Switchable product selectivity in dehydration of N-acetyl-d-glucosamine promoted by choline chloride-based deep eutectic solvents

• Published in: iScience Vol. 26; no. 7; p. 106980
• Main Authors: Zhao, Jiancheng, Pedersen, Christian Marcus, Chang, Honghong, Hou, Xianglin, Wang, Yingxiong, Qiao, Yan
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 21.07.2023; Elsevier
• Subjects: Green chemistry; Organic chemistry; Organic chemistry; Green chemistry
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2023.106980

Herein, we report choline chloride-based deep eutectic solvents (DESs) promoted conversion of N-acetyl-d-glucosamine (GlcNAc) into nitrogen-containing compounds, i.e., 3-acetamido-5-(1′,2′-dihydroxyethyl) furan (Chromogen III) and 3-acetamido-5-acetylfuran (3A5AF). The binary deep eutectic solvent choline chloride-glycerin (ChCl-Gly), was found to promote the dehydration of GlcNAc to form Chromogen III, which reaches a maximum yield of 31.1%. On the other hand, the ternary deep eutectic solvent, choline chloride-glycerol-B(OH)3 (ChCl-Gly-B(OH)3), promoted the further dehydration of GlcNAc into 3A5AF with a maximum yield of 39.2%. In addition, the reaction intermediate, 2-acetamido-2,3-dideoxy-d-erythro-hex-2-enofuranose (Chromogen I), was detected by in situ nuclear magnetic resonance (NMR) techniques when promoted by ChCl-Gly-B(OH)3. The experimental results of the 1H NMR chemical shift titration showed ChCl-Gly interactions with α-OH-3 and α-OH-4 of GlcNAc, which is responsible for promoting the dehydration reaction. Meanwhile, the strong interaction between Cl− and GlcNAc was demonstrated by 35Cl NMR. [Display omitted] •GlcNAc was promoted by DESs to selectively produce Chromogen III or 3A5AF•Reaction intermediates were detected by in situ NMR experiments•The relationship between DESs and GlcNAc was investigated by NMR technologies Organic chemistry; Green chemistry