Regiocontrol in the cobalt-catalyzed hydrosilylation of alkynes

Hydrofunctionalizations of unsaturated hydrocarbons are key
strategies for the synthesis of functionalized building blocks. Here,
we report highly versatile cobalt-catalyzed hydrosilylations of alkynes
that operate with minute amounts of the inexpensive, bench-stable
pre-catalyst Co(OAc)24H2O under mild conditions (0.1–1 mol%, THF,
r.t., 1 h). Near-perfect regiocontrol/stereocontrol was induced by the
choice of the ligand: bidentate phosphines afforded (E)-b-vinylsilanes;
a-vinylsilanes formed with bipyridine ligands.