A broad range of benzaldimines and ketimines can be hydrosilated efficientl
y, employing B(C6F5)(3) as a catalyst in conjunction with PhMe2SiH. Spectra
l evidence supports the intermediacy of a silyliminium cation with a hydrid
oborate counterion formed via abstraction of a hydride from PhMe2SiH by B(C
6F5)(3) in the presence of imines.