RESEARCH ARTICLE

Sustainable production of value-added N-heterocycles from biomass-derived carbohydrates via spontaneous self-engineering

¹ Key Lab of Applied Chemistry of Zhejiang Province, Department of Chemistry, Zhejiang University, Hangzhou 310028, China
² Key Lab of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
³ State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, China
⁴ Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China

^* Corresponding authors (emails: fengyu16@zju.edu.cn or fengyu16@gmail.com (Feng Yu); fsxiao@zju.edu.cn (Feng-Shou Xiao))

Received: 20 March 2023
Revised: 3 July 2023
Accepted: 5 July 2023

Abstract

Synthetic N-heterocyclic compounds, such as quinoxalines, have shown a crucial role in pharmaceutical as well as food and dye industries. However, the traditional synthesis toward N-heterocycles relies on multistep energy and cost-intensive non-sustainable processes. Here, we report a facile approach that allows one-step conversion of biomass-derived carbohydrates to valuable quinoxalines in the presence of aryl-1,2-diamines in water without any harmful metal catalysts/organic solvents via spontaneously engineering involved cascade reactions under hydrothermal conditions. Aryl-1,2-diamines are revealed as the key to propel this transformation through boosting carbohydrate fragmentation into small 1,2-dicarbonyl intermediates and subsequently trapping them for constituting stable quinoxaline scaffolds therefore avoiding a myriad of undesired side reactions. The tunability of product selectivity can be also achievable by adjusting the basicity of the reaction environment. Both batch and continuous-flow integrated processes were verified for production of quinoxalines in an exceptionally eco-benign manner (E-factor <1), showing superior sustainability and economic viability.