Thomas Ziegler

Find an error

Name:

Organization: Universit?t Tübingen

Department: Institute of Organic Chemistry

Title:

TOPICS

Organic Chemistry

Asymmetric Synthesis Peptide Synthesis

Chemicals
References

Synthesis of ruthenium and palladium complexes from glycosylated 2,2′-bipyridine and terpyridine ligands

Co-reporter:Daniel Schmollinger, Jochen Kraft, Carolin Ewald, Thomas Ziegler

Tetrahedron Letters 2017 Volume 58, Issue 37(Issue 37) pp:

Publication Date(Web):13 September 2017

DOI:10.1016/j.tetlet.2017.08.008

•Glycosylated bipyridine complexes.•Triazole ligands.•Click reaction.A series of glucosylated mono- and di-(1H-1,2,3-triazol-4-yl)pyridines were prepared from glucosyl azides and 2-ethynyl and 2,6-diethynyl pyridine via Click reaction. Glucosylation of the silver salt of 4-hydroxy-2,2′-bipyridine with acetobromoglucose afforded the corresponding glucosylated 2,2′-bipyridine. Treatment of five examples of the latter pyridine ligands with [cis-Ru(bipy)2Cl2], [Ru(tpy)Cl3] or [Pd(COD)Cl2] gave the corresponding ruthenium(II) and palladium(II) complexes in 62%-quantitative yield.Download high-res image (82KB)Download full-size image

Carbohydrate-Derived 3,2-Enolones in the Base-Catalyzed Rearrangement to Highly Functionalized C4-Quaternary 4-Hydroxy-2-cyclopentenones

Co-reporter:Daniel Borowski;Regina M. Oechsner;Eva Jürgens

European Journal of Organic Chemistry 2017 Volume 2017(Issue 30) pp:4490-4499

Publication Date(Web):2017/08/17

DOI:10.1002/ejoc.201700846

3,4,6-O-benzylated β-2-ulosides were subjected to 3,4-elimination, providing carbohydrate-derived 3,2-enolones. Reaction of these enolones under basic conditions in polar aprotic solvents afforded highly functionalized racemic 5-alkoxy-2-benzyloxy-4-benzyloxymethyl-4-hydroxy-2-cyclopentenones. The influence of the nature of the base as well as solvent effects were investigated. The rearrangement products obtained from this reaction exhibit a 4-hydroxy-C4-quaternary stereogenic center. In contrast, the rearrangement of comparable dihydropyran-3-ones was reported to furnish the C5-quaternary 5-hydroxy-2-cyclopentenones. Plausible mechanisms for the described rearrangement and subsequent isomerization processes are given.

First example of an octa-glycoconjugated magnesium(II)porphyrazine

Co-reporter:Thomas Klein, Thomas Ziegler

Tetrahedron Letters 2016 Volume 57(Issue 4) pp:495-497

Publication Date(Web):27 January 2016

DOI:10.1016/j.tetlet.2015.12.076

•First synthesis of an octa-glycoconjugated magnesium(II)porphyrazine.•Physical properties and characterization by spectroscopy and spectrometry.•Possible application as photosensitizer in photodynamic therapy.Treatment of disodium maleonitriledithiolate with 1,2:3,4-di-O-isopropylidene-6-O-trifluoromethanesulfonyl-α-d-galactopyranose gives 2,3-bis(6-deoxy-1,2:3,4-di-O-isopropylidene-6-thio-α-d-galactopyranos-6-yl)maleonitrile in 87% yield. Heating of the latter with magnesium bis(butan-1-olate) in butan-1-ol affords [2,3,7,8,12,13,17,18-octakis(6-deoxy-1,2:3,4-di-O-isopropylidene-6-thio-α-d-galactopyranos-6-yl)porphyrazinato]magnesium(II) in 53% yield. The glycoconjugated porphyrazine has an absorbance maximum at 673 nm and is a candidate as photosensitizer for photodynamic therapy.

Synthesis of Vicinal Diketoses by Using a MetathesisHydroxylationOxidation Sequence

Co-reporter:Melchior Menzel

European Journal of Organic Chemistry 2014 Volume 2014( Issue 34) pp:7658-7663

Publication Date(Web):

DOI:10.1002/ejoc.201403140

Abstract

Symmetrical vicinal diuloses were prepared from 2,3:4,5-di-O-isopropylidene-D-arabinose and -L-arabinose by using methyltriphenylphosphonium bromide to convert both enantiomers into the corresponding 1,2-dideoxy-3,4:5,6-di-O-isopropylidene-arabino-hex-1-enitols D-5 and L-5. The metathesis reactions of D-5 with itself and with L-5, respectively, by using the Hoveyda–Grubbs catalyst gave diastereomeric dec-5-enitols DD-6 and DL-6, which were dihydroxylated with osmium tetroxide to give 1,2:3,4:7,8:9,10-tetra-O-isopropylidene-protected decitols DD-7 and DL-7. Swern oxidation of the decitols afforded isopropylidene-protected deco-5,6-diuloses DD-8 and DL-8, which gave unprotected deco-5,6-diuloses DD-9 and DL-9 upon acidic cleavage of the isopropylidene groups. The structures of both diastereomers were confirmed by NMR spectroscopy and X-ray crystal structure analysis.

Strategy for catch and release of azide-tagged biomolecules utilizing a photolabile strained alkyne construct

Co-reporter:Martin Golkowski, Carlo Pergola, Oliver Werz and Thomas Ziegler

Organic & Biomolecular Chemistry 2012 vol. 10(Issue 23) pp:4496-4499

Publication Date(Web):26 Apr 2012

DOI:10.1039/C2OB25440A

A photolabile o-nitrobenzyl linker–cyclooctyne conjugate was prepared, immobilized on poly(methacrylate) beads and utilized as a trap for azide-functionalized compounds. These could be released by 365 nm UV light irradiation in high yield and purity. The “reagent-free” and time economic catch and release protocol was deemed useful for chemical proteomics applications.

Synthesis of octyl S-glycosides of tri- to pentasaccharide fragments related to the GPI anchor of Trypanosoma brucei

Co-reporter:Ralf Dettmann, Thomas Ziegler

Carbohydrate Research 2011 Volume 346(Issue 15) pp:2348-2361

Publication Date(Web):8 November 2011

DOI:10.1016/j.carres.2011.08.001

The three oligosaccharide octyl-S-glycosides Man-α1,6-Man-α1,4-GlcNH2-α1,S-Octyl (19), Man-α1,6-(Gal-α1,3)Man-α1,4-GlcNH2-α1,S-Octyl (27) and Man-α1,2-Man-α1,6-(Gal-α1,3)Man-α1,4-GlcNH2-α1,S-Octyl (37), related to the GPI anchor of Trypanosoma brucei were prepared by a stepwise and block-wise approach from octyl 2-azido-2-deoxy-3,6-di-O-benzyl-1-thio-α-d-glucopyranoside (8) and octyl 2-O-benzoyl-4,6-O-(1,1,3,3-tetraisopropyl-1,3-disiloxane-1,3-diyl)-1-thio-α-d-mannopyransoside (9). Glucosamine derivative 8 was obtained from 1,3,4,6-tetra-O-acetyl-2-azido-2-desoxy-β-d-glucopyranose (1) in five steps. Mannoside 9 was converted into the corresponding imidate 12 and coupled with 8 to give disaccharide octyl-S-glycoside 13 which was further mannosylated to afford trisaccharide 19 upon deprotection. Likewise, mannoside 9 was galactosylated, converted into the corresponding imidate and coupled with 8 to give trisaccharide 25. Mannosylation of the latter afforded tetrasaccharide 27 upon deprotection. Condensation of 25 with disaccharide imidate 35 gave, upon deprotection of the intermediates, the corresponding pentasaccharide octyl-S-glycoside 37. Saccharides 19, 27 and 37 are suitable substrates for studying the enzymatic glycosylation pattern of the GPI anchor of T. brucei.

Anomerically glycosylated zinc(II) naphthalocyanines

Co-reporter:Zafar Iqbal, Alexey Lyubimtsev, Michael Hanack, Thomas Ziegler

Tetrahedron Letters 2009 50(40) pp: 5681-5685

Publication Date(Web):

DOI:10.1016/j.tetlet.2009.07.127

Synthesis of an octasubstituted galactose zinc(II) phthalocyanine

Co-reporter:Zafar Iqbal, Michael Hanack, Thomas Ziegler

Tetrahedron Letters 2009 50(8) pp: 873-875

Publication Date(Web):

DOI:10.1016/j.tetlet.2008.12.015

Synthesis of Both Enantiomers of Conduritol C Tetraacetate and of meso-Conduritol D Tetraacetate by Oxidation of Benzoquinone Bis(ethylene acetal)

Co-reporter:Martin Lang

European Journal of Organic Chemistry 2007 Volume 2007(Issue 5) pp:768-776

Publication Date(Web):5 DEC 2006

DOI:10.1002/ejoc.200600764

Epoxidation of p-benzoquinone bis(ethylene acetal) (1) with m-chloroperbenzoic acid or hydrogen peroxide/benzonitrile afforded corresponding monoepoxide 2, which was converted into p-benzoquinone mono(ethylene acetal) monoepoxide 5 with perchloric acid. Dihydroxylation of 1 with osmium tetroxide or ruthenium trichloride/sodium periodate afforded corresponding cis-diol 6, which was subsequently acetylated to give diacetate 7. One ethyleneacetal moiety in 7 could be selectively hydrolyzed with silica gel/ferric chloride under solvent-free conditions to give ketone 8, which, upon reduction with sodium borohydride and subsequent acetylation of the formed alcohol group, afforded two diastereomeric triacetates 10. Hydrolysis of the remaining acetal functions in the two diastereomers 10, followed by reduction of the second carbonyl group as described above, afforded racemic conduritol C and meso-conduritol D tetraacetates 12 and 13, respectively. Enzymatic resolution of the racemic arabino-configured triacetate 10 with Lipozym failed, while the ribo-configured counterpart reacted smoothly to give enantiomerically pure D-ribo- and L-ribo-configured triacetates 10. The latter pair of enantiomerically pure triacetates were converted into both enantiomers of conduritol C tetraacetate 13 as described for the racemic compounds. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Synthesis of Pentasaccharide Fragments Related to the O-Specific Polysaccharide of Shigella flexneri Serotype 1a

Co-reporter:Gregor Lemanski

European Journal of Organic Chemistry 2006 Volume 2006(Issue 11) pp:

Publication Date(Web):27 MAR 2006

DOI:10.1002/ejoc.200600078

The synthesis of the pentasaccharide 5-aminopentylglycosides α-L-Rhap-(13)-[α-D-Glcp-(14)]-β-D-GlcpNAc-(12)-α-L-Rhap-(12)-α-L-Rhap-1-O-(CH₂)₅NH₂ (29) andα-L-Rhap-(13)-α-L-Rhap-(13)-[α-D-Glcp-(14)]-β-D-GlcpNAc-(12)-α-L-Rhap-1-O-(CH₂)₅NH₂ (28), related to the O-specific polysaccharide of Shigella flexneri serotype 1a by coupling of the suitably protected trisaccharides α-D-Glcp-(14)-β-D-Glcp(12)-α-L-Rhap-1-O-(CH₂)₅NH₂ (23) and α-L-Rhap-(13)-[α-D-Glcp-(14)]-β-D-Glcp-1-SPh (26) with the corresponding rhamnosyl glycosides α-L-Rhap-(13)-α-L-Rhap-1-SEt (17) and α-L-Rhap-(13)-α-L-Rhap-1-O-(CH₂)₅NH₂ (13), is described. Building blocks 23 and 26 were prepared by intramolecular glycosylation of an unsymmetrically tethered cellobiosamine derivative. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)

A Versatile Direct Approach to ortho-Substituted Azobenzenes from Benzotriazoles

Co-reporter:Xavier Àlvarez Micó ;Lakshiminarayanapuram R. Subramanian Dr.

Angewandte Chemie 2004 Volume 116(Issue 11) pp:

Publication Date(Web):2 MAR 2004

DOI:10.1002/ange.200352782

. ‥ und Trumpf: Das verborgene Potenzial von Benzotriazolen als Diazonium-Synthons zeigt sich in den Reaktionen von 1-[(Nonafluorbutyl)sulfonyl]-1H-1,2,3-benzotriazol mit Natriumphenoxid zu ortho-substituierten Azobenzolen. Die Reaktion kann durch unterschiedliche Lösungsmittel in Richtung ortho- oder para-Substitution gelenkt werden (siehe das Gemälde von Mathias Hansen, das die Zweigeteiltheit symbolisiert).

A Versatile Direct Approach to ortho-Substituted Azobenzenes from Benzotriazoles

Co-reporter:Xavier Àlvarez Micó ;Lakshiminarayanapuram R. Subramanian Dr.

Angewandte Chemie International Edition 2004 Volume 43(Issue 11) pp:

Publication Date(Web):2 MAR 2004

DOI:10.1002/anie.200352782

A new trump in the synthetic pack: The hidden potential of benzotriazoles to act as diazonium synthons has been witnessed in the reactions of 1-[(nonafluorobutyl)sulfonyl]-1H-1,2,3-benzotriazole with sodium phenoxide in which ortho-substituted azobenezenes were formed. The reaction can be steered towards ortho or para substitution simply by changing the solvent (this dichotomy is shown in an abstract fashion in the painting by Mathias Hansen).

Preparation of glycosyl amino acids as building blocks for the combinatorial synthesis of neoglycoconjugates

Co-reporter:Thomas Ziegler, Dirk Röseling, Lakshminarayanapuram R. Subramanian

Tetrahedron: Asymmetry 2002 Volume 13(Issue 9) pp:911-914

Publication Date(Web):24 June 2002

DOI:10.1016/S0957-4166(02)00212-4

Several neoglycosyl amino acids possessing a sugar residue, a spacer and a trifunctional amino acid moiety were synthesized both in solution and solid phase by activating the carboxylic group as its pentafluorophenyl ester for condensation. The methodology is useful for application in combinatorial syntheses of neoglycoconjugates as potential mimics for oligosaccharides.Several pentafluorophenyl activated glycosyl amino acids have been prepared and used for solution- and solid-phase synthesis of neoglycoconjugates. A library of 256 fully glycosylated tetrapeptides has been prepared by the split–mix methodology.N-Fluorenylmethoxycarbonyl α-([5-aminopentyl]-2,3,4,6-tetra-O-acetyl-β-d-galactopyranosyl)-l-asparaginic acid pentafluorophenyl esterC44H45F5N2O15[α]D20=−7.1 (c 1.0, CHCl3)Source of chirality: optical pure starting materialsN-t-Butyloxycarboyl α-([5-aminopentyl]-2,3,4,6-tetra-O-acetyl-β-d-galactopyranosyl)-l-asparaginic acid benzyl esterC35H50N2O15[α]D20=−6.1 (c 1.0, CHCl3)Source of chirality: optical pure starting materialsα-([5-Aminopentyl]-β-d-glucopyranosyl)-l-asparagyl-(Nα-COα)-l-alaninyl-(Nα-COβ) α-([5-aminopentyl]-β-d-galactopyranosyl)-l-asparaginic acidC33H59N5O18[α]D20=−10.5 (c 0.5, H2O)Source of chirality: optical pure starting materialsN-Fluorenylmethoxycarbonyl α-([5-aminopentyl]-2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl)-l-asparaginic acid pentafluorophenyl esterC44H45F5N2O15[α]D20=−8.6 (c 1.0, CHCl3)Source of chirality: optical pure starting materialsN-t-Butyloxycarbonyl α-([5-aminopentyl]-2,3,4,6-tetra-O-acetyl-β-d-glucopyranosyl)-l-asparaginic acid pentafluorophenyl esterC34H43F5N2O15[α]D20=−14.2 (c 1.0, CHCl3)Source of chirality: optical pure starting materialsN-Fluorenylmethoxycarbonyl α-([5-aminopentyl]-2,3,4,6-tetra-O-acetyl-α-d-mannopyranosyl)-l-asparaginic acid pentafluorophenyl esterC44H45F5N2O15[α]D20=+19.9 (c 1.0, CHCl3)Source of chirality: optical pure starting materials1-(ε-[N-α-Fluorenylmethoxycarbonyl-α-pentafluorophenyl-l-lysine]-4,5,6,7-tetra-O-acetyl-3,7-anhydro-d-glycero-d-gulo-octanosyl amideC43H43F5N2O14[α]D20=−11.5 (c 1.0, CHCl3)Source of chirality: optical pure starting materials

Strategy for catch and release of azide-tagged biomolecules utilizing a photolabile strained alkyne construct

Co-reporter:Martin Golkowski, Carlo Pergola, Oliver Werz and Thomas Ziegler

Organic & Biomolecular Chemistry 2012 - vol. 10(Issue 23) pp:NaN4499-4499

Publication Date(Web):2012/04/26

DOI:10.1039/C2OB25440A