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Start Over Author "Li Ang" Journal journal of the american chemical society
43 results on '"Li Ang"'

3. Atomic Replacement of PtNi Nanoalloys within Zn-ZIF-8 for the Fabrication of a Multisite CO2 Reduction Electrocatalyst

Author

Wang, Xiaolu, primary, Fu, Ninghua, additional, Liu, Jin-Cheng, additional, Yu, Ke, additional, Li, Zhi, additional, Xu, Zhongfei, additional, Liang, Xiao, additional, Zhu, Peng, additional, Ye, Chenliang, additional, Zhou, Awu, additional, Li, Ang, additional, Zheng, Lirong, additional, Liu, Li-Min, additional, Chen, Chen, additional, Wang, Dingsheng, additional, Peng, Qing, additional, and Li, Yadong, additional

Published
2022
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4. Thermal Atomization of Platinum Nanoparticles into Single Atoms: An Effective Strategy for Engineering High-Performance Nanozymes

Author

Chen, Yuanjun, primary, Wang, Peixia, additional, Hao, Haigang, additional, Hong, Juanji, additional, Li, Haijing, additional, Ji, Shufang, additional, Li, Ang, additional, Gao, Rui, additional, Dong, Juncai, additional, Han, Xiaodong, additional, Liang, Minmin, additional, Wang, Dingsheng, additional, and Li, Yadong, additional

Published
2021
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10. Low Temperature Oxidation of Ethane to Oxygenates by Oxygen over Iridium-Cluster Catalysts

Author

Jin, Renxi, primary, Peng, Mi, additional, Li, Ang, additional, Deng, Yuchen, additional, Jia, Zhimin, additional, Huang, Fei, additional, Ling, Yunjian, additional, Yang, Fan, additional, Fu, Hui, additional, Xie, Jinglin, additional, Han, Xiaodong, additional, Xiao, Dequan, additional, Jiang, Zheng, additional, Liu, Hongyang, additional, and Ma, Ding, additional

Published
2019
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11. Bismuth Single Atoms Resulting from Transformation of Metal–Organic Frameworks and Their Use as Electrocatalysts for CO2 Reduction

Author

Zhang, Erhuan, primary, Wang, Tao, additional, Yu, Ke, additional, Liu, Jia, additional, Chen, Wenxing, additional, Li, Ang, additional, Rong, Hongpan, additional, Lin, Rui, additional, Ji, Shufang, additional, Zheng, Xusheng, additional, Wang, Yu, additional, Zheng, Lirong, additional, Chen, Chen, additional, Wang, Dingsheng, additional, Zhang, Jiatao, additional, and Li, Yadong, additional

Published
2019
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14. Constructing NiCo/Fe3O4 Heteroparticles within MOF-74 for Efficient Oxygen Evolution Reactions

Author

Wang, Xiaolu, primary, Xiao, Hai, additional, Li, Ang, additional, Li, Zhi, additional, Liu, Shoujie, additional, Zhang, Qinghua, additional, Gong, Yue, additional, Zheng, Lirong, additional, Zhu, Youqi, additional, Chen, Chen, additional, Wang, Dingsheng, additional, Peng, Qing, additional, Gu, Lin, additional, Han, Xiaodong, additional, Li, Jun, additional, and Li, Yadong, additional

Published
2018
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17. Total Synthesis of Hybridaphniphylline B

Author

Zhang, Wenhao, primary, Ding, Ming, additional, Li, Jian, additional, Guo, Zhicong, additional, Lu, Ming, additional, Chen, Yu, additional, Liu, Lianchao, additional, Shen, Yun-Heng, additional, and Li, Ang, additional

Published
2018
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19. Total Synthesis and Stereochemical Assignment of Delavatine A: Rh-Catalyzed Asymmetric Hydrogenation of Indene-Type Tetrasubstituted Olefins and Kinetic Resolution through Pd-Catalyzed Triflamide-Directed C–H Olefination

Author

Zhang, Zhongyin, primary, Wang, Jinxin, additional, Li, Jian, additional, Yang, Fan, additional, Liu, Guodu, additional, Tang, Wenjun, additional, He, Weiwei, additional, Fu, Jian-Jun, additional, Shen, Yun-Heng, additional, Li, Ang, additional, and Zhang, Wei-Dong, additional

Published
2017
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20. Elucidation of the Structure of Pseudorubriflordilactone B by Chemical Synthesis.

Author

Yang, Peng, Li, Jian, Sun, Li, Yao, Ming, Zhang, Xiang, Xiao, Wei-Lie, Wang, Jian-Hua, Tian, Ping, Sun, Han-Dong, Puno, Pema-Tenzin, and Li, Ang

Abstract

Rubriflordilactone B (1) is a schinortriterpenoid isolated by Sun and colleagues, which possesses a tetrasubstituted benzene moiety and eight stereocenters. The previous synthesis of 1by Li and co-workers uncovered the existence of its naturally occurring stereoisomer "pseudorubriflordilactone B". Here we report a collaborative study by the two groups that elucidates the structure of pseudorubriflordilactone B to be 16,17-bis-epi-rubriflordilactone B (26). Chemical synthesis served as an important tool in the structure determination. Taking advantage of a modular synthetic route, we systematically "mutated" the configurations of C-23, C-22, C-20, and C-16/C-17 located at the right-hand domain of 1, and thus prepared its 15 stereoisomers for spectrum comparison. The 1H NMR spectra of synthetic 26in deuterated chloroform and pyridine were identical to those of authentic pseudorubriflordilactone B, respectively. This synthetic sample displayed anti-HIV activity (EC50= 0.288 μM) in vitro.

Published
2020
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22. Asymmetric Total Synthesis of Arcutinidine, Arcutinine, and Arcutine

Author

Zhou, Shupeng, Xia, Kaifu, Leng, Xuebing, and Li, Ang

Abstract

We have accomplished the asymmetric total synthesis of arcutinidine, arcutinine, and arcutine, three arcutine-type C20-diterpenoid alkaloids. A pentacyclic intermediate was rapidly assembled by using two Diels–Alder reactions. We developed a cascade sequence of Prins cyclization and Wagner–Meerwein rearrangement to construct the core of arcutinidine, which was then elaborated into an oxygenated pentacycle through a scalable route. Chemoselective reductive amination followed by spontaneous imine formation furnished the pyrroline motif in the final stage. We clarified the Sconfiguration of the α-carbon of the acyl group within arcutine through chemical synthesis and crystallographic analysis.

Published
2024
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31. Constructing NiCo/Fe3O4Heteroparticles within MOF-74 for Efficient Oxygen Evolution Reactions

Author

Wang, Xiaolu, Xiao, Hai, Li, Ang, Li, Zhi, Liu, Shoujie, Zhang, Qinghua, Gong, Yue, Zheng, Lirong, Zhu, Youqi, Chen, Chen, Wang, Dingsheng, Peng, Qing, Gu, Lin, Han, Xiaodong, Li, Jun, and Li, Yadong

Abstract

Metal–organic frameworks (MOF) have recently emerged as versatile precursors to fabricate functional MOF derivatives for oxygen evolution reactions (OER). Herein, we developed a controlled partial pyrolysis strategy to construct robust NiCo/Fe3O4heteroparticles within MOF-74 for efficient OER using trimetallic NiCoFe-MOF-74 as precursor. The partial pyrolysis method preserves the framework structure of MOF for effective substrates diffusion while producing highly active nanoparticles. The as-prepared NiCo/Fe3O4/MOF-74 delivered remarkably stable OER current with an overpotential as low as 238 mV at 10.0 mA cm–2and an Tafel slop of 29 mV/dec, outperforming those of pristine NiCoFe-MOF-74, totally decomposed MOF derivatives, and most reported non-noble metal based electrocatalysts. The key for the formation of NiCo/Fe3O4/MOF-74 nanostructures is that the metals can be decomposed from NiCoFe-MOF-74 in the order of Ni, Co, and Fe under controlled heat treatment. Density functional theory calculations reveals that the underlying NiCo promotes the OER activity of Fe3O4through exchange stabilization of active oxygen species.

Published
2018
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32. Nanoscopic Cylindrical Dual Concentric and Lengthwise Block Brush Terpolymers as Covalent Preassembled High-Resolution and High-Sensitivity Negative-Tone Photoresist Materials

Author

Sun, Guorong, primary, Cho, Sangho, additional, Clark, Corrie, additional, Verkhoturov, Stanislav V., additional, Eller, Michael J., additional, Li, Ang, additional, Pavía-Jiménez, Adriana, additional, Schweikert, Emile A., additional, Thackeray, James W., additional, Trefonas, Peter, additional, and Wooley, Karen L., additional

Published
2013
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38. Atomic Replacement of PtNi Nanoalloys within Zn-ZIF-8 for the Fabrication of a Multisite CO2Reduction Electrocatalyst

Author

Wang, Xiaolu, Fu, Ninghua, Liu, Jin-Cheng, Yu, Ke, Li, Zhi, Xu, Zhongfei, Liang, Xiao, Zhu, Peng, Ye, Chenliang, Zhou, Awu, Li, Ang, Zheng, Lirong, Liu, Li-Min, Chen, Chen, Wang, Dingsheng, Peng, Qing, and Li, Yadong

Abstract

Exploring the transformation/interconversion pathways of catalytic active metal species (single atoms, clusters, nanoparticles) on a support is crucial for the fabrication of high-efficiency catalysts, the investigation of how catalysts are deactivated, and the regeneration of spent catalysts. Sintering and redispersion represent the two main transformation modes for metal active components in heterogeneous catalysts. Herein, we established a novel solid-state atomic replacement transformation for metal catalysts, through which metal atoms exchanged between single atoms and nanoalloys to form a new set of nanoalloys and single atoms. Specifically, we found that the Ni of the PtNi nanoalloy and the Zn of the ZIF-8-derived Zn1on nitrogen-doped carbon (Zn1-CN) experienced metal interchange to produce PtZn nanocrystals and Ni single atoms (Ni1-CN) at high temperature. The elemental migration and chemical bond evolution during the atomic replacement displayed a Ni and Zn mutual migration feature. Density functional theory calculations revealed that the atomic replacement was realized by endothermically stretching Zn from the CN support into the nanoalloy and exothermically trapping Ni with defects on the CN support. Owing to the synergistic effect of the PtZn nanocrystal and Ni1-CN, the obtained (PtZn)n/Ni1-CN multisite catalyst showed a lower energy barrier of CO2protonation and CO desorption than that of the reference catalysts in the CO2reduction reaction (CO2RR), resulting in a much enhanced CO2RR catalytic performance. This unique atomic replacement transformation was also applicable to other metal alloys such as PtPd.

Published
2022
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39. Atomic Replacement of PtNi Nanoalloys within Zn-ZIF-8 for the Fabrication of a Multisite CO 2 Reduction Electrocatalyst.

Author

Wang X, Fu N, Liu JC, Yu K, Li Z, Xu Z, Liang X, Zhu P, Ye C, Zhou A, Li A, Zheng L, Liu LM, Chen C, Wang D, Peng Q, and Li Y

Abstract

Exploring the transformation/interconversion pathways of catalytic active metal species (single atoms, clusters, nanoparticles) on a support is crucial for the fabrication of high-efficiency catalysts, the investigation of how catalysts are deactivated, and the regeneration of spent catalysts. Sintering and redispersion represent the two main transformation modes for metal active components in heterogeneous catalysts. Herein, we established a novel solid-state atomic replacement transformation for metal catalysts, through which metal atoms exchanged between single atoms and nanoalloys to form a new set of nanoalloys and single atoms. Specifically, we found that the Ni of the PtNi nanoalloy and the Zn of the ZIF-8-derived Zn 1 on nitrogen-doped carbon (Zn 1 -CN) experienced metal interchange to produce PtZn nanocrystals and Ni single atoms (Ni 1 -CN) at high temperature. The elemental migration and chemical bond evolution during the atomic replacement displayed a Ni and Zn mutual migration feature. Density functional theory calculations revealed that the atomic replacement was realized by endothermically stretching Zn from the CN support into the nanoalloy and exothermically trapping Ni with defects on the CN support. Owing to the synergistic effect of the PtZn nanocrystal and Ni 1 -CN, the obtained (PtZn) n /Ni 1 -CN multisite catalyst showed a lower energy barrier of CO 2 protonation and CO desorption than that of the reference catalysts in the CO 2 reduction reaction (CO 2 RR), resulting in a much enhanced CO 2 RR catalytic performance. This unique atomic replacement transformation was also applicable to other metal alloys such as PtPd.

Published
2022
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40. Bismuth Single Atoms Resulting from Transformation of Metal-Organic Frameworks and Their Use as Electrocatalysts for CO 2 Reduction.

Author

Zhang E, Wang T, Yu K, Liu J, Chen W, Li A, Rong H, Lin R, Ji S, Zheng X, Wang Y, Zheng L, Chen C, Wang D, Zhang J, and Li Y

Abstract

The electrocatalytic reduction reaction of CO 2 (CO 2 RR) is a promising strategy to promote the global carbon balance and combat global climate change. Herein, exclusive Bi-N 4 sites on porous carbon networks can be achieved through thermal decomposition of a bismuth-based metal-organic framework (Bi-MOF) and dicyandiamide (DCD) for CO 2 RR. Interestingly, in situ environmental transmission electron microscopy (ETEM) analysis not only directly shows the reduction from Bi-MOF into Bi nanoparticles (NPs) but also exhibits subsequent atomization of Bi NPs assisted by the NH 3 released from the decomposition of DCD. Our catalyst exhibits high intrinsic CO 2 reduction activity for CO conversion, with a high Faradaic efficiency (FE CO up to 97%) and high turnover frequency of 5535 h -1 at a low overpotential of 0.39 V versus reversible hydrogen electrode. Further experiments and density functional theory results demonstrate that the single-atom Bi-N 4 site is the dominating active center simultaneously for CO 2 activation and the rapid formation of key intermediate COOH* with a low free energy barrier.

Published
2019
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41. Constructing NiCo/Fe 3 O 4 Heteroparticles within MOF-74 for Efficient Oxygen Evolution Reactions.

Author

Wang X, Xiao H, Li A, Li Z, Liu S, Zhang Q, Gong Y, Zheng L, Zhu Y, Chen C, Wang D, Peng Q, Gu L, Han X, Li J, and Li Y

Abstract

Metal-organic frameworks (MOF) have recently emerged as versatile precursors to fabricate functional MOF derivatives for oxygen evolution reactions (OER). Herein, we developed a controlled partial pyrolysis strategy to construct robust NiCo/Fe 3 O 4 heteroparticles within MOF-74 for efficient OER using trimetallic NiCoFe-MOF-74 as precursor. The partial pyrolysis method preserves the framework structure of MOF for effective substrates diffusion while producing highly active nanoparticles. The as-prepared NiCo/Fe 3 O 4 /MOF-74 delivered remarkably stable OER current with an overpotential as low as 238 mV at 10.0 mA cm -2 and an Tafel slop of 29 mV/dec, outperforming those of pristine NiCoFe-MOF-74, totally decomposed MOF derivatives, and most reported non-noble metal based electrocatalysts. The key for the formation of NiCo/Fe 3 O 4 /MOF-74 nanostructures is that the metals can be decomposed from NiCoFe-MOF-74 in the order of Ni, Co, and Fe under controlled heat treatment. Density functional theory calculations reveals that the underlying NiCo promotes the OER activity of Fe 3 O 4 through exchange stabilization of active oxygen species.

Published
2018
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42. Total Synthesis of Longeracinphyllin A.

Author

Li J, Zhang W, Zhang F, Chen Y, and Li A

Abstract

The first and asymmetric total synthesis of longeracinphyllin A, a hexacyclic Daphniphyllum alkaloid, has been accomplished. A tetracyclic intermediate was prepared through silver-catalyzed alkyne cyclization and Luche radical cyclization. A phosphine-promoted [3 + 2] cycloaddition reaction was exploited to construct the sterically congested E ring bearing vicinal tertiary and quaternary centers. The cyclopentenone motif was assembled by using intramolecular Horner-Wadsworth-Emmons olefination. Raney Ni reduction delivered the tertiary amine from a thioamide precursor at a late stage.

Published
2017
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43. Total synthesis of (-)-fusarisetin A and reassignment of the absolute configuration of its natural counterpart.

Author

Deng J, Zhu B, Lu Z, Yu H, and Li A

Subjects
Catalysis, Fusarium chemistry, Models, Molecular, Molecular Structure, Palladium, Antineoplastic Agents chemical synthesis, Fusarium metabolism, Heterocyclic Compounds, 4 or More Rings chemical synthesis
Abstract

The first total synthesis of (-)-fusarisetin A, the enantiomer of naturally occurring acinar morphogenesis inhibitor (+)-fusarisetin A, was accomplished in 13 steps, leading to the reassignment of the absolute configuration of the natural product. The synthesis featured a Lewis acid-promoted intramolecular Diels-Alder reaction, a Pd-catalyzed O→C allylic rearrangement, a chemoselective Wacker oxidation, and a Dieckmann condensation/hemiketalization cascade., (© 2011 American Chemical Society)

Published
2012
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