Visible-light-induced triple catalysis for a ring-opening cyanation of cyclopropyl ketones.

An unprecedented triple catalytic, general ring-opening cyanation reaction of cyclopropyl ketones for the construction of γ-cyanoketones is described. The key is to merge photoredox catalysis with Lewis acid catalysis and copper catalysis to enable the selective cleavage of the carbon-carbon bonds and the selective coupling of the generated radical and cyanide anion.