B(C 6 F 5 ) 3 -Catalyzed Reductive Denitrogenation of Benzonitrile Derivatives.

A B(C 6 F 5 ) 3 -catalyzed reductive denitrogenation of aromatic nitriles is reported, achieving the metal-free transformation of a cyano into a methyl group in a single synthetic operation. Tris(phenylsilyl)amine is liberated as the nitrogen-containing byproduct. On the basis of control experiments as well as a nuclear magnetic resonance spectroscopic analysis, an S N 1-type mechanism involving a trisilylammonium ion as a key intermediate is proposed.