Photocatalysis in Organic Synthesis – Past, Present, and Future

The use of visible light as a catalyst in organic reactions has developed greatly in the last decade as a result of the increasing urge to implement energy‐efficient and green processes and through the availability of light‐emitting diodes as convenient sources of visible light. Although photoredox reactions with visible light have been used in a broad range of transformations, the mechanism behind these reactions needs to be understood to design better catalytic systems.