Reactivities of Photoredox Generated Nickel‐Nucleophilic Reactive Organometallic Species

Abstract

Dual photoredox catalysis has revolutionized the field of cross‐coupling reactions, enabling the discovery of numerous highly efficient reactions. This breakthrough is attributed to the exceptional combination of nickel catalysis with photoredox catalysis. Nickel exhibits both oxidative addition and reductive elimination processes, and a wide range of oxidation states (ranging from I to IV) accessible within a single catalytic cycle. Furthermore, nickel complexes are capable of catalyzing various processes through radical mechanisms. The latest feature has proven to be incredibly potent in facilitating the formation of new C–C and C–X bonds (X = H, O, S, N). The powerful combination of photoredox and nickel catalysis reveals an expansive domain of unexplored possibilities. It offers unparalleled opportunities for improving reactions and exploring innovative pathways. Under photoredox conditions, it is possible to form nucleophilic reactive organometallic intermediates, useful in reaction with electrophiles. We have devoted a research program towards the rediscovery and use of organometallic reagents, introduced by Corey, Hegedus, and Semmelack many years ago. The results unveiled the extraordinary capabilities of photoredox catalysis, enabling the creation and efficient utilization of potent nucleophilic organometallic reagents under mild conditions, free from the need for strong bases or stoichiometric metal reductants.

Photoredox/Nickel Dual-Catalyzed Allylation of Aldehydes with Allylic Alcohols and Mechanistic Insights in the Presence of CO2

“…Over the past decade, the integration of photoredox catalysis and transition-metal catalysis has emerged as a significant research orientation in the synthetic methodology owing to its mild and credible reaction conditions . Additionally, considerable attention has been directed toward nucleophilic allylation utilizing latest and classical allyl precursor via metallaphotoredox catalysis . The transformation from classical organometallic allylation reaction to a photoredox/transition-metal dual-catalyzed fashion was first realized by Glorius et al and Kanai et al, with the ingenious alliance of photoredox and Cr(II) catalysis.…”