Hydroporphyrins synthesis

The tetramerization of suitable monopyrroles is one of the simplest and most effective approaches to prepare porphyrins (see Section 1.1.1.1.). This approach, which is best carried out with a-(hydroxymethyl)- or ot-(aminomethyl)pyrroles, can be designated as a biomimetic synthesis because nature also uses the x-(aminomethyl)pyrrole porphobilinogen to produce uroporphyrinogen III. the key intermediate in the biosynthesis of all kinds of naturally occurring porphyrins, hydroporphyrins and corrins. The only restriction of this tetramerization method is the fact that tnonopyrroles with different -substituents form a mixture of four constitutionally isomeric porphyrins named as porphyrins I, II, III, and IV. In the porphyrin biosynthesis starting from porphobilinogen, which has an acetic acid and a propionic acid side chain in the y6-positions, this tetramerization is enzymatically controlled so that only the type III constitutional isomer is formed. 

Hydrogen ligands, 689-711 Hydrogen selenide metal complexes, 663 Hydrogen sulfide metal complexes, 516 Hydrogen telluride metal complexes, 670 Hydroporphyrins, 814-856 basicity, 853 dehydrogenation, 853 demetallation, 854 deuteration, 853 mass spectra, 852 metallation, 854 NMR, 852 non-aromatic, 855 photochemistry, 854 redox chemistry, 855 synthesis, 852... 

Homolytic substitution of heteroaromatic compounds, 16, 123 Hydantoins, chemistry of, 38, 177 Hydrogen cyanide derivatives, synthesis of heterocycles from, 41, 1 Hydrogen exchange base-catalyzed, 16, 1 one-step (labeling) methods, 15, 137 Hydrogenated porphyrin derivatives hydroporphyrins, 43, 73 Hydroxamic acids, cyclic, 10, 199 1 -Hydroxyindoles, 1 -hydroxytryptophans, and 1-hydroxytryptamines,... 

During the last decade a remarkable number of hydroporphyrins have been synthesized, mostly with regard to biochemical problems. Ring synthesis proves particularly important in this area since a possible control of single steps of the synthetic sequence allows for an establishment of a specific substitution pattern. Examples of this section are presented in a file of decreasing size of the re-systems, i.e., chlorins are followed by bacteriochlorins, etc. 

Synthesis and characterization of other related macrocycles, including chlorins, " isobacteriochlorins, bacteriochlorins, mono- and dioxoporphyrins, " other more highly saturated hydroporphyrins, N-alkyl- or A-arylporphyrins, some of which are chiral, porphodimethenes, thiaporphyrins, " oxaporphyrins, N-confused " and carbapor-phyrins, porphycenes " and corrphycenes, " tetraazaporphyrins, phthalocyanines, the ring-expanded sapphyrins, texaphyrins and others, and the ring-contracted corroles " and corrolazines have also been synthesized and are discussed in the indicated references. 

Montforts FP, Gerlach B, Hoper F (1994) Discovery and Synthesis of Less Common Natural Hydroporphyrins. Chem Rev 94 327... 

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