Photogenerated electrophilic radicals for the umpolung of enolate chemistry

The use of enolate chemistry is the election choice when a CC bond formation is required exploiting the acidity of carbonyl derivatives in the α position. However, a reversed-polarity equivalent of enolate chemistry is emerging making use of electrophilic radicals having a radical site in place of a negative charge in the same α position. Visible light photoredox catalysis is becoming the ideal tool for the generation of these radicals thus allowing their wide application in several synthetic routes. Aim of this review is to collect recent examples of the chemistry of photogenerated electrophilic radicals for the forging of new CC or other CY bonds.