1
|
Shu S, Song T, Wang C, Dai H, Duan L. [2+1] Cycloadditions Modulate the Hydrophobicity of Ni-N 4 Single-Atom Catalysts for Efficient CO 2 Electroreduction. Angew Chem Int Ed Engl 2024:e202405650. [PMID: 38695268 DOI: 10.1002/anie.202405650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Indexed: 06/11/2024]
Abstract
Microenvironment regulation of M-N4 single-atom catalysts (SACs) is a promising way to tune their catalytic properties toward the electrochemical CO2 reduction reaction. However, strategies that can effectively introduce functional groups around the M-N4 sites through strong covalent bonding and under mild reaction conditions are highly desired. Taking the hydrophilic Ni-N4 SAC as a representative, we report herein a [2+1] cycloaddition reaction between Ni-N4 and in situ generated difluorocarbene (F2C:), and enable the surface fluorocarbonation of Ni-N4, resulting in the formation of a super-hydrophobic Ni-N4-CF2 catalyst. Meanwhile, the mild reaction conditions allow Ni-N4-CF2 to inherit both the electronic and structural configuration of the Ni-N4 sites from Ni-N4. Enhanced electrochemical CO2-to-CO Faradaic efficiency above 98 % is achieved in a wide operating potential window from -0.7 V to -1.3 V over Ni-N4-CF2. In situ spectroelectrochemical studies reveal that a highly hydrophobic microenvironment formed by the -CF2- group repels asymmetric H-bonded water at the electrified interface, inhibiting the hydrogen evolution reaction and promoting CO production. This work highlights the advantages of [2+1] cycloaddition reactions on the covalent modification of N-doped carbon-supported catalysts.
Collapse
Affiliation(s)
- Siyan Shu
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou, 310024, China
| | - Tao Song
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou, 310024, China
- School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin, 150001, China
| | - Cheng Wang
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou, 310024, China
| | - Hao Dai
- Department of Chemistry, Southern University of Science and Technology, Shenzhen, 518055, China
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou, 310024, China
| | - Lele Duan
- Center of Artificial Photosynthesis for Solar Fuels and Department of Chemistry, School of Science, Westlake University, Hangzhou, 310024, China
- Division of Solar Energy Conversion and Catalysis at Westlake University, Zhejiang Baima Lake Laboratory Co., Ltd, Hangzhou, 310000, Zhejiang, China
- Institute of Natural Sciences, Westlake Institute for Advanced Study, Hangzhou, 310024, China
| |
Collapse
|
2
|
Pan S, Xie Q, Wang X, Huang R, Lu Y, Ni C, Hu J. Controllable Double Difluoromethylene Insertions into S-Cu Bonds: (Arylthio)tetrafluoroethylation of Aryl Iodides with TMSCF 2Br. Angew Chem Int Ed Engl 2024; 63:e202400839. [PMID: 38358953 DOI: 10.1002/anie.202400839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 02/14/2024] [Accepted: 02/14/2024] [Indexed: 02/17/2024]
Abstract
A new method of constructing "ArSCF2CF2Cu" from ArSCu and TMSCF2Br (TMS=trimethylsilyl) has been developed. The cross-coupling reactions of the obtained "ArSCF2CF2Cu" with diverse aryl iodides (Ar'I) provide an efficient access to Ar'CF2CF2SAr. Mechanistic studies demonstrate that the "ArSCF2CF2Cu" species were generated through controllable double difluoromethylene insertions into ArS-Cu bonds rather than the 1,2-addition of ArSCu to tetrafluoroethylene.
Collapse
Affiliation(s)
- Shitao Pan
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| | - Qiqiang Xie
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| | - Xiu Wang
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| | - Rumin Huang
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| | - Yuhao Lu
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| | - Chuanfa Ni
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| | - Jinbo Hu
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| |
Collapse
|
3
|
Xie Q, Hu J. A Journey of the Development of Privileged Difluorocarbene Reagents TMSCF 2X (X = Br, F, Cl) for Organic Synthesis. Acc Chem Res 2024; 57:693-713. [PMID: 38354302 DOI: 10.1021/acs.accounts.3c00719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
ConspectusAs fluorine has played an increasingly important role in modulating the physical, chemical, and biological properties of organic molecules, the selective introduction of fluorine atom(s) or fluorinated moieties into target molecules has become a powerful tool in the development of new pharmaceuticals, agrochemicals, and functional materials. In this context, the difluoromethylene (CF2) and difluoromethyl (CF2H) groups are of special interest because of their ability to serve as bioisosteres of ethereal oxygen atoms and hydroxyl (OH) and thiol (SH) groups, respectively. Difluorocarbene is one of the most versatile reactive intermediates to incorporate CF2 and CF2H groups; however, before 2006, most of the previously known difluorocarbene reagents suffered from several drawbacks such as using ozone-depleting substances (ODSs), difficult-to-handle reagents, or harsh reaction conditions or having narrow substrate scope and/or low yields. Moreover, the reactivity of difluorocarbene generated from different precursors (reagents) was often unpredictable, since the difluorocarbene generation conditions (activation modes) of various difluorocarbene precursors are different, and these conditions may mismatch those required for subsequent difluorocarbene-involved transformations. Therefore, the development of new environmentally friendly and versatile difluorocarbene reagents, as well as the investigation of the mechanistic insights into difluorocarbene-involved reactions, has been highly desirable.In this Account, we summarize our contributions to the development of new difluorocarbene reagents and their applications in organic synthesis since 2006. We have developed seven new difluorocarbene reagents, including 2-chloro-2,2-difluoroacetophenone (1), chlorodifluoromethyl phenyl sulfone (2), S-difluoromethyl-S-phenyl-N-tosylsulfoximine (3), difluoromethyltri(n-butyl)ammonium chloride (4), (chlorodifluoromethyl)trimethylsilane (TMSCF2Cl, 5), (bromodifluoromethyl)trimethylsilane (TMSCF2Br, 6), and (trifluoromethyl)trimethylsilane (TMSCF3, 7). In this journey, we realized the key factor for an ideal difluorocarbene reagent that can be used for a broad range of reactions, that is, the reagent should allow various activation modes for the generation of difluorocarbene species, such as under basic/acidic/neutral conditions, at wide range of temperatures, and in different solvents, which are compatible with a wide range of difluorocarbene-involved transformations. Among all known difluorocarbene reagents, silanes TMSCF2X (X = Br, F, Cl) have stood out as privileged ones, which paves a new avenue for further developing difluorocarbene chemistry. In particular, TMSCF2Br was recognized as an "all-rounder": TMSCF2Br can be applied in almost all common difluorocarbene-involved reactions, and more importantly, TMSCF2Br also enables many other novel transformations that other difluorocarbene reagents cannot achieve, thanks to its unique structure and rich activation modes of releasing difluorocarbene under different reaction conditions. It can be expected that with the commercial availability of TMSCF2X reagents (X = Br, F, Cl) now, the development of difluorocarbene chemistry will be accelerated in the years to come.
Collapse
Affiliation(s)
- Qiqiang Xie
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China
| | - Jinbo Hu
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China
| |
Collapse
|
4
|
Liu A, Zhang X, Zhao F, Ni C, Hu J. Controllable Fluorocarbon Chain Elongation: TMSCF 2Br-Enabled Trifluorovinylation and Pentafluorocyclopropylation of Aldehydes. J Am Chem Soc 2024; 146:1806-1812. [PMID: 38193677 DOI: 10.1021/jacs.3c12919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
Controllable fluorocarbon chain elongation (CFCE) is a promising yet underdeveloped strategy for the well-defined synthesis of structurally novel polyfluorinated compounds. Herein, the direct and efficient trifluorovinylation and pentafluorocyclopropylation of aldehydes are described by using TMSCF2Br (TMS = trimethylsilyl) as the sole fluorocarbon source, accomplishing the goals of CFCE from C1 to C2 and from C1 to C3, respectively. The key to the success of these CFCE processes lies in the unique and diversified chemical reactivity of TMSCF2Br, which can serve as two different precursors, namely, a TMSCF2 radical precursor and a difluorocarbene precursor. Various functional groups are amenable to this new synthetic protocol, providing streamlined access to a broad range of alcohols containing trifluorovinyl or pentafluorocyclopropyl moieties from abundantly available aldehydes. The potential utility of these methods is further demonstrated by the gram-scale synthesis, derivatization, and measurement of log P values of the products.
Collapse
Affiliation(s)
- An Liu
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China
| | - Xianghong Zhang
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China
| | - Feng Zhao
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China
| | - Chuanfa Ni
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China
| | - Jinbo Hu
- Key Laboratory of Fluorine and Nitrogen Chemistry and Advanced Materials, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai 200032, China
| |
Collapse
|
5
|
Feng Z, Riemann L, Guo Z, Herrero D, Simon M, Golz C, Mata RA, Alcarazo M. Pentafluorocyclopropanation of (Hetero)arenes Using Sulfonium Salts: Applications in Late-Stage Functionalization. Angew Chem Int Ed Engl 2023; 62:e202306764. [PMID: 37402213 DOI: 10.1002/anie.202306764] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/03/2023] [Accepted: 07/03/2023] [Indexed: 07/06/2023]
Abstract
The evaluation of the pentafluorocyclopropyl group as a chemotype in crop protection and medicinal chemistry has been hampered in the past by the lack of suitable methodologies that enable the practical incorporation of this moiety into advanced synthetic intermediates. Herein, we report the gram-scale synthesis of an unprecedented sulfonium salt, 5-(pentafluorocyclopropyl)dibenzothiophenium triflate, and its use as a versatile reagent for the photoinduced C-H pentafluorocyclopropylation of a broad series of non-previously functionalized (hetero)arenes through a radical mediated mechanism. The scope and potential benefits of the protocol developed are further demonstrated by the late-stage introduction of the pentafluorocyclopropyl unit into biologically relevant molecules and widely used pharmaceuticals.
Collapse
Affiliation(s)
- Zeyu Feng
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr 2, 37077, Göttingen, Germany
| | - Lucas Riemann
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr 2, 37077, Göttingen, Germany
| | - Zichen Guo
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr 2, 37077, Göttingen, Germany
| | - David Herrero
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr 2, 37077, Göttingen, Germany
| | - Martin Simon
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr 2, 37077, Göttingen, Germany
| | - Christopher Golz
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr 2, 37077, Göttingen, Germany
| | - Ricardo A Mata
- Institut für Physikalische Chemie, Georg-August-Universität Göttingen, Tammannstr 6, 37077, Göttingen, Germany
| | - Manuel Alcarazo
- Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr 2, 37077, Göttingen, Germany
| |
Collapse
|
6
|
Zhu J, Xu M, Gong B, Lin A, Gao S. ( Z)-Selective Synthesis of Bromofluoroalkenes via the TMSCF 2Br-Mediated Tandem Reaction with para-Quinone Methides. Org Lett 2023; 25:3271-3275. [PMID: 37104568 DOI: 10.1021/acs.orglett.3c01007] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
We report herein a tandem reaction of para-quinone methides with TMSCF2Br to construct bromofluoroalkenes in a Z-selective manner. While TMSCF2Br has been documented as the precursor of difluoro carbene, it exhibits another possibility in this transformation, a formal bromofluoro carbene surrogate. The alkenyl bromide unit of the products could directly engage in a variety of transformations.
Collapse
Affiliation(s)
- Jie Zhu
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, P. R. China
| | - Menghua Xu
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, P. R. China
| | - Baihui Gong
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, P. R. China
| | - Aijun Lin
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, P. R. China
| | - Shang Gao
- State Key Laboratory of Natural Medicines (SKLNM) and Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, Nanjing 210009, P. R. China
| |
Collapse
|
7
|
Liu A, Ni C, Xie Q, Hu J. Transition-Metal-Free Controllable Single and Double Difluoromethylene Formal Insertions into C-H Bonds of Aldehydes with TMSCF 2 Br. Angew Chem Int Ed Engl 2023; 62:e202217088. [PMID: 36517973 DOI: 10.1002/anie.202217088] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 12/13/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
We have developed a new strategy for controllable single and double difluoromethylene (CF2 ) formal insertions into C-H bonds of aldehydes with nearly full selectivity under transition-metal-free conditions. The key to the success of controllable CF2 insertions lies in the well-defined formation of 2,2-difluoroenolsilyl ether and 2,2,3,3-tetrafluorocyclopropanolsilyl ether intermediates using difluorocarbene reagent TMSCF2 Br (TMS=trimethylsilyl). These two intermediates can react with various electrophiles including proton sources and various halogenation reagents, allowing for the access to diverse arrays of ketones containing difluoromethylene (CF2 ) and tetrafluoroethylene (CF2 CF2 ) units. The first synthesis of relatively stable 2,2,3,3-tetrafluorocyclopropanolsilyl ethers has been achieved, which offers a new platform to explore other unknown chemical space.
Collapse
Affiliation(s)
- An Liu
- Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| | - Chuanfa Ni
- Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| | - Qiqiang Xie
- Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| | - Jinbo Hu
- Key Laboratory of Organofluorine Chemistry, Center for Excellence in Molecular Synthesis, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Chinese Academy of Sciences, 345 Ling-Ling Road, Shanghai, 200032, China
| |
Collapse
|
8
|
Li SW, Wang G, Ye ZS. Difluorocarbene Enabled Ester Insertion/1,4-Acyl Rearrangement of 2-Acetoxylpyridines: Modular Access to gem-Difluoromethylenated 2-Pyridones. Tetrahedron Lett 2023. [DOI: 10.1016/j.tetlet.2023.154413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
|
9
|
Cui H, Ban C, Zhu F, Yuan J, Du J, Huang Y, Xiao Q, Huang C, Huang J, Zhu Q. Difluorocarbene-Triggered Acyl Rearrangement Reaction: A Strategy for the Direct Introduction of the gem-Difluoromethylene Group. Org Lett 2023; 25:99-103. [PMID: 36546836 DOI: 10.1021/acs.orglett.2c03907] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A novel metal- and catalyst-free dearomative reaction of 2-oxypyridines to construct gem-difluoromethylenated N-substituted 2-pyridones has been developed. The reaction involves an attractive acyl rearrangement from O to CF2 of difluorocarbene-derived pyridinium ylides, which provides a new strategy for the direct introduction of the gem-difluoromethylene group with high efficiency and selectivity as well as broad substrate scope. Gram-scale synthesis and synthetic transformations have also been demonstrated.
Collapse
Affiliation(s)
- Haitao Cui
- Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, Guangxi 530100, People's Republic of China
| | - Caijin Ban
- Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, Guangxi 530100, People's Republic of China
| | - Fengting Zhu
- Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, Guangxi 530100, People's Republic of China
| | - Jingmei Yuan
- Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, Guangxi 530100, People's Republic of China
| | - Juan Du
- Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, Guangxi 530100, People's Republic of China
| | - Yanmin Huang
- Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, Guangxi 530100, People's Republic of China
| | - Qi Xiao
- Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, Guangxi 530100, People's Republic of China
| | - Chusheng Huang
- Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, Guangxi 530100, People's Republic of China
| | - Jun Huang
- Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, Guangxi 530100, People's Republic of China
| | - Qiang Zhu
- Guangxi Key Laboratory of Natural Polymer Chemistry and Physics, Nanning Normal University, Nanning, Guangxi 530100, People's Republic of China.,State Key Laboratory of Respiratory Disease, Guangzhou Institutes of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou, Guangdong 510530, People's Republic of China
| |
Collapse
|