Regiodivergent and Stereoselective Hydrosilylation of 1,3-Disubstituted Allenes.

Methods for the highly stereoselective and regiodivergent hydrosilylation of 1,3-disubstituted allenes have been developed. The synthesis of E allylsilanes is accomplished with palladium NHC catalysts, and trisubstituted Z alkenylsilanes are accessed with nickel NHC catalysts. Unsymmetrically substituted allenes are well tolerated with nickel catalysis and afford Z alkenylsilanes. Evidence for a plausible mechanism was obtained through an isotopic double-labeling crossover study.