Macrocyclic compounds as chiral solvating agents for phosphinic, phosphonic, and phosphoric acids
摘要:
Novel macrocyclic compounds, synthesized and used as chiral solvating agents for phosphinic, phosphonic, and phosphoric acids, are reported in this article. NMR (H-1 NMR and/or P-31 NMR) studies demonstrate that these acids have large nonequivalent chemical shifts in the presence of these macrocyclic compounds. Quantitative analyses of a series of the selected phosphinic acids with different enantiomeric purities show the high accuracy of this method. (c) 2007 Elsevier Ltd. All rights reserved.
Macrocyclic compounds as chiral solvating agents for phosphinic, phosphonic, and phosphoric acids
摘要:
Novel macrocyclic compounds, synthesized and used as chiral solvating agents for phosphinic, phosphonic, and phosphoric acids, are reported in this article. NMR (H-1 NMR and/or P-31 NMR) studies demonstrate that these acids have large nonequivalent chemical shifts in the presence of these macrocyclic compounds. Quantitative analyses of a series of the selected phosphinic acids with different enantiomeric purities show the high accuracy of this method. (c) 2007 Elsevier Ltd. All rights reserved.
The novel macrocyclic compounds 1-8 and acyclic compound 9 were designed and synthesized. (1)H NMR studies demonstrated that 1 and 2 were the best chiral solvating agents, and are effective for the determination of the enantiomeric excess of a wide range of alpha-chiral carboxylic acids. Large non-equivalent chemical shifts (up to 411.2 Hz) can be achieved in the presence of 1 and 2. Quantitative analyses of a series of mandelic acids with different enantiomeric purities demonstrate that 1 and 2 are excellent chiral solvating agents for carboxylic acids. (C) 2008 Elsevier Ltd. All Fights reserved.