Palladium single-atom/cluster cocatalyst supported on non-enzymatic browning glucose breaks the activity-selectivity trade-off in C(sp3)-H arylation

Using Pd homogeneous catalysts for direct C-H arylation is an attractive approach for synthesizing natural products and organic functional materials, but limitations in terms of cost and catalyst recovery could be alleviated by alternative heterogeneous catalysts. Here we demonstrated that a type of Pd single atoms/clusters cocatalyst localized on non-enzymatic browning glucose acted as a highly active and stable heterogeneous catalyst for direct coupling of a variety of inert C-H bonds with aryl iodides. Oriented to either C(sp³)-H or C(sp²)-H bond activation, designing targeted heterogeneous Pd catalyst was achieved by tailoring the structure of support in our catalyst. Multi-technique characterizations confirmed that the strong metal-support interaction (SMSI) between Pd single atoms/clusters with various coordination groups, especially imino (C = N), of support cans stabilize high valent (d electron-deficient) active Pd sites on support surface in reaction process and break the activity-stability trade-off in chelation-assisted C(sp³)-H arylation reaction via Pd^II/Pd^IV catalytic cycle.