101615-87-6Relevant articles and documents
Successive C1-C2 bond cleavage: The mechanism of vanadium(v)-catalyzed aerobic oxidation of d-glucose to formic acid in aqueous solution
Niu, Muge,Hou, Yucui,Wu, Weize,Ren, Shuhang,Yang, Ru
, p. 17942 - 17951 (2018)
Vanadium(v)-catalyzed aerobic oxidation in aqueous solution shows high selectivity in the field of C-C bond cleavage of carbohydrates for chemicals with less carbon atoms. However, the pathway of C-C bond cleavage from carbohydrates and the conversion mechanism are unclear. In this work, we studied the pathway and the mechanism of d-glucose oxidation to formic acid (FA) in NaVO3-H2SO4 aqueous solution using isotope-labeled glucoses as substrates. d-Glucose is first transformed to FA and d-arabinose via C1-C2 bond cleavage. d-Arabinose undergoes similar C1-C2 bond cleavage to form FA and the corresponding d-erythrose, which can be further degraded by C1-C2 bond cleavage. Dimerization and aldol condensation between carbohydrates can also proceed to make the reaction a much more complicated mixture. However, the fundamental reaction, C1-C2 bond cleavage, can drive all the intermediates to form the common product FA. Based on the detected intermediates, isotope-labelling experiments, the kinetic isotope effect study and kinetic analysis, this mechanism is proposed. d-Glucose first reacts with a vanadium(v) species to form a five-membered-ring complex. Then, electron transfer occurs and the C1-C2 bond weakens, followed by C1-C2 bond cleavage (with no C-H bond cleavage), to generate the H3COO-vanadium(iv) complex and d-arabinose. FA is generated from H3COO that is oxidized by another vanadium(v) species. The reduced vanadium species is oxidized by O2 to regenerate to its oxidation state. This finding will provide a deeper insight into the process of C-C bond cleavage of carbohydrates for chemical synthesis and provide guidance for screening and synthesizing new highly-efficient catalyst systems for FA production.
Paramolybdate anion-exchange resin, an improved catalyst for the C-1-C-2 rearrangement and 2-epimerization of aldoses.
Clark Jr.,Hayes,Barker
, p. 263 - 270 (2007/10/02)
Aqueous solutions of molybdate at 90 degrees bring about the inversion of the C-1-C-2 fragment of aldoses having four or more carbon atoms, generating thermodynamically equilibrated mixtures of the starting aldose and its 2-epimer. In some cases, notably with the aldopentoses, substantial proportions of the 3-epimers are produced, as well as 2-epimers that have not undergone inversion of the C-1-C-2 fragment. These side-reactions can be controlled by using the paramolybdate form of an anion-exchange resin (AG MP-1) together with the formate form of the same resin. The latter acts to scavenge unbound molybdate and paramolybdate anions that appear to be responsible for the side reactions.
