JOURNAL OF ORGANIC CHEMISTRY
·
2021
·
IF 4.354
Ming Li,Jun-Yang Tao,Liang-Neng Wang,Jia-Wei Li,Yue-Jin Liu,Ming-Hua Zeng
Modification of commercially available biaryl monophosphine ligands via ruthenium(II)-catalyzed P(III)-directed-catalyzed ortho C–H secondary alkylation is described. The use of highly ring-strained norbornene as a secondary alkylating reagent is the key to this transformation. A series of highly bulky ligands with a norbornyl group were obtained in excellent yields. The modified ligands with secondary alkyl group outperformed common substituted phosphines in the Suzuki–Miyaura cross-coupling reaction at a ppm mole level of Pd catalyst.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2023
·
IF 3.6
Huanhuan Song,Jingwen Li,Yinbin Zhang,Ke Chen,Le Liu,Junjie Zhang,Xin-Hua Duan,Mingyou Hu
Difluoromethylated heterocyclic compounds have found broad applications in numerous bioactive molecules. Herein, we report photoredox catalysis-induced direct C–H difluoromethylation of heterocycles by using bis(difluoromethyl) pentacoordinate phosphorane (PPh3(CF2H)2, 1) as the reagent. A variety of heterocycles, such as quinoxalin-2(1H)-one, thiophene, indole, and coumarin, are readily tailored with a difluoromethyl group. The method is featured as transition-metal-free by using an organic compound Erythrosin B as the catalyst and O2 as the oxidant.
研究领域:
有机化学
·
药物化学
✓ 已验证
DOI
PubMed
高影响因子
CEMENT & CONCRETE COMPOSITES
·
2023
·
IF 10.5
Zhongtao Luo,Tianyi Zhi,Xiaohai Liu,Kunpeng Yin,Han Pan,Hu Feng,Yatao Song,Yanfeng Su
The early hydration of UHPC can be retarded by the low water/binder ratio, the high polycarboxylate superplasticizers dosage, and the large supplementary cementitious materials (SCM) content. In this study, the effects of the prepared nanoscale C–S–H seeds and nano-silica (NS) on the early performance of UHPC were compared. The mechanism of nanomaterials influencing the early hydration of UHPC was further characterized by calorimetry , thermal analysis, nuclear magnetic resonance (NMR), and mercury intrusion porosimetry . The results showed that the 1-day compressive strength of UHPC samples with 0.3 wt% C–S–H seeds and NS increased by 457% and 25% respectively compared to the control sample. Compared to NS, C–S–H seeds were more effective in accelerating the early (before 3 d) hydration to produce hydrates and refine the pore structure of UHPC. The NMR results further implied that compared with the NS, the C–S–H seeds was 12% and 343% more efficient in accelerating the early hydration of cement and SCMs, respectively. However, the performance enhancement of nanomaterials was effective at 1 d and had little effect thereafter.
研究领域:
土木工程
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材料科学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2019
·Vol. 9
·期 9
·2132-2143
·
IF 5.726
Jie Zhang,Zhihua Huang,Lanjian Xu,Xiaomin Zhang,Xinzhi Zhang,Yangyang Yuan,Lei Xu
The methanol to hydrocarbons reaction over a unidimensional 10-membered-ring zeolite, H-ZSM-48, was investigated in the temperature range of 723–973 K. C3–5 olefins were the dominant products of reaction at 723 K. Multiple approaches (constant, transient, co-feed and isotope labelling experiments) have been adopted to clarify the underlying reaction pathway. The results indicate that both of the olefin- and aromatics-based cycles contribute to light olefin formation, and the aromatics-based cycle can be significantly enhanced with increasing reaction temperature. Ethene is formed predominantly from the aromatics-based cycle while propene and higher olefins are mainly derived from the olefin-based cycle. The 12C/13C-methanol isotopic switching experiments manifest that hexamethylbenzene is the most active aromatic intermediate. Co-feeding of 13C-methanol and 12C-benzene at 543 K reveals that the paring mechanism is the dominant mechanism for aromatic dealkylation. More importantly, the first experimental evidence that the two carbons of ethene are derived from aromatic ring carbons is obtained based on the isotopic pattern. Furthermore, the investigation on coke-covered H-ZSM-48 reveals that the reaction of methylbenzenes occurs mainly inside the channels. This work will shed new light on the reaction pathway of the MTH reaction over unidimensional zeolites.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Jianfeng Fan,Jiarong Huang,Liming Cao,Shiheng Yin,Yukun Chen
Recyclable polyvinylidene fluoride/silicone rubber (PVDF/SR) thermoplastic vulcanizates (TPVs) containing a high mass ratio of SR (50%) with excellent mechanical performances and shape memory behavior were fabricated. The inert PVDF was first dehydrofluorinated via β-H elimination reaction to introduce reactive double bonds. Then, the functional groups were initiated by dicumyl peroxide (DCP) during dynamic vulcanization to realize interfacial grafting (SR-g-PVDF) simultaneously. In situ grafted PVDF chains tightly bridge the immiscible phases, leading to the excellent interfacial adhesion. Consequently, the tensile strength, elongation at break, and tensile toughness were significantly increased to 14.5 MPa, 174.6%, and 12.3 kJ/m3, respectively, which were almost 2.0, 13.6, and 10.3 times than that without interfacial grafting reaction (7.2 MPa, 12.8%, and 1.2 kJ/m3). Also, their excellent mechanical properties were almost perfectly maintained after multiple repetitive processing. Furthermore, the chemical anchoring structure of SR-g-PVDF across the interface could effectively and quickly transfer the force, contributing to the shape memory performances. The obtained TPVs (m60 and m80) showed an impressive shape recovery ratio (>80%) even after two fixing-recovery cycles.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ORGANIC CHEMISTRY
·
2018
·
IF 4.805
Chao Zhang,Yugang Song,Zhihui Sang,Lingpeng Zhan,Yu Rao
A strategy combining O- and N-containing directing groups has been developed for the synthesis of 2,2′-biaryl via Pd-mediated C–H bond activation and oxidative coupling. This new transformation may proceed through a mechanism involving Pd(II) and Pd(IV) intermediates. We found the use of PTSA and HFIP to be critical for the reaction and suggest that these reagents could serve as efficient ligands for this C–C bond formation. This methodology provides broad functional group tolerance, excellent reactivity, and high yields.
研究领域:
有机化学
·
合成化学
✓ 已验证
DOI
高影响因子
KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2020
·Vol. 37
·期 6
·961-968
·
IF 2.69
Dai Ping,Sun Xiaowei,Xu Dongyan,Tan Feng
Alumina supported bimetallic cobalt-iron oxide (Co 3 O 4 -Fe 2 O 3 /Al 2 O 3 ) catalyst was prepared via co-impregnation of boehmite with the mixture solution of cobalt nitrate and iron nitrate followed by calcination in air. X-ray photoelectron spectroscopy and high-resolution transmission electron microscope analyses confirmed the existence of highly dispersed Co 3 O 4 and Fe 2 O 3 nanoparticles in the as-prepared catalysts. The catalytic activity of Co 3 O 4 -Fe 2 O 3 /Al 2 O 3 was evaluated for the degradation of H-acid in aqueous solution by heterogeneous activation of peroxymonosulfate. The results indicated that the Co 3 O 4 -Fe 2 O 3 /Al 2 O 3 catalyst exhibited an identical initial activity but much better recyclability than Co 3 O 4 /Al 2 O 3 due to its low amount of metal leaching and possible redox circle of Co(II)/Co(III). Electron paramagnetic resonance spectroscopy and radical quenching experiments suggested that singlet oxygen ( 1 O 2 ) contributed much more than ·OH and SO 4 • to H-acid degradation, and the degradation mainly followed a nonradical reaction mechanism.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
ChemPlusChem
·
2024
·
IF 3
Yong Wang,Xueying Lin,Xianyu Ying,Shan Hu,Hongjun Zhu
A facile C–H amination of quinazoline employing N-fluorobenzenesulfonimide (NFSI) as the amination source has been disclosed in the absence of any metal, oxidant or additive. The methodology shows a board range of quinazolines with different functional groups in moderate to good yields up to 87%. Furthermore, gram-scale reaction, desulfonylation to amine and synthesis of pharmaceutical intermediate were also investigated, which demonstrates potential applications in medicinal chemistry. A plausible amination mechanism is proposed via F+ transfer accompanied by the removal of one molecule of PhSO2F. DFT studies with experimental work suggest that the mechanism via F+ transfer is more favorable than the free radical one.
研究领域:
有机化学
·
药物化学
·
合成化学
✓ 已验证
DOI
PubMed
高影响因子
MACROMOLECULES
·
2020
·
IF 5.918
Jia Wang,Yue Chen,Canbin Ye,Anjun Qin,Ben Zhong Tang
The heteroatom-containing polymers are important components of advanced functional materials. Among the tremendous synthetic methodologies, polymerization via C–H activation is a powerful tool for the preparation of functional heteroatom-containing polymers, which should be further enriched, especially via C(sp3)–H activation. In this work, a new atom economic Pd(0)/benzoic acid catalyzed polymerization of internal diynes and secondary diamines via C(sp3)–H activation; i.e., C(sp3)–H polyamination of internal alkynes was successfully established. A series of regio- and stereoregular functional poly(allylic tertiary amine)s with high weight-average molecular weights (Mw, up to 25 600) were synthesized in excellent yields (up to 98%). The resultant polymers possess good solubility and film-forming ability, and their thin films exhibit high refraction indices (RI) with the range of 1.7207–1.6797 at 632.8 nm. Moreover, all the poly(allylic tertiary amine)s are emissive in solution and solid states. Thanks to the tolerance to functional groups of this polymerization, the tetraphenylethene (TPE) moiety could be facilely incorporated to endow the resultant polymers with the unique aggregation-enhanced emission (AEE) characteristics. Thus, this work not only establishes a powerful C(sp3)–H polyamination but also provides a strategy to facilely prepare functional nitrogen-containing acetylenic polymers.
研究领域:
有机化学
·
高分子化学
·
材料科学
✓ 已验证
DOI
高影响因子
TETRAHEDRON
·
2018
·
IF 2.377
Jie Zhu,Wenhui Zhu,Ping Xie,Charles U. Pittman,Aihua Zhou
A novel and efficient Ni-catalyzed aryl- and alkyl-selenation of imidazo[1,2-α]pyridines employing selenium powder has been developed for the first time. The significant advantages of this protocol are that it is an inexpensive nickel catalyst and exhibits broad functional-group compatibility and good reaction yields.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Meng-Juan Yang,Shu-Yu Tang,Yan-Ran Weng,Feng Zhou,Yu Shi,Yong-Ju Bai,Yong Ai
Hybrid organic–inorganic perovskites (HOIPs) have emerged as multifunctional materials with remarkable optical and electronic properties. In particular, 2D-layered lead iodide-based HOIPs possess great practical application potential in the photoelectric field. In this work, we report H/F substitution-induced 1D-to-2D increment of lead iodide HOIPs. The enantiomeric HOIPs, S- and R-FPPbI3 (FP = 3-fluoropyrrolidinium), were achieved by monofluoride substitution on the spacer cations of the parent HOIP, PyPbI3 (Py = pyrrolidinium), showing mirror image structural relationship and reversible solid-state phase transition. A 2D-layered HOIP, (DFP)2PbI4 (DFP = 3,3-difluoropyrrolidinium), was achieved with a low band gap of 2.09 eV through difluoride substitution, thanks to the expansion of the Pb–I network from 1D to 2D. This work highlights the exploration of 1D chiral and 2D-layered HOIP materials with reversible phase transitions through H/F substitution strategies.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Minghu Zhao,Jiuhu Zhao,Ran Ding,Rongshu Zhu,Haiyan Li,Zhi Li,Jingwen Zhang,Yongji Zhu,Huiying Li
The existence of sulfur dioxide and water vapor in the flue gas generated from waste-to-energy stations could lead to catalyst deactivation , which has adverse effects on NO x removal. It is thus particularly important to study the reaction mechanism of catalyst resistance to poisoning. Herein, we report the mechanism of In-Co 3 O 4 -Ga 2 O 3 /H-Beta catalyst to SO 2 and H 2 O resistance in the selective catalytic reduction (SCR) of NO x by CH 4 . The catalyst could achieve 74.6% NO x removal efficiency in the presence of 100 ppm SO 2 and 5% H 2 O. In this catalyst, Co 3 O 4 is attributed to enhancing the reversible poisoning of SO 2 and CH 4 activation and increasing the number of Brønsted acid sites by decomposing H 2 O. However, the InO + active center was still eroded by a small amount of water vapor, leading to a reduction in NO x removal efficiency. The addition of Ga 2 O 3 primarily provided an important intermediate NO 2 for CH 4 -SCR reaction and reduced the aggregates of Co 3 O 4 to increase the exposure of indium sites, and could reduce a part of SO 2 to S 2− . This study provides a good candidate for preparing catalysts with superior resistance towards SO 2 and H 2 O for CH 4 -SCR.
研究领域:
环境科学
·
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）