Preparation of Six Isomeric Bis-acylporphyrins with Chromophores Reaching the Near-Infrared via Intramolecular Friedel−Crafts Reaction

• Published in: Journal of organic chemistry Vol. 68; no. 24; pp. 9200 - 9208
• Main Authors: Richeter, Sébastien, Jeandon, Christophe, Kyritsakas, Nathalie, Ruppert, Romain, Callot, Henry J
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 28.11.2003; Amer Chemical Soc
• Subjects: Chemistry; Chemistry, Organic; Exact sciences and technology; Heterocyclic compounds; Heterocyclic compounds with several n hetero atoms in the same ring, in separated rings or in fused rings; Organic chemistry; Physical Sciences; Preparations and properties; Science & Technology; PYRROLIC COMPOUNDS; PORPHYRIN OLIGOMERS; COMPLEXES; CHEMISTRY; PETROPORPHYRINS; RING-SYSTEMS; METAL-IONS; DIMERS; DERIVATIVES; CYCLIZATION; Intramolecular reaction; Regioselectivity; Carbonyl Organic compounds; Diketone; X ray diffraction; Characterization; Intermolecular interaction; Near infrared spectrometry; Friedel Crafts reaction; Electron spectra; Bathochromism; Aromatic compound; Nickel complex; Metalloporphyrin; Chemical synthesis; Acylation; Chromophore; Ultraviolet visible spectrometry
• ISSN: 0022-3263; 1520-6904
• DOI: 10.1021/jo035108m

We describe the preparation of six diketones based on the frameworks of five bis-naphthoporphyrins and one perinaphthoporphyrin. All diketones derive from meso-tetraarylporphyrins having incorporated two carbonyl groups, each one connected to one β-pyrrole carbon and one ortho carbon atom from a meso-aryl group. These compounds were all produced in good yield by intramolecular Friedel−Crafts acylation, either from porphyrins meso-substituted by o-carboxyphenyl or o,o ‘-dicarboxyphenyl substituents or from porphyrins bearing carboxy groups attached to the pyrrolic β-positions. Although the former reaction does not show significant regioselectivity when run on nickel complexes, the opposite is true for the corresponding free bases. All diketones show a spectacular bathochromic shift of the UV−vis absorption, the longest wavelength bands absorbing in the 700−825 nm range. Two compounds were structurally characterized by X-ray diffraction. In the case of the diketone, whose carbonyl groups are attached to vicinal pyrrolic β-positions, a significant intermolecular interaction between the two carbonyl groups and an aromatic hydrogen atom was detected.