This paper describes the first direct approach to alkenyl nitriles from allylarenes or alkenes facilitated by an inexpensive homogeneous iron catalyst. Three C− H bond cleavages occur under the mild conditions during this process. Mechanistic studies indicate that the cleavage of the allyl C (sp3)− H bond is involved in the rate-determining step. This observation may provide an opportunity to achieve C (sp3)− H functionalization catalyzed by an iron ...