Imidazo[1,2-a]pyridine derivatives synthesis from lignin β-O-4 segments via a one-pot multicomponent reaction

Luxian Guo; Yangming Ding; Hua Wang; Yuxuan Liu; Qian Qiang; Qi Luo; Fei Song; Changzhi Li

doi:10.1016/j.isci.2023.106834

Imidazo[1,2-a]pyridine derivatives synthesis from lignin β-O-4 segments via a one-pot multicomponent reaction

iScience. 2023 May 9;26(6):106834. doi: 10.1016/j.isci.2023.106834. eCollection 2023 Jun 16.

Authors

Luxian Guo^{1

2}, Yangming Ding¹, Hua Wang¹, Yuxuan Liu¹, Qian Qiang^{1

2}, Qi Luo^{1

3}, Fei Song^{1

3}, Changzhi Li^{1

2}

Affiliations

¹ CAS Key Laboratory of Science and Technology on Applied Catalysis, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
² University of Chinese Academy of Sciences, Beijing 100049, China.
³ Faculty of Light Industry and Chemical Engineering, Dalian Polytechnic University, Dalian, Liaoning 116034, China.

Abstract

The catalytic conversion of lignin into N-containing chemicals is of great significance for the realization of value-added biorefinery concept. In this article, a one-pot strategy was designed for the transformation of lignin β-O-4 model compounds to imidazo[1,2-a]pyridines in yields up to 95% using 2-aminopyridine as a nitrogen source. This transformation involves highly coupled cleavage of C-O bonds, sp³C-H bond oxidative activation, and intramolecular dehydrative coupling reaction to construction of N-heterobicyclic ring. With this protocol, a wide range of functionalized imidazo[1,2-a]pyridines sharing the same structure skeleton as those commercial drug molecules, such as Zolimidine, Alpidem, Saripidem, etc., were synthesized from different lignin β-O-4 model compounds and one β-O-4 polymer, emphasizing the application feasibility of lignin derivatives in N-heterobicyclic pharmaceutical synthesis.

Keywords: Applied chemistry; Organic chemistry.