Consecutive β,β′‐Selective C(sp(3))−H Silylation of Tertiary Amines with Dihydrosilanes Catalyzed by B(C(6)F(5))(3)

Tris(pentafluorophenyl)borane has been found to catalyze the two‐fold C(sp(3))−H silylation of various trialkylamine derivatives with dihydrosilanes, furnishing the corresponding 4‐silapiperidines in decent yields. The multi‐step reaction cascade involves amine‐to‐enamine dehydrogenation at two alkyl residues and two electrophilic silylation reactions of those enamines, one inter‐ and one intramolecular.