Unprecedented Transformation of a Directing Group Generated In Situ and Its Application in the One-Pot Synthesis of 2-Alkenyl Benzonitriles

摘要

An unprecedented protocol for the transformation of benzoyl azides into benzonitrile derivatives via iminophosphoranes generated in situ is described. The strategy was successfully applied to the de-novo synthesis of 2-alkenylated benzonitrile derivatives from benzoyl azides through ortho CH activation/alkenylation followed by subsequent rearrangement. The salient features of this protocol involve incorporation of two important functionalities through cyanation and olefination in one pot under mild reaction conditions by using a less expensive Ru catalyst. The mechanism was established by isolating and characterising (using (PNMR)-P-31) an intermediate with two ortho functionalities, iminophosphorane and olefin, under specific reaction conditions.