Borinic Acid-Catalyzed Regioselective Ring-Opening of 3,4- and 2,3-Epoxy Alcohols with Halides

Abstract Methods for the regioselective ring-opening of 3,4-epoxy alcohols and 2,3-epoxy alcohols with halide nucleophiles, using a diarylborinic acid catalyst, are disclosed. Ring-opening occurs at the position proximal to the OH group, an effect ascribed to a catalytic tethering mechanism whereby coordination to the substrate OH group positions the diarylborinic acid to deliver a coordinated halide nucleophile. These methods provide access to halohydrin substitution patterns that were not previously accessible through catalytic epoxide ring-opening reactions.