Overcoming limitations in dual photoredox/nickel-catalysed C–N cross-couplings due to catalyst deactivation

Dual photoredox/nickel-catalyzed C–N cross-couplings face challenges with low yields for electron-rich aryl halides due to catalyst deactivation by nickel-black formation and reproducibility issues. We propose two strategies to address these challenges: using a broad-spectrum-absorbing carbon nitride photocatalyst to control reductive elimination rates and prevent nickel-black formation during cyclic secondary amine and aryl halide couplings, and employing high-concentration conditions to enhance oxidative addition rates, enabling coupling of primary amines with electron-rich aryl halides using stabilizing additives for low-valent nickel intermediates. These protocols ensure reproducible, selective C–N cross-couplings of electron-rich aryl bromides, extendable to electron-poor aryl chlorides.