A magnetically isolable iron oxide nanoparticles is introduced as an efficient heterogeneous photocatalyst for non‐directed C‒H arylation employing aryl diazonium salts as the aryl precursors. This first‐row transition metal‐based photocatalyst revealed versatile activities and is applicable to a wide range of substrates, demonstrating brilliant efficacy and superior recyclability. Detailed catalytic characterization describes the physical properties and redox behavior of the Fe‐catalyst. Adequate control experiments helped to establish the radical‐based mechanism for the C‒H arylation.
A magnetically isolable iron oxide nanoparticles is introduced as an efficient heterogeneous photocatalyst for non‐directed C‒H arylation employing aryl diazonium salts as the aryl precursors. This first‐row transition metal‐based photocatalyst revealed versatile activities and is applicable to a wide range of substrates, demonstrating brilliant efficacy and superior recyclability. Detailed catalytic characterization describes the physical properties and redox behavior of the Fe‐catalyst. Adequate control experiments helped to establish the radical‐based mechanism for the C‒H arylation.