Visible light induced cyclopropanation of dibromomalonates with alkenes via double-SET by photoredox catalysis

We report herein a visible light induced generation of a carbanion via double-SET and its application in cyclopropanation of alkenes. This new synthetic approach to form cyclopropane derivatives was conducted under mild conditions, using sunlight in open air, showing the features such as environmental benignness and an easy to handle procedure.