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

Jiancheng Zhao; Christian Marcus Pedersen; Honghong Chang; Xianglin Hou; Yingxiong Wang; Yan Qiao

doi:10.1016/j.isci.2023.106980

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

iScience. 2023 Jun 1;26(7):106980. doi: 10.1016/j.isci.2023.106980. eCollection 2023 Jul 21.

Authors

Jiancheng Zhao^{1

2}, Christian Marcus Pedersen³, Honghong Chang⁴, Xianglin Hou^{1

2}, Yingxiong Wang^{1

5}, Yan Qiao^{1

2}

Affiliations

¹ Shanxi Engineering Research Center of Biorefinery, Institute of Coal Chemistry, Chinese Academy of Sciences, 27 South Taoyuan Road, Taiyuan 030001, China.
² Center of Materials Science and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
³ Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark.
⁴ Shanxi Tihondan Pharmaceutical Technology Co., Ltd., Jinzhong 030600, China.
⁵ College of Chemistry, Taiyuan University of Technology, 79 Yingze West Street, Taiyuan, Wanbailin District 030024, China.

Abstract

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.

Keywords: Green chemistry; Organic chemistry.