Electrochemical\nDehydrogenative [3 + 2]/[5 + 2] Annulation\nof <i>N</i>‑Arylacrylamides with γ,σ-Unsaturated\nMalonates via Direct C(sp<sup>3</sup>)–H/C(sp<sup>2</sup>)–H\nFunctionalization

Herein, we introduce an electrochemical dehydrogenative\n[3 + 2]/[5\n+ 2] annulation of easily available <i>N</i>-arylacrylamides\nwith γ,σ-unsaturated malonates through C(sp<sup>3</sup>)–H/C(sp<sup>2</sup>)–H functionalization. The employment\nof inexpensive ferrocene as the redox catalyst allows access to diverse\nbenzo[<i>b</i>]azepin-2-ones in moderate to excellent yields\nwithout stoichiometric oxidants. This protocol features broad substrate\nscope and excellent selectivity, and mechanistic studies indicated\nthat the reaction proceeded through the oxidation of a C(sp<sup>3</sup>)–H bond to generate an alkyl radical, radical addition across\nthe CC bond, [3 + 2]/[5 + 2] annulations, and C(sp<sup>2</sup>)–H functionalization cascades.