Facile Synthesis of Porphyrin Based Covalent Organic Frameworks via an A₂B₂ Monomer for Highly Efficient Heterogeneous Catalysis

Abstract

A new porphyrin covalent organic framework (A2B2-Por-COF) was readily constructed via self-polycondensation of an A2B2 porphyrin monomer. In contrast to the previously reported porphyrin COFs prepared by co-condensation method, this A2B2 monomer (i.e., two-in-one) strategy provides identically equal stoichiometry of the two different functional groups, and highly crystalline COFs can be obtained much more easily without exhaustive screening of synthetic conditions as used before. Furthermore, comprehensive studies indicated that the A2B2-Por-COF served as efficient heterogeneous catalysts for selective oxidation of sulfides (up to 98% conversion efficiency and selectivity of >99%) and Knoevenagel condensation (>99% conversion) with excellent stability and recyclability.