axially Chiral Ligand-Enabled Copper-Catalyzed Asymmetric Oxidative Coupling of 2-Naphthols for the Synthesis of 6,6'-Disubstituted BINOLs.

Novel axially chiral ligands have been designed and synthesized by merging the chelating picolinic acid with substituted BINOLs. The in-situ-prepared copper catalysts from the ligands and CuI enable the asymmetric oxidative coupling of 2-naphthols, affording 6,6'-disubstituted BINOLs in up to 89% yield with good enantioselectivities (up to 96:4 e.r.).