A Clean Conversion ofD-Glucosamine Hydrochloride to a Pyrazine in the Presence of Phenylboronate or Borate

Rohovec, Jan; Kotek, Jan; Peters, Joop A.; Maschmeyer, Thomas

doi:10.1002/1099-0690(200110)2001:20<3899::aid-ejoc3899>3.0.co;2-g

Cited by 45 publications

(18 citation statements)

References 17 publications

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“…7). [44][45][46] Based on the above NMR spectral study, a plausible reaction pathway was proposed in order to elucidate the catalysis process for the formation of the two pyrazine derivatives with this specific [C 2 C 1 Im][OAc]. The surprising finding was that the mechanism of catalysis highlighted the importance of not only the electrophilic nucleophilic dual activation through hydrogen bonding interactions but also activation of the nitrogen lone pair electrons by [C 2 C 1 Im][OAc], facilitating further nucleophilic addition reactions and leading to the formation of DOF and FZ.…”

Section: Resultsmentioning

confidence: 99%

Glucosamine condensation catalyzed by 1-ethyl-3-methylimidazolium acetate: mechanistic insight from NMR spectroscopy

Jia

Pedersen

Qiao

et al. 2015

Phys. Chem. Chem. Phys.

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The basic ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2C1Im][OAc]) could efficiently catalyze the conversion of 2-amino-2-deoxy-d-glucose (GlcNH2) into deoxyfructosazine (DOF) and fructosazine (FZ). Mechanistic investigation by NMR studies disclosed that [C2C1Im][OAc], exhibiting strong hydrogen bonding basicity, could coordinate with the hydroxyl and amino groups of GlcNH2via the promotion of hydrogen bonding in bifunctional activation of substrates and further catalyzing product formation, based on which a plausible reaction pathway involved in this homogeneous base-catalyzed reaction was proposed. Hydrogen bonding as an activation force, therefore, is responsible for the remarkable selectivity and rate enhancement observed.

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Section: Resultsmentioning

confidence: 99%

Glucosamine condensation catalyzed by 1-ethyl-3-methylimidazolium acetate: mechanistic insight from NMR spectroscopy

Jia

Pedersen

Qiao

et al. 2015

Phys. Chem. Chem. Phys.

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“…Remarkably, typical byproducts observed in GlcNH 2 conversion, such as 5-HMF, LA and low molecule weight volatile pyrazine derivatives were not detected in our experiments. 15,18 In previous research, pyrolysis of solid-state GlcNH 2 at high temperature (200 C) or thermal degradation of GlcNH 2 in aqueous solution above 100 C yielded a mixture of products, such as furans, pyrazines and pyridines. 30 Severe reaction conditions and unsuitable reaction systems may be responsible for the production of unwanted byproducts so that these methods cannot achieve a selective production of desired compounds.…”

Section: Characterization Of the Productsmentioning

confidence: 99%

“…13,14 Moreover, GlcNH 2 , the monomer unit of chitosan, could undergo self-condensation to produce DOF as the sole product catalyzed by phenylboronic acid and sodium hydroxide with relatively high yield. 15 In addition, condensation of two moles of GlcNH 2 or D-mannosamine in hot methanol could produce FZ. 16 However, the distribution of the reaction products could be easily inuenced by the additional amino acids, different kinds of ammonium salts and the pH of the reaction mixture.…”

Section: Introductionmentioning

confidence: 99%

“…Because of the complexity of the Maillard reaction, species with different molecular weight, such as furfural, volatile and semivolatile pyrazine derivatives, could be observed as by-products in such reactions. 13,15,16 Although high product yield and substrate conversion could be achieved for the catalytic Maillard reactions in aqueous solution, conventional bases or organic acids are commonly employed. Consequently, neutralization and salt removal procedures are necessary, which make reaction processes relatively complex and bring undesired side products to the reaction system.…”

Section: Introductionmentioning

confidence: 99%

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Efficient one-pot synthesis of deoxyfructosazine and fructosazine fromd-glucosamine hydrochloride using a basic ionic liquid as a dual solvent-catalyst

et al. 2014

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An efficient one-pot dehydration process for convert D-glucosamine hydrochloride (GlcNH 2 ) into 2-(D-arabino-1 0 ,2 0 ,3 0 ,4 0 -tetrahydroxybutyl)-5-(D-erythro-2 00 ,3 00 ,4 00 -trihydroxybutyl)pyrazine (deoxyfructosazine, DOF) and 2,5-bis-(D-arabino-1,2,3,4-tetrahydroxybutyl)pyrazine (fructosazine, FZ) was reported. A taskspecific basic ionic liquid, 1-butyl-3-methylimidazolium hydroxide ([BMIM]OH), was employed as an environmentally-friendly solvent and catalyst. The products were qualitatively and quantitatively characterized by MALDI-TOF-MS, 1 H NMR and 13 C NMR spectroscopy. The influences of GlcNH 2 concentrations, reaction temperature, reaction time, additives and co-solvents on the yields of products were studied. The maximum yield of 49% was obtained in the presence of [BMIM]OH and DMSO under optimized conditions (120 C, 180 min). In addition, a plausible mechanism was proposed. Our project was to develop efficient, atom economical and eco-compatible routes for the synthesis of heterocyclic compounds from marine biomass (or nitrogen-containing biomass). The obtained aromatic heterocyclic compounds showed potential pharmacological action and physiological effects, and they also could be utilized as flavoring agents in the food industry.

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“…The observed shift of the signal to a lower frequency indicated additional structural transformation of the spirocyclic borate anions. Most likely, these species were more tightly incorporated into the polymer matrix through additional N-type (amino) cross-links, 34 For preliminary experimental verification of the proposed sixmembered spirocyclic borate anions we applied 1 H− 11 B correlation spectroscopy. In this respect, we focused on probing the 1 H polarization transfer from oxymethylene hydrogen atoms (ca.…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Structure and Distribution of Cross-Links in Boron-Modified Phenol–Formaldehyde Resins Designed for Soft Magnetic Composites: A Multiple-Quantum ¹¹B–¹¹B MAS NMR Correlation Spectroscopy Study

et al. 2015

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Despite the extensive use of boron-modified phenol−formaldehyde polymers as insulating materials in soft magnetic composites (SMCs), the structure and arrangement of the inorganic cross-linking units in these systems have not been fully elucidated. To clarify the structure, configuration, and distribution of the boron cross-links in these materials, phenol−formaldehyde resins modified by boric acid were synthesized and characterized using advanced multiplequantum 11 B− 11 B MAS NMR correlation techniques combined with the quantum chemical geometry optimizations and the subsequent 11 B NMR chemical shielding calculations. The analyses of the resulting spectra revealed a well-evolved (highdensity) phenol−formaldehyde polymer network additionally strengthened by nitrogen and boron cross-links. The boron-based cross-links were attributed to monoester (ca. 10%) and diester (ca. 90%) complexes (six-membered spirocyclic borate anions) with strictly tetrahedral coordination (B IV ). During the thermal treatment, the monoester and diester borate complexes underwent additional transformation in which the spirocyclic borate anions were more tightly incorporated into the polymer matrix via additional N-type (amino) cross-links. A 11 B− 11 B double-quantum correlation MAS NMR experiment revealed that the majority of the monoester and diester borate complexes (ca. 80%) were uniformly distributed within and effectively isolated by the polymer matrix, with an average 11 B··· 11 B interatomic distance greater than 6 Å. A non-negligible part of the spirocyclic borate anion complexes (ca. 20%), however, existed in pairs or small clusters in which the average 11 B··· 11 B interatomic distance was less than 5.5 Å. In addition, the formation of homodimers (diester−diester) was demonstrated to be preferred over the formation of heteroclusters (monoester−diester).

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A Clean Conversion ofD-Glucosamine Hydrochloride to a Pyrazine in the Presence of Phenylboronate or Borate

Cited by 45 publications

References 17 publications

Glucosamine condensation catalyzed by 1-ethyl-3-methylimidazolium acetate: mechanistic insight from NMR spectroscopy

Glucosamine condensation catalyzed by 1-ethyl-3-methylimidazolium acetate: mechanistic insight from NMR spectroscopy

Efficient one-pot synthesis of deoxyfructosazine and fructosazine fromd-glucosamine hydrochloride using a basic ionic liquid as a dual solvent-catalyst

Structure and Distribution of Cross-Links in Boron-Modified Phenol–Formaldehyde Resins Designed for Soft Magnetic Composites: A Multiple-Quantum ¹¹B–¹¹B MAS NMR Correlation Spectroscopy Study

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A Clean Conversion ofD-Glucosamine Hydrochloride to a Pyrazine in the Presence of Phenylboronate or Borate

Cited by 45 publications

References 17 publications

Glucosamine condensation catalyzed by 1-ethyl-3-methylimidazolium acetate: mechanistic insight from NMR spectroscopy

Glucosamine condensation catalyzed by 1-ethyl-3-methylimidazolium acetate: mechanistic insight from NMR spectroscopy

Efficient one-pot synthesis of deoxyfructosazine and fructosazine fromd-glucosamine hydrochloride using a basic ionic liquid as a dual solvent-catalyst

Structure and Distribution of Cross-Links in Boron-Modified Phenol–Formaldehyde Resins Designed for Soft Magnetic Composites: A Multiple-Quantum 11B–11B MAS NMR Correlation Spectroscopy Study

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Structure and Distribution of Cross-Links in Boron-Modified Phenol–Formaldehyde Resins Designed for Soft Magnetic Composites: A Multiple-Quantum ¹¹B–¹¹B MAS NMR Correlation Spectroscopy Study