Chiral covalent organic frameworks synthesized via a Suzuki-Miyaura-coupling reaction: enantioselective recognition of d/l-amino acids

Considering chiral covalent organic frameworks (COFs) featuring the intriguing properties of porous organic materials, chiral recognition, and separation, the design and synthesis of chiral COFs with high crystallinity has remained a daunting challenge. A brominated functionalized COF (COF-Br) with high crystallinity and stability was synthesized. Using the post-synthetic modification strategy of the Suzuki-Miyaura cross-coupling reaction, a chiral COF (COF-l-Phe) was successfully constructed by combining COF-Br and the chiral functional groups of 4-borono-l-phenylalanine. The chiral recognition ability of COF-l-Phe was verified using an experimental adsorption model. Furthermore, COF-l-Phe-modified capillary columns have been used for the separation of racemic phenylalanine using capillary electrochromatography. This work will provide guidance for constructing chiral COFs for chirality related applications.