CATALYSIS LETTERS
·
2017
·Vol. 147
·期 11
·2764-2771
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IF 2.799
Liu Yang,Mao Guijie,Zhao Hongyan,Song Jinyi,Han Huatao,Li Zhuofei,Chu Wenyi,Sun Zhizhong
Abstract A series of DBU-based (DBU = 1, 8-diazabicyclo [5.4.0] undec-7-ene) dicationic ionic liquids with different anions were successfully synthesized by the reaction of DBU and 1, 6-dichlorohexane. Therein, the dicationic ionic liquid 1, 1′-(hexane-1, 6-diyl)bis(1, 8-diazabicyclo [5.4.0]undec-7-enium) dichlorine ( IL-1 ) was successfully employed as an efficient catalyst in esterification reaction of carboxylic acids with primary chloroalkanes under mild conditions without any additional basic reagents. Moreover, the optimum catalyst could be efficiently reused for five times without any significant change on the catalytic effect. The improved protocol is not only efficient, but also green and pollution-free. Graphical Abstract
研究领域:
化学
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催化化学
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DOI
高影响因子
CELLULOSE
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2021
·Vol. 28
·期 16
·10373-10384
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IF 5.044
Cao Qinghua,Dai Jinyue,Bao Xin,Zhang Zhenyu,Liu Fei,Feng Yuhong,Na Haining,Zhu Jin
Abstract A series of cellulose-based fluorescent materials are prepared under relative mild conditions by use of the DMSO/1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)/CO 2 system to utilize as coating pigments. Through the observation under 365 nm UV light, the cellulose-based fluorescent materials exhibit good fluorescence response and bright color. Furthermore, due to the limitation of the molecular skeleton of cellulose, the intrinsic aggregation caused quenching phenomenon commonly existed in conventional organic fluorescent pigments can be effectively inhibited, which is very helpful to retain good fluorescence response in epoxy-based coating material and its coating films. Moreover, the addition of cellulose-based fluorescent materials also increases the mechanical properties of the coating film. The increase of tensile strength and tensile modulus respectively reaches ~39% and ~66%. Solvent resistance and thermal property of the coating films generally remain unchanged. The fabrication of cellulose-based fluorescent materials in DMSO/DBU/CO 2 system provides a feasible way to develop the functional application of cellulose. Graphic abstract
研究领域:
材料科学
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化学工程
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2016
·
IF 5.267
Yuling Zhao,Jikuan Qiu,Li Tian,Zhiyong Li,Maohong Fan,Jianji Wang
Carbon dioxide (CO2) is an abundant and renewable feedstock for the production of high-value chemicals. Herein, CuI and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) were employed as an efficient catalyst system to synthesize 2-oxazolidinones through the coupling reaction of CO2 and propargylic amines. It was found that this cost-competitive catalyst system could efficiently catalyze the reaction within only 4 h at atmospheric pressure CO2, and a wide range of substrates were suitable for this reaction. Various target products were obtained in excellent yields. Furthermore, the catalytic mechanism of the CuI/DBU system was investigated by using density functional theory. It was shown that copper(I) and DBU played synergistic roles in activating both the C≡C triple bond and the amino group of propargylic amines in the reaction.
研究领域:
有机化学
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催化化学
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DOI
高影响因子
POLYMER
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2021
·
IF 4.43
Shan Lu,Jinling Li,Fei Liu,Meiling Chen,Haining Na,Jin Zhu
Modification of cellulose homogeneously by graft copolymerization via grafting-from or grafting-to approaches is an attractive and versatile way to impart specific properties onto this promising renewable material. The grafting efficiency is greatly influenced by the solvent and catalyst used during this process. In this study, cellulose- graft -poly ( l -lactic acid) (C- g -PLLA) was prepared by ring opening polymerization of l -lactide (LA) (grafting-from) and transesterification of PLLA (grafting-to) with cellulose dissolved in CO 2 switchable solvent. The impact of the presence of 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) was then elucidated by comparing the grafting efficiency of the process with or without adding extra amount of this organic superbase . Results showed that without adding extra DBU, the grafting efficiency increased with an increase in concentration of grafting agents (LA or PLLA). However, when extra DBU was added, the grafting efficiency decreased with increased levels of DBU. These results indicate that the DBU protonated by the hydroxyl group from cellulose participated in the dissolution of cellulose after capture of CO 2 in the switchable solvent, and played a role in the graft copolymerization to produce C- g -PLLA. On the other hand, the free DBU that was unprotonated displayed an antagonistic effect towards grafting copolymerization . Detailed graft copolymerization pathways and related modes of action were then considered in attempt to provide new insight into the role of CO 2 switchable solvent for cellulose modification by ROP or transesterification .
研究领域:
材料科学
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高分子化学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2025
·
IF 8.5
Jianyun Gan,Lihua Zhang,Qinqin Xu,Yuanlong Guo,Haibo Xie
The dissolution and homogeneous processing of lignocellulosic biomass presents a significant challenge for advanced biorefineries. In this work, we firstly investigated the dissolution behavior of corn stover-based lignocellulose in 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU)/CO 2 /DMSO solvent system. The dissolution proportion reached 74.3 % via a two-step procedure, which involved pretreating of corn stover in DBU/DMSO solvent at 140 °C for 4 h, followed by dissolution at 50 °C for 6 h under 5 MPa CO 2 . Furthermore, the solubility of the corn stover can be improved by ball-milling treatment. Rheological behavior revealed that the solution viscosity and the intermolecular interactions decreased following ball-milling treatment. Subsequently, a small amount of wood pulp cellulose was incorporated to produce mechanically robust, fully UV-shielding, and all-biomass composite films. The tensile strength of the composite film containing 50 wt% wood pulp cellulose reached 47 MPa. This study provides significant insights into the development of green dissolution systems for lignocellulose and the development of lignocellulose-based advanced materials.
研究领域:
生物化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2019
·Vol. 33
·期 10
·e5145
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IF 3.259
Zhiguo Lv,Shuying Zhang,Zhenmei Guo,Xi Cheng,Jiaomei Wang,Chao Zhang
The synthesis of alcohol ester 12 is one of the valuable industrial processes, but it was impeded by poor separating property and recycling ability of the catalytic systems. Herein, four novel DBU-based basic ionic liquids (DBILs) of [BDBU]IM, [BDBU]OH, [ODBU]IM, [[ODBU]OH were synthesized successfully by introducing the alkyl chains of 1-bromobutane or 1-bromooctane to 1,8-diazabicyclo [5.4.0] undec-7-ene (DBU), and then, employing imidazole (IM − ) or hydroxide (OH − ) as counter ions. The above obtained four ionic liquids were applied in the synthesis of alcohol ester 12 in isobutyraldehyde (IBD)/aqueous media for the first time. Interestingly, after reaction, production of alcohol ester 12 can be self-separated from ionic liquids/water (ILs/W) catalytic system automatically. Furthermore, the self-separated ILs/W can be recycled and used in next catalytic reaction for at least 5 times without obvious loss of catalytic performance. In this work, the structure, purity, thermal stability and alkalinity of DBILs were characterized systematically. [BDBU]IM shows high alkalinity and thus enhances yield of 66.17%. From thermo gravimetric analyzer (TGA), [BDBU]IM also exhibits excellent thermal stability. So [BDBU]IM was chosen for the further studying. Furthermore, quantum chemistry is applied to calculate the interaction forces and electron energies of reactants by DFT, and the calculation results illustrate the feasibility of synthetic process of DBILs. The self-separation strategy of DBILS in this work may open up a new avenue for the clean synthesis of other industrial products.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Yuyan Zheng,Zinan Li,Meiling Chen,Jiyang Zuo,Tao Yang,Wenhua Miao,Yadong Zhao,Fei Liu,Jinggang Wang,Jin Zhu
The high value-added utilization of cellulose with various functions is a hot topic in the field of bio-based materials. The existing high value-added utilization methods mainly rely on the dissolution and functionalization of cellulose in two steps in a homogeneous system. Herein, a new CS 2 /DBU/DMSO solvent system was successfully designed by combining viscose and CO 2 switchable solvent, and then obtained regenerated product (DCC) with metal ion detection and antibacterial functions through a simple process from dissolution to regeneration. Cellulose dissolves mildly and efficiently in this system. In addition, the metal ion test paper prepared from DCC can quickly respond to Co 2+ , Cu 2+ , and Fe 3+ ions and produce significant visual color changes in a short period of time. Finally, the experiment showed that the DCC film has good antibacterial activity against S. aureus and E. coli . This study lays the foundation for the dissolution, derivation, and processing of cellulose, and provides new ideas for the production of functional materials using cellulose in the future.
研究领域:
生物基材料
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化学工程
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材料科学
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环境科学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
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2021
·Vol. 11
·期 21
·7072-7082
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IF 6.119
Xiao-Chao Chen,Kai-Chun Zhao,Yin-Qing Yao,Yong Lu,Ye Liu
The development of an efficient methodology to transform CO2 into valuable chemicals has attracted increasing attention concerning the challenging issues of CO2-utilization. Herein, an efficient approach for the preparation of oxazolidinones from CO2, primary (aliphatic/aromatic) amines and 1,2-dichloroethane (or its derivatives) catalyzed by DBU organo-superbase was achieved with yields of 47–97% under mild conditions (80–100 °C, 12 h, 1.0 MPa CO2). Control experiments demonstrated that the formation of an ion-pair carbamate salt intermediate IS-B derived from the reaction of CO2, DBU (catalyst) and an amine (substrate) was the key step for this three-component reaction. The available DBU–amine–CO2 adduct intermediate (like IS-B-2) with fair stability will evolve into the thermodynamically stable product oxazolidinones upon attack of 1,2-dichloroethane (or its derivatives), along with the regeneration of the DBU catalyst. Alternatively, the decomposition of the DBU–aryl amine–CO2 adduct (like IS-B-1) with relatively poor stability also could result in the competitive substitution reaction of 1,2-dichloroethane (or its derivatives) with the aryl amine. This work provides insights into synergetic CO2-activation by the DBU-catalyst and a nucleophilic amine-substrate via the formation of robust carbamate salt intermediates responsible for the final production of oxazolidinones.
研究领域:
有机化学
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环境化学
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DOI
高影响因子
GREEN CHEMISTRY
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2021
·Vol. 23
·期 16
·5856-5865
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IF 10.182
Lihua Zhang,Wentao Shi,Hailiang Sheng,Song Feng,Minglong Yao,Peng Chen,Qiang Zheng,Haibo Xie
The reaction of cellulose with CO2 in the presence of various organic superbases resulted in a novel CO2 derivative dissolution strategy for cellulose, presenting a special solvent system for cellulose dissolution processing and derivatization. The properties of the cellulose solution are important for the preparation of particular regenerated materials via dissolution processing. Herein, properties of the cellulose solution in a CO2/1.8-diazabicyclo[5.4.0]undec-7-ene/dimethyl sulfoxide (CO2/DBU/DMSO) solvent system were first systematically studied, and it was found that the apparent viscosities of cellulose solutions were highly dependent on the cellulose type, concentration and temperature. The overlap concentrations (c*) were determined to be 2 and 0.6 wt% for the microcrystalline cellulose (MCC) and wood pulp solutions, respectively. The Cox–Merz rule was valid for cellulose solutions in the CO2/DBU/DMSO solvent system. Furthermore, taking advantage of the reversible chemistry of CO2 in this solvent system, a reversible CO2-controlled sol–gel transition of the newly achieved cellulose solution in CO2/DBU/DMSO was identified by dynamic rheology of measuring the temperature dependence of storage modulus (G′) and loss modulus (G′′). Furthermore, the interesting CO2-controlled sol–gel transition was developed via integrated thermal-induced CO2 release and anti-solvent extraction for the preparation of regenerated cellulosic gel materials and then cellulose films with a tensile strength of 44.3 MPa. Interestingly, it was found that the regenerated cellulose through this approach turned out to be a cellulose IVI crystalline structure.
研究领域:
材料科学
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化学工程
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生物质材料
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DOI
高影响因子
POLYMER DEGRADATION AND STABILITY
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2019
·
IF 3.78
Fusheng Liu,Jiao Guo,Penghui Zhao,Yongqiang Gu,Jun Gao,Mengshuai Liu
Several DBU-based protic ionic liquids were facilely synthesized, they were successfully used as solvents and catalysts for alcoholysis of poly(lactic acid) (PLA) to yield lactate esters . The structure of ionic liquids and reaction parameters were optimized. Using [HDBU][AA] as the catalytic medium, which was composed by a 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) cation and an acetate anion, the PLA could be completely depolymerized with a 91% methyl lactate yield under the conditions of 100 °C, 5 mol% catalyst loading for 5 h. The effect of alcohol structures on the catalytic behaviors was studied, and good to excellent product yields were obtained. Moreover, the developed [HDBU][AA] showed excellent recyclability and structure stability. A possible reaction mechanism concerning the synergistic effect of the anion-cation ions was proposed. The DBU-based protic ionic liquids presented herein are low-cost and one-step synthesized, exhibiting great potential as green and efficient platform for direct and selective alcoholysis of PLA.
研究领域:
化学
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材料科学
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环境科学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2023
·
IF 4.7
Xinyu Li,Xiaojia Wu,Hui Yu,Chuanqi Geng,Haiguo Wei,Zhiyong Zhou,Zhongqi Ren
Based on the structural designability of ionic liquids (ILs), 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU)-based ILs ([Bz-DBU]NTF 2 ) were designed and synthesized. Their physical properties were analyzed by FT-IR, 1 H NMR, DSC and TGA. Highly selective separation between aromatic and alkane by [Bz-DBU]NTF 2 was achieved. Under the optimal conditions, the distribution coefficient ( D ) and separation selectivity ( S ) of [Bz-DBU]NTF 2 for tetraline were 0.833 and 54.2. The IL was regenerated six times without decrease in separation selectivity, demonstrating good stability. For the multi-component simulated diesel, nearly 100% of the bicyclic alkanes could be removed by five-stage cross-flow extraction processes. While the removal rate of total aromatics reached up to 84.39 and the contents of alkanes and total saturated alkanes reached 56.64% and 96.69%, respectively. For the real diesel, after two-stage cross-flow extraction experiments, the removal rates of monocyclic, bicyclic, tricyclic aromatic hydrocarbons reached 63.9%, 91.3% and 100%, respectively. The final product reached the standard of high quality ethylene cracking feedstock.
研究领域:
化学工程
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
GREEN CHEMISTRY
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2021
·Vol. 23
·期 24
·9922-9934
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IF 10.182
Yuqing Shen,Chaoping Yuan,Xianyi Zhu,Qin Chen,Shenjun Lu,Haibo Xie
The facile design and preparation of polyelectrolytes is a frontier topic in the fields of polymer science, energy storage devices and catalysis. Herein, linear water soluble cellulosic poly(protic ionic liquid) (CPIL) electrolytes were facilely and atom economically prepared after the dissolution of cellulose in the newly developed DBU/CO2/DMSO solvent system, followed by the simple addition of succinic anhydride under mild conditions. The DBU not only participated in the dissolution of cellulose as a solvent component, but also acted as an organocatalyst for the acylation reaction of cellulose with succinic anhydride, as well as a cation component in the targeted CPIL electrolytes. The reaction was optimized, and the effect of the reaction conditions on the chemical and physical properties of the CPILs was investigated. And then, as a proof of concept, the CPIL electrolyte aqueous solution was successfully used as the catalytic reaction media for the Knoevenagel condensation reaction. It was found that the reaction was homogeneous at the beginning, and the products could precipitate out from the media with the proceeding of the reaction, thus affording satisfactory filtration yields ranging from 56.7% to 93.8%. The solution properties of the CPIL aqueous solution were primarily investigated towards an in-depth understanding of the catalytic mechanism, by which a synergetic catalytic mechanism of the CPILs was proposed, and the reaction started with a nucleophilic addition reaction, and was then followed by a fast dehydration reaction. Finally, the direct reusability potential of the CPIL aqueous solution after the product filtration was also primarily investigated for the Knoevenagel condensation reaction.
研究领域:
聚合物科学
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催化化学
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能源存储设备
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）