Low-Cost Hypercrosslinked Polymers by Direct Knitting Strategy for Catalytic Applications

Direct knitting of nucleophilic arene monomers in the presence of electrophilic cross-linker, like formaldehyde dimethyl acetal, is proven to be a cost-effective and versatile method for the synthesis of porous organic polymers. The resulting hypercrosslinked polymers (HCPs) are featured by hierarchical porous structure, high surface area, and pore volume. Coordinating functional groups can be easily installed with this method into the rigid aryl network. Direct knitting to HCPs has therefore been widely used in preparing heterogeneous solid catalysts. Wise selection of monomers with rational design of 3D structure and the synergy between the HCP support and the catalytically active species often lead to high efficiency of tailor-made catalysts without sophisticated operations. On account of all these excellent properties, enthusiasm of researchers to use HCPs in catalysis is increasing rapidly. This review documents the necessity, feasibility, and the great contributions of using HCPs as invaluable tools for catalysis research, and summarizes state of the art of this chemistry. Similar type catalysts obtained by one-step Scholl reaction are also included in this review.