Metallaphotoredox C-O and C-N Cross-coupling using Donor-Acceptor Cyanoarene Photocatalysts

Herein we report a study on the use of donor-acceptor cyanoarenes as photocatalysts for C-O and C-N coupling reactions promoted by nickel. We found that some of these stable and readily available organic compounds can replace the precious metal photocatalysts originally employed in these methodologies. After reaction optimization, the application scope of the best performing dyes was investigated and found to cover several nucleophiles (alcohols and amines) and aryl bromides. Control experiments, fluorescence quenching studies and examination of yield trends suggest that both etherification and amination probably proceed via a dark NiI/NiIII-catalytic cycle initiated and sustained by a photoredox cycle involving the organic photocatalysts.