CHEMICAL COMMUNICATIONS
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2011
·Vol. 48
·期 14
·2024-2026
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IF 5.787
Jian Gao,Qing-Wen Song,Liang-Nian He,Zhen-Zhen Yang,Xiao-Yong Dou
An iron(III)-catalyzed three-component coupling reaction of alkynes, CH2Cl2 and amines was developed for facile synthesis of propargylamines. Preliminary mechanism investigation using in situFT-IR reveals that the crucial Fe-acetylide intermediate could be formed through C–H bond activation of alkynes thanks to cooperative effect of FeCl3 and 1,1,3,3-tetramethylguanidine.
研究领域:
有机化学
·
催化化学
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产品关联
DOI
PubMed
高影响因子
Polymer Chemistry
·
2021
·Vol. 12
·期 46
·6694-6704
·
IF 5.582
Yu Liu,Weichen Sheng,Ren Yin,Kan Zhang
Aniline is a very common amine source for benzoxazine synthesis, but it generally results in relatively high ring-opening polymerization temperatures. The exploration of alternative amine sources to lower the polymerization temperature of benzoxazine resins is a prerequisite for further development of high performance polybenzoxazines. In this work, three propargyl-containing benzoxazine monomers with different numbers of oxazine rings (PH-pa, BA-pa and TH-pa) have been synthesized using phenol/bisphenol-A/1,1,1-tris(4-hydroxyphenyl)ethane, propargylamine, and paraformaldehyde as the starting materials. The structures of these benzoxazines are characterized using NMR, FT-IR and HR-MS spectra, which indicate the successful incorporation of the reactive oxazine ring and the propargyl group into the molecular structure of each monomer. In addition, the polymerization behavior of each benzoxazine has been monitored by in situ FT-IR spectroscopy and differential scanning calorimetry (DSC), which shows that each resin can be completely polymerized through complex polymerization mechanisms including the ring-opening polymerization of the oxazine ring and additional ethynyl polymerization. Moreover, the thermal stability and the flammability of the resulting thermosets have been investigated by thermogravimetric analysis (TGA) and micro-scale combustion calorimetry (MCC), respectively. Notably, the thermoset derived from TH-pa exhibits the highest thermal stability with a peak degradation temperature of 418 °C and a char yield value of 50.2% at 800 °C in nitrogen. It also exhibits the lowest heat release capacity (87.0 J g−1 K−1) and total heat release value (17.4 kJ g−1) among the newly obtained polybenzoxazines.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
Catalysis Science & Technology
·
2019
·Vol. 10
·期 3
·736-741
·
IF 5.726
Shaorui Yan,Ruinian Zhou,Feng Han,Mengmeng Feng,Chengxia Miao,Shuai Zhang,Shiyun Ai
A CO2-induced ROCO2Na/ROCO2H buffer solution is developed and employed in the carboxylative cyclization of propargyl alcohol to generate α-alkylene cyclic carbonates. The introduction of CO2 into the propargyl alcohol/sodium tertiary pentoxide system can provide the ROCO2Na/ROCO2H buffer solution with both basic and acidic species. The basic and acidic species can simultaneously promote the generation of a carbonate anion intermediate and the interaction between the alkyne moieties of propargyl alcohol and protons (H+), facilitating carboxylative cyclization. Furthermore, the bulky (n-C4H9)4N+ cation of tetrabutylammonium bromide as an additive plays a crucial role in enhancing the nucleophilicity of the carbonate anion intermediate. Various α-alkylene cyclic carbonates are obtained in this catalytic system with relatively good yields at 80 °C.
研究领域:
化学
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环境科学
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产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Weiyu Wang,Qiang Wang,Yueying Chu,Guodong Qi,Shenhui Li,Jun Xu,Feng Deng
Alkyne semihydrogenation offers a key approach for the synthesis of stereodefined molecules. The stereoselective hydrogenation of propyne to propene over Al2O3-supported Pd–Ag bimetallic catalysts is studied by using parahydrogen-induced polarization (PHIP) NMR technique. The supported catalysts were prepared by an incipient-wetness impregnation method, and their properties were systemically tuned by altering Pd and Ag components. Structural characterization by X-ray diffraction, infrared spectra, and transmission electron microscope shows the formation of highly dispersed bimetallic Pd–Ag nanoparticles with random alloy structures on Al2O3 support. For the hydrogenation of propyne over Pd–Ag catalysts with higher Ag concentration, the adsorbed protons are mostly restricted on the active Pd ensembles, which favors a higher pairwise hydrogen addition to propyne, leading to a stronger PHIP effect. The product stereoselectivity measurements show that the pairwise syn-addition to propyne increases with Ag content in the Pd–Ag alloy. The reaction conditions impact the pairwise hydrogenation stereoselectivity. A lower H2/propyne ratio of reactant flow or a higher total reactant flow rate enhances the apparent pairwise syn-addition stereoselectivity, which can be accounted for by the suppressed cis–trans isomerization process and/or a higher intrinsic pairwise syn-addition selectivity.
研究领域:
催化化学
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物理化学
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材料科学
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DOI
高影响因子
JOURNAL OF CATALYSIS
·
2025
·
IF 6.5
Lingfang Kong,Yi Liu,Zhonggao Zhou,Zhichao He,Yun Bai,Guohai Xu,Yunxiang Pan,Hongyu Zhen,Yiwang Chen
The conversion of carbon dioxide (CO 2 ) and propargylamines to 2-oxazolidinones is an essential reaction in industry, but efficiently activating both feedstocks remains a huge challenge for majority of catalysts. Herein, we developed a long-term stable copper catalyst, co-coordinated with sugar acetates (acetylglucose, AcGlu) and 2-methyl-imidazolium (Im-Cu A ). This catalyst features multi-active site, enabling it to efficiently capture and activate CO 2 , activate propargylamines, and stabilize the catalyst species simultaneously. As expected, 2-oxazolidinone was synthesized by this cyclization reaction with an exciting turnover frequency of 880 h −1 , which is around 180 times higher than that of CuCl 2 . Moreover, the catalytic activity of Im-Cu A did not decrease even after 20 replicates, which is exceptionally rare for homogeneous catalysts. Density functional theory calculations indicate that the electron-donating AcGlu and 2-methyl-imidazolium units facilitate electrons transport from Im-Cu A to CO 2 . Moreover, the high electron density of AcGlu and 2-methyl-imidazolium groups is believed to play a crucial role in the long-term stability across various temperatures and excellent catalytic performance of Im-Cu A . This represents a significant advancement in the development of a highly stable copper catalyst with multi-active site that effectively activates all reaction substrates. This strategy could improve the development of metal catalysts with sustained superior performance for CO 2 conversion.
研究领域:
化学催化
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材料科学
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环境科学
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DOI
高影响因子
AICHE JOURNAL
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2025
·
IF 4
Ziqi Bian,Minhao Chen,Xiaohu Ge,Ningchao Zhu,Yueqiang Cao,Hao Jiang,Jing Zhang,Gang Qian,Xinggui Zhou,Xuezhi Duan
Designing and fabricating uniformly dispersed non-precious metal active sites with tuned geometric configurations and local coordination environments for the selective conversion of functional groups to desired products is of great importance but remains challenging in industrial catalytic processes. In this work, we propose a straightforward method for synthesizing the Co 3 Sn 2 intermetallic catalyst through the structural conversion of layered double hydroxide precursors, thereby constructing suitable Sn-modified Co active sites and an optimized catalytic environment for propyne semihydrogenation. Characterizations using x-ray diffraction, high-resolution transmission electron microscopy, and x-ray absorption spectroscopy characterizations are combined to identify the formation of P6 3 /mmc Co 3 Sn 2 intermetallic phase. Catalytic performance tests show that the Co 3 Sn 2 catalyst achieves 95.0% propylene selectivity with nearly complete propyne conversion. Temperature-programmed surface reaction and desorption measurements combined with theoretical calculations demonstrate that the good selectivity is driven by the facile desorption of propylene from Sn-modified Co sites rather than its further hydrogenation.
研究领域:
催化化学
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材料科学
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产品关联
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
✓ 已验证
产品关联
DOI
高影响因子
ANALYTICAL CHEMISTRY
·
2025
·
IF 6.7
Jiaheng Yu,Li Song,Guangyang Xu,Wei Li,Shiyi Liu,Han Xie,Jinping Tang,Jinyu Zhu,Xiao Xia Han
Inducing programmed cell death is an efficient strategy for cancer treatments, and a deep understanding of the molecular mechanisms underlying cell death pathways is of significance for the rational design of anticancer drugs. Herein, propiolamide-mediated crosstalk between ferroptosis and apoptosis is investigated. In situ monitoring of reactive oxygen species (ROS) formation and the structural changes of propiolamide compounds is achieved by Raman spectroscopy. The molecular mechanisms of propiolamides in inducing monooxygenase-mediated ROS generation and inhibiting GPX4 activities are revealed. Furthermore, the pro-ferroptotic and pro-apoptotic roles of the propiolamides containing terminal alkynes are verified. This study provides an in situ and label-free strategy for monitoring enzyme–drug interactions and their dynamics. It is a first attempt to study the structural basis of molecular crosstalk through two important enzymes in cell death. This study paves the way for designing novel drugs that are capable of triggering a synergistic contribution of multiple cell death forms to anticancer efficacy.
研究领域:
生物化学
·
肿瘤学
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药物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Yongxing Zhang,Jia Hu,Yong Xu,Xiangyu Yan,Siqi Zhang,Kang Duan,Cheng Chen,Ye Yuan,Francis Verpoort
An unexpected CO 2 -induced dissolution of ZnO into ionic liquids was discovered. This process exhibited high dissolution speed and the dissociated mixture was applied as an efficient Zn-based catalytic system for the CO 2 -promoted hydration of propargylic alcohols under atmospheric pressure with broad substrate scope. Moreover, this system could be recycled and reused for at least 16 times with excellent yields continuously obtained, which is an unprecedented record for this reaction. Significantly, this system could employ waste pigments as the ZnO source and work even under flue gas atmosphere. In the mechanistic investigations, the interaction between ZnO, CO 2 and ionic liquids to give N-heterocyclic carbene/CO 2 adducts proved to be the key factor for this specific dissolution. These adducts were further identified to exhibit better reactivity than the normal CO 2 by experimental data and density functional theory (DFT) calculations, which might be responsible for the excellent performance of the abovementioned catalytic system.
研究领域:
化学
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催化科学
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材料科学
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产品关联
DOI
高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
·
2020
·Vol. 18
·期 6
·1073-1077
·
IF 3.412
Lingchun Zhang,Yanle Chu,Peizhi Ma,Shujuan Zhao,Qiaoyan Li,Boya Chen,Xuejiao Hong,Jun Sun
In this report, we describe a simple visible light-triggered Barbier-type reaction by employing acetenyl ketones with benzyl trifluoroborates. Through a radical–radical cross-coupling process, this photocatalytic protocol furnished a wide range of tertiary propargyl alcohols. Mechanistic investigation indicated that proton-coupled electron transfer (PCET) might be involved in the photochemical transformations.
研究领域:
有机化学
·
光化学
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DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2022
·
IF 10.383
Weibo Huang,Yan Wang,Linze Lv,Yueyue Wang,Xiang Li,Honghe Zheng
Silicon (Si) is deemed to be the next-generation lithium-ion battery anode. However, on account of the poor electronic conductivity of Si materials and the instability of the solid electrolyte interphase layer, the electrochemical performance of Si anodes is far from reaching the application level. In this work, a multifunctional poly(propargylamine) (PPA) interlayer is constructed on the Si surface via a simple in situ polymerization method. Benefiting from the electronic conductivity, ionic conductivity, robust interphase interactions for hydrogen bonding, and stability of multifunctional PPA, the optimized Si@PPA-7% electrode shows improved lithium storage capability. A high capacity of 1316.3 mAh g–1 is retained after 500 cycles at 2.1 A g–1, and 2370.3 mAh g–1 can be delivered at 42 A g–1, which are in stark contrast to the unmodified Si electrode. Furthermore, the rate and cycle capabilities of the LiFePO4//Si@PPA-7% full cell are also obviously better than those of LiFePO4//Si.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
ACS Catalysis
·
2019
·
IF 12.221
Yong Xu,Wenyi Bian,Qi Pan,Mingyu Chu,Muhan Cao,Youyong Li,Zhongmiao Gong,Rui Wang,Yi Cui,Haiping Lin,Qiao Zhang
The development of highly selective catalysts has been remarkably relying on the understanding of catalytic active sites. Pd-catalyzed semihydrogenation of propyne has been a focus of research with industrial applications toward the production of polymer-grade propylene. In this work, combining density functional theory (DFT) calculations and experimental observations, we propose that, different from the existing debates where the formation of palladium carbide (Pd–C) species or specific facets of Pd nanoparticles are critical, the apexes of Pd (111) octahedrons are the active sites for highly selective propyne semihydrogenation. The propylene selectivity on Pd octahedrons can be ascribed to site-selective propyne adsorption on the apexes prior to reactions and subsequent difficult to access intermediate states toward overhydrogenation. To reveal the active sites of Pd, propyne semihydrogenation was performed on shaped-Pd nanoparticles with designed exposed facets: e.g., (111) and (100) facets. Of practical importance, the propyne conversion and propylene selectivity exceed ∼94% and ∼96% on Pd octahedrons, respectively, at low temperature (35 °C) and atmospheric pressure. In addition, more control experiments have been performed to verify the effects of apexes of Pd octahedrons on propylene selectivity. It is shown that the propylene selectivity decreases to ∼50% when the apexes of Pd octahedrons are gradually removed. The experimental observations have further confirmed that the apexes of Pd octahedrons can be used as the active sites for propyne semihydrogenation, which is in good agreement with the results from theoretical calculations. This work may not only reveal the active sites of Pd nanoparticles for selective semihydrogenation of propyne but also open an avenue for designing highly active and selective catalysts in the chemical industry.
研究领域:
催化化学
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材料科学
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工业化学
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产品关联
DOI
高影响因子
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