Lewis Acid/Base Au–Mn Pairs in Metal Nanoclusters for Enhanced Photocatalytic C(sp ² )–H Arylation

Integrating polar bimetallic active sites on the metal nanocatalysts for advanced cross‐coupling reactions holds great promise, yet is challenging. Here, we report the successful synthesis of Lewis acid/base bimetallic nanocluster Au 20 Mn 2 and demonstrate its catalytic potential in visible‐light‐driven direct C(sp 2 )–H arylation of aryl halides. The cluster comprises two Au 11 incomplete icosahedra fused into an Au 20 kernel, which features four uncoordinated gold atoms in a rhombic pattern and is protected by two bridged Mn(CO) 5 moieties. Experimental and computational studies disclose that the Mn sites function as electron donors, facilitating polarized Au(δ + )−Mn(δ − ) bonds with pronounced [Mn(CO) 5 ] − →Au 20 σ donation interactions. The Lewis acid/base pair bestows Au 20 Mn 2 with exceptional photocatalytic performance in C(sp 2 )–H arylation of various substituted (hetero)aryl bromides and chlorides with electron‐rich‐to‐deficient arenes under mild conditions. This protocol boasts high functional group tolerance, supports gram‐scale synthesis, and is applicable to both the late‐stage functionalization of complex molecules and the targeted synthesis of bioactive products. Mechanism analyses uncover that the collaboration between the gold‐involved single electron transfer activation of aryl halides and Mn π‐base activation of arenes accounts for the remarkable efficiency of this system.