Expanding Perchlorate Use for C–H Oxidative Transformations: A Tandem Photo- and Iron-Catalytic Strategy

We report an iron-catalyzed, light-driven method to enable the use of perchlorate (ClO₄^–) to promote C–H oxygenation reactions. In comparison to thermal reactions, introduction of an anthraquinone (AQ) photocatalyst provided distinct reaction outcomes that are proposed to be facilitated by distinct hydrogen atom transfer reactivity. Acyclic substrates such as di- and triphenylmethane were oxygenated to form ketones or alcohols, while benzylic substrates containing S or N heteroatoms underwent C(sp³)–X (X = S or N) oxidative cleavage to form aldehydes. Appended aniline hydrogen bonds (H-bonds) within the ligand’s secondary sphere serve a primary role to facilitate both reactions.