19F NMR-Based Chiral Analysis of Organoboron Compounds via Chiral Recognition of Fluorine-Labeled Boronates with Cobalt Complexes

Abstract

This study aims to develop a method for the chiral analysis of organoboron compounds using nuclear magnetic resonance (NMR) spectroscopy. It addresses the longstanding challenge associated with these chiral organoboron compounds, which often require derivatization and pretreatment prior to chromatographic analysis. Our method utilizes tridentate ligands to facilitate effective ligand exchange and incorporates fluorine labels, allowing for the precise discrimination of ¹⁹F NMR signals. This is achieved in conjunction with a chiral cationic cobalt complex, serving as the chiral solvating agent. This approach provides reliable and rapid determination of enantiomeric excess in a wide range of organoboron compounds, featuring various functional groups, and establishes a universal tool for assessing the optical purity of these substances.