Energy-Transfer-Enabled 1,4-Amino Migration and C–O Diradical Recombination for Norrish–Yang-Type Epoxidation

An energy-transfer-enabled photochemical strategy merges 1,4-nitrogen migration with Norrish-Yang-type epoxidation to achieve skeletal editing of molecular frameworks. This approach bypasses classical di-π-methane rearrangements, providing an oxidant-free and atom-economical route to epoxides via controlled C-O diradical recombination. The protocol accommodates >40 diverse substrates, including arenes, heterocycles, and bioactive motifs, enabling late-stage functionalization of complex architectures. Scalability is demonstrated through gram-scale synthesis (84% yield) and one-pot cascades. Mechanistic studies reveal a triplet energy-transfer pathway distinct from radical chain processes, with nitrogen migration directing regioselective diradical recombination.