Pd-catalyzed Cyanation of Arenediazonium Tetrafluoroborate with 2-(piperidin-1- yl)acetonitrile as CN Source Under Mild Conditions
Abstract The present study reports a new organic CN reagent, 2-(piperidin-1-yl)acetonitrile which could cyanate commercially aryldiazonium tetrafluoroborate with Palladium as catalyst under mild reaction conditions. A large substrate scope for Pd-catalyzed cyanation of aromatic diazonium substrates was found, yielding cyanated products in medium to high amounts (50%‒88%). An attempt is also made to modify the method for preparation of etravirine and strategies for the transformations of 2-cyanoindole which are used as anti-AIDS, NMDA receptor antagonists and have high potential against mutant HIV strains. The mechanism of this Pd-catalyzed cyanation of aryldiazonium tetrafluoroborate involved CN ions construction was proved by paper indicator strategy. However, Pd/(Me3Si)2 system has been identified to cleave C − CN bond at low temperature and transferred the CN group to aryl ring of diazonium substrate in one pot.