600-17-9Relevant articles and documents
Rambaud
, p. 1348 ()
Shape-selective Valorization of Biomass-derived Glycolaldehyde using Tin-containing Zeolites
Tolborg, S?ren,Meier, Sebastian,Saravanamurugan, Shunmugavel,Fristrup, Peter,Taarning, Esben,Sádaba, Irantzu
, p. 3054 - 3061 (2016/11/17)
A highly selective self-condensation of glycolaldehyde to different C4 molecules has been achieved using Lewis acidic stannosilicate catalysts in water at moderate temperatures (40–100 °C). The medium-sized zeolite pores (10-membered ring framework) in Sn-MFI facilitate the formation of tetrose sugars while hindering consecutive aldol reactions leading to hexose sugars. High yields of tetrose sugars (74 %) with minor amounts of vinyl glycolic acid (VGA), an α-hydroxyacid, are obtained using Sn-MFI with selectivities towards C4 products reaching 97 %. Tin catalysts having large pores or no pore structure (Sn-Beta, Sn-MCM-41, Sn-SBA-15, tin chloride) led to lower selectivities for C4 sugars due to formation of hexose sugars. In the case of Sn-Beta, VGA is the main product (30 %), illustrating differences in selectivity of the Sn sites in the different frameworks. Under optimized conditions, GA can undergo further conversion, leading to yields of up to 44 % of VGA using Sn-MFI in water. The use of Sn-MFI offers multiple possibilities for valorization of biomass-derived GA in water under mild conditions selectively producing C4 molecules.
Mechanistic Studies on the Cascade Conversion of 1,3-Dihydroxyacetone and Formaldehyde into α-Hydroxy-γ-butyrolactone
Yamaguchi, Sho,Matsuo, Takeaki,Motokura, Ken,Sakamoto, Yasuharu,Miyaji, Akimitsu,Baba, Toshihide
, p. 853 - 860 (2015/06/02)
Abstract The chemical synthesis of commercially and industrially important products from biomass-derived sugars is absolutely vital to establish biomass utilization as a sustainable alternative source of chemical starting materials. α-Hydroxy-γ-butyrolactone is a useful synthetic intermediate in pharmaceutical chemistry, and so novel biomass-related routes for its production may help to validate this eco-friendly methodology. Herein, we report the specific catalytic activity of homogeneous tin halides to convert the biomass-derived triose sugar 1,3-dihydroxyacetone and formaldehyde into α-hydroxy-γ-butyrolactone. A detailed screening of catalysts showed the suitability of tin catalysts for this reaction system, and isotope experiments using [D2]paraformaldehyde, substrate screening, and time profile measurements allowed us to propose a detailed reaction pathway. In addition, to elucidate the activated species in this cascade reaction, the effect of additional water and the influence of additional Bronsted acids on the reaction preferences for the formation of α-hydroxy-γ-butyrolactone, lactic acid, and vinyl glycolate were investigated. The active form of the Sn catalyst was investigated by 119Sna NMR spectroscopy. Specific catalytic activity of homogeneous tin halides: We present a complete map of the synthetic pathway to α-hydroxy-γ-butyrolactone and related byproducts from 1,3-dihydroxyacetone and formaldehyde. Furthermore, we propose a catalytic mechanism and a valence state of the catalyst in the reaction mixture based on the results of 119Sn NMR spectroscopy.
