The Merger of Photoredox and Cobalt Catalysis

In the past decade, synthetic chemists have discovered the outstanding generality and potential of visible-light-driven photoredox catalysis, which converts visible light into chemical energy, realizing numerous transformations of small molecules. The current state-of-the-art strategy in photoredox catalysis, combining photoredox and transition-metal catalysis, has received considerable attention in organometallic chemistry. In parallel with the rapid development of nickel/photoredox and copper/photoredox catalysis, cobalt/photoredox catalysis has emerged as a distinct new option in this area. This short review covers the general strategy, characteristics compared with other metallaphotoredox systems, and future perspectives of cobalt/photoredox catalysis. To our knowledge, this is the first review encompassing the general combination of cobalt and photoredox catalysis in synthetic chemistry.