Meso-tetraphenylporphyrin, synthesis

Romain L, Mien V, Karine T, Rachida Z, Vincent S, Pierre K (2008) A facile and rapid iodine-catalyzed meso-tetraphenylporphyrin synthesis using microwave activation. Tetrahedron Lett 49 5537-5539... 

Extension of the 1,3-DC approach to the synthesis of novel pyrazoline-fused chlorin 78 by the reaction of P-nitro-meso-tetraphenylporphyrin le with diazomethane has also been explored by Cavaleiro and co-workers (Scheme 27) <02S 1155>. The resulting chlorin 78 could be further converted into the pyrazole-fused porphyrin 79 by treatment with DBU or into the methanochlorin 80 by refluxing in toluene. 

Because of the occurrence of isomers, the synthesis from pyrroles is only useful for porphyrins with eight identical /8-pyrrolic and four identical methine bridge substituents. Famous examples are the syntheses of chloroform-soluble /8-octaethyl-porphyrin and meso-tetraphenylporphyrin which have been used in innumerable studies on porphyrin reactivity (K.M. Smith, 1975). Porphyrins with four long meso-alkyl side-chains can be obtained by use of analogous reactions. These porphyrins have melting points below 100 °C and are readily soluble in petroleum ether. Sulfonation of olefinic double bonds leads to highly charged, water soluble porphyrins (J.-H. Fuhrhop, 197 ). 

Synthesis of a series of hi- and terthiophenes (115) substituted with meso-tetraphenylporphyrin groups by an oxaalkyl chain has been described by Bauerle and coworkers [233]. The corresponding electrogenerated polymers were considered for the detection of polychlorinated phenols in amperometric sensors. 

Kadish, K.M., Z. Ou, X. Tan, T. Boschi, D. Monti, V. Fares, and P. Tagliatesta (1999). Synthesis and electrochemistry of cobalt y8-halogenated meso-tetraphenylporphyrins containing a nitrosyl axial hgand. Crystal structure of (TPPBr4N02)Co(NO). J. Chem. Soc Dalton Trans. 1595-1601. 

The synthesis of porphyrinoids containing nonpyrrolic heterocycles is of interest for studying the intrinsic properties of porphoryins. These porphyrin-like molecules possess varying absorption and emission properties and abilities to interact with metals or other analytes. Akhigbe and Bruckner converted meso-tetraphenylporphyrine 140 to diketone 141 using osmium tetroxide and DDQ oxidation (Scheme 5.33T Oxime formation followed by a... 

Terazono Y, Dolphin D (2003) Synthesis and characterization of trifluoromethyl-meso-tetraphenylporphyrins. J Org Chem 68 1892-1900... 

Gandini et have used proton NMR in conjunction with optical and ESR spectroscopies to determine the solution forms of the water-soluble high-spin ferric porphyrin, meso-tetrakis(4-N-methylpyridiniumyl)porphyrin. A number of species were found, both 5- and 6-coordinate, including monomers in several states of protonation and a fx-oxo dimer. Song has used proton NMR to demonstrate the formation of a novel hydride-bonded porphyrin complex in which BH4" coordinates to the Fe(III) of Fe(lII)-tetraphenylporphyrin. Wasser et report the synthesis and complete proton NMR assignment of p-oxo (02-)-bridged heme/non-heme diiron complexes, which they study as models for the active site of nitric oxide reductase. 

The structure of N-confused porphyrin (41 in Figure 9.11) was first proposed by Aronoff and Calvin in 1943 when they reexamined Rothemund s synthesis of tetraphenylporphyrin [43]. Because of lack of supporting experimental studies, the concept was under hibernation until the 5,10,15,20-tetraphenyl-substituted 41 was isolated as the byproduct in the Lindsey synthesis of meso-aryl porphyrins, 50 years later [44]. Currently, many more N-confused and X-confused porphyrins have been synthesized and characterized [37,45]. There are indeed innumerable analogs, in addition to the common derivatives of porphyrin, that constitute a huge molecular library. Every individual porphyrinoid has its own characteristic properties. Their aromaticity can be controlled by means of ingenious structural modifications. This encourages researchers to synthesize novel porphyri-noids with tuned properties as required for the destined applications. 

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