Molecular Catalysis
·
2024
·
IF 3.9
Qiang Liu,Qiaobo Liao,Chenghua Zhang,Congxin Du,Lei Zhou,Jiao Geng,Kai Xi,Xingbang Hu
Frustrated Lewis Pairs (FLPs) were widely used as metal-free catalysts in current chemistry. More and more researches began to focus on heterogeneous FLPs to meet industrial production needs. Nevertheless, these reported heterogeneous FLPs were mostly constructed based on solid-state Lewis bases (LB) combined with small molecule Lewis acids (LA), such as B(C 6 F 5 ) 3 , which led to incomplete recovery of more expensive LA. In order to construct heterogeneous FLPs with stability and cyclicity based on solid LA, herein, we propose the strategy of first preparing heterogeneous COFs-B(C 6 F 5 ) 2 (solid LA) by reducing part of the C=N bonds on COFs through H-B(C 6 F 5 ) 2 , followed by introducing 1,8-diazabicycloundecano-7-ene (DBU) to construct semi-solid heterogeneous FLPs COFs-B(C 6 F 5 ) 2 /DBU. Simultaneously, these FLPs catalysts showed excellent catalytic performance in the field of terminal alkyne hydrogenation to olefins and could be cycled 8 times without loss of catalytic activity.
研究领域:
催化
·
材料科学
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2016
·
IF 0.661
Haidong Liu,Bo Chen,Jin Cai,Junqing Chen,Min Ji
Eleven 1,3-diynes have been prepared by a highly efficient base-catalysed homocoupling of terminal alkynes mediated by a novel combination of CuSCN/4-nitrobenzenediazonium tetrafluoroborate.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Shiliang Liu,Rui Yang,Qixin Zhuang,Guozhu Zhan,Peiyuan Zuo,Xiaoyun Liu
In this study, six thermosetting benzoxazole monomers with endo-alkynyl groups are prepared, and the effect of the endo-alkynyl groups and substituent group on the curing behavior and solubility of monomers, and on the thermal properties and dielectric properties of polybenzoxazoles are investigated. Our findings reveal that incorporating endo-alkynyl groups enhances the cross-linked network in the benzoxazole monomers, thereby improving their thermal stability, hydrophobicity , and dielectric constant . However, this modification also results in decreased solubility and curing properties of the monomers. In addition, the position of the fluorine atoms can affect the curing behavior of monomer and the dielectric properties of polybenzoxazoles. When a fluorine atom is positioned ortho to the cyano group , it impedes the curing of the cyanide group, which increases the curing reaction temperature. Moreover, while it is generally believed that the addition of fluorine typically lowers the dielectric constant of a material, the placement of fluorine atoms ortho to the cyano group can lead to overlapping electronic effects. This overlap may increase the polarity of the curing network, which increases the dielectric constant and dielectric loss of the polybenzoxazoles. Among the six thermosetting benzoxazole monomers studied, poly (2 F-JQ) containing m -diethynyl groups exhibit a 5 % thermal decomposition temperature (Td 5 ) of 610 °C, and a low dielectric loss of 0.0045 at 1 MHz. Compared with other polybenzoxazoles, poly (2 F-JQ) possesses a moderate dielectric constant, excellent thermal stability, and extremely low dielectric loss. In summary, this study provides a new approach for preparing resins that feature high-temperature resistance and low dielectric loss.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Jianguo Liu,Nan Wang,Jianan Liu,Ming Li,Ying Xu,Chenguang Wang,Yanzhi Wang,Haoquan Zheng,Longlong Ma
Highly selective catalytic hydrogenation of alkynes to alkenes is a highly important reaction owing to its industrial and commercial application. Specifically, semihydrogenation of terminal alkynes has been more challenging than internal alkenes even using Lindlar catalysts. Also, the high reduction degree state metal-supported catalysts like Pd0/C, Pt0/C, and Ru0/C have been well-known to be used widely in hydrogenation due to their super activity. However, charcoal can absorb a large amount of water; Pd/C with 50% water is convenient on a large-scale synthesis. Charcoal generally bears oxygen groups on its surface, which are responsible for low selectivity and undesired products. Even typically, only 10–60% of the Pd metal atoms are exposed, they still suffer from poor stability in acids owing to leaching. Herein, we intend to design active and stable metal catalysts with features as the following to avoid leaching: having strong interaction with the support and coordinatively unsaturated metal sites or low valence state metals physically isolated from the acid environment. Herein, a highly efficient semihydrogenation of terminal alkynes to produce alkenes has been realized using a heterogeneous Pd(II)/POP-GIEC catalyst, imine-linked, crystalline, and porous organic polymer supporter modified by coordination of Pd(OAc)2 to its walls under mild conditions. Surprisingly, for the first time, modified POP-supported low reduction degree PdII catalysts were synthesized efficiently, and they were successfully used in semihydrogenation of terminal alkynes. The substrate scope was studied and included both unfunctionalized as well as functionalized substituents on the para, ortho, and meta position of aromatic alkynes. The substrate having a substituent with the functionality of fluoro protected at the meta position was semihydrogenated with a high alkyne conversion of 100% and olefin selectivity (up to 99%).
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2025
·
IF 3.6
Lei Xu,Gen-Qiang Chen,Xumu Zhang
The synthesis of terminal alkynes from inexpensive aryl chlorides remains a challenging task in organic synthesis. Here, a Heck–Cassar reaction of aryl chlorides with (triisopropylsilyl)acetylene catalyzed by low loadings of palladium (0.08 mol %) has been developed. Through subsequent desilylation, aryl-substituted terminal alkynes can be readily prepared. This reaction features robustness and good functional group compatibility, making it suitable for the late-stage modification of drug molecules.
研究领域:
有机化学
·
药物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2022
·
IF 5.723
Hao Liu,Yajun Fu,Xin Wang,Weiping Luo,Weijun Yang
By encapsulating metal nanoparticles (NPs), the synergistic effect between the metalloporphyrins and the metal nanoparticles in metalloporphyrin organic frameworks (P-MOFs) can boost its catalytic performance. The self-coupling reaction of terminal alkynes is a kind of important organic reaction and can take place with the aid of the catalyst. A nanorod-like metal-organic skeleton PCN-222(Cu) with carboxy porphyrins as ligands was synthesized as the precursor. By a double-solvent approach, the composite catalysts with varying copper nano-loadings in PCN-222(Cu) pores were obtained. Among them, 1.9 wt% of Cu NPs in Cu@PCN-222(Cu) has excellent catalytic activity and stability for the self-coupling reaction of terminal alkynes. PCN-222(Cu) can stabilize the Cu NPs, control the size selectivity and crystal form. The copper porphyrins and Cu NPs in Cu@PCN-222(Cu) both serve as the catalytic active sites. This strategy, which using porphyrin-structured MOFs to construct dual active sites with the same element, has promising applications in MOFs catalysis.
研究领域:
有机化学
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Minkang Li,Lina Zhang,Zhongzheng Zhang,Jialin Shi,Yuefeng Liu,Jiansong Chen,Nannan Sun,Wei Wei
Integration of adequate activity, stability, and productivity in a catalyst is of strategical importance to achieve high performance, particularly for inactive reactants, e.g., CO2. Here, using a reversed microemulsion method, ultrafine metallic Ag nanoparticles coated with porous SiO2 can be facilely obtained using micelles as separated nanoreactors for the preparation. Such architectures allowed the rigid SiO2 matrices to act as physical spacers, so that aggregation of the Ag particles could be avoided. Meanwhile, due to the templating effect from the surfactant, large mesopores could be induced in the SiO2 shell, and thus the diffusion barrier of reactants could be minimized. When used as a heterogeneous catalyst for carboxylation of terminal alkynes by CO2 under mild conditions, the prepared xAg@SiO2 catalysts showed extraordinary performance in terms of excellent activity, stability, productivity, and wide substrate scope. The knowledge developed here may also enrich the toolbox for performance promotion of metal catalysts via specially fabricated structures.
研究领域:
材料科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2015
·Vol. 29
·期 9
·608-611
·
IF 2.248
Yuanping Hao,Jingyang Jiang,Yanhua Wang,Zilin Jin
The carbonylative Sonogashira coupling of aryl iodides with terminal alkynes was studied by using thermoregulated ligand–palladium as an efficient and reusable catalyst at 80 °C in water. The corresponding alkynone products were obtained in good to excellent yields under 1 atm of carbon monoxide. The isolation of the products was readily achieved by extraction with ethyl acetate, and the catalyst recovered in water can be reused and recycled up to four times without significant loss in catalytic activity. Copyright © 2015 John Wiley & Sons, Ltd.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2018
·Vol. 20
·期 11
·2588-2595
·
IF 8.586
Da Yang,Huan Liu,Dong-Liang Wang,Zhoujie Luo,Yong Lu,Fei Xia,Ye Liu
A bi-functional ligand (L1) containing a diphosphino fragment and sulfonic acid group (–SO3H) enabled PdCl2(MeCN)2 to efficiently catalyze the tandem bis-alkoxycarbonylation of terminal alkynes to produce aryl-/alkyl-substituted succinate (α,ω-diesters). It was found that the –SO3H incorporated in L1 indispensably assisted the Pd-catalyst in accomplishing this tandem reaction via intramolecular synergic effects. Co-catalysis over the L1-based Pd-catalyst was not due to the physical mixture of Xantphos and MeSO3H. In situ FTIR analysis verified that the formation and stability of Pd–H active species were facilitated by the presence of L1. The formation of stabilized diacylpalladium intermediate (F) was the critical driving force for the second-step methoxycarbonylation. DFT calculation was carried out to optimize the geometric structure of F, which indicated that the developed intramolecular O⋯H hydrogen bonds were an important structural feature to stabilize F. In addition, the L1-based Pd-catalyst could be recycled successfully for at least 3 runs in the ionic liquid [Bmim]NTf2 without obvious activity loss and detectable metal leaching.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Miao Zhang,Peng Zhu,Jianxin Liu,Huapeng Zhang,Yanjun Tang
In recent years, click reactions with cellulose nanocrystals (CNC) participation have gradually become a research hotspot. Carboxylamine condensation is the most used method to introduce terminal alkyne groups at the reducing end of CNC as reaction sites for click reactions. However, hydroxyl groups on CNC surface would be slightly oxidized during the carboxyamine condensation process , inducing the potential positions of introduced alkynes would be not only at the reducing end but also on CNC surface. Here, aldimine condensation was proposed to introduce terminal alkyne groups just at the reducing end of CNC, and a systematic comparison analysis was conducted with carboxylamine condensation. Firstly, the selectivity and extent of alkynylation were characterized by XPS and EA. Secondly, the end aldehyde content in these CNC samples was measured by the BCA method, which quantitatively explained the grafting efficiency of aldimine condensation and further verified its feasibility. Thirdly, the clickability of the modified CNC samples was confirmed through XPS analysis of the products after a pre-designed click reaction. In sum, aldimine condensation was proven to be a simple and effective strategy for introducing terminal alkyne groups at the reducing end of CNC, which could be used as reaction sites for further click reactions.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ULTRASONICS SONOCHEMISTRY
·
2016
·
IF 4.556
Da-wei Zhang,Yu-min Zhang,Jing Li,Tian-qi Zhao,Qiang Gu,Feng Lin
An efficient synthesis of 1,4-disubstituted 1,2,3-triazole derivatives was studied. 1,4-Disubstituted 1,2,3-triazoles containing isoxazole and thymidine structures were synthesized in 84–96% yields starting from various terminal isoxazole ether alkynes and β -thymidine azide derivatives via a 1,3-dispolar cycloaddition using copper acetate, sodium ascorbate as the catalyst under ultrasonic assisted condition. All the target compounds were characterized by HRMS, FT-IR, 1 H NMR and 13 C NMR spectroscopy. Furthermore, the quorum sensing inhibitory activities of synthesized compounds were evaluated with Chromobacterium violaceum ( C. Violaceum CV026) based on their inhibition of violacein production, with compound C 10 -HSL as a positive control. The compounds 8a , 8c and 8f exhibited considerable levels of inhibitory activity against violacein production, and IC 50 values were 217 ± 19, 223 ± 20 and 42.8 ± 4.5 μM, respectively, which highlighted the potential of these compounds as lead structures for further research towards the development of novel QS inhibitors.
研究领域:
有机化学
·
药物化学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED ORGANOMETALLIC CHEMISTRY
·
2022
·Vol. 37
·期 1
·e6951
·
IF 4.072
Wenna Xie,Shiwen Liu
We developed a highly regioselective synthesis of multi-substituted alkenylboronates via a heterogeneous ligand-free nano-copper catalyst that was highly dispersed and supported on the porous polyvinyl chloride. In this catalytic system, substituents on the terminal alkynes could affect the configuration of products. Terminal alkynes and general internal alkynes gave β-selective borylation products, whereas heteroatom-substituted alkynes like alkynamides, thioacetylenes, and ynol ethers gave α-selective borylation products in good chemical yields with exclusive regioselectivity.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）