CuI Catalyzed Regio‐ and Stereo‐selective Hydroboration of Ynamides: α‐ and β‐Borylation via Hydro‐Cupration and Borylation

Abstract A Cu I ‐catalyzed hydrocupration and borylation protocol for the regio‐ and stereoselective borylation of ynamides utilizing pinacolatoborane (HBpin) as the borylating agent has been developed. The reaction features mild conditions, good substrate scope and functional group tolerance‐representing a highly efficient and practical method for the synthesis of regio‐ and stereoselective tri‐substituted alkenylboronates from readily available ynamides. The regioselectivity is controlled by altering substituents on the ynamides (alkyl vs aryl) and utilizing a catalytic species [LCuH] generated in situ from HBpin and [LCuX]. Suzuki coupling and other transformations highlight the synthetic utility of the method.