Optical Resolution of the Water-Soluble Ti4(embonate)6 Cages for Enantioselective Recognition of Chiral Drugs

• Published in: Chemistry of materials 2018-11, Vol.30 (21), p.7769-7775
• Main Authors: He, Yan-Ping, Yuan, Lv-Bing, Song, Jin-Shuai, Chen, Guang-Hui, Lin, Qipu, Li, Chunsen, Zhang, Lei, Zhang, Jian
• Format: Article
• Language: English
• ISSN: 0897-4756; 1520-5002
• DOI: 10.1021/acs.chemmater.8b03174

Synergetic optical resolution and chiral amplification of tetrahedral Ti4L6 cages by enantiopure coordination cations have been realized in this work. Anionic ΔΔΔΔ-[Ti4L6] and ΛΛΛΛ-[Ti4L6] cages (L = embonate) have been completely resolved by enantiopure Λ-[Mn­(1R,2R-DCH)3] and Δ-[Mn­(1S,2S-DCH)3] cations, respectively. Accordingly, two homochiral compounds (PTC-108­(Δ) and PTC-108­(Λ)) with three-dimensional supramolecular architectures were formed, containing larger diamondoid cages. Such an unusual resolution process clearly shows the stepwise transfer of homochirality from an enantiopure molecule to a resolved hydrogen-bonding aggregation and a final homochiral framework. Moreover, the separated homochiral Ti4L6 cage presents enantioselective recognition toward chiral organic and pharmaceutical molecules. This work opens a novel resolution-dependent homochiral framework construction approach, and it also takes the homochiral tetrahedral Ti4L6 cages with high solubility and stability into promising enantioselective application.