Successive Cleavage and Reconstruction of Lignin beta-O-4 Models and Polymer to Access Quinoxalines

Liu, Yuxuan, Luo, Qi, Qiang, Qian, Wang, Hua, Ding, Yangming, Wang, Chao, Xiao, Jianliang ORCID: 0000-0003-2010-247X, Li, Changzhi and Zhang, Tao (2022) Successive Cleavage and Reconstruction of Lignin beta-O-4 Models and Polymer to Access Quinoxalines. CHEMSUSCHEM, 15 (21). e202201401.

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Official URL: http://dx.doi.org/10.1002/cssc.202201401

Abstract

The construction of N-heterocyclic compounds from lignin remains a great challenge due to the complex lignin structure and the involvement of multiple steps, including the cleavage of lignin C-O linkages and the formation of heterocyclic aromatic rings. Herein, the first example of KOH mediated sustainable synthesis of quinoxaline derivatives from lignin β-O-4 model compounds in a one-pot fashion under transition-metal-free conditions has been achieved. Mechanistic studies suggested that this transformation includes highly coupled cascade steps of cleavage of C-O bonds, dehydrative condensation, sp<sup>3</sup> C-H bond oxidative activation, and intramolecular dehydrative coupling reaction. With this protocol, a wide range of functionalized quinoxalines, including an important drug compound AG1295, were synthesized from lignin β-O-4 model compounds and β-O-4 polymer, showcasing the application potential of lignin in pharmaceutical synthesis.

Item Type:	Article
Uncontrolled Keywords:	biomass, lignin, N-heterocyclic compounds, quinoxalines, transition-metal-free
Divisions:	Faculty of Science and Engineering > School of Physical Sciences
Depositing User:	Symplectic Admin
Date Deposited:	19 Apr 2023 08:55
Last Modified:	02 Sep 2023 01:30
DOI:	10.1002/cssc.202201401
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3169724