Asymmetric Borylative Propargylation of Ketones Catalyzed by a Copper(I) Complex.

A copper(I)-catalyzed asymmetric borylative propargylation of simple ketones was disclosed. Additive NaBARF was found to be pivotal to achieve excellent enantioselectivity. This reaction enjoyed advantages of broad substrate scope, good tolerance of functional groups, high diastereo- and enantioselectivities, and reaction robustness. The borylative product served as a suitable cross-coupling partner in a palladium-catalyzed Suzuki-Miyaura reaction. Finally, the synthetic utility of the methodology was showcased by the asymmetric synthesis of a chiral piperidine derivative.