Copper‐Catalyzed Monoborylation of Silylalkynes; Regio‐ and Stereoselective Synthesis of (Z)‐β‐(Borylvinyl)silanes

The selective copper‐catalyzed borylation of silylalkynes in the presence of a diboron reagent and methanol produced a variety of (Z)‐β‐(borylvinyl)silanes. The appropriate use of a selective ligand for copper allows the chemo‐, regio‐, and stereoselective monoborylation of silylalkynes. The β‐regioselectivity of an N‐heterocyclic carbene (NHC)‐copper catalyst was investigated by DFT calculations.