Marcel Meiland | Friedrich-Schiller-Universität Jena (original) (raw)

Papers by Marcel Meiland

Research paper thumbnail of Studies on the boronation of methyl-β-d-cellobioside—a cellulose model

Carbohydrate Research, 2010

The conversion of phenylboronic acid (PBA) with methyl-beta-D-cellobioside (Me-beta-D-clb) and ce... more The conversion of phenylboronic acid (PBA) with methyl-beta-D-cellobioside (Me-beta-D-clb) and cellodextrins (DP(w) 12) was investigated to gain a basic understanding of the interactions of boric acid derivatives with oligo- and polyglucans. By means of MS and NMR experiments, it was possible to show a first stage formation of a six-membered ring at C-4 and C-6 of the non-reducing glucose occurs as in the case of monosaccharides. If the amount of reagent is increased the formation of seven-membered rings at the secondary OH moieties is observed. Even the existence of two of these large ring-systems in the direct neighborhood was found. Application of an excess of boronation reagent led to dimerization reactions of Me-beta-D-clb via the primary reducing glucose residue as confirmed by DOSY NMR studies. Preliminary (13)C NMR studies for the interaction of cellodextrins with PBA in DMSO solution confirmed a functionalization at the trans-1,2-diol moieties of these oligomers. The amount of reagent applied may either was shown to lead to soluble products or to insoluble cross-linked material.

Research paper thumbnail of Alkyl β-d-cellulosides: non-reducing cellulose mimics

Cellulose, Aug 17, 2011

Non-reducing cellulose mimics, termed alkyl β-d-cellulosides, were successfully prepared by two e... more Non-reducing cellulose mimics, termed alkyl β-d-cellulosides, were successfully prepared by two efficient multi-step syntheses starting from commercially available microcrystalline cellulose or cellulose triacetate. Introduction of the alkoxy moiety and degradation of the cellulose backbone was carried out in the presence of a Lewis acid, on one hand. On the other hand, cellulose hydrolysis mediated by mineral acids was combined with

Research paper thumbnail of Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose

Macromolecular Materials and Engineering, May 3, 2011

Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose www.mme-journal.de Schul... more Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose www.mme-journal.de Schulze from the Thuringian Institute of Textile and Plastics Research e.V., Rudolstadt, for the X-ray scattering measurements.

Research paper thumbnail of Seven-membered ring boronates at trans-diol moieties of carbohydrates

Tetrahedron Letters, 2009

Research paper thumbnail of Cellulose-Modellverbindungen : Darstellung und Interaktion mit Boronsäuren

Selektive, effiziente und komplexe Modifizierungsschritte am Biopolymer Cellulose sind haufig nur... more Selektive, effiziente und komplexe Modifizierungsschritte am Biopolymer Cellulose sind haufig nur nach Aktivierung oder einem gezielten Losen vor der Umsetzung moglich. So werden bei industriellen Verfahren zur Hydroxyalkylierung und Carboxymethylierung von Zellstoff zur Gewinnung von wasserloslichen Cellulosederivaten Borsaure und Borate als Aktivierungsreagenzien eingesetzt. Es existiert allerdings kein detailliertes Verstandnis zum Aktivierungsprozess und den gebildeten Intermediaten. Ziel der Arbeit war es daher einen grundlegenden Beitrag zum Verstandnis der Borsaureinteraktion mit Cellulose zu leisten. Dazu wurden auf der einen Seite sowohl reduzierende als auch nicht-reduzierende Cellulose-Modellverbindungen mit einem breiten Spektrum an durchschnittlichen Polymerisationsgraden dargestellt. Auf der anderen Seite untersuchte man die Wechselwirkung von Modellverbindungen mit Boronsauren, die im Vergleich zu trivalenter Borsaure weniger zur Vernetzung der Celluloseketten neigen,...

Research paper thumbnail of Seven-membered ring boronates at trans-diol moieties of carbohydrates

Tetrahedron Letters, 2009

Research paper thumbnail of Alkyl β-d-cellulosides: non-reducing cellulose mimics

Cellulose, 2011

Non-reducing cellulose mimics, termed alkyl β-d-cellulosides, were successfully prepared by two e... more Non-reducing cellulose mimics, termed alkyl β-d-cellulosides, were successfully prepared by two efficient multi-step syntheses starting from commercially available microcrystalline cellulose or cellulose triacetate. Introduction of the alkoxy moiety and degradation of the cellulose backbone was carried out in the presence of a Lewis acid, on one hand. On the other hand, cellulose hydrolysis mediated by mineral acids was combined with

Research paper thumbnail of Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose

Macromolecular Materials and Engineering, 2011

Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose www.mme-journal.de Schul... more Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose www.mme-journal.de Schulze from the Thuringian Institute of Textile and Plastics Research e.V., Rudolstadt, for the X-ray scattering measurements.

Research paper thumbnail of Studies on the boronation of methyl-�- d-cellobioside�a cellulose model

Research paper thumbnail of Studies on the boronation of methyl-β-D-cellobioside-a cellulose model

Carbohydrate Research, Jan 26, 2010

The conversion of phenylboronic acid (PBA) with methyl-β-d-cellobioside (Me-β-d-clb) and cellodex... more The conversion of phenylboronic acid (PBA) with methyl-β-d-cellobioside (Me-β-d-clb) and cellodextrins (DPw 12) was investigated to gain a basic understanding of the interactions of boric acid derivatives with oligo- and polyglucans. By means of MS and NMR experiments, it was possible to show a first stage formation of a six-membered ring at C-4 and C-6 of the non-reducing glucose occurs

Research paper thumbnail of Seven-membered ring boronates at trans-diol moieties of carbohydrates

Tetrahedron Letters, 2009

C NMR spectroscopy 11 B NMR spectroscopy trans-1,2-Diol Methyl-a-D-glucopyranoside a b s t r a c ... more C NMR spectroscopy 11 B NMR spectroscopy trans-1,2-Diol Methyl-a-D-glucopyranoside a b s t r a c t MS and 1 H, 13 C and 11 B NMR results are presented revealing the formation of cyclic seven-membered boronate structures at trans-1,2-diol moieties of carbohydrates providing new opportunities for the activation, protection and analysis of glucopyranose-based oligomers and polymers such as cellulose or starch. 'Coordination-induced shifts' in 13 C NMR spectra were identified for the esterification by boronic acids of carbohydrates, which can be applied for further studies.

Research paper thumbnail of Alkyl β-d-cellulosides: non-reducing cellulose mimics

Cellulose, 2011

Non-reducing cellulose mimics, termed alkyl β-d-cellulosides, were successfully prepared by two e... more Non-reducing cellulose mimics, termed alkyl β-d-cellulosides, were successfully prepared by two efficient multi-step syntheses starting from commercially available microcrystalline cellulose or cellulose triacetate. Introduction of the alkoxy moiety and degradation of the cellulose backbone was carried out in the presence of a Lewis acid, on one hand. On the other hand, cellulose hydrolysis mediated by mineral acids was combined with

Research paper thumbnail of Studies on the boronation of methyl-β-d-cellobioside—a cellulose model

Carbohydrate Research, 2010

The conversion of phenylboronic acid (PBA) with methyl-beta-D-cellobioside (Me-beta-D-clb) and ce... more The conversion of phenylboronic acid (PBA) with methyl-beta-D-cellobioside (Me-beta-D-clb) and cellodextrins (DP(w) 12) was investigated to gain a basic understanding of the interactions of boric acid derivatives with oligo- and polyglucans. By means of MS and NMR experiments, it was possible to show a first stage formation of a six-membered ring at C-4 and C-6 of the non-reducing glucose occurs as in the case of monosaccharides. If the amount of reagent is increased the formation of seven-membered rings at the secondary OH moieties is observed. Even the existence of two of these large ring-systems in the direct neighborhood was found. Application of an excess of boronation reagent led to dimerization reactions of Me-beta-D-clb via the primary reducing glucose residue as confirmed by DOSY NMR studies. Preliminary (13)C NMR studies for the interaction of cellodextrins with PBA in DMSO solution confirmed a functionalization at the trans-1,2-diol moieties of these oligomers. The amount of reagent applied may either was shown to lead to soluble products or to insoluble cross-linked material.

Research paper thumbnail of Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose

The degradation of cellulose to lmw samples with DP w varying from 15 to 130 is investigated. Cel... more The degradation of cellulose to lmw samples with DP w varying from 15 to 130 is investigated. Cellulose samples prepared from the hydrolysis of regenerated cellulose fibers in dilute HCl possess DP w ¼ 50. Applying homogenous degradation of microcrystalline cellulose in H 3 PO 4 at RT for 3 weeks, samples with DP w ¼ 35 and a PDI of 1.58 are obtained. Decreasing the hydrolysis temperature to 8 8C results in lmw cellulose with DP w > 70. Fractionation in DMA/LiCl provides samples with DP w ¼ 12 to 130, together with a narrow molecular weight distribution. Detailed structural analysis by 2D NMR spectroscopy reveals that the prepared lmw celluloses are suitable as mimics for cellulose.

Research paper thumbnail of Studies on the boronation of methyl-β-d-cellobioside—a cellulose model

Carbohydrate Research, 2010

The conversion of phenylboronic acid (PBA) with methyl-beta-D-cellobioside (Me-beta-D-clb) and ce... more The conversion of phenylboronic acid (PBA) with methyl-beta-D-cellobioside (Me-beta-D-clb) and cellodextrins (DP(w) 12) was investigated to gain a basic understanding of the interactions of boric acid derivatives with oligo- and polyglucans. By means of MS and NMR experiments, it was possible to show a first stage formation of a six-membered ring at C-4 and C-6 of the non-reducing glucose occurs as in the case of monosaccharides. If the amount of reagent is increased the formation of seven-membered rings at the secondary OH moieties is observed. Even the existence of two of these large ring-systems in the direct neighborhood was found. Application of an excess of boronation reagent led to dimerization reactions of Me-beta-D-clb via the primary reducing glucose residue as confirmed by DOSY NMR studies. Preliminary (13)C NMR studies for the interaction of cellodextrins with PBA in DMSO solution confirmed a functionalization at the trans-1,2-diol moieties of these oligomers. The amount of reagent applied may either was shown to lead to soluble products or to insoluble cross-linked material.

Research paper thumbnail of Alkyl β-d-cellulosides: non-reducing cellulose mimics

Cellulose, Aug 17, 2011

Non-reducing cellulose mimics, termed alkyl β-d-cellulosides, were successfully prepared by two e... more Non-reducing cellulose mimics, termed alkyl β-d-cellulosides, were successfully prepared by two efficient multi-step syntheses starting from commercially available microcrystalline cellulose or cellulose triacetate. Introduction of the alkoxy moiety and degradation of the cellulose backbone was carried out in the presence of a Lewis acid, on one hand. On the other hand, cellulose hydrolysis mediated by mineral acids was combined with

Research paper thumbnail of Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose

Macromolecular Materials and Engineering, May 3, 2011

Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose www.mme-journal.de Schul... more Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose www.mme-journal.de Schulze from the Thuringian Institute of Textile and Plastics Research e.V., Rudolstadt, for the X-ray scattering measurements.

Research paper thumbnail of Seven-membered ring boronates at trans-diol moieties of carbohydrates

Tetrahedron Letters, 2009

Research paper thumbnail of Cellulose-Modellverbindungen : Darstellung und Interaktion mit Boronsäuren

Selektive, effiziente und komplexe Modifizierungsschritte am Biopolymer Cellulose sind haufig nur... more Selektive, effiziente und komplexe Modifizierungsschritte am Biopolymer Cellulose sind haufig nur nach Aktivierung oder einem gezielten Losen vor der Umsetzung moglich. So werden bei industriellen Verfahren zur Hydroxyalkylierung und Carboxymethylierung von Zellstoff zur Gewinnung von wasserloslichen Cellulosederivaten Borsaure und Borate als Aktivierungsreagenzien eingesetzt. Es existiert allerdings kein detailliertes Verstandnis zum Aktivierungsprozess und den gebildeten Intermediaten. Ziel der Arbeit war es daher einen grundlegenden Beitrag zum Verstandnis der Borsaureinteraktion mit Cellulose zu leisten. Dazu wurden auf der einen Seite sowohl reduzierende als auch nicht-reduzierende Cellulose-Modellverbindungen mit einem breiten Spektrum an durchschnittlichen Polymerisationsgraden dargestellt. Auf der anderen Seite untersuchte man die Wechselwirkung von Modellverbindungen mit Boronsauren, die im Vergleich zu trivalenter Borsaure weniger zur Vernetzung der Celluloseketten neigen,...

Research paper thumbnail of Seven-membered ring boronates at trans-diol moieties of carbohydrates

Tetrahedron Letters, 2009

Research paper thumbnail of Alkyl β-d-cellulosides: non-reducing cellulose mimics

Cellulose, 2011

Non-reducing cellulose mimics, termed alkyl β-d-cellulosides, were successfully prepared by two e... more Non-reducing cellulose mimics, termed alkyl β-d-cellulosides, were successfully prepared by two efficient multi-step syntheses starting from commercially available microcrystalline cellulose or cellulose triacetate. Introduction of the alkoxy moiety and degradation of the cellulose backbone was carried out in the presence of a Lewis acid, on one hand. On the other hand, cellulose hydrolysis mediated by mineral acids was combined with

Research paper thumbnail of Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose

Macromolecular Materials and Engineering, 2011

Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose www.mme-journal.de Schul... more Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose www.mme-journal.de Schulze from the Thuringian Institute of Textile and Plastics Research e.V., Rudolstadt, for the X-ray scattering measurements.

Research paper thumbnail of Studies on the boronation of methyl-�- d-cellobioside�a cellulose model

Research paper thumbnail of Studies on the boronation of methyl-β-D-cellobioside-a cellulose model

Carbohydrate Research, Jan 26, 2010

The conversion of phenylboronic acid (PBA) with methyl-β-d-cellobioside (Me-β-d-clb) and cellodex... more The conversion of phenylboronic acid (PBA) with methyl-β-d-cellobioside (Me-β-d-clb) and cellodextrins (DPw 12) was investigated to gain a basic understanding of the interactions of boric acid derivatives with oligo- and polyglucans. By means of MS and NMR experiments, it was possible to show a first stage formation of a six-membered ring at C-4 and C-6 of the non-reducing glucose occurs

Research paper thumbnail of Seven-membered ring boronates at trans-diol moieties of carbohydrates

Tetrahedron Letters, 2009

C NMR spectroscopy 11 B NMR spectroscopy trans-1,2-Diol Methyl-a-D-glucopyranoside a b s t r a c ... more C NMR spectroscopy 11 B NMR spectroscopy trans-1,2-Diol Methyl-a-D-glucopyranoside a b s t r a c t MS and 1 H, 13 C and 11 B NMR results are presented revealing the formation of cyclic seven-membered boronate structures at trans-1,2-diol moieties of carbohydrates providing new opportunities for the activation, protection and analysis of glucopyranose-based oligomers and polymers such as cellulose or starch. 'Coordination-induced shifts' in 13 C NMR spectra were identified for the esterification by boronic acids of carbohydrates, which can be applied for further studies.

Research paper thumbnail of Alkyl β-d-cellulosides: non-reducing cellulose mimics

Cellulose, 2011

Non-reducing cellulose mimics, termed alkyl β-d-cellulosides, were successfully prepared by two e... more Non-reducing cellulose mimics, termed alkyl β-d-cellulosides, were successfully prepared by two efficient multi-step syntheses starting from commercially available microcrystalline cellulose or cellulose triacetate. Introduction of the alkoxy moiety and degradation of the cellulose backbone was carried out in the presence of a Lewis acid, on one hand. On the other hand, cellulose hydrolysis mediated by mineral acids was combined with

Research paper thumbnail of Studies on the boronation of methyl-β-d-cellobioside—a cellulose model

Carbohydrate Research, 2010

The conversion of phenylboronic acid (PBA) with methyl-beta-D-cellobioside (Me-beta-D-clb) and ce... more The conversion of phenylboronic acid (PBA) with methyl-beta-D-cellobioside (Me-beta-D-clb) and cellodextrins (DP(w) 12) was investigated to gain a basic understanding of the interactions of boric acid derivatives with oligo- and polyglucans. By means of MS and NMR experiments, it was possible to show a first stage formation of a six-membered ring at C-4 and C-6 of the non-reducing glucose occurs as in the case of monosaccharides. If the amount of reagent is increased the formation of seven-membered rings at the secondary OH moieties is observed. Even the existence of two of these large ring-systems in the direct neighborhood was found. Application of an excess of boronation reagent led to dimerization reactions of Me-beta-D-clb via the primary reducing glucose residue as confirmed by DOSY NMR studies. Preliminary (13)C NMR studies for the interaction of cellodextrins with PBA in DMSO solution confirmed a functionalization at the trans-1,2-diol moieties of these oligomers. The amount of reagent applied may either was shown to lead to soluble products or to insoluble cross-linked material.

Research paper thumbnail of Tailoring the Degree of Polymerization of Low Molecular Weight Cellulose

The degradation of cellulose to lmw samples with DP w varying from 15 to 130 is investigated. Cel... more The degradation of cellulose to lmw samples with DP w varying from 15 to 130 is investigated. Cellulose samples prepared from the hydrolysis of regenerated cellulose fibers in dilute HCl possess DP w ¼ 50. Applying homogenous degradation of microcrystalline cellulose in H 3 PO 4 at RT for 3 weeks, samples with DP w ¼ 35 and a PDI of 1.58 are obtained. Decreasing the hydrolysis temperature to 8 8C results in lmw cellulose with DP w > 70. Fractionation in DMA/LiCl provides samples with DP w ¼ 12 to 130, together with a narrow molecular weight distribution. Detailed structural analysis by 2D NMR spectroscopy reveals that the prepared lmw celluloses are suitable as mimics for cellulose.