An Effective Strategy in the Creating of Asymmetric MOFs for Chirality Induction: Chiral Zr-based MOF in Enantioselective Epoxidation
Recently the construction of chiral MOFs (CMOFs) as a challenge is very difficult and complex. For the first time, we synthesized a chiral Zr-based MOF with L-tartaric acid by solvent assisted ligand incorporation (SALI). We showed that a CMOF can be postsynthetically generated by the simple method: incorporated chiral carboxylic groups on the achiral NU-1000. The post-synthesized chiral NU-1000 was used as an asymmetric support for producing a chiral catalyst with molybdenum catalytic active centers as Lewis acid sites. Enantioselective epoxidation of various prochiral alkens to epoxids by using [C-NU-1000-Mo] is comparable to the other asymmetric homogeneous and heterogeneous catalysts along with high enantiomeric excess and selectivity to epoxide (up to 100%). The CMOF could be reused in the styrene oxidation after five cycles without substantial deterioration in the CMOF crystallinity or catalytic performance after five cycles.