A thiolate ligand on a cytochrome P-450 mimic permits the use of simple environmentally benign oxidants for biomimetic steroid hydroxylation in water

Fang, Zhifeng; Breslow, Ronald

doi:10.1016/j.bmcl.2005.08.090

Cited by 34 publications

(23 citation statements)

References 19 publications

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“…All derivatives were substituted with three α-mannose units on each porphyrin in the hope of targeting tumor cells which contained over-expressed lectin-type membrane receptors. The four oligomers (418)(419)(420)(421) were all synthesized from a single parent monomer 417 with varying π-conjugation linkers between the porphyrin moieties. The parent monomer 417 was pre-formed in five steps and the trimethylsilyl group was deprotected for oligomer synthesis.…”

Section: Glycosidation Reactions O-linked Systemsmentioning

confidence: 99%

“…Initially, imidazole had been incorporated as the fifth ligand in such P450 mimics [180,414,415,418]. Inclusion of thiolates in the P450 mimic either covalently attached (see 665) or via hydrogen bounding to the catalyst allowed the use of H 2 O 2 as oxidant [419] . However, the turnovers were modest (15 with NaOCl, 10 with hydrogen peroxide), which may be due to the incorporation of only two perfluorinated phenyl rings.…”

Section: Catalysismentioning

confidence: 99%

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Chemical Synthesis and Medicinal Applications of Glycoporphyrins

Moylan¹,

Scanlan²,

Senge

2015

CMC

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Abstract:This review presents an in-depth overview of the modification of porphyrins with bioconjugates and their applications in medicine today. Porphyrin bioconjugates ranging from nucleotides to steroids are under active scrutiny. However, carbohydrates have been at the forefront of such research in recent years and offer significant potential. This is attributed to their own selectivity to lectins on the surface of cancer cells and their influence on the amphiphilicity of the porphyrin macrocycle. These characteristics and the tendency of porphyrin photosensitizers to accumulate in tumor tissues make glycoporphyrins promising candidates for use as photosensitizers. Thus, a detailed overview of the synthesis and biological evaluation of glycoporphyrins is given with a particular focus on their applications in photodynamic therapy and their future prospects as drug candidates have been reported.

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Section: Glycosidation Reactions O-linked Systemsmentioning

confidence: 99%

Section: Catalysismentioning

confidence: 99%

Chemical Synthesis and Medicinal Applications of Glycoporphyrins

Moylan¹,

Scanlan²,

Senge

2015

CMC

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“…21 Although the action of the cysteinyl thiolate ligand in the catalytic cycle of cytochrome P 450 is not understood, it is well known that the cysteinyl thiolate can stabilise the active species and facilitate the O-O bond cleavage of the ferric hydroperoxy species in the catalytic cycle of P 450 . 22 According to the currently accepted catalytic cycle of cytochrome P 450 , most of the active intermediate species are formed through protonation or deprotonation with the aid of the cysteinyl thiolate ligand.…”

Section: Mechanism Considerations About the Disulfide Bondmentioning

confidence: 99%

Synthesis of Disulfide-Derivatised Metallodeuteroporphyrins as Novel Catalysts to Imitate Cytochrome P₄₅₀ in the Selective Oxidation of Cyclohexane

Sun

Zhou

et al. 2011

Journal of Chemical Research

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Metallodeuteroporphyrins with two side chains linked by a terminal cystine dimethyl ester [M(PDTEP), where M = ClFe(III), ClMn(III), Co(II)], have been synthesised. These metalloporpyirn complexes were found to act as efficient catalysts in the oxidation of cyclohexane to cyclohexanol and cyclohexanone using air as the oxygen source and in the absence of additives and solvents. The influence of the central metal, reaction temperature and pressure on the catalytic behavior of M(PDTEP) were evaluated. The high conversion and selectivity of M(PDTEP) was ascribed to the existence of intramolecular coordination by the M(PDTEP).

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“…[72][73][74][75][76][77] Their scope is indicated by the activity of a ditelluride b-cyclodextrin dimer as a glutathione peroxidase mimic, which catalyzes the reduction of cumene peroxide by an aryl thiol 200 000 times more effectively than diphenyl diselenide. [64] We have used cyclodextrins to reverse the regioselectivity of nitrile oxide cycloadditions (Scheme 1), thus changing the ratio of formation of the regioisomeric cycloadducts by factors of up to 120; from 1:8 for the isoxazoles 6 a and 7 a to 15:1 for their analogous cyclodextrin derivatives 3 a and 4 a.…”

Section: Introductionmentioning

confidence: 99%

Reversal of Regioselectivity and Enhancement of Rates of Nitrile Oxide Cycloadditions through Transient Attachment of Dipolarophiles to Cyclodextrins

Barr

Lincoln

Easton

2006

Chemistry A European J

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The reactions of nitrile oxides with monosubstituted dipolarophiles, such as propiolamide, typically afford proportionally 80 % or more of the 3,5-disubstituted cycloadducts. By contrast, the reactions of 6(A)-deoxy-6(A)-propynamido-beta-cyclodextrin with 4-tert-butylbenzonitrile oxide and 4-phenylbenzonitrile oxide afford >90 % and approximately 85 % of the corresponding 3,4-disubstituted isoxazoles, respectively. As well as reversing the regioselectivity, the cyclodextrin increases the rates of these cycloadditions. The extent of the acceleration is up to more than three orders of magnitude for the production of the cycloadduct preferred by the cyclodextrin, but even the rate of reaction to give the less favored regioisomer is increased. With 6(A)-deoxy-6(A)-propynamido-beta-cyclodextrin, the cycloadducts are not easily separated from the cyclodextrin, as the amide bond is not readily cleaved. In comparison, the regioselectivity of the cycloadditions of 4-tert-butylbenzonitrile oxide with acrylic acid, methacrylic acid, and crotonic acid is also altered by formation of the corresponding cyclodextrin esters, by factors of 500, >10, and >100, respectively. The rates of cycloaddition are also increased by up to 475 times, and in these cases the products of cycloaddition are readily released from the cyclodextrin through ester hydrolysis. Incorporating these processes into a reaction cycle, acylation of beta-cyclodextrin with p-nitrophenyl acrylate and subsequent treatment first with 4-tert-butylbenzonitrile oxide and then with base, the latter to catalyze ester hydrolysis and regenerate the beta-cyclodextrin, affords proportionally fivefold more of the 3,4-disubstituted isoxazoline than is produced directly from acrylic acid.

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A thiolate ligand on a cytochrome P-450 mimic permits the use of simple environmentally benign oxidants for biomimetic steroid hydroxylation in water

Cited by 34 publications

References 19 publications

Chemical Synthesis and Medicinal Applications of Glycoporphyrins

Chemical Synthesis and Medicinal Applications of Glycoporphyrins

Synthesis of Disulfide-Derivatised Metallodeuteroporphyrins as Novel Catalysts to Imitate Cytochrome P₄₅₀ in the Selective Oxidation of Cyclohexane

Reversal of Regioselectivity and Enhancement of Rates of Nitrile Oxide Cycloadditions through Transient Attachment of Dipolarophiles to Cyclodextrins

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A thiolate ligand on a cytochrome P-450 mimic permits the use of simple environmentally benign oxidants for biomimetic steroid hydroxylation in water

Cited by 34 publications

References 19 publications

Chemical Synthesis and Medicinal Applications of Glycoporphyrins

Chemical Synthesis and Medicinal Applications of Glycoporphyrins

Synthesis of Disulfide-Derivatised Metallodeuteroporphyrins as Novel Catalysts to Imitate Cytochrome P450 in the Selective Oxidation of Cyclohexane

Reversal of Regioselectivity and Enhancement of Rates of Nitrile Oxide Cycloadditions through Transient Attachment of Dipolarophiles to Cyclodextrins

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Synthesis of Disulfide-Derivatised Metallodeuteroporphyrins as Novel Catalysts to Imitate Cytochrome P₄₅₀ in the Selective Oxidation of Cyclohexane