Enhancement of Catalytic Activity in Epoxide Hydration by Increasing the Concentration of Cobalt(III)/Salen in Porous Polymer Catalysts

Graphical Rational design : A porous organic polymer with a very high salen concentration is rationally synthesized from the self-polymerization of a salen-based monomer. After the loading of Co 3+ , the heterogeneous catalyst shows even better properties than the homogeneous version in the catalytic hydration of epoxides because of the enrichment of activated reactants. The rational design of catalytic materials from the reaction characteristics is expected to be a useful strategy to create highly efficient catalysts. Herein, according to a well-established reaction pathway of epoxide hydration catalyzed a dual-molecular system of Co 3+ /salen in which a high concentration of active sites is favorable to enhance the activity, we provide an alternative way to prepare a highly efficient heterogeneous catalyst with a high concentration of Co 3+ /salen from the polymerization of vinyl-functionalized salen monomers followed by the loading of Co 3+ species (Co 3+ /POL-salen). Co 3+ /POL-salen has a hierarchical porosity and an extraordinary hydrothermal stability. Importantly, catalytic tests in epoxide hydration demonstrate that Co 3+ /POL-salen affords excellent high activities, which are even better than those of the homogeneous version. This phenomenon is related to the very high concentration of Co 3+ /salen in the catalyst. In addition, this catalyst can be recycled readily because of its excellent hydrothermal stability.