Detection and Chiral Recognition of α‐Hydroxyl Acid through 1H and CEST NMR Spectroscopy Using a Ytterbium Macrocyclic Complex. (30th October 2019)

• Record Type: Journal Article
• Authors: He, Haonan; Zhao, Kelu; Xiao, Long; Zhang, Yi; Cheng, Yi; Wan, Sikang; Chen, Shizhen; Zhang, Lei; Zhou, Xin; Liu, Kai; Zhang, Hongjie
• Is Part Of: Angewandte Chemie. Volume 131:Number 50(2019)
• Page Start: 18454
• Page End: 18457
• Publication Date: 2019-10-30
• Subjects: α-Hydroxysäuren -- CEST -- Chirale Erkennung -- NMR-Spektroscopie -- Yb-Komplexe; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201912072
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: Chiral α‐hydroxyl acids are of great importance in chemical synthesis. Current methods for recognizing their chirality by 1 H NMR are limited by their small chemical shift differences and intrinsic solubility problem in organic solvents. Herein, we developed three YbDO3A(ala)3 derivatives to recognize four different commercially available chiral α‐hydroxyl acids in aqueous solution through 1 H NMR and chemical exchange saturation transfer (CEST) spectroscopy. The shift difference between chiral α‐hydroxyl acid observed by proton and CEST NMR ranged from 15–40 and 20–40 ppm, respectively. Our work demonstrates for first time, that even one chiral center on the side‐arm chain of cyclen could set the stage for rotation of the other two non‐chiral side chains into a preferred position. This is ascribed to the lower energy state of the structure. The results show that chiral YbDO3A‐like complexes can be used to discriminate chiral α‐hydroxyl acids with a distinct signal difference. Abstract : Drei YbDO3A(ala)3 ‐Derivate dienen als Reagenz zur chiralen Erkennung von α‐Hydroxysäuren. Die Erkennung basiert auf Protonen‐ und CEST‐NMR‐Spektroskopie in wässriger Umgebung. Die Empfindlichkeit lag zwischen 15 und 40 ppm.