Photo- or Electrochemical Cyclization of Dienes with Diselenides to Access Seleno-Benzo[b]azepines

A cascadeselenylation/cyclization of dienes with diselenides hasbeen realized under visible-light irradiation or electrolysis conditions.Employing O-2 or electricity as a "green"oxidant, this protocol provides a green and efficient method for anarray of biologically important seleno-benzo-[b]-azepinederivatives in moderate to good yields. The direct sunlight irradiationand gram-scale reaction render the approach practical and attractive.