Use of chiral lanthanide shift reagents in the elucidation of NMR signals from enantiomeric mixtures of polycyclic compounds†

Abstract

¹ H and ¹³C NMR is used to study the effects on a set of racemic polycyclic compounds of the application of the chiral shift reagents europium(III) tris[3-(trifluoromethylhydroxymethylene)-(+)-camphorate] and europium(III) tris[3-(heptafluoropropylhydroxymethylene)-(+)-camphorate]. The study compares the chiral shift reagents to find the conditions resulting in optimum enantiomeric (ΔΔδ) and spectral resolution (Δδ). Of the two reagents Eu(hfc)₃ proved to be the more efficient. In addition, the effect of the achiral lanthanide shift reagent Eu(fod)₃, used in combination with the chiral lanthanide shift reagents, was investigated.