Asymmetric Synthesis of Silicon-Stereogenic Vinylhydrosilanes by Cobalt-Catalyzed Regio- and Enantioselective Alkyne Hydrosilylation with Dihydrosilanes.

The strategic carbon-to-silicon substitution at a stereogenic center can produce chiral silanes with significantly improved properties relative to their carbon congeners. We herein report an unprecedented cobalt-catalyzed asymmetric hydrosilylation of unsymmetric alkynes with dihydrosilanes that furnishes silicon-stereogenic vinylhydrosilanes with high regio- and enantioselectivity. The absolute configurations of the products were determined by chiroptical methods in combination with DFT calculations. The synthetic versatility of the vinylhydrosilanes as chiral building blocks was further demonstrated by asymmetric Si-H insertion and catalytic hydroboration reactions.