POROUS ORGANIC LIGANDS (POLS) AS NEW PLATFORMS FOR PREPARING EFFICIENT HETEROGENEOUS CATALYSTS

摘要

Heterogeneous catalysts with good recyclabilities have been widely applied in industrial processes, but their activities are normally lower than those of homogeneous catalysts due to lower exposed degree of active sites to reactants. Organic ligands such as triphenylphosphine (PPh3) are of critical importance for synthesis of homogeneous catalysts used for organic transformation. However, their recycles are complicated. To solve this problem, the strategies such as supporting homogenenous catalysts have been developed, but their catalytic properties cannot compare with those of homogeneous catalysts. Here we show a generalized methodology for synthesizing a series of porous organic ligands (POLs) from solvothermal polymerization of vinyl-functionalized organic ligands. The POLs have high surface area, large pore volume, hierarchical porosity, superior thermal stability, high concentration of organic ligands, strong coordination ability, and quantitative yields. As a typical example, porous organic ligand of PPh3 (POL-PPh3) was synthesized from solvothermal polymerization of vinyl-functionalized PPh3 ligand in an autoclave. Interestingly, the POL-PPh3 supported Rh and Pd species as heterogeneous catalysts (M/POL-PPh3) exhibit unprecedentedly high activities and excellent recyclabilities in catalytic hydroformylation and Suzuki reactions. Particularly, the heterogeneous M/POL-PPh3 catalysts show even higher activities than corresponding homogeneous catalysts.