Opportunities and challenges of visible-light-driven triple-synergistic catalysis

In recent years, visible-light photoredox catalysis has been esteemed as one sustainable and efficient catalytic strategy. The rational combination of visible-light photoredox catalysis with transition-metal catalysis and organocatalysis provides new paradigms for organic synthesis; meanwhile, this triple-synergistic catalysis enriches the synthetic scope of transition-metal catalysis and organocatalysis, with which a series of novel organic transformations have been realized. This new strategy generally enables bond constructions that would not otherwise be possible or influences the enantioselectivity or site selectivity. This perspective summarizes the recent developments of the triple-catalysis system of the combination of photocatalysis with other catalytic modes for C-C and C-X bonds forming. The opportunities and challenges faced by triple-synergistic catalysis aim to attract more momentum in aspects of updating catalytic systems, designing new reactions, and studying the mechanism in multiple catalysis. Challenges and opportunities •The compatibility of multiple catalytic systems is still the first issue in the development of triple catalysis. In addition, for complex molecules containing multiple reaction sites, the regioselectivity of the reaction is still a problem. •The high reactivity of the radical reaction determines that the enantioselective synthesis of the target product is an inherent challenge. •The research on the reaction mechanism of triple catalysis involving visible-light photocatalysis mainly focuses on theoretical calculations, and the experimental evidence is relatively weak. The triple catalysis involving visible-light photocatalysis shows obvious advantages in the construction of C-C bonds and C-heterobonds and miscellaneous reactions. It enriches the reaction types and application scope of traditional transition-metal catalysis and organic catalysis. Although the triple catalysis of visible light has achieved good results, it still faces some challenges.