A combination strategy of HPLC and boric acid modified β-CD polymer for super-efficiently separating chiral substances with O/N atoms in chiral and/or adjacent carbons

Background Cyclodextrins (CDs) and their derivatives have been widely used as chiral selectors in HPLC. However, many derivatized CDs lack specificity for certain drugs and often exhibit limited resolution. Furthermore, their synthesis typically involves complex multi-step procedures, hindering scalability and cost-efficiency. To overcome these limitations, this study aims to develop a simple and scalable boric acid-modified β-cyclodextrin polymer (BA-β-CDP), targeting chiral substances with O/N atoms in chiral and/or adjacent carbons. Results BA-β-CDP was synthesized on a large scale using inexpensive reagents and a random substitution strategy, avoiding tedious protection-purification steps. Structural and chromatographic compatibility was confirmed by nine characterization techniques. In HPLC using the chiral mobile-phase additive (CMPA) method, BA-β-CDP enabled the efficient separation of 25 racemates. Among them, 24 achieved complete or baseline separation, and 10 exhibited resolution (Rs) values > 10. Typical cases included bisoprolol (Rs = 48.19), propranolol (Rs = 45.50), chlorpheniramine (Rs = 38.36), and metoprolol (Rs = 20.26). Additionally, the material demonstrated excellent batch-to-batch reproducibility, recyclability, and reusability. Significance and novelty This work presents a practical and cost-effective chiral selector. The synergistic mechanism offers strong and specific recognition toward chiral substances with O/N atoms in chiral and/or adjacent carbons. This approach represents a novel strategy for efficient and economical HPLC-based enantioseparation using widely accessible materials and methods.