A novel use of cobalt(III) meso‐tetraphenylporphyrin as a chiral shift reagent

The NMR spectra of the diastereomeric complexes formed by the coordination of nitrogenous enantiomeric bases with cobalt(III) meso ‐tetraphenylporphyrin (CoTPP) allow the immediate differentiation of these complexes. The spectra are interpreted on the basis of symmetry ( RR and SS ) and pseudo‐chirality ( RS and SR ) considerations. The effects are observed in both the proton and carbon spectra and the complexes are stable in both CDCl 3 and DMSO‐ d 4 solution. This technique, in principle, allows the ready determination of the optical purity of multifunctional ligands.