Chemical and electrocatalytic cascade cyclization of Guareschi imides: ‘one-pot’ simple and efficient way to the 2,4-dioxo-3-azabicyclo[3.1.0]hexane scaffold

Electrolysis of Guareschi imides in alcohol in an undivided cell in the presence of sodium bromide as mediator results in fast and efficient cyclization with formation of a substituted 3-azabicyclo[3.1.0]hexane system in 80–98%. The fast (30 min) electrocatalytic reaction proceeds smoothly under neutral and mild conditions. The use of electrocatalysis in a cascade cyclization reaction is an efficient approach to the medicinally relevant 3-azabicyclo[3.1.0]hexane scaffold avoiding the inconvenient direct use of molecular halogen or halogenated substrates, and is also beneficial from the viewpoint of diversity-orientated large-scale processes.