Catalytic conversion of carbohydrates into 5-hydroxymethylfurfural by germanium(IV) chloride in ionic liquids.

Zehui Zhang, Qian Wang, Haibo Xie, Wujun Liu, Zongbao Kent Zhao

Index: ChemSusChem 4(1) , 131-8, (2011)

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Abstract

Direct conversion of carbohydrates into 5-hydroxymethylfurfural (HMF) catalyzed by germanium(IV) chloride in ionic liquids has been investigated in search of an efficient and environmentally friendly process. Monosaccharides D-fructose and D-glucose, disaccharides sucrose and maltose, and even the polysaccharide cellulose were successfully converted into HMF with good yields under mild conditions (yield up to 92 % in 5 min in the case of fructose). The structure of ionic liquids, catalyst loading, reaction temperature and water content had noticeable effects on this catalytic system. Addition of 5 Å molecular sieves during the dehydration of glucose resulted in an increase in HMF yield from 38.4 % to 48.4 %. A mechanism for glucose conversion to HMF catalyzed by germanium(IV) chloride was proposed according to ¹³C NMR spectra obtained in situ under different conditions using D-glucose-2-¹³C as the substrate.Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.