Boosting the utilization efficiency of glucose via a favored C–C coupling reaction

Abstract

The efficient utilization of renewable glucose has enormous potential to reduce the excessive dependence on fossil resources, but remains challenging owing to the inevitable formation of undesirable humins and multistep processes.

1H NMR Elucidation of Observed Stable Sugar-NaCl-water Complexes in Aqueous Solution

“…Recommended absolute amount of NaCl in solution is 3.5 -4.0 equivalent to total hydroxyl of saccharides (including protons on amine moiety if glucosamine-based saccharides were used) based on observed maximum NMR shift forming stable sugar-NaCl-water complexes. This recommended ideal usage is consistent with optimized condition in recent reported literature20…”

“…Further system study of the role of metal halide in enhancing the dehydration of xylose to furfural by K. R. Enslow et.al 16 and insights from quantum mechanics/molecule dynamics on sodium ion interaction by H. B. Mayes et.al 17 both confirmed the previous hypothesis, which states that the cation has a stronger effect than the anion on glucose with the anions acting to stabilize critical intermediates. However, very recent higher yield productions of chemicals from monosaccharides in aqueous solution promoted by NaCl [18][19][20] challenged the minor role hypothesis of chloride anion in a NaCl promoted system. The nature of complex-formation between sodium and monosaccharides is not yet well understood, particularly at atom level.…”

1H NMR Elucidation of Observed Stable Sugar-NaCl-water Complexes in Aqueous Solution

“…Recommended absolute amount of NaCl in solution is 3.5 -4.0 equivalent to total hydroxyl of saccharides (including protons on amine moiety ifglucosamine-based saccharides were used) based on observed maximum H NMR shift forming stable sugar-NaCl-water complexes. This recommended ideal usage is consistent with optimized condition in recent reported literature 20 . For temperature, room temperature is usually sufficient for monosaccharides and oligosaccharides which are soluble in water; however, typically increase of temperature was pretty necessary for cellulose depolymerization according to a recent report 22 that "NaCl effect" was only be obvious at above 210℃.…”

1H NMR Elucidation of Observed Stable Sugar-NaCl-water Complexes in Aqueous Solution

“…Further system study of the role of metal halide in enhancing the dehydration of xylose to furfural by K. R. Enslow et.al 16 and insights from quantum mechanics/molecular dynamics on sodium ion interaction by H. B. Mayes et.al 17 both confirmed the previous hypothesis, which states that the cation has a stronger effect than the anion on glucose with the anions acting to stabilize critical intermediates. However, very recent higher yield productions of chemicals from monosaccharides in aqueous solution promoted by NaCl [18][19][20] challenged the minor role hypothesis of chloride anion in NaCl promoted system. The nature of complex-formation between sodium and monosaccharides…”