Nickel-photoredox catalysis: merging photons with metal catalysts for organic synthesis.

Nickel (Ni)-catalyzed photoredox reactions are revolutionary methods that transform organic synthesis, enabling highly efficient and selective reactions under mild conditions. The synergy between Ni catalysis and photoredox catalysis is efficacious in activating inert bonds, creating potential reaction pathways, and accessing otherwise inaccessible molecular architectures. This review provides a detailed overview of advances in nickel/photoredox dual catalysis, with particular reference to insights into mechanisms and reaction scope. Among the key developments are enantioselective allyl carbamates, -phenethylamines, and aryl--nucleosides, as well as methods for hydroalkylation, aryl alkylation, and C-N/C-O coupling reactions. The single electron transfer (SET) processes and versatile oxidation states of Ni, coupled with organic and metal-based photocatalysts, underpin the dual catalytic cycles. Such innovations render Ni-catalyzed photoredox reactions more sustainable and cost-effective, providing a strong foundation for future advances in this area.