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Publikationen - Natur- und Wirkstoffchemie

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Publikation

Puentes, A. R.; Neves Filho, R. A. W.; Rivera, D. G.; Wessjohann, L. A.; Total Synthesis of Cordyheptapeptide A Synlett 28, 1971-1974, (2017) DOI: 10.1055/s-0036-1588433

The first total synthesis of cordyheptapeptide A is described. The synthesis is accomplished by a convergent approach featuring a combination of peptide coupling and the Ugi reaction for the preparation of the main building blocks and the acyclic precursor. The assembly of an N-methylated fragment by the Ugi reaction comprised the utilization of a convertible isonitrile followed by activation of the C-terminal amide. Two different macrocyclization sites were evaluated, proving greater efficacy the macrolactamization at the site Ile-Tyr, likely due of a more suitable conformational bias of the acyclic precursor having an internal β-turn centered at the N-Me-d-Phe-Pro moiety.
Publikation

Brauer, M. C. N.; Neves Filho, R. A. W.; Westermann, B.; Heinke, R.; Wessjohann, L. A.; Synthesis of antibacterial 1,3-diyne-linked peptoids from an Ugi-4CR/Glaser coupling approach Beilstein J. Org. Chem. 11, 25-30, (2015) DOI: 10.3762/bjoc.11.4

A library of ten 1,3-diyne-linked peptoids has been synthesized through an Ugi four-component reaction (U-4CR) followed by a copper-catalysed alkyne homocoupling (Glaser reaction). The short and chemoselective reaction sequence allows generating diverse (pseudo) dimeric peptoids. A combinatorial version allows the one-pot preparation of, e.g., six-compound-libraries of homo- and heterodimers verified by ESI-MS and HPLC. In a preliminary evaluation, some compounds display moderate activity against the Gram-positive bacterium Bacillus subtilis.
Bücher und Buchkapitel

Wessjohann, L. A.; Neves Filho, R. A. W.; Puentes, A. R.; Morejon, M. C.; Macrocycles from Multicomponent Reactions (Zhu, J., et al., eds.). 231-264, (2015) ISBN: 9783527678174 DOI: 10.1002/9783527678174.ch09

This chapter focuses on approaches where IMCRs were used in the macrocyclization step itself. In contrast to the conventional approach, IMCR‐based protocols not only mediate the ring‐closing step, but also allow for the incorporation of one or more components as diversity elements into the final product, in an atom‐economical way without additional activation required. However, multicomponent reactions (MCRs) are very suited for the straightforward synthesis of macrocycles endowed with a high level of diversity. The first part concentrates on IMCR‐based macrocyclizations involving a single bifunctional building block (e.g., peptides), followed by those including two bifunctional or trifunctional building blocks. Finally, it discusses the sequential IMCR‐based macrocyclization approaches.
Bücher und Buchkapitel

Wessjohann, L. A.; Kaluđerović, G. N.; Neves Filho, R. A. W.; Morejon, M. C.; Lemanski, G.; Ziegler, T.; Further Components Carboxylic Acid and Amine (Ugi Reaction) (Müller, T. J. J., ed.). Science of Synthesis 415-502, (2014) ISBN: 9783132064614 DOI: 10.1055/sos-SD-210-00242

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Publikation

Neves Filho, R. A. W.; Stark, S.; Westermann, B.; Wessjohann, L. A.; The multicomponent approach to N-methyl peptides: total synthesis of antibacterial (–)-viridic acid and analogues Beilstein J. Org. Chem. 8, 2085-2090, (2012) DOI: 10.3762/bjoc.8.234

Two syntheses of natural viridic acid, an unusual triply N-methylated peptide with two anthranilate units, are presented. The first one is based on peptide-coupling strategies and affords the optically active natural product in 20% overall yield over six steps. A more economical approach with only four steps leads to the similarly active racemate by utilizing a Ugi four-component reaction (Ugi-4CR) as the key transformation. A small library of viridic acid analogues is readily available to provide first SAR insight. The biological activities of the natural product and its derivatives against the Gram-negative bacterium Aliivibrio fischeri were evaluated.
Publikation

Neves Filho, R. A. W.; Brauer, M. C. N.; Palm-Forster, M. A. T.; de Oliveira, R. N.; Wessjohann, L. A.; Patented Catalysts for the Synthesis and Biological Applications of Dihydropyrimidinones: Recent Advances of the Biginelli Reaction Recent Pat. Catal. 1, 51-73, (2012) DOI: 10.2174/2211548X11201010051

The acid-catalyzed and thermal multicomponent cyclocondensation between an aldehyde, a beta-keto ester and urea to generate dihydropyrimidinones (DHPMs) is one of the best studied multicomponent reactions in organic synthesis. It is frequently employed in the synthesis of natural products and biologically active compounds. After several years under academic development, this reaction drew the attention of researchers in the chemical and pharmaceutical industry. This critical review is focused on the development and applications of the Biginelli three component reaction (B-3CR) patented in the last three decades.
Publikation

Neves Filho, R. A. W.; Stark, S.; Morejon, M. C.; Westermann, B.; Wessjohann, L. A.; 4-Isocyanopermethylbutane-1,1,3-triol (IPB): a convertible isonitrile for multicomponent reactions Tetrahedron Lett. 53, 5360-5363, (2012) DOI: 10.1016/j.tetlet.2012.07.064

The synthesis and applications of 4-isocyanopermethylbutane-1,1,3-triol (IPB) as a new convertible isonitrile (isocyanide) for isocyanide-based multicomponent reactions (IMCRs) like Ugi, Ugi-Smiles, and Passerini reactions are described. The primary products obtained from these IMCRs can be converted into highly activated N-acylpyrroles, which upon treatment with nucleophiles can be transformed into carboxylic acids, esters, amides, alcohols, and olefins. In this sense the reagent can be seen as a neutral carbanion equivalent to formate (HO2C−), and carboxylates or carboxamides etc. (RNu-CO−).
Bücher und Buchkapitel

Wessjohann, L. A.; Neves Filho, R. A. W.; Rivera, D. G.; Multiple Multicomponent Reactions with Isocyanides (Nenajdenko, V. G., ed.). 233-262, (2012) ISBN: 9783527652532 DOI: 10.1002/9783527652532.ch7

This chapter contains sections titled:IntroductionOne‐Pot Multiple IMCRsIsocyanide‐Based Multiple Multicomponent MacrocyclizationsSequential Isocyanide‐Based MCRsConclusionsReferences
Publikation

Neves Filho, R. A. W.; Westermann, B.; Wessjohann, L. A.; Synthesis of (−)-julocrotine and a diversity oriented Ugi-approach to analogues and probes Beilstein J. Org. Chem. 7, 1504-1507, (2011) DOI: 10.3762/bjoc.7.175

An improved total synthesis of (−)-julocrotine in three steps from Cbz-glutamine, in 51% overall yield, is presented. To demonstrate the potential of the heterocyclic moiety for diversity oriented synthesis, a series of (−)-julocrotine analogues was synthesized by employing the heterocyclic precursor as an amino input in Ugi four-component reactions (Ugi-4CR) [1].
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