Halogenation/Cyanation vs. Cyanation/Halogenation of Alkenes Using ICN and BrCN.

In a tris(pentafluorophenyl)borane [B(C6F5)3]‐catalyzed reaction of alkenes with cyanogen halides (XCN), BrCN proceeds in a cyanation/bromination manner, in which a cationic CN character is realized. The reaction using ICN switched the mode to iodination/cyanation for enamide substrates and electron‐enriched styrenes. The origin of the iodination/cyanation is the B(C6F5)3‐enhanced σ‐hole generated on ICN. [ABSTRACT FROM AUTHOR]