NMR elucidation of novel ligands derived from (R)-(+)-camphor

The complete NMR elucidation of five camphor-derived ligands is reported. 2D NMR techniques such as NOESY are used to assist in the determination of the orientation of the donor groups in space. The compounds were synthesized as ligands to be used in asymmetric catalysis. They represent the first instance where both donor groups are pendant on the C3 position of the camphor skeleton. The single crystal X-ray structure of one of the ligands was obtained and was helpful in determining the potential NOESY interactions within the molecule. For the other ligands, density functional theory (DFT) optimizations was performed [B3LYP/6-31+g(d)] to visualize possible NOE interactions.