Mizoroki–Heck reaction is one of the most common examples of using metal/ligand catalytic system to synthesize multiple substituted olefins by introducing an aromatic group to the C=C bond. The key issue of this reaction is to regulate the position where an aromatic group is inserted into olefins. The heterogenization of corresponding homogeneous catalysts is an attractive tool to achieve recyclable catalysts and highly selective organic synthesis. For heterogeneous catalysts, decreasing the size of catalytic metals can maximize the utilization of precious metals, and only a small number of metal particles with appropriate size distribution can be used as catalytic active sites, whereas particles of other sizes are either inert or cause side reactions. Dispersing metal active sites into isolated metal atoms (ions) is an effective strategy to solve these problems. In the past, many researchers were keen to synthesize novel catalysts, and then used various classical coupling, selective oxidation and other reactions to prove the superiority of the catalyst. The use of heterogeneous catalysts of atomic discrete levels to solve the problem of regioselectivity of organic reactions has so far been reported in sporadic cases.

They developed a novel precoordination/polymerization strategy to synthesize atomic dispersed mononuclear palladium catalysts. The catalyst can not only integrate the pore effect, electronic effect and discrete sites of the carrier material, but also effectively inherit the electronic and spatial effects of the ligand under homogeneous conditions. The oxidative Heck reaction of the regioselective electronic unbiased olefin can successfully achieved under this strategy. This is the first time that a recyclable and highly regioselective HECK reaction was achieved. This work is instructive for the precise synthesis and industrial production of natural products with cinnamyl skeletons or drug-based drug molecules.