Nickel/Photoredox Dual Catalytic Cross-Coupling of Alkyl and Amidyl Radicals to Construct C(sp3)-N Bonds

The construction of C(sp(3))-N bonds via direct radical-radical cross-coupling under benign conditions is a desirable but challenging approach. Herein, the cross-coupling of alkyl and amidyl radicals to build aliphatic C-N bonds in a concise, mild, and oxidant-free manner is implemented by nickel/photoredox dual catalysis. In this protocol, the single electron transfer strategy is successfully employed to generate N- and C-centered radicals from sulfonyl azides/azidoformates and alkyltrifluoroborates, respectively. The photocatalyst-induced triplet-triplet energy-transfer mechanism, however, might not be applicable to this reaction. The oxidative quenching pathway of the excited photocatalyst (Ru-II/*Ru-II/Ru-III/Ru-II) combined with a possible Ni-I/Ni-II/Ni-III/Ni-I catalytic cycle is proposed to account for the nickel/photoredox dual-catalyzed C(sp(3))-N bond formation based on synergistic experimental and computational studies.

Automated summary

The study demonstrates the successful construction of aliphatic C-N bonds via nickel/photoredox dual catalysis, utilizing single electron transfer and photocatalyst-induced mechanisms. Synergistic experimental and computational studies propose a reaction pathway involving oxidative quenching of the photocatalyst and a potential Ni-catalyzed cycle for C(sp(3))-N bond formation.