Catalyst-free alkoxysulfonyl radical generation unlocks divergent sulfonylative cyclizations: electrochemical access to sulfonate-functionalized phenanthridines and spiro-γ-lactams

A unified electrochemical strategy delineates bisulfite radical-enabled sulfonylative heteroannulation and spirolactamization, furnishing sulfonate-functionalized phenanthridines and spiro-γ-lactams under constant-current electrolysis in an undivided cell at room temperature. Anodic sulfite oxidation generates radicals that drive cascade cyclizations, affording S(VI)-functionalized heterocycles from simple starting materials.