AIBN as an Electrophilic Reagent for Cyano Group Transfer.

AIBN is a convenient electrophilic cyanation reagent for transforming ArLi into ArCN under mild conditions. The addition/fragmentation cascade is controlled by Li···N chelation in which AIBN nitrogens assist in the nearly barrierless fragmentation into the desired ArCN product. Acidic C-H bonds in the fragmented byproduct partially consume ArLi by protonation. Density functional theory calculations and isotopic labeling probe the mechanism and explain the switch to substituted hydrazones in reactions with BuLi.