New syntheses of deuterated protoporphyrin-IX derivatives for heme protein nmr studies

Smith, Kevin M.; Eivazi, Fahimeh; Langry, Kevin C.; ALMEIDA, J. A. P. BAPTISTA DE; Kenner, G. W.

doi:10.1016/0045-2068(79)90050-6

Cited by 23 publications

(8 citation statements)

References 17 publications

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“…We followed Smith's strategy for the preparation of pyrroles bearing deuteriated β-methyl groups [38,39]. Thus, acetylacetone (1) underwent alkylation with CD 3 I to give the reported 3-trideuteriomethyl-2,4-pentadione 2 [45], which was exhaustively deuteriated via underlying keto-enol tautomerism to give 1,3-diketone 3 [46] (Scheme 2).…”

Section: Resultsmentioning

confidence: 99%

“…Given that (1) the exchange was incomplete and had an obligatory requirement for the presence of the ferric chelate, and (2) metalation of electron-rich bacteriochlorins is challenging [37], we elected to pursue the de novo synthesis of BC-2 beginning with suitable deuteriated precursors. The synthesis of pyrroles bearing deuteriated β-methyl groups is strongly precedented by work in the porphyrin arena, chiefly by Smith and coworkers [38][39][40][41][42][43][44]. A key question in the present work was whether such a deuteriated pyrrole could be converted with isotopic fidelity to the corresponding bacteriochlorin.…”

Section: Chart 1 Natural Bacterial Photosynthetic Pigmentsmentioning

confidence: 92%

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De Novo Synthesis of Bacteriochlorins Bearing Four Trideuteriomethyl Groups

et al. 2022

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Site-specific introduction of isotopes in tetrapyrrole macrocycles provides the foundation for probing physicochemical features germane to photosynthetic energy-transduction processes, but has chiefly been done with porphyrins rather than the more biologically relevant hydroporphyrin analogues of native photosynthetic pigments. A prior study incorporated pairwise 13C or 15N atoms in the skeleton of a bacteriochlorin containing a gem-dimethyl group in each pyrroline ring. Here, a complementary effort is reported that installs deuterium atoms in substituents at the perimeter of a bacteriochlorin. Thus, perdeuteriated 3-methyl-2,4-pentanedione was converted in an 8-step synthesis via the intermediacy of tert-butyl 5-formyl-3,4-bis(trideuteriomethyl)pyrrole-2-carboxylate to the 2,3,12,13-tetrakis(trideuteriomethyl)-8,8,18,18-tetramethylbacteriochlorin (BC-2). The fidelity of isotope substitution was maintained throughout the synthesis. Resonance Raman spectroscopy of the copper chelate (CuBC-2) revealed that addition of the four β-pyrrolic substituents alone is not sufficient to account for the vibronic complexity observed for the copper chelate of bacteriochlorophyll a (CuBChl a). The increased vibronic activity exhibited by the natural pigments and CuBChl a must arise from the increased structural complexity of the macrocycle.

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Section: Resultsmentioning

confidence: 99%

Section: Chart 1 Natural Bacterial Photosynthetic Pigmentsmentioning

confidence: 92%

De Novo Synthesis of Bacteriochlorins Bearing Four Trideuteriomethyl Groups

et al. 2022

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“…When a solution of chlorobenzene (3a, 0.01 mol) in DMF was added to the suspension of MeSeLi (0.03 mol) in THF and the temperature was raised to 120 °C, so that all the THF distilled off from the reaction mixture, the chlorine atom was displaced by the methyl selenide anion to give the phenyl methyl selenide (4). This compound, however, was rapidly dealkylated by the MeSe anion to give the phenyl selenide anion 5 (Scheme I).…”

Section: Resultsmentioning

confidence: 99%

Nucleophilic aromatic substitutions of unactivated aryl halides by methyl selenide anions. Synthesis and selective dealkylations of aryl alkyl selenides

Tiecco¹,

Testaferri²,

Tingoli³

et al. 1983

J. Org. Chem.

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Preparation of Hydrocarbons. Bicyclo[3.2.1]octene (2) and bicyclo[3.2.1 ] octadiene (1) were prepared according to the procedure reported by Moore.25 Bicyclo[3.2.2]nonatriene (6) was prepared from cycloheptatriene as described by Grutzner and Winstein.16 Bicyclo[3.2.2]nonadiene (5) was synthesized from bicyclo[3.2.2]non-6-en-2-one (11).26 Ketone 11 was reacted sequentially with NaBH4, TosCl, and t-BuOK/ 18-crown-6-ether in THF at 25 °C. All the hydrocarbons were purified by preparative GLPC.Acidity Measurements. The procedures devised by were used in which a weighed amount of a polyarylmethane, whose pKa and anionic extinction coefficient had been determined, was added at 20 °C to CHA containing cesium cy-

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“…The yellow-white precipitate was carefully washed with cold water and collected by filtration. After drying under vacuo at room temperature the yield of la was 90% contaminated with a few percent of l-acetyl-3,4,5-tribromo-lH-pyrazole: 'H NMr (CDC13) 6 6.64 (s, 1, H-4), 6 2.68 (s, N-acetyl, 2-3%).…”

Section: 5-dibromo-4-nitro-l-phenyl-lh-pyrazole (4)mentioning

confidence: 99%

Pyrazoles. 19. Selective thermolysis reactions of bromo-1-nitro-1H-pyrazoles. Formation of 3-nitro-1H- vs. 4-nitro-1H-pyrazoles

Juffermans¹,

Habraken²

1986

J. Org. Chem.

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1833 with Z > 3u(O were retained for solution and refinement of the structure. The large number of unmeasured reflections stems from the small crystal size of 0.020 X 0.175 X 0.325 mm. The structure was solved by direct methods and refined to a final R value of 0.069. In the final refinement Fe and C1 atoms were assigned anisotropic thermal parameters and hydrogen atoms were included a t calculated positions using a riding model and U(H) = 1.2U(bonded C). The largest feature in a final difference map was 0.5, the size of a hydrogen and of no possible chemical significance. H(45) is the largest peak on a difference map computed with it omitted. Tables of anisotropic thermal parameters, hydrogen atom coordinates, and complete tables of bond distances and angles are available as supplementary material.Refluxing 3,4,5,-tribromo-l-nitro-1H-pyrazole (la) in benzene results in the evolution of bromine and NO2 and gives the 4-nitro-1H-pyrazole 2 and the 1-phenyl-1H-pyrazoles 4 and 5, while heating la in toluene gives 2 and benzyl bromide. Thermolysis of la in refluxing acetonitrile affords both 2 and the isomeric 5-nitro-1H-pyrazole 6a. Refluxing la mixed with the electron-rich 3,5-dimethyl-lH-pyrazole (7) in all three solvents gives 6a and 4-bromo-3,5-dimethyl-lH-pyrazole (8), whereas refluxing la mixed with anisole in benzene solution gives 2 and bromoanisoles. 3,5-Dibromo-l-nitro-lH-pyrazole (lb) in refluxing acetonitrile gives mainly 3,4-dibromo-5-nitro-1H-pyrazole (6a) and 3,5-dibromo-IH-pyrazole (3b), but refluxing l b mixed with 7 affords 3-bromo-5-nitro-1H-pyrazole (6b). Possible mechanisms are discussed involving intramolecular rearrangements to intermediates 3-bromo-3-nitro-3H-pyrazoles 9a,b and 4-bromo-4-nitro-4H-pyrazole 10 responsible both for the loss of bromine and NOP as well as for the electrophilic bromination of 7 and anisole. (1) Pyrazoles Studies. Part 19. Part 18: Berbee, R. P. M.; Habraken, C. L. J. Heterocycl. Chem. 1981, 18, 559-560. (2) Janssen, J. W. A. M.; Habraken, C. L.; Louw, R. J. Org. Chem. 1976, 41, 1758-1762 and earlier publications cited therein. (3) (a) Habraken, C. L.; Cohen-Fernandes, P. J. Chem. SOC., Chem. Commun. 1972, 38. (b) Pevzner, M. S.; Kulibabina, T . N.; Loffe, S. L.; Maslina, I. A,; Gidaspov, B. V.; Tartakovskii, V. A. Khim. Geterotsikl. Soedzn. 1979, 15, 550-554. Fernandes, P.; Habraken C. L. J . Org. Chem. 1984, 49, 3310-3314. (4) Zibuck, R.; Stahl, M. A.; Barchiesi, B.; Waalwijk, P. S.; Cohen-0 1986 American Chemical Society Selective Thermolysis Reactions Scheme I1

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New syntheses of deuterated protoporphyrin-IX derivatives for heme protein nmr studies

Cited by 23 publications

References 17 publications

De Novo Synthesis of Bacteriochlorins Bearing Four Trideuteriomethyl Groups

De Novo Synthesis of Bacteriochlorins Bearing Four Trideuteriomethyl Groups

Nucleophilic aromatic substitutions of unactivated aryl halides by methyl selenide anions. Synthesis and selective dealkylations of aryl alkyl selenides

Pyrazoles. 19. Selective thermolysis reactions of bromo-1-nitro-1H-pyrazoles. Formation of 3-nitro-1H- vs. 4-nitro-1H-pyrazoles

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