Deoxygenative Suzuki-Miyaura Arylation of Tertiary Alcohols

The coupling of tertiary alcohols with boronic esters is described, providing a direct access to quaternary carbon scaffolds without needing to proceed by a highly activated intermediate such as an alkyl halide. A dual catalyst system is employed with both Ni(0) and Bi(III) components playing a critical role along with a mild chlorosilane reactant that enhances the yield by alcohol silylation. This method was found to tolerate diverse functional groups including chloro, nitro, olefin, ketone, ester and phenol moieties, while also being applicable to the derivatization of heterocyclic scaffolds. Mechanistic studies suggest the combination of Lewis acid catalyst and organosilane promote heterolytic cleavage of the substrate C–O bond by an SN1-like reaction pathway, providing a powerful strategy for derivatizing readily available alcohols.