Nickel-catalyzed group transfer of radicals enables hydrocyanation of alkenes and alkynes

Transfer functionalization has emerged as an efficient strategy for the synthesis of organic functional compounds. This article reports a new cleavage model of functional radicals, which enables transfer hydrocyanation of alkenes, dienes, and alkynes. By introducing readily available, low-toxic azobisisobutyronitrile (AIBN) as a hydrocyanation reagent, we have developed a practical and economic method for the preparation of nitrile compounds. Mechanistic studies showed that the hydrocyanation proceeds through a relay transfer of the cyano group and the hydrogen atom of cyanoisopropyl radicals generated by pyrolysis of AIBN. The reaction represents the first example of group transfer of α-functional radicals.