Synthesis of modified partial structures of the bacterial cell wall. 1. Lipopeptides containing nonproteinogenic amino acids

Schneider, Hans‐Jürgen; Sigmund, Gerhard; Schricker, Bettina; Thirring, K.; Berner, H.

doi:10.1021/jo00055a022

Cited by 21 publications

(13 citation statements)

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“…An alternative approach was developed for the preparation of 5‐amino‐5‐ethyl‐1‐phenylbarbituric acid ( 12 k ). Diethyl [( tert ‐butyloxycarbonyl)amino]malonate was alkylated with ethyl bromide, and the resulting malonic ester 3 was reacted with phenylurea to give the N‐protected barbituric acid 10 k . After removal of the Boc group upon treatment with an HCl solution in 1,4‐dioxane at room temperature, the desired phenyl derivative 12 k was liberated from the hydrochloride 11 k .…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Antiangiogenic Properties of Tetrafluorophthalimido and Tetrafluorobenzamido Barbituric Acids

et al. 2016

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The development of novel thalidomide derivatives as immunomodulatory and anti-angiogenic agents has revived over the last two decades. Herein we report the design and synthesis of three chemotypes of barbituric acids derived from the thalidomide structure: phthalimido-, tetrafluorophthalimido-, and tetrafluorobenzamidobarbituric acids. The latter were obtained by a new tandem reaction, including a ring opening and a decarboxylation of the fluorine-activated phthalamic acid intermediates. Thirty compounds of the three chemotypes were evaluated for their anti-angiogenic properties in an ex vivo assay by measuring the decrease in microvessel outgrowth in rat aortic ring explants. Tetrafluorination of the phthalimide moiety in tetrafluorophthalimidobarbituric acids was essential, as all of the nonfluorinated counterparts lost anti-angiogenic activity. An opening of the five-membered ring and the accompanying increased conformational freedom, in case of the corresponding tetrafluorobenzamidobarbituric acids, was well tolerated. Their activity was retained, although their molecular structures differ in torsional flexibility and possible hydrogen-bond networking, as revealed by comparative X-ray crystallographic analyses.

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Section: Resultsmentioning

confidence: 99%

Synthesis and Antiangiogenic Properties of Tetrafluorophthalimido and Tetrafluorobenzamido Barbituric Acids

et al. 2016

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“…Several alternative methods reported herein are based on the ene reaction. In earlier studies, we 4a and others , had employed nonstereoselective ene reactions to assemble the DAP skeleton. In addition to other approaches, we now describe the use of chiral auxiliaries and catalysts in such ene condensations.…”

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Stereoselective Synthesis of meso-2,6-Diaminopimelic Acid and Its Selectively Protected Derivatives

1998

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Four synthetic routes to selectively protected derivatives and isomers of meso-diaminopimelic acid (DAP) (1a), a key constituent of bacterial peptidoglycan, were investigated. N-(tert-butyloxycarbonyl)-d-allylglycine (2) and N-(benzyloxycarbonyl)-l-allylglycine (4) were esterified to ethylene glycol and cyclized via olefin metathesis to a protected derivative 7 of 2,7-diaminosuberic acid. Analogous linking of propane-1,3-diol with 2 and potential precursors of N-(benzyloxycarbonyl)-l-vinylglycine moieties, such as N-(benzyloxycarbonyl)-l-glutamate or N-(benzyloxycarbonyl)-l-methionine sulfoxide, gave 12 or 15, both of which produced the α,β-unsaturated ester 14 upon attempted generation of the vinylglycine precursor for olefin metathesis to DAP derivatives. An alternative route, based on SnCl4-catalyzed ene reaction of methyl N-(benzyloxycarbonyl)-l-allylglycinate (18) with glyoxylate esters of phenylcyclohexanol isomers as chiral auxiliaries, gave ca. 85:15 ratios of diastereomeric alcohols (19 or 20). These could be transformed to DAP derivatives in a series of steps employing azide displacement of corresponding mesylates to introduce the second nitrogen. A third method, involving reduction of pure dimethyl (6S)-2-keto-6-[N-(benzyloxycarbonyl)amino]pimelate (32) to the corresponding alcohol 33 with (S)-binaphthol−ruthenium catalyst as the key step, gives a 79:21 isomeric ratio. The fourth route employs the bis(oxazoline)−copper complex 41 as a chiral catalyst for the ene reaction of methyl (S)-4-(phenylthio)allylglycinate (39) and methyl glyoxylate to afford 42 in 94:6 isomeric ratio. Nickel boride removal of sulfur and the double bond in the presence of the Cbz group gives the desired alcohol, dimethyl (2S,6S)-6-[N-(benzyloxycarbonyl)amino]-2-hydroxyheptane-1,7-dioate (33). The required selectively protected second nitrogen is introduced using Mitsunobu inversion with N-tert-butyl [[2-(trimethylsilyl)ethyl]sulfonyl]carbamate (34) as a key step.

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“…As we have shown earlier, 7 the above acids could not be obtained from alkylene-bisbromomalonates. Numerous examples of the C-alkylation of N-acylaminomalonates 8,9 seemed to be promising as an alternative method of synthesis. However, our attempts to obtain tetraesters of α,α'-diamino-α,α'-dicarboxyadipic acid 1 by reactions of 1,2-dihaloethanes (Hal = Cl, Br) with N-formyl-and N-acetylaminomalonates failed, as previously with N-benzoylaminomalonate.…”

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α,α’-Diamino-α,α’-dicarboxyadipic acid tetraester: synthesis, lactamisation and dilactam structure

Kostyanovsky

El’natanov

Krutius

et al. 1998

Mendeleev Communications

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Synthesis of modified partial structures of the bacterial cell wall. 1. Lipopeptides containing nonproteinogenic amino acids

Cited by 21 publications

References 0 publications

Synthesis and Antiangiogenic Properties of Tetrafluorophthalimido and Tetrafluorobenzamido Barbituric Acids

Synthesis and Antiangiogenic Properties of Tetrafluorophthalimido and Tetrafluorobenzamido Barbituric Acids

Stereoselective Synthesis of meso-2,6-Diaminopimelic Acid and Its Selectively Protected Derivatives

α,α’-Diamino-α,α’-dicarboxyadipic acid tetraester: synthesis, lactamisation and dilactam structure

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