Preferential α-Hydrosilylation of Terminal Alkynes by Bis-N-Heterocyclic Carbene Rhodium(III) Catalysts.

We describe a bis-N-heterocyclic carbene rhodium(III) complex, featuring two trifluoroacetato ligands, that affords a variety of α-vinylsilanes in good yields by hydrosilylation of terminal alkynes. Selectivities around 7:1 α/β-( E) were reached, while the β-( Z) product was only marginally obtained. This example sharply contrasts with the β-( Z)-selectivity observed for its parent diiodido complex [ABSTRACT FROM AUTHOR]