A simple protocol for determination of enantiopurity of amines using BINOL derivatives as chiral solvating agents via 1 H- and 19 F-NMR spectroscopic analysis.
Pooja ChaudharyGeeta Devi YadavSurendra SinghPublished in: RSC advances (2022)
A rapid and simple protocol for the determination of enantiopurity of primary and secondary amines was developed by using ( S )-BINOL/( S )-BINOL derivatives/( R )-1,1'-binaphthyl-2,2'-diyl hydrogenphosphate as chiral solvating agents via 1 H- and 19 F-NMR spectroscopic analysis. In this protocol, the analyte and chiral solvating agent were directly mixed in an NMR tube in chloroform- d and after shaking for 30 seconds the 1 H- and 19 F-NMR spectra were recorded, which affords well-resolved resonance peaks for both the enantiomers present in an analyte. The enantiomeric excess of 1,2-diphenylethylenediamine was determined and linear relationship with coefficient of R 2 = 0.9995 was observed. The binding constant and associated Δ G values were also calculated for diastereomeric complexes formed between both the enantiomers of analyte 5 with CSA ( S )-3a by using UV-visible spectroscopy.