Amino Acids and Peptides; XLIII1. Dehydroamino Acids; XVIII2. Synthesis of Dehydroamino Acids and Amino Acids fromN-Acyl-2-(dialkyloxyphosphinyl)-glycin Esters; II

Schmidt, Ulrich; Lieberknecht, Albrecht; Wild, Jochen

doi:10.1055/s-1984-30730

Cited by 192 publications

(65 citation statements)

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“…[14] The Horner-Wadsworth-Emmons protocol worked well for most furfurals, except for the 3-(trifluoromethyl)phenylsubstituted derivative 13 f (entry 6) for which only 34 % of the (Z)-dehydroamino acid ester 15 f could be isolated by crystallization (the residual product remained in the mother liquor). Initial hydrogenation reactions were attempted with compound 15 a.…”

Section: Resultsmentioning

confidence: 99%

Asymmetric Rhodium‐Catalyzed Hydrogenation Meets Gold‐Catalyzed Cyclization: Enantioselective Synthesis of 8‐Hydroxytetrahydroisoquinolines

Hashmi

Haufe

Schmid

et al. 2006

Chemistry A European J

126

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Different furyl-substituted (Z)-dehydroamino acid derivatives were hydrogenated with the rhodium/Mandyphos(OMe)-system to give enantiomeric excesses between 80 and 98 %. The absolute configuration of the newly formed stereogenic center was determined by anomalous diffraction to be R. These chiral furyl alanines were transferred into 8-hydroxytetrahydroisoquinolines by employing gold-catalyzed arene synthesis as the key step. During the latter reaction sequence, also including either a propargylation or a reduction, a protection of the hydroxy group, and a subsequent propargylation, no racemization of the stereogenic center was observed. With very electron-rich furans, instead of the 8-hydroxytetrahydroquinolines as products, furans anellated to seven-membered rings with exocyclic C-C double bonds are formed under the same reaction conditions.

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Section: Resultsmentioning

confidence: 99%

Asymmetric Rhodium‐Catalyzed Hydrogenation Meets Gold‐Catalyzed Cyclization: Enantioselective Synthesis of 8‐Hydroxytetrahydroisoquinolines

Hashmi

Haufe

Schmid

et al. 2006

Chemistry A European J

126

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“…To this end bifunctional DAP (Table II, a) was synthesized from benzyloxycarbonyl-protected L-glutamate and a known glycine phosphonate (23,24) via a WittigHorner reaction to get the 2,3-dehydro-DAP. Catalytic hydrogenation using Wilkinson's catalyst gave a 3:2 D:L ratio of the newly created stereogenic center.…”

Section: Methodsmentioning

confidence: 99%

Structural Requirements of Synthetic Muropeptides to Synergize with Lipopolysaccharide in Cytokine Induction

Traub

Kubasch

Morath

et al. 2004

Journal of Biological Chemistry

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Muropeptides contribute to the recognition of bacteria by modulating immune responses: the structural requirements for adjuvant activity were described in the seventies. During the last years, our knowledge of bacterial pattern recognition has increased dramatically and the importance of the absence of contaminations in both muropeptide preparations and other bacterial stimuli has become clear. We investigated a panel of 15 synthetic Limulus-negative muropeptides, four of them synthesized for the first time, as to their potency to synergize with lipopolysaccharide (LPS) in cytokine induction in human whole blood. No muropeptide was capable of stimulating cytokine release from human blood. However, as little as 20 nM of the muropeptides N-acetyl-muramyl-L-alanyl-D-isoglutamine (muramyl dipeptide, M(ADiQ)), N-acetyl-glucosamine-muramyl dipeptide GM(ADiQ), or C 18 M(ADiQ), which carries a non-natural additional fatty acid, sufficed to induce an up to 3 log-order shift in tumor necrosis factor ␣-release in response to 100 pg/ml LPS. The release of interleukin-1␤, interleukin-6, and interleukin-10 was also significantly enhanced although to a lesser extent. The synergistic effect was stereoselective with M(ADiQ) being the minimal active principle. Synergy was also observed on the transcriptional level by means of real-time PCR. Smaller molecules like N-acetylmuramic acid (M), AM, carrying a naturally occurring 1,6-anhydro-bound in M or M(A), containing only the amino acid L-alanine neither synergized with LPS nor influenced the synergy of other muropeptides with LPS. In conclusion, these data show that nanomolar quantities of muropeptides dramatically potentiate LPS-induced monocyte activation. This has implications for pyrogenicity testing and endotoxemia in patients.

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“…29 The widest application of α-(dialkoxyphosphoryl)glycinates is their use in the WadsworthEmmons synthesis of α,β-dehydro-α-amino acids. 7,30,38, The latter compounds are common components of naturally occurring peptides; 71,[74][75][76][77] apart from that, their hydrogenation using Wilkinson-type chiral catalysts is considered to be one of the most general methods for the enantioselective synthesis of α-amino acids. [71][72]76 The synthesis of α,β-dehydro-α-amino acids, including their synthesis from α-(dialkoxyphosphoryl)glycinates in the Wadsworth-Emmons reaction, was the subject matter of a few excellent reviews.…”

Section: Scheme 25mentioning

confidence: 99%

“…38 Schmidt's method consists in the condensation of N-acyl-α-(dialkoxyphosphoryl)glycinates with aromatic, heteroaromatic or aliphatic aldehydes in CH 2 Cl 2 at -60 o C in the presence of potassium t-butoxide, which gives yields in the range of 80-95% (Scheme 27). 38 Under such conditions, Z-isomers are formed preferentially from aldehydes, whereas ketones do not react. Other bases, e.g.…”

Section: Scheme 25mentioning

confidence: 99%

α-Amino acid derivatives with a Cα-P bond in organic synthesis

Mazurkiewicz¹,

Kuźnik²,

Grymel³

et al. 2007

Arkivoc

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α-Amino acid derivatives with a C α -P bond have been used for a wide range of chemical transformations, including synthesis of many kinds of bioactive compounds, e.g. nonproteinogenic α-amino acids, α,β-dehydro-α-amino acids, dehydropeptides, β-lactam antibiotics and glycopeptides. The present review is focused on methods of synthesis of the title compounds, their properties and application in organic synthesis.

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Amino Acids and Peptides; XLIII¹. Dehydroamino Acids; XVIII². Synthesis of Dehydroamino Acids and Amino Acids fromN-Acyl-2-(dialkyloxyphosphinyl)-glycin Esters; II

Cited by 192 publications

References 0 publications

Asymmetric Rhodium‐Catalyzed Hydrogenation Meets Gold‐Catalyzed Cyclization: Enantioselective Synthesis of 8‐Hydroxytetrahydroisoquinolines

Asymmetric Rhodium‐Catalyzed Hydrogenation Meets Gold‐Catalyzed Cyclization: Enantioselective Synthesis of 8‐Hydroxytetrahydroisoquinolines

Structural Requirements of Synthetic Muropeptides to Synergize with Lipopolysaccharide in Cytokine Induction

α-Amino acid derivatives with a Cα-P bond in organic synthesis

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