Au-Mediated Enhanced Charge Separation in Cs 2 AgBiBr 6 /Au/UiO-66 for Photocatalytic Synthesis of Thiosulfonates

Thiosulfonates are versatile scaffolds in pharmaceuticals. Their synthesis, however, lacks sustainable methods, employing straightforward, benign, and readily available reagents. Herein, we disclose an eco-efficient synthetic strategy for the synthesis of thiosulfonates, which relies on the selective oxidation of thiols with air as a cost-free, environmentally benign oxidant, and Au-immobilized Cs 2 AgBiBr 6 /Au/UiO-66 heterojunction as the heterogeneous catalyst. This green protocol exhibits excellent scalability, facile operation, broad functional-group tolerance, and high chemoselectivity. Notably, metallic Au species serve as solid-state electron mediators, effectively facilitating the transfer of photogenerated charge carriers between the constituent photocatalysts. Mechanistic experimental studies indicate that this heterojunction possesses superior photocatalytic activity toward the selective activation of adsorbed O 2, thereby generating superoxide radicals ( • O 2 – ) as the main reactive oxygen species (ROS), which favors selective oxidation of thiols to form thiosulfonates.