Novel porous organic polymer supported chloramphenicol base derivatives: A highly enantioselective, recyclable heterogeneous organocatalyst for asymmetric desymmetrization reaction

A series of porous organic polymer (POP) supported chloramphenicol base (ANP) derived catalysts are designed and prepared. A deep study of the polymerization condition, including reaction temperature, the ratio of monomers and the option of polymetric position on ANP scaffold was conducted. The best catalyst, poly-Ia, performs high stereoselectivity and catalytic activity (up to 98% yield and 99% ee) in asymmetric alcoholysis of meso-cyclic anhydride with the possibility of high recyclability (at least 10 times). More importantly, poly-Ia even obtains higher enantioselectivity compared to its homogeneous monomer, which overcomes the common drawback of heterogeneous organocatalysts, for instance, lower selectivity and diminished reactivity.