Nickel-Catalyzed Asymmetric Ring Opening of Oxa­benzo­norborna­dienes with Arylboronic Acids

A new, versatile, and highly efficient nickel-catalyzed asymmetric ring-opening (ARO) reaction of oxabenzo­norborna­dienes with a wide variety of arylboronic acids has been developed, yielding <i>cis</i>-2-aryl-1,2-dihydro­naph­thalen-1-ols in high yields (up to 99%) with good to excellent enantioselectivities (up to 99% ee) under very mild conditions. The effects of various nickel precursors, chiral bidentate ligands, catalyst loadings, bases, solvents, and temperatures on the yield and enantioselectivity of the reaction were also investigated. A plausible mechanism was proposed to account for the formation of the corresponding <i>cis</i>-ring-opened products based on the X-ray structure of product <b>4b</b>.