Cobalt‐Catalyzed One‐Pot Asymmetric Difunctionalization of Alkynes to Access Chiral gem‐(Borylsilyl)alkanes

Enantioselective cobalt‐catalyzed one‐pot hydrosilylation and hydroboration of terminal alkynes has been developed employing a cobalt catalyst generated from Co(acac)2 and (R,R)‐Me‐Ferrocelane. A variety of terminal alkynes undergo this asymmetric transformation, affording the corresponding gem‐(borylsilyl)alkane products with high enantioselectivity (up to 98 % ee). This one‐pot reaction combines (E)‐selective hydrosilylation of alkynes and consecutive enantioselective hydroboration of (E)‐vinylsilanes with one chiral cobalt catalyst. This protocol represents the most straightforward approach to access versatile chiral gem‐(borylsilyl)alkanes from readily available alkynes with commercially available cobalt salt and chiral ligand. Enantioselective cobalt‐catalyzed sequential hydrosilylation/hydroboration of alkynes is developed to access synthetically versatile chiral gem‐(borylsilyl)alkanes with Co(acac)2 and (R,R)‐Me‐Ferrocelane. A range of terminal alkynes react to afford the corresponding gem‐(borylsilyl)alkanes with excellent enantioselectivity.