Photoinduced Mn catalysis for efficient platform for C-heteroatom bond coupling of aryl halides

Photoinduced transition metal catalysis offers innovative strategies for fostering novel chemical reactions and improving established ones. In this work, we present a highly efficient, photoinduced Mn(II)-bipyridine catalyzed C-N, C-O and C-S coupling reaction between aryl halides-particularly less reactive aryl chlorides-and nucleophiles containing nitrogen, oxygen, and sulfur. This protocol does not need an external photocatalyst, as the single Mn(II)-bipyridine complex simultaneously serves as both the light-harvester and the metal catalyst. This method exhibits excellent substrate scope, covering eight different nitrogen sources for C-N coupling, as well as C-O coupling with alcohols, C-S coupling with thiophenols, encompassing more than 150 examples, with yields reaching up to 94%. Mechanistic studies suggest that this reaction may be initiated and sustained by the Mn(I) species through the photoinduced homolysis of the catalyst precursor bipyridine-Mn(II)(OAc)₂, likely proceeding via a Mn(I)/Mn(III) catalytic cycle.