A practical copper‐catalysed oxidative radical alkylarylation of activated alkenes using AIBN (azobisisobutyronitrile) and related reagents has been developed. This has allowed the general incorporation of nitrile moieties into oxindoles by a cascade addition/C(sp2)–H cyclization process. This protocol demonstrates for the first time that DIAD (diisopropyl azodicarboxylate) can act as a new activator for the C(sp3)–H functionalization of acetonitrile instead of the usual Ag salts. The use of an inexpensive copper salt as the catalyst, the general access to primary and tertiary nitriles, as well as the air‐ and moisture‐tolerant reaction conditions make this protocol a highly attractive approach to cyano‐containing oxindoles. A copper‐catalysed oxidative radical alkylarylation of activated alkenes using azobisisobutyronitrileand related compounds has been developed. Oxindoles with primary, and tertiary nitrile moieties at the 3‐position were synthesized efficiently by a cascade addition/C(sp2)–H cyclization process.