Simple protocols for NMR analysis of the enantiomeric purity of chiral primary amines.
A simple three-component chiral derivatization protocol for determining the enantiopurity of chiral primary amines by 1H NMR spectroscopic analysis is described here. The method involves condensation of the amines with 2-formylphenylboronic acid and enantiopure 1,1'-bi-2-naphthol. This approach affords a mixture of diastereoisomeric iminoboronate esters whose ratio can be determined by the integration of well-resolved diastereotopic resonances in their 1H NMR spectra, thus enabling the enantiopurity of the parent amine to be determined easily. The protocol, as described, takes less than 90 min to complete.
Pérez-Fuertes
Yolanda
Y
Department of Chemistry, University of Bath, Bath BA2 7AY, UK.
Kelly
Andrew M
AM
Fossey
John S
JS
Powell
Magdalena E
ME
Bull
Steven D
SD
James
Tony D
TD
D000588:Amines / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D001547:Benzaldehydes / Q000737:chemistry; D001596:Benzylamines / Q000737:chemistry / Q000378:metabolism; D001897:Boronic Acids / Q000737:chemistry; D004952:Esters / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D015394:Molecular Structure; D009284:Naphthols / Q000737:chemistry
C532809:2-formylphenylboronic acid; D000588:Amines; C406944:BINOL, naphthol; D001547:Benzaldehydes; D001596:Benzylamines; D001897:Boronic Acids; D004952:Esters; D009284:Naphthols; C412332:1,1'-bi-2-naphthol