C–C and C–Heteroatom bonds photocatalyzed and photoinitiated by carbonyls

In the last 15 years, literature examples of applications of photochemical reactions that are promoted by small organic molecules, the so-called photoorganocatalysts, are increasing exponentially. These small organic molecules have proven to be an excellent alternative to the use of metal-center complexes that perform photoredox reactions. An important class of organic molecules that can absorb light and transform it to forge new bonds are carbonyl compounds. These molecules can perform complex chemical transformations, mainly through three distinct pathways: Hydrogen Atom Transfer (HAT), Single Electron Transfer (SET) or Triplet Energy Transfer (EnT). Through these different reactivities, photoorganocatalysts can overcome the challenges of polar chemistry, leading to the formation of new C–C and C–heteroatom bonds. Herein, we will focus on the photochemical reactions promoted by specific carbonyl compounds to form C–C and C–heteroatom bonds during the last six years.