Article
Chemistry, Multidisciplinary
Le Jia, Chao-Jun Li, Huiying Zeng
Summary: Lignin, as a component of lignocellulosic biomass, poses a great challenge for degradation and utilization due to its strong and stable linkages. A cleavage/cross-coupling strategy has been developed to convert lignin model compounds into high value-added compounds. This study presents a palladium-catalyzed cleavage/cross-coupling reaction for the preparation of benzyl amine compounds and phenols through dual C-O bond cleavage.
CHINESE CHEMICAL LETTERS
(2022)
Article
Energy & Fuels
Jing-Pei Cao, Tao Xie, Xiao-Yan Zhao, Chen Zhu, Wei Jiang, Ming Zhao, Yun-Peng Zhao, Xian-Yong Wei
Summary: The study found that isopropanol is a good hydrogen donor solvent to promote the hydrogenolysis of lignin model compounds, with a higher yield of products compared to under H-2 atmosphere.
Article
Energy & Fuels
Lei Wang, Jun Yin, Jungang Jiang, Yifan Zhang, Mingyao Song, Ran Zhang, Zhiguo Dong, Haiping Yang, Hongbo Yu
Summary: The study investigates the pyrolysis property of lignin using multi-scale lignin model components and reveals multiple bond cleavage mechanisms even in smaller lignin molecules. It also shows that lower pyrolysis temperature is beneficial for the enrichment of guaiacols as the main bio-oil. This research provides important theoretical and practical insights for the utilization of lignin.
Article
Chemistry, Multidisciplinary
Yangming Ding, Tenglong Guo, Zhewei Li, Bo Zhang, Fritz E. Kuhn, Chang Liu, Jian Zhang, Dezhu Xu, Ming Lei, Tao Zhang, Changzhi Li
Summary: A one-pot cascade reaction was developed for the synthesis of quinoline from beta-O-4 model compounds, achieving high yields. The reaction pathway involves selective cleavage of C-O bonds, dehydrogenation, aldol condensation, and C-N bond formation.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2022)
Article
Engineering, Environmental
Shibo Shao, Ke Wang, Jason B. Love, Jialin Yu, Shangfeng Du, Zongyang Yue, Xianfeng Fan
Summary: A sulfur-rich zinc indium sulfide photocatalyst was developed to promote the cleavage of C-beta-O linkages in lignin, using water as a hydrogen donor. The reaction selectivity for aromatic monomers increased and the conversion rate of lignin model compounds improved significantly. This study provides a new and effective strategy to promote the cleavage of C-beta-O linkages and is helpful for the future development of photocatalytic lignin valorization.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Jana Klein, Siegfried R. R. Waldvogel
Summary: A sustainable electrochemical pathway for the degradation and thermal treatment of technical lignosulfonate is proposed. This method allows for the production of significant quantities of low molecular weight compounds, including vanillin and acetovanillone. The electrochemical degradation is carried out using a simple two-electrode setup in aqueous media, which can be easily scaled up. The biopolymer is oxidized at the anode, while hydrogen is evolved at the cathode. Subsequent thermal treatment further degrades the robust chemical structure of lignosulfonates. Under optimized electrolytic conditions, vanillin can be obtained in a yield of 9.7 wt% relative to the dry mass of lignosulfonate used. By-products such as acetovanillone or vanillic acid are also observed but in lower yields. Overall, this study establishes a new and reliable one-pot, two-step degradation process for various technically relevant lignosulfonates, offering the advantage of using electrons as an oxidizing agent and resulting in minimal reagent waste.
Article
Chemistry, Physical
Mary Mensah, Richard Tia, Evans Adei, Nora H. de Leeuw
Summary: The potential energy surfaces of the reactions involved in the catalytic cleavage of a model compound of the beta-O-4 linkage in lignin have been studied using different complexes of iridium and cobalt catalysts. Both iridium and cobalt catalysts are active towards the cleavage of the beta-O-4 linkage, with iridium preferring the 'initial C-H addition' pathway and cobalt preferring the 'direct C-O insertion' pathway. The cobalt-catalyzed reaction goes through a two-state reactivity along the preferred pathway.
Article
Energy & Fuels
Guodian Zhu, Yuehua Wu, Yuebin Xi, Shaoqu Xie, Guoqiang Yin, Xiaojing Lv, Xuliang Lin
Summary: This work demonstrates that the dehydration of benzylic alcohol can significantly enhance the cleavage reactivity of the beta-O-4 bond in lignin model dimer. The reaction rate of the beta-O-4 bond is higher when attached to alpha-hydroxyl group compared to alpha-carbonyl group. The easy formation of alpha-hydrogen atom contributes to the enhancement of beta-O-4 bond cleavage reactivity. Therefore, this study highlights the prospect of efficient depolymerization of lignin into monoaromatics.
Article
Chemistry, Multidisciplinary
Mo Zhang, Zheng Li, Yeqin Feng, Xing Xin, Guo-Yu Yang, Hongjin Lv
Summary: Selective photocatalytic hydrogenolysis of lignin beta-O-4 models was achieved using Ni-containing polyoxometalate (POM) catalysts and CdS quantum dots under blue LED light irradiation. The system demonstrated high conversion and selectivity in transforming lignin beta-O-4 models to phenols and ketones. A potential photocatalytic mechanism was proposed based on experimental and spectroscopic analyses. This facile strategy has the potential for the photocatalytic production of various value-added chemicals from natural or biomass derivatives.
Article
Energy & Fuels
Ji Zhao, Xian-Yong Wei, Jing-Hui Lv, Qian-Qian Kong, Jia-Hao Li, Zhuang Li, Zi-Chun Fan, Li Li, Yang-Yang Zhang, Zhi-Min Zong
Summary: Ni/CeO2 catalyst with medium-strong acidity was prepared using in-situ carbon templating and reduction with H2. It showed excellent activity in the conversion of lignin-related model compounds, producing cyclohexane and methylcyclohexane. Moreover, the catalyst exhibited good reusability.
Article
Chemistry, Multidisciplinary
Yuxuan Liu, Qi Luo, Qian Qiang, Hua Wang, Yangming Ding, Chao Wang, Jianliang Xiao, Changzhi Li, Tao Zhang
Summary: The sustainable synthesis of quinoxaline derivatives from lignin beta-O-4 model compounds under transition-metal-free conditions has been achieved for the first time in this study. Mechanistic studies showed that this transformation involves highly coupled cascade steps. With this method, a wide range of functionalized quinoxalines, including an important drug compound, were successfully synthesized, demonstrating the potential application of lignin in pharmaceutical synthesis.
Article
Chemistry, Multidisciplinary
Hua Zhou, Zhenhua Li, Si-Min Xu, Lilin Lu, Ming Xu, Kaiyue Ji, Ruixiang Ge, Yifan Yan, Lina Ma, Xianggui Kong, Lirong Zheng, Haohong Duan
Summary: The study presents an efficient electrochemical strategy for upgrading lignin derivatives to carboxylates using MnCoOOH catalyst, with yields of 80-99% and operational stability up to 200 hours. A tandem oxidation mechanism is revealed, allowing for effective transformation of lignin derivatives into carboxylates.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Chemistry, Organic
Lu Liu, Lei Li, Xin Wang, Ran Sun, Ming-Dong Zhou, He Wang
Summary: The synthesis of N-unprotected 2-aryl-3-cyanoindoles was achieved through Mn(III)-mediated radical cascade cyclization, using o-alkenyl aromatic isocyanides and boronic acids as substrates. The proposed mechanism involves sequential intermolecular radical addition, intramolecular cyclization, and cleavage of the C-C bond under mild reaction conditions. Mechanistic studies suggest that H2O or O-2 may provide the oxygen source for benzaldehyde elimination.
Article
Chemistry, Physical
K. Beliaeva, N. Grimaldos-Osorio, E. Ruiz-Lopez, L. Burel, P. Vernoux, A. Caravaca
Summary: The production of H-2 via electrolysis is considered the best alternative to traditional catalytic reforming processes. Research aims to gain deeper insights into the cleavage of main chemical bonds in the complex lignin structure across different Ni oxidation states.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2021)
Article
Chemistry, Multidisciplinary
Jiali Zhang, Puyi Lei, Daobo Yu, Yanfang Li, Min Zhong, Wenzhuo Shen, Shouwu Guo
Summary: In this study, Co nanoparticles embedded in a three-dimensional nitrogen-doped graphene network (Co/NG@3DNG-X) were prepared. The catalytic activities of the Co/NG@3DNG-X for the cleavage of beta-O-4 linkage in lignin were explored. It was found that the catalytic activity of Co/NG@3DNG-X could be tuned by adjusting the pyrolysis conditions, and Co/NG@3DNG-900 showed the highest activity due to its unique structural features.
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Chemistry, Organic
Fuying Zhu, Yamei Lin
Summary: In this study, a low-metal iron-supported catalyst (Fe20/NC-Mg) was reported for the efficient synthesis of quinoxaline compounds, using water as a solvent and without additional bases. The synergistic effect of FeNx site and Mg (OH)2 nanorods in the catalyst played a key role in achieving high yields (82-91%) in 16 examples. The gram-level synthesis and reusability of the catalysts after four cycles demonstrated its industrial application potential.
Article
Chemistry, Organic
Mikhail Kozlov, Alexey Tyurin, Andrey Dmitrenok, Vyacheslav Rusak, Aleksander Fedorov, Igor Zavarzin, Yulia Volkova
Summary: This study presents a novel and practical synthesis method for phosphorus-substituted 1,3,4-thiadiazolines using phosphorylthioformic acid hydrazides and ketones. The protocol demonstrates operational simplicity, availability of reagents, and tolerance towards different functional groups.
Article
Chemistry, Organic
Jisna Jose, Thomas Mathew
Summary: 2-Cyclopentenone and its derivatives are highly esteemed synthetic intermediates with exceptional utility in organic synthesis. They are favored structural motifs in numerous pharmaceutical drugs and natural products, highlighting their significance. The review discusses the various methods used to synthesize cyclopentenones from 2016 to 2023.
