1H and 13C NMR characterization of a new chiral porphyrin, meso-Tetra(α, β, α, β-o-camphanylamidophenyl)porphyrin, and its rhodium(III) complex
✍ Scribed by Silvia Licoccia; Maurizio Paci; Pietro Tagliatesta; Roberto Paolesse; Simonetta Antonaroli; Tristano Boschi
- Publisher
- John Wiley and Sons
- Year
- 1991
- Tongue
- English
- Weight
- 566 KB
- Volume
- 29
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
Abstract
The synthesis of a new chiral porphyrin, meso‐tetra(α, β, α, β‐o‐camphanylamidophenyl)porphyrin, and its Mn(III) and Rh(III) derivatives is reported. Complete resonance assignments of both the ^1^H and ^13^C spectra of the ligand has been achieved via homo‐ and hetero‐nuclear 2D NMR. Insertion of metal ions into the porphyrin ring was performed both in order to test the catalytic properties of the resulting complexes and to characterize the effect of of metal coordination on the spatial distribution of the bulky substituents. The Mn complex was then tested in catalytic chiral epoxidation reactions, giving low enantiomeric excesses (20%). The 2D NMR spectra of the Rh derivative indicate the existence of four molecular species generated by the interaction of the metal atom with the peripheral substituents of the porhyrin ring. In fact, a complex combination of axial coordination, together with the chirality of the camphanyl substituents, removed the symmetry of the porphyrin plane.