N-Silylation of amines mediated by Et3SiH/KOtBu

Silylation of primary and secondary amines is reported, using triethylsilane as the silylating reagent in the presence of potassium tert-butoxide (KOtBu). The reaction proceeds well in the presence of 0.2 equiv of KOtBu. In competition experiments, aniline is selectively silylated over aliphatic amines. Computational studies support a catalytic mechanism which is initiated by KOtBu interacting with the silane to form KH and silylated amine. The KH then takes over the role of base in the propagation of the cyclic mechanism, and deprotonates the amine. This reacts with R3SiH to afford the product R3SiNR’R” and regenerate KH.