Visible-Light-Induced N-Heterocyclic Carbene-Catalyzed Single Electron Reduction of Mono-Fluoroarenes

Fluoroarenes are abundant and readily available feedstocks. However, due to the high reduction potentials of mono-fluoroarenes, their photoreduction remains a continuing challenge, motivating the development of efficient activation modes to address this issue. This report presents the blue light-induced N-heterocyclic carbene (NHC)-catalyzed single electron reduction of mono-fluoroarenes for biaryl cross-couplings. We discovered that under blue light irradiation, NHC/tBuOK combination could construct powerful photoactive architectures to promote single electron transfer for C-aryl-F bond reduction via forming highly reducing NHC radical anion. Notably, the strategy was also successful to reduce C-aryl-O, C-aryl-N, and C-aryl-S bonds for biaryl cross-couplings.

Automated summary

This report presents a study on the blue light-induced N-heterocyclic carbene (NHC)-catalyzed single electron reduction method for the synthesis of biaryl cross-coupling products. It was found that under blue light irradiation, the NHC/tBuOK combination could construct powerful photoactive architectures to promote single electron transfer for the reduction of C-aryl-F bonds, resulting in the formation of highly reducing NHC radical anions. It was also observed that this strategy successfully reduced C-aryl-O, C-aryl-N, and C-aryl-S bonds for biaryl cross-couplings.