27226-50-2Relevant academic research and scientific papers
Synthesis and reactivity of 2-thionoester pyrroles: A route to 2-formyl pyrroles
Kim, Min Joon,Gaube, Sophie M.,Beh, Michael H. R.,Smith, Craig D.,Thompson, Alison
, p. 31773 - 31780 (2019/10/19)
2-Functionalised pyrroles exhibit considerable synthetic utility. Herein, the synthesis and reactivity of 2-thionoester (-C(S)OR) pyrroles is reported. 2-Thionoester pyrroles were synthesised using a Knorr-type approach from aliphatic starting materials. 2-Thionoester pyrroles were reduced to the corresponding 2-formyl pyrroles, or the deuterated formyl variant, in one step using RANEY nickel, thereby removing the need for the much-utilised hydrolysis/decarboxylation/formylation steps that are typically required to convert Knorr-type 2-carboxylate pyrroles into 2-formyl pyrroles. 2-Thionoester pyrroles proved tolerant of typical functional group interconversions for which the parent 2-carboxylate pyrroles have become known.
Normal and abnormal heme biosynthesis. 1. Synthesis and metabolism of di- and monocarboxylic porphyrinogens related to coproporphyrinogen-III and harderoporphyrinogen: A model for the active site of coproporphyrinogen oxidase
Lash, Timothy D.,Mani, Ukti N.,Drinan, Martin A.,Zhen, Chun,Hall, Troii,Jones, Marjorie A.
, p. 464 - 477 (2007/10/03)
Coproporphyrinogen oxidase (copro'gen oxidase), which catalyses the conversion of coproporphyrinogen-III via a monovinylic intermediate to protoporphyrinogen-IX, is one of the least well understood enzymes in the heme biosynthetic pathway. To develop a model for the substrate recognition and binding recognition for this enzyme, a series of substrate analogues were prepared with two alkyl substituents on positions 13 and 17 in place of the usual propionate residues. Although the required substrate probes are porphyrinogens (hexahydroporphyrins), the corresponding porphyrin methyl esters were initially synthesized via a,c-biladiene intermediates. These were hydrolyzed and reduced with 3% sodium amalgam to give the unstable porphyrinogens needed for the biochemical investigations. These modified structures were metabolized by avian preparations of copro'gen oxidase to give monovinylic products, but the second propionate residue was not further metabolized. In three cases, the metabolites were isolated and further characterized by proton NMR spectroscopy and mass spectrometry. When methyl or ethyl groups were placed at the 13 and 17 positions, the resulting porphyrinogens were very good substrates (although the ethyl version, mesoporphyrinogen-VI, gave slightly better results), but when propyl units were introduced metabolism was significantly inhibited and the butyl- substituted structure was only slightly transformed after long incubation periods. These results suggest the presence of an active site lipophobic region near the catalytic site for copro'gen oxidase. The observation that the related 3-vinyl- and 3-ethylporphyrinogens with 13,17-diethyl substituents were not substrates for this enzyme confirmed the need for a second propionate residue to hold the substrate in place at the catalytic site.
Thermochemistry of substituted pyrroles
Berezin, M. V.,Semeikin, A. S.,V'yugin, A. I.,Krestov, G. A.
, p. 449 - 453 (2007/10/02)
The heats of solution of a series of substituted pyrroles in benzene, carbon tetrachloride, chloroform, DMF, and pyridine were measured by a calorimetric method at 298.15 K.The influence of substituents in the pyrrole molecule on the energy parameters of solvation by organic solvents is discussed.
Tetrapyrrole products from electrochemical cyclization of 1′,8′-disubstituted-a,c-biladiene salts
Swanson, Kristin L.,Snow, Kevin M.,Jeyakumar,Smith, Kevin M.
, p. 685 - 696 (2007/10/02)
Anodic oxidation of 1′,8′-dimethyl- and other 1′,8′-disubstituted a.c-biladiene salts affords novel cyclized products. In addition to porphyrin, an unconjugated macrocyclic intermediate product resulting from oxidadve cyclizatfon during porphyrin synthesis is isolated, structurally identified, and characterized with regard to its spectroscopy, electrochemical behavior and chemical reactivity. The formation of a novel homoporphyrin from a 1′-ethoxycarbonylmethy-8′-(2-methoxycarbonylethyl)-a,c-biladiene salt is also briefly discussed.
The Chemistry of Pyrrolic Compounds. LXI Petroporphyrins from the Julia Creek Oil Shale: Further Evidence for the Derivation of Aetiotype Petroporphyrins from Chlorophyll
Clezy, Peter S.,Fookes, Christopher J. R.,Prashar, Jognandan K.
, p. 775 - 786 (2007/10/02)
The synthesis of the porphyrins (2c-j) has been achieved by the oxidative cyclization of appropriately substituted biladienes-ac.The availability of authentic material has allowed the finalization of the structure of a series of aetiotype fossil porphyrins which vary in substitution pattern at positions 3 and 13.All combinations of H, Me and Et at these positions have now been isolated from natural sources.This points to a common precursor, possibly a divinylporphyrin, and strengthens the belief that the chlorophylls are the prime source of the petroporphyrins.A vinyl group, or a close derivative, is found at position 3 of all chlorophylls while fragmentation of the ubiquitous isocyclic ring of the chlorophylls could yield the vinyl group at position 13.
Synthetic Studies Relevant to Biosynthetic Research on Vitamin B12. Part 2. Syntheses of C-Methylated Chlorins Via Lactams
Battersby, Alan R.,Fookes, Christopher J. R.,Snow, Roger J.
, p. 2733 - 2741 (2007/10/02)
C-Metylyted chlorins have been synthesised by two approaches.For one, ring-B and ring-C of the final chlorin were built sequentially onto a thiolactam system which acted as the A-D component.The preferred alternative method involved joining together a lac
Syntheses of Methyl-devinylporphyrins Related to Protoporphyrin -IX. Initial Studies on the Mechanism of the Copper(II) Catalysed Cyclization of 1',8'-Dimethyl-a,c-biladiene Salts
Smith, Kevin M.,Kehres, Lisa A.
, p. 2329 - 2335 (2007/10/02)
Using copper(II) catalysed cyclization of a,c-biladiene dihydrobromide salts, porphyrins related to protoporphyrin-IX dimethyl ester (8), but in which both vinyls are replaced with methyls, or where either the 2- or 4-vinyls are individually replaced with methyls, are synthesized.These compounds are required for reconstitution of the corresponding hemes into hemoproteins, to enable the study of the rotational disorder of prosthetic heme groups in reconstituted hemoproteins.By way of 13C n.m.r. spectroscopy of enriched a,c-biladienes and porphyrins, the copper(II) catalysed cyclization of 1',8'-dimethyl-a,c-biladiene dihydrobromides is shown to afford porphyrins in which one of the 1'- and 8'-methyl groups becomes the new linking meso carbon atom.
