Selective Hydrosilylation of 1-Alkynes Using Iridium Catalyst with Biphosphinine Ligand

The iridium-catalyzed hydrosilylation of alkynes in the presence of 4,4′,5,5′-tetramethylbiphosphinine (tmbp) has been explored. The hydrosilylation of alkynes in the presence of tmbp proceeds effectively to give β-(E)-vinylsilanes highly selectively in moderate to high yields, whereas a similar hydrosilylation in the absence of tmbp produces β-(Z)-vinylsilanes selectively. The stereoselectivity of these reactions suggests the importance of the electron-withdrawing properties of tmbp coordinated to iridium.