Scheme 2.

Scope I: Variation of the tertiary amine. Reaction conditions (0.10 mmol scale): B(C₆F₅)₃ (20 mol %), Me₃SiOTf (40 mol %), Ph₂SiH₂ (2 a, 2.0 equiv), and p‐xylene (0.80 mL) at 150 °C for 2 h. Yields are isolated yields. [a] See Table 1, entry 20. [b] Starting from N‐ethyl‐N‐(3‐methoxybenzyl)ethanamine (1 l). [c] 40 mol % of B(C₆F₅)₃, 80 mol % of Me₃SiOTf, and 4.0 equiv of Ph₂SiH₂ (2 a) used. Bn=benzyl, Cy=cyclohexyl.