Estimation of Enantiomeric Excess Based on Rapid Host–Guest Exchange

Chiral molecules possess enantiomers that have non-superimposable chemical structures but exhibit identical nuclear magnetic resonance (NMR) spectra. This feature prevents the use of NMR spectroscopic methods for determination enantiomeric excesses (ee) chiral molecules, using simple mixtures their enantiomers. Recently, however, it was reported addition a symmetrical prochiral molecule (a reporter or host) into solution analyte can lead to estimation ee through interactions involving rapid exchange (guest) in formed host–guest complex. is due ee-dependent splitting resonances host based on averaging shift non-equivalency caused by presence guest. The mechanism not dependent diastereomer formation, and 1:1 complexes also show peak splitting. Prochiral capable sensing technique are now referred as so-called solvating agents (pro-CSAs). pro-CSAs represent family reagents distinct from commonly used derivatizing (where auxiliaries derivatize diastereomers) interact an asymmetric manner with enantiomers). pro-CSA unique since neither nor contains factors, making neutral respect chirality. Here, we review our recent work this matter several different nominally achiral receptor whose guest binding properties characteristics (especially regard spectroscopy) allow corresponding guests.