ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Kun Li,Chengjie Duan,Weitao Mao,Dongliang Wang,Yumeng Liang,Wenbo Ye,Guangke He,Xiang Liu
A direct and efficient synthesis of N-methyl-1,2,3,4-tetrahydroquinolines (MTHQs) is achieved through the one-pot reductive N-methylation of quinolines. The SnOx-decorated Pt/Al2O3 (Pt-SnOx/Al2O3) catalyst proves to be highly effective in the transformation from quinolines to MTHQs, using methanol as the exclusive source for hydrogen (H) and methyl (CH3), without the addition of additional bases or additives. Mechanistic and kinetic studies reveal a tandem reaction pathway: (1) the dehydrogenation of methanol, (2) reduction of quinolines to 1,2,3,4-tetrahydroquinolines (THQs), and (3) N-methylation of THQs to MTHQs, with the dehydrogenation of methanol identified as the rate-determining step. Characterization and catalytic performance results demonstrate that SnOx modifies the morphology and electronic properties of Pt-based metal active sites, which dramatically facilitates the cleavage of O–H and less reactive C–H bonds in methanol, and maintains a delicate balance between methanol dehydrogenation and reductive N-methylation of quinolines, thus obtaining a high reactivity for the total transformation.
研究领域:
催化化学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Mei Ma,Jia-qi Bai,Huangfei Liu,Ben Liu,Zhangkai Qian,Suiqin Li,Jingshuai Chen,Mengdie Cai,Song Sun
The preparation of methyl-substituted amines by direct N-methylation of amines with CO2/H2 is an important reaction for CO2 utilization and organic synthesis. However, the design and construction of effective and stable non-noble-metal catalysts for this reaction remain challenging. Here, a cheap non-noble-Cu-based catalyst was prepared and applied in the direct N-methylation reaction of N-methylaniline with CO2 and H2. 5%Cu-ZnO(3.75%)/TiO2 showed 98.8% yield with an initial TOF of 7.7 h–1 after 24 h under 453 K, 1.5 MPa CO2, and 4.5 MPa H2, which was superior to 5%Cu/TiO2, 5%Cu/ZnO, and reported Cu-based catalysts. Furthermore, 5%Cu-ZnO(3.75%)/TiO2 can be reused at least four times and applied to the direct N-methylation of various amines with excellent selectivity. The various characterizations and experimental results showed that Cu0 was the active site, and 5%Cu-ZnO(3.75%)/TiO2 exhibited the largest surface Cu0 amount, thereby contributing to superior catalytic performance. The reaction mechanism of the direct N-methylation reaction of N-methylaniline with CO2 and H2 was proposed based on spectroscopic studies, kinetic studies, and control experiments. The reaction proceeded with the HCHO and N-methylformanilide intermediates, and the formation of HCHO from H2 and CO2 was the rate-determining step.
研究领域:
化学工程
·
催化科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ChemCatChem
·
2019
·Vol. 11
·期 16
·3919-3926
·
IF 4.495
Ke Liu,Zhenbo Zhao,Weiwei Lin,Qiang Liu,Qifan Wu,Ruhui Shi,Chao Zhang,Haiyang Cheng,Masahiko Arai,Fengyu Zhao
Graphical Another drop of copper : A non-noble metal catalyst of Cu/TiO 2 is effective for the heterogeneous N -methylation of N -methylaniline with CO 2 and H 2 , in which CHO* is formed as methyl reagent, and it reacts with N -methylaniline to produce intermediate N -methylformanilide followed by its hydrogenation to N,N -dimethylaniline. A non-noble heterogeneous catalyst of Cu/TiO 2 was prepared for N -methylation of N -methylaniline (MA) with CO 2 and H 2 . 5 wt.–% Cu loaded TiO 2 (P25) catalyst exhibited a high performance, with 82 % MA conversion and 98 % N,N -dimethylaniline (DMA) selectivity under the reaction conditions used (4 MPa H 2 , 2 MPa CO 2 , 180 °C, 36 h). The Cu/TiO 2 catalyst was more effective with respective to the total conversion and the DMA selectivity as compared to 5 wt.–% Cu loaded catalysts on CeO 2 , ZnO and activated carbon materials. The possible active species of Cu/TiO 2 catalyst should be both Cu + and Cu 0 which contributed to the high activity as the reaction conversion increased linearly with them exposed on the surface of catalyst. Moreover, the reaction pathways involved were studied; it was likely that the reaction took place via an intermediate of formaldehyde that was formed from CO 2 and H 2 , as confirmed by in situ diffuse reflectance Fourier-transform infrared spectroscopy, then it reacted with MA to give N -methylformanilide (MFA), and finally MFA was hydrogenated to DMA.
研究领域:
催化化学
·
环境化学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2018
·Vol. 21
·期 3
·567-577
·
IF 8.586
Wenfeng Zhao,Xiaoping Chi,Hu Li,Jian He,Jingxuan Long,Yufei Xu,Song Yang
Catalytic fixation of CO2 to produce valuable fine chemicals is of great significance to develop a green and sustainable circulation of excessive carbon in the environment. Herein, a series of non-toxic, biodegradable and recyclable acetylcholine-carboxylate bio-ionic liquids with different cations and anions were simply synthesized for producing formamides and methylamines using atmospheric CO2 as a carbon source, and phenylsilane as a hydrogen donor. The selectivity toward products was tuned by altering the reaction temperature under solvent or solvent-free conditions. N-Methylamines (ca. 96% yield) were obtained in acetonitrile at 50 °C, while N-formamides (ca. 99% yield) were attained without a solvent at 30 °C. The established bio-ionic liquid catalytic system found a wide range of applicability in substrates and possessed a high potentiality in scale-up to gram-grade production. The developed catalytic system was fairly stable, which could be easily reused without an apparent loss of reactivity, possibly due to the strong electrostatic interactions between the cation and anion. The combination of experimental and computational results explicitly elucidated the reaction mechanism: PhSiH3 activated by a bio-IL was favorable for the formation of silyl formate from hydrosilylation of CO2, followed by a reaction with an amine to give an N-formamide, while an N-methylamine was formed by further hydrosilylation of the N-formamide.
研究领域:
绿色化学
·
环境科学
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Hao Zhang,Junyan Wang,Minjie Liu,Di Liu
Cu/Al 2 O 3 catalyst was developed by a double hydrolysis precipitation. Over the Cu/Al 2 O 3 catalyst, a continuous mode of N-methylations of nitroarenes with methanol was successfully achieved under the exogenous base- and H 2 - free condition. Methylation process of nitroarenes could be controlled just by adjusting reaction conditions, affording the desired N-monomethylanilines or N, N-dimethylanilines, respectively. The characterization displayed that the double hydrolysis precipitation method made active metal Cu surface enrichment and high dispersion, meanwhile endow Cu/Al 2 O 3 with more developed pore system, which were responsible for the higher performance of our catalyst relative to Cu/Al 2 O 3 -CP. Compared with the reported batch mode, our procedure possessed the merits of low cost, environment-friendliness, better controllability and wide universality.
研究领域:
催化化学
·
绿色化学工程
✓ 已验证
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Zhangkai Qian,Jia-qi Bai,Mei Ma,Huangfei Liu,Mengdie Cai,Jingshuai Chen,Song Sun
N -methylation of amines, nitro compounds and nitriles with CO 2 and H 2 offers a promising strategy for CO 2 utilization. However, developing highly efficient and stable Cu-based catalysts for selective mono- N -methylation of aniline remains challenging. Herein, we report the successful synthesis of a Cu-ZnO/TiO 2 catalyst, with the optimized 5 %Cu-7.5 %ZnO/TiO 2 catalyst achieving a 96.7 % yield of N -methylaniline (MA) and an initial turnover frequency (TOF) of 7.4 h −1 after 6 h under 453 K, 2 MPa CO 2 and 4 MPa H 2 . This performance surpasses all reported Cu-based catalysts and rivals noble metal-based systems. The catalyst demonstrated reusability at least four cycles and versatility in the N -methylation of various amines, nitro compounds, and nitriles. Kinetic studies revealed reaction orders of 0 with respect to aniline concentration and CO 2 pressure, and 1 with respect to H 2 pressure. Based on kinetics and extensive characterization, we propose a reaction mechanism over 5 %Cu-7.5 %ZnO/TiO 2 , identifying Cu nanoparticles as the active sites. The process proceeds via N -phenylcarbamic acid and N -phenylformamide intermediates, with the hydrogenation of N -phenylcarbamic acid as the rate-determining step.
研究领域:
化学工程
·
催化科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
ORGANOMETALLICS
·
2020
·
IF 3.804
Shuang Huang,Xi Hong,He-Zhen Cui,Bing Zhan,Zhi-Ming Li,Xiu-Feng Hou
Herein, an unprecedented bimetallic bis-NHC Cp*Ir complex 1 bearing 2-arylbenzo[d]oxazolyl and NHC ligands is reported. A significant increase in activity was observed for N-methylation of amines and reduction of aldehydes with MeOH catalyzed by 1 compared to the monometallic analogues (2–11). Under the optimal conditions, it showed to be highly effective in N-methylation of nitroarenes with MeOH as both C1 and H2 source. Substrates, including aromatic amines, ketones, and nitro compounds with various functional groups, can be well-tolerated. Mechanistic studies and DFT calculation highlight the significance of bimetallic centers cooperativity.
研究领域:
无机化学
·
催化
·
有机金属化学
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2019
·Vol. 48
·期 15
·5072-5082
·
IF 4.052
Shuang Huang,Xi Hong,He-Zhen Cui,Quan Zhou,Yue-Jian Lin,Xiu-Feng Hou
Seven new chelated cyclometalated Ir complexes of ABON,P, ABON,O, and ABON,C(carbene) based on a rigid and tunable 2-arylbenzo[d]oxazole backbone have been prepared for the N-methylation of amines. Among these three coordinated modes, ABON,C(carbene)-chelated iridium-based catalysts exhibited good performance in the monomethylation of aromatic amines with methanol (MeOH) as the green methylation reagent. The steric-modified synthesis of ABON,C(carbene) complexes was described. The most active ABON,C(carbene) complex with marginal steric hindrance as a catalyst was obtained from the benzoxazole ring without a substituent and methyl group of the benzimidazole ring on the N-heterocyclic carbene (NHC) ligand. A variety of amines including para- and meta-substituted aromatic amines, as well as heterocyclic amines, were formulated as suitable substrates. Importantly, this catalyst considerably promoted the yield of the N-methylation of ortho-substituted aromatic amines. Controlled kinetic experiments and deuterium-labeling reactions of these ortho-substituted amines were conducted under optimized conditions. On the basis of the experimental results, a plausible mechanism was proposed.
研究领域:
有机化学
·
催化
·
合成化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Jincheng Mu,Jianfang Liu,Zhenzhen Ran,Muhammad Arif,Min Gao,Chen Wang,Shengfu Ji
MOF-808(Zr) with the coordinated unsaturated (CUS) Zr4+ centers was synthesized by the thermal reflux method, and a series of Au/MOF-808(Zr) catalysts with different Au loading percentages have been prepared by the impregnation–reduction method. The related X-ray diffraction, Fourier transform infrared spectroscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, N2 adsorption–desorption, Inductively coupled plasma-mass spectrometry, and NH3 temperature-programmed desorption characterizations have been undertaken to understand the structure of catalysts. The catalytic activity in CO2 with aniline/H2 to N-methylation and N-formylation has been studied in a batch reactor. Results show that the MOF-808(Zr) structures in catalysts are of high quality and damage-free. The Au nanoparticles (NPs) are highly dispersed on the surface of the MOF-808(Zr) cage with a mean size of 2–20 nm. Also, the catalysts could catalyze the conversion of CO2 with aniline/H2 to N-methylation and N-formylation products with a high efficiency. With a 3.0 wt % Au/MOF-808(Zr) catalyst, the conversion of aniline is 18.4%, and the selectivity of N-methylaniline is 80.9% and that of N,N-dimethylaniline is 19.1%. The preliminary reaction mechanism and the critical role of CUS were also studied. It is determined that H2 is adsorbed and activated on Au NPs. CO2 is adsorbed on the CUS Zr4+ acidic sites and O2– basic sites. The primary and secondary amines are adsorbed on the CUS Zr4+ acidic sites, where they react with CO2 and H2 to form N-formamide. Subsequently, N-formamide reacts with activated H2 to yield N-methylamine.
研究领域:
催化
·
材料科学
·
化学工程
·
环境化学
✓ 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）