Pyridine-directed carbon–carbon single bond activation: Rhodium-catalyzed decarbonylation of aryl and heteroaromatic ketones

Demonstrating Synergistic Activity of Magnetic Iron Oxide Nano Photocatalyst for C-H Activation in Heterogeneous Phase

This report describes a dual catalytic approach for the versatile C-H arylation of arenes under photo-excitation at room temperature. The cooperative catalysis utilizes iron oxide magnetic nanoparticles (which mostly contain Fe3O4 along with some γ-Fe2O3) as the potential photocatalyst, which merges with the Pd-catalyzed C-H activation cycle for the reductive generation of aryl radical from aryl diazonium salt, revealing its photocatalytic activities. The method is applicable to a wide range of aryl coupling partners and different directing groups, demonstrating excellent productivity, nice co-operativity and recyclability. Adequate control experiments and mechanistic studies assisted in establishing the radical-based reaction mechanism for the C-H arylation occurring in the heterogeneous phase.