The present study describes the one-pot palladium-catalyzed cyanation of commercially
available aryldiazonium tetrafluoroborate derivatives with 2-(piperidin-1-yl)acetonitrile
(an organic cyano reagent) under mild conditions. This process utilizes a Pd/(Me3Si)2 system and is applied to a wide scope of aromatic diazonium substrates to give the
corresponding nitrile-containing products in moderate to high yields (59–92%). This
methodology is employed for the preparation of etravirine, a drug used for the treatment
of HIV, and for transformations of 1H-indole-2-carbonitrile into compounds that are used as a NMDA receptor antagonists
and that have high potential against mutant HIV strains. The mechanism proposed for
this Pd-catalyzed cyanation involves cyanide ions, as confirmed using indicator paper.
Key words
C–CN cleavage - cyanation - Pd catalyst - coupling reaction - organic CN source