ChemistryOpen
·
2020
·Vol. 9
·期 10
·996-1000
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IF 2.37
Fangjun He,Rumeng Qu,Jie Su,Muyao Du,Junqiang Liu,Yiping Chen,Bo Wang
Graphical Solving the puzzle : The role of the amine in direct amidation of aromatic ketones has been investigated. Amines act as both the reactant and catalyst, as such the excess amount (two or more equivalents) of amines are required to afford reasonable conversions/yields in the classical amidation. The direct amidation of aromatic ketones has been achieved at mild reaction conditions. In the classical amidation between aromatic ketones and amines, 2.0 equivalents of amines are necessarily required to gain satisfying yields. The specific role of the amine in the direct amidation already puzzled us for a long time. In this work, we disclosed that the amine acts as both reactant and catalyst. Specifically, the determination of reaction intermediates revealed the full mechanism, based on which, the introduction of one equivalent base in the amidation is showcased here that a high yield (∼95 %) can be afforded using only 1.1 equiv. of amine.
研究领域:
有机化学
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催化化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2018
·
IF 4.805
Zhenhua Dong,Jinwei Yuan,Yongmei Xiao,Pu Mao,Wentao Wang
A rapid and practical protocol for the chemoselective deoxygenation of various aromatic ketones and aldehydes was described, which used a tandem catalyst composed of heterogeneous Pd/TiO2 + homogeneous FeCl3 with the green hydrogen source, polymethylhydrosiloxane (PMHS). The developed catalytic system was robust and scalable, as exemplified by the deoxygenation of acetophenone, which was performed on a gram scale in an atmospheric environment utilizing only 0.4 mol % Pd/TiO2 + 10 mol % FeCl3 catalyst to give the corresponding ethylbenzene in 96% yield within 10 min at room temperature. Furthermore, the Pd/TiO2 catalyst was shown to be recyclable up to three times without an observable decrease in efficiency and it exhibited low metal leaching under the reaction conditions. Insights toward the reaction mechanism of Pd-catalyzed reductive deoxygenation for aromatic ketones and aldehydes were investigated through operando IR, NMR, and GC-MS techniques.
研究领域:
有机化学
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催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2020
·
IF 3.687
Hai-Min Shen,Lei Liu,Bei Qi,Meng-Yun Hu,Hong-Liang Ye,Yuan-Bin She
Non-solvent and non-additive oxidation of secondary benzylic C–H bonds to aromatic ketones utilizing simple metalloporphyrins as catalysts and O 2 was investigated systematically. Based on systematical studies on reaction parameters, such as the structures of porphyrins, the types of central metals, the amount of catalyst, the pressure of oxygen, and the temperature, most aromatics with secondary benzylic C–H had been converted efficiently and selectively to their corresponding aromatic ketones catalyzed by the optimized metalloporphyrin catalyst T(2,3,6-triCl)PPCo. And the selectivity towards aromatic ketones reached up to 80 %–95 % with acceptable conversions in lower catalyst-loading (2.4 × 10 −3 %, mol/mol). The highest selectivity was achieved for substrate 1,2,3,4-tetrahydronaphthalene with the selectivity of 95.0 % in the conversion of 46.3 %. The superior catalytic performance of T(2,3,6-triCl)PPCo could be mainly ascribed to its excellent plane structure, superior ability for electron transfer and low positive charge around the central metal. All of above properties promoted the formation of catalytic active species high-valence cobalt-oxo complexes, and facilitated the approach of substrates to the catalytic active centers. This work presented an optimized balance among higher selectivity, milder conditions, lower catalyst-loading, and simpler catalysts compared with current documents, which was not only an efficient, practical and significant strategy to functionalize the widely available aromatics possessing secondary benzylic C H with high efficiency and selectivity under milder conditions, but also an important instance in the effective functionalization and utilization of other C H bonds employing optimized catalytic systems based on metalloporphyrins.
研究领域:
有机化学
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催化化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMISTRY
·
2015
·Vol. 33
·期 5
·578-582
·
IF 1.578
Minting Liang,Xiaofeng Xia,Xiang Liu,Hexing Li
In the presence of the inexpensive and non-toxic polymethylhydrosiloxane, the combination of copper(II) acetate and a chiral diphosphine displayed high catalytic efficiency in the asymmetric hydrosilylation of a series of aromatic ketones in air atmosphere and at room temperature. ( R )-1-Arylethanols were obtained with up to 99% yield and 93% enantiomeric excess. Meanwhile, the electron effect and steric hindrance of substituents on the aromatic ring had an interesting influence on both the yields and enantioselectivities. Furthermore, a possible mechanism was presented to explain the influence of some key factors on 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
TETRAHEDRON
·
2013
·
IF 2.803
Hai-Min Shen,Hong-Bing Ji
Eight amino alcohol-modified β-CDs CD-1–CD-8 have been synthesized in acceptable yields and were employed to form artificial metalloenzymes with [RuCl 2 (Benzene)] 2 and [RuCl 2 (Mesitylene)] 2 , respectively. All the conformations of CD-1–CD-8, the complexes between CD-1–CD-8 and [RuCl 2 (Arene)] 2 , and the inclusion complexes between CD-1–CD-8 and acetophenone were characterized by UV, 1 H NMR, 1 H ROESY NMR , and quantum calculation. The catalytic activity of the formed artificial metalloenzymes in the asymmetric hydrogenation of aromatic ketones , especially the effect of the aromatic ligands' volume on the enantioselectivity were investigated in detail, in which it was obvious that the enantioselectivity increased as the increase in the aromatic ligands' volume. For the best artificial metalloenzyme constructed from the complex between CD-8 and [RuCl 2 (Mesitylene)] 2 , which not only exhibits a good tolerance to a wide range of substrates but also demonstrates some substrate selectivity, 76.39% ee was obtained for acetophenone and 79.67% ee for 2-acetylnaphthalene. A strategy to improve the enantioselectivity in the asymmetric reactions catalyzed by the artificial metalloenzymes based on CDs has been provided.
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
Journal of CO2 Utilization
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2018
·
IF 5.503
Yu Cao,Ran Ma,Ning Wang,Mei-Yan Wang,Xue-Dong Li,Liang-Nian He
Selective hydrogenolysis is a crucial challenge for lignin valorization. A PdCl 2 -catalyzed hydrogenolysis of C OH bond of various lignin β-O-4 alcohol model compounds was developed for preparation of corresponding phenethoxybenzene in 78–98% isolated yield. Notably, the introduction of low-pressure CO 2 (1 MPa) remarkably improves the reaction efficiency and selectivity of phenethoxybenzene. Neither over-reduction of aromatic ring nor further debenzylation was detected. This is understandable that the in situ methylcarbonic acid generated from CO 2 and methanol acts as an acidic catalyst and enhances the leaving ability of hydroxyl group of β-O-4 alcohols. Besides, the present PdCl 2 /CO 2 /MeOH catalyst system proved to be effective for reductive cleavage of C O bonds of β-O-4 ketones, producing ethylbenzenes accompanied with phenols in high yields. Furthermore, this protocol could also be extended to selective hydrodeoxygenation of the carbonyl group to methylene in aromatic ketones. As a sound reaction medium, such in situ CO 2 /MeOH acidic system could be inherently neutralized by depressurizing CO 2 , providing feature advantages for simple post-processing and none waste disposal.
研究领域:
化学
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催化反应
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生物质转化
✓ 已验证
产品关联
DOI
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2013
·
IF 3.365
Lan-Lan Lou,Huanling Du,Yanbin Shen,Kai Yu,Wenjun Yu,Qiu Chen,Shuangxi Liu
Chiral 9-amino epi -cinchonine was anchored on external surface passivated SBA-15 as well as calcined SBA-15. The two resulting materials were used as catalysts for the asymmetric transfer hydrogenation of aromatic ketones after complexing with [Ir(COD)Cl] 2 . Higher enantioselectivities were obtained over the passivated SBA-15 supported catalyst compared with the catalyst based on calcined SBA-15 as well as the homogeneous counterpart. Especially for the substrate of acetophenone, an obviously high enantiomeric excess (ee) of 74% (homogeneous ee: 60%) was achieved with comparable conversion to the homogeneous catalyst (97% vs. 98%). Furthermore, the passivated SBA-15 supported catalyst demonstrated higher stability during the asymmetric transfer hydrogenation reaction as compared with the catalyst based on calcined SBA-15.
研究领域:
催化化学
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有机合成
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材料化学
·
纳米材料
·
均相与多相催化
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMISTRY
·
2025
·
IF 5.5
Meng Li,Yu-Na Jiang,Zheng Li,Zhaobo Liu,Zehua Chen,Yufei Mao,Kang Yuan,Jiting Cui,Haiming Zhu,Shu Xing,Ming Wang,Bing Wang
Comprehensive Summary Aromatic ketones, such as 9-fluorenone (9-FO), are known for their high intersystem crossing quantum yields ( Φ ISC ≈ 1), rendering them highly valuable for photochemical reactions and dye-sensitized solar cells. However, their use as photosensitizers in biological contexts has been hindered by their low extinction coefficients, high excitation energies, and weak fluorescence. To address these limitations, we conjugated 9-FO with a fused-ring electron donor, resulting in an acceptor-donor-acceptor derivative IDT-9F. This strategy has successfully redshifted the absorption peak of 9-FO (380 nm) into the visible light range (498 nm) and significantly enhanced its light absorption capability (~310-fold) and fluorescence quantum yield (~100-fold). Furthermore, IDT-9F was encapsulated within pH-responsive nanoparticles using an acid-induced charge-reversal polymer as the amphiphilic matrix, and enabled fluorescence imaging-guided photodynamic inactivation of Gram-positive bacteria in acidic environment with a remarkable bacterial inhibition rate exceeding 99.9%.
研究领域:
光化学
·
生物光子学
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纳米医学
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有机化学
·
抗菌治疗
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2016
·Vol. 8
·期 6
·1199-1207
·
IF 4.724
Lan-Lan Lou,Shanshan Li,Huanling Du,Jiong Zhang,Wenjun Yu,Kai Yu,Shuangxi Liu
Graphical Short support : A short-mesochannel SBA-15 material is applied to the immobilization of a chiral 9-amino epicinchonine iridium catalyst, which exhibit excellent catalytic activity and notably improved enantioselectivity for the asymmetric transfer hydrogenation of aromatic ketones. A short-mesochannel SBA-15 material functionalized with propylthiol groups was prepared by co-condensation and applied to the immobilization of chiral 9-amino epicinchonine. After complexing with [Ir(cod)Cl] 2 (cod=1,5-cyclooctadiene), these mesoporous materials were evaluated as catalysts for the asymmetric transfer hydrogenation of aromatic ketones. Higher enantioselectivities and comparable, or even higher, catalytic activities were achieved compared with the free catalyst. Both the short mesochannel and co-condensation approach for short-mesochannel SBA-15 materials functionalized with propylthiol groups, [SSBA-SH( x )] materials were demonstrated to contribute to the excellent catalytic performance. In addition, the catalyst SSBA-AEC(5)/Ir (AEC=9-amino epicinchonine), with low 3-mercaptopropyltrimethoxysilane (MPTMS) content, showed the best catalytic performance; a high enantiomeric excess of 84 % (homogeneous ee =60 %) along with a conversion of 97 % was achieved within 1 h for asymmetric transfer hydrogenation of acetophenone. Moreover, these immobilized catalysts showed high stability during the reaction and could be recovered for reuse.
研究领域:
材料化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2019
·
IF 3.261
Qiwen Du,Weichen Jia,Jingyu Dai,Chao Du,Aiyun Shao,Rongmin Zhang,Yuefei Ji
Natural organic matter (NOM) contains a large number of aromatic ketones and quinones, which can produce reactive oxygen species (ROS), such as 1 O 2 and HO·, through photosensitization. These ROS play important roles in the attenuation of organic pollutants in sunlit surface water. The NOM components fractionated with XAD-8 resin at different pH influence the photo-generation of ROS, which may be related to the degree of dissociation of functional groups. In this study, probe chemicals were used to investigate the effect of dissociation degree (p K a ) of NOM model compounds on ROS production under 254 nm UV irradiation. Experimental results showed that six model compounds with similar molecular weights and structures but different p K a values have different ROS production abilities in a pH 7.0 reaction system. The ability for DHB 2,5 (2.97), DHB 3,4 (4.48), and GUA (9.99) to photo-generate 1 O 2 increased with increasing dissociation. The ability for DHB 3,4 and GUA to photo-generate HO· followed the same trend. The correlation between NOM dissociation constant and ROS generation is preliminary established, which explains the influence of functional groups. Our results may provide some basic information for understanding the correlation between NOM structural features and ROS generation.
研究领域:
环境化学
·
光化学
·
水处理
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2024
·
IF 3.1
Lei Zhenyu,Sun Honglei,Dong Zhehan,Sun Shuaishuai,Bi Chongyao,Zhan Junling,Wu Lin,Jia Mingjun
The rational design of efficient heterogeneous catalysts for Friedel-Crafts acylation reactions is highly desirable for meeting the need for the industrial production of various aromatic ketone compounds and biomass-derived chemicals. Herein, we reported that graphitic carbon wrapped FeCo bimetallic nanoparticles confined in nitrogen-doped carbon nanotubes, which were prepared by pyrolysis of FeCo-based Prussian blue analogue and melamine via a two-stage programmed heating procedure, exhibited excellent catalytic activity and recyclability for the acylation of aromatic compounds with acyl chlorides. The oxidized bimetallic species embedded in the external graphitic carbon shell should be the main active sites for the acylation reaction. The graphitic carbon shell and the carbon nanotube could provide effective protection on the active metal species against leaching through multiple interactions, leading to the formation of a highly active and durable heterogeneous catalyst for the acylation reaction.
研究领域:
催化
·
材料科学
·
化学工程
·
纳米技术
✓ 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）