Xiaoqiang Sun

Changzhou University, Wujin, Jiangsu Sheng, China

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Publications (68)123.1 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The first Lewis acid–catalyzed intramolecular interrupted Nazarov cyclization of 1,4-pentadien-3-ols is described. Using FeBr3 as the catalyst, a series of new substituted cyclopenta[b]indoles was prepared—through a sequence of Nazarov cyclization, nucleophilic amination, and isomerization—with good yields and high diastereo- and regioselectivities. The key reaction intermediate, 2,3,3a,4-tetrahydrocyclopenta[b]indole, was isolated and the cyclopentyl allylic carbocation species was trapped using EtOH as an external nucleophile. A similar catalytic process was developed for the synthesis of structurally interesting spiro[indene-1,4´-quinoline]s.
    No preview · Article · Dec 2015 · Chemical Communications
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    ABSTRACT: Isothiocyanates were prepared from the reactions of phenyl chlorothionoformate and various primary amines vis one-step or two-step process without. additional base. The one-step process is good at highly active amines, while two-step approach is suitable for all kinds of amines. This method has many merits such as environment-friendly, easily available raw materials, low toxicity and convenient operation, which has a good application prospect in industry.
    No preview · Article · Sep 2015 · Chinese Journal of Organic Chemistry
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    ABSTRACT: Three-dimensional Ni@graphene (NG) was prepared for the first time at a low temperature by a one-step facile calcination method. The obtained NG showed a high specific capacitance of 765 F g-1 at a current density of 1 A g-1 and only 5% loss of the initial specific capacitance after 3000 charge-discharge cycles.
    No preview · Article · Aug 2015 · RSC Advances
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    Zhengyi Li · Kun Zhou · Yuan Lai · Xiaoqiang Sun · Leyong Wang
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    ABSTRACT: Five chiral calix[4]proline derivatives were designed and synthesized from aminocalix[4]arenes, and their structures were characterized by 1H NMR, 13C NMR, IR, ESI-MS and elemental analysis. The chiral recognition ability for enantiomers of mandelic acid was investigated by NMR techniques, and the results showed that 5,11-diprolinamides substituted calix[4]arene 2b could well and selectively recognize the two enantiomers of mandelic acid (KL/KD≈94). A possible recognition mechanism was proposed, which was constructed by cooperative multi-supramolecular interactions including intermolecular acid-base, hydrogen bond and π…π stacking interactions.
    Preview · Article · Jul 2015 · Chinese Journal of Organic Chemistry
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    Zhengyi Li · Song Shi · Kun Zhou · Liang Chen · Xiaoqiang Sun
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    ABSTRACT: The title compound, C17H17NO3, prepared by the condensation reaction of 2-(1,3-dioxan-2-yl)aniline and salicyl-aldehyde, has an E conformation about the C=N bond. The six-membered O-heterocycle adopts a chair conformation, with the bond to the aromatic ring located at its equatorial position. The dihedral angle between the aromatic rings is 36.54 (9)°. There is an intra-molecular N-H⋯O hydrogen bond forming an S(6) ring motif. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming chains along the a-axis direction. Within the chains, there are C-H⋯π inter-actions involving adjacent mol-ecules.
    Preview · Article · May 2015
  • Xingzhu Xu · Haibo Wu · Zhengyi Li · Xiaoqiang Sun · Zhiming Wang
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    ABSTRACT: The development of bimetallic iron oxide-silver magnetic nanoparticles (Fe2O3-Ag MNPs) catalytic system provides an efficient heterogeneous synthetic pathway to allylic amines and 1,2-dihydroquinolines involving the direct inter/intramolecular nucleophilic substitution of π-activated alcohols with electron-deficient amines. The major advantages of the present method are wide substrate scope, simple product separation, low catalyst loading, and magnetically recyclable catalyst.
    No preview · Article · Mar 2015 · ChemInform
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    Zhengyi Li · Rong Liu · Meilan Zhu · Liang Chen · Xiaoqiang Sun
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    ABSTRACT: The title compound, C26H22N4O5 (systematic name: methyl 2-eth-oxy-1-{4-[2-(5-oxo-4,5-di-hydro-1,2,4-oxa-diazol-3-yl)phenyl]benz-yl}-1H-1,3-benzo-diazole-7-carboxyl-ate ethyl acetate hemisolvate), was obtained via cyclization of methyl (Z)-2-eth-oxy-1-{(2'-(N'-hy-droxy-carbamimido-yl)-[1,1'-biphen-yl]-4-yl)meth-yl}-1H-benzo[d]imidazole-7-carboxyl-ate with diphen-yl carbonate. There are two independent mol-ecules (A and B) with different conformations and an ethyl acetate solvent mol-ecule in the asymmetric unit. In mol-ecule A, the dihedral angle between the benzene ring and its attached oxa-diazole ring is 59.36 (17); the dihedral angle between the benzene rings is 43.89 (15) and that between the benzene ring and its attached imidazole ring system is 80.06 (11)°. The corres-ponding dihedral angles in mol-ecule B are 58.45 (18), 50.73 (16) and 85.37 (10)°, respectively. The C-O-C-Cm (m = meth-yl) torsion angles for the eth-oxy side chains attached to the imidazole rings in mol-ecules A and B are 93.9 (3) and -174.6 (3)°, respectively. In the crystal, the components are linked by N-H⋯N and C-H⋯O hydrogen bonds, generating a three-dimensional network. Aromatic π-π stacking inter-actions [shortest centroid-centroid separation = 3.536 (3)Å] are also observed.
    Preview · Article · Feb 2015
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    Liang Chen · Zhengyi Li · Linlin Jin · Xiaoqiang Sun · Zhiming Wang
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    ABSTRACT: The title compound, C 19 H 16 F 4 O 4 , was prepared by the condensation reaction of 2,6-difluorobenzaldehyde and pentaerythritol. The whole molecule is generated by twofold rotational symmetry. The two six-membered O-heterocycles adopt chair conformations through a shared spiro-carbon atom that is located on the crystallographic twofold rotation axis. In this conformation, the two aromatic rings are located at the equatorial positions of the O-heterocycles. The conformation of this doubly substituted tetraoxaspiro system is chiral. In the crystal, molecules are linked by C—H...O hydrogen bonds, forming layers parallel to (100). These layers are linked by C—H...F hydrogen bonds into a three-dimensional structure.
    Preview · Article · Feb 2015
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    Linyan He · Quanzi Hu · Haitao Xi · Xiaoqiang Sun
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    ABSTRACT: Two new 3-morpholin boron-dipyrrolemethene (BODIPY) derivatives, 4,4-difluoro-8-[4'-(3-morpholinopropoxy)- phenyl]-3-morpholin-4-bora-3a,4a-diaza-s-indacene and 4,4-difluoro-8-(4-methoxyphenyl)-3-morpholin-4-bora-3a,4a-diazas-indacene, were designed and synthesized from p-hydroxybenzaldehyde and pyrrole. The key intermediates and the target compounds were characterized by 1H NMR and LC-MS. The mechanism of direct functionalization of BODIPY dyes at the 3-position was investigated with similarity experiments and the crystal structure.
    Preview · Article · Jan 2015 · Chinese Journal of Organic Chemistry
  • Jingwen Sun · Yongsheng Fu · Guangyu He · Xiaoqiang Sun · Xin Wang
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    ABSTRACT: We report a stable palladium/graphene (Pd/G) nanocomposite with differing Pd content for use in the catalytic hydrogenation of nitrophenols and nitrotoluenes. Various microscopic and spectroscopic techniques were employed to characterize the as-prepared catalysts. Catalytic hydrogenation reactions of nitrophenols were conducted in aqueous solution by adding NaBH4, while the nitrotoluene hydrogenation was carried out in methanol in the presence of H2 because of the poor solubility in water. The Pd/G hybrids exhibited much higher activity and higher stability than the commercial Pd/C. Due to the presence of a large excess of NaBH4 compared to p-nitrophenol, the kinetic data can be explained by the assumption of a pseudo-first-order reaction with regard to p-nitrophenol. The resulting high catalytic activity can be attributed to the graphene sheets’ strong dispersion effect for Pd nanoparticles and good adsorption ability for nitrobenzene derivatives via π-π stacking interactions. A plausible mechanism is proposed. Considering inductive and conjugation effects that may affect the reactions, the reactivity of nitrophenols in this study is expected to follow the order m-NP > o-NP > p-NP > 2,4-DNP > 2,4,6-TNP, which is in good agreement with the experimental results.
    No preview · Article · Jun 2014 · Catalysis Science & Technology
  • Jingwen Sun · Yongsheng Fu · Pan Xiong · Xiaoqiang Sun · Binhai Xu · Xin Wang
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    ABSTRACT: A straightforward strategy is designed for the fabrication of a magnetically separable P25/CoFe2O4/graphene photocatalyst with differing P25 contents via a facile one step hydrothermal approach. TEM observations show that graphene sheets are exfoliated and decorated with well-dispersed TiO2 and CoFe2O4 nanoparticles. The adsorption capacity and visible-light-driven photocatalytic activity are evaluated in terms of the efficiencies of adsorption and photodegradation of various dyes, including methylene blue (MB), methyl orange (MO) and neutral dark yellow (DY). The evaluation results demonstrate that the P25/CoFe2O4/graphene photocatalyst exhibits the best performance among P25/CoFe2O4/graphene (PCG), CoFe2O4/graphene (CG), P25/CoFe2O4 (PC) and P25/graphene (PG) photocatalysts, not only in the adsorption progress, but also in the photocatalytic degradation. The significant enhancement after combination can be attributed to the synergistic effect among individual components. Furthermore, CoFe2O4 nanoparticles themselves have excellent magnetic properties, which are largely maintained in the composite, and therefore, it is no longer necessary to introduce additional magnetic supports for magnetic separation in a suspension system.
    No preview · Article · Oct 2013 · RSC Advances
  • Huajie Huang · Qun Chen · Mingyang He · Xiaoqiang Sun · Xin Wang
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    ABSTRACT: Ultrafine Pt nanoparticles with an average diameter of only 1.7 nm are uniformly dispersed onto MnO2-functionalized graphene sheets by a facile and cost-effective method. In such a ternary Pt/MnO2/graphene sheets (Pt/MnO2/GS) nanohybrid, each component provides unique and critical function to achieve optimized utilization of metallic platinum, allowing it to express ultrahigh electrocatalytic activity ability in methanol oxidation (the forward anodic peak current density is up to 1224 mA mg(-1)) in comparison with Pt/graphene sheets (Pt/GS), Pt/Vulcan XC-72 (Pt/XC-72) and Pt/MnO2/XC-72 catalysts. This work could provide new insights into the fabrication of the next generation high-performance electrocatalyst and promote their practical application in fuel-cell technologies.
    No preview · Article · Oct 2013 · Journal of Power Sources
  • Guangyu He · Maogong Qian · Xiaoqiang Sun · Qun Chen · Xin Wang · Haiqun Chen
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    ABSTRACT: We designed the reduced graphene oxide (RGO)-based Ag@Ag3PO4 hetero-photocatalyst by coprecipitation and photoreduction. The graphene sheets are fully coated with Ag@Ag3PO4 nanocrystals with an average diameter of 200 nm. Ag@Ag3PO4/RGO hetero-photocatalyst showed strong absorbance in the visible region and low recombination rate of holes and electrons. Compared with Ag@Ag3PO4, Ag3PO4 and Ag3PO4/GO, Ag@Ag3PO4/RGO hetero-photocatalyst exhibited greatly enhanced photocatalytic activity under visible-light irradiation for the photodegradation of not only cationic dye (rhodamine B) but also anionic dye (methyl orange), which is usually difficult to be degraded over other catalysts. Moreover, the hetero-photocatalyst can be used repetitively with a high photocatalytic activity. The mechanism was explored and confirmed, showing that the improvements are attributed to the effective charge transfer from Ag3PO4 nanocrystals to RGO through Ag nanoparticles, which hinders the recombination of electron/hole pairs and the photocorrosion of Ag3PO4. This study could provide new insights in the design and fabrication of highly efficient visible-light-driven novel photocatalysts for solving energy and environmental problems.
    No preview · Article · Sep 2013 · Powder Technology
  • Pan Xiong · Lianjun Wang · Xiaoqiang Sun · Xu Binhai · Xin Wang
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    ABSTRACT: A straightforward strategy is designed for the fabrication of magnetically recyclable ternary titania–cobalt ferrite–polyaniline (P25-CoFe2O4-PANI) photocatalysts with differing P25/CoFe2O4 ratio. The pseudo-second-order and Langmuir models are found to be most suitable for describing the adsorption of methyl orange (MO) onto the photocatalysts. The photocatalytic activity of P25-CoFe2O4-PANI is evaluated by the degradation of various dyes under visible light irradiation, and the results show that the ternary P25-CoFe2O4-PANI photocatalyst exhibits high photocatalytic activity due to the good adsorption capacity of the hybrid and the introduction of P25, which can further improve the separation of the light-induced electron–hole pairs. The degradation of anionic dyes is much more effective than that of cationic dyes due to the negatively charged groups of anionic dyes undergo electrostatic attraction with the positively charged backbone of PANI, and such an effective adsorption helps in promoting the degradation.
    No preview · Article · Jul 2013 · Industrial & Engineering Chemistry Research
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    ABSTRACT: Pseudomonas aeruginosa PAO1 is a Gram-negative, opportunistic bacterial human pathogen which infects immunocompromised individuals. The bacterium carries a type III secretion system (T3SS) as a major virulence determinant. The strategy of T3SS inhibitors is to prevent the bacterium from injecting effector proteins into the host, and causing a change in the pathophysiology of the host cells. Based on the structure of a known T3SS inhibitor of P. aeruginosa, 20 new α-phenoxyacetamide derivatives have been designed and synthesized, and the structure-activity relationship results for these new derivatives have been discussed. Five derivatives have shown strong inhibitory effect against exoS gene expression of P. aeruginosa, and among them, N-(2-pyridylmethyl)-2-(2,4-dichlorophenoxy)-butanamide (5r) has not only exhibited stronger potency than the known T3SS inhibitor, but also better solubility in aqueous solution.
    Preview · Article · Jun 2013 · Chinese Journal of Organic Chemistry
  • Guangyu He · Yuan Yuan · Liang Wang · Haiqun Chen · Xiaoqiang Sun · Xin Wang
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    ABSTRACT: A facile chemical strategy was developed to anchor MnO2 nanoparticles on the surface of graphene sheet. Compared with literature, this approach requires neither extra pretreatment of acid functionalization of graphite nor any post-treatment for the conductivity compensation. Graphene sheet serves as both the nucleation center of the MnO2 nanoparticles and high-efficiency miniature current collectors, endowing an effective rise in electrochemical performance of the overall system. Meanwhile, few layers graphene restrain the aggregation of MnO2 nanoparticles and act as template for the "sandwich structure," which boosts accessible surface areas for the high rates charge and discharge processes. The internal resistance drops of the electrode were small, which is propitious to the high discharge delivery. And the nanocomposite with the unique structure displayed a specific capacitance as high as 340.5 F g(-1). Moreover, the capacitance decrease was only 3.7% after 1000 cycles.
    No preview · Article · May 2013 · Journal of Nanoscience and Nanotechnology
  • Guangyu He · Lin Wang · Haiqun Chen · Xiaoqiang Sun · Xin Wang
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    ABSTRACT: NiCo2O4 nanowires-loaded reduced graphene oxide composite (NiCo2O4@RGO) was prepared by a facile hydrothermal method without any surfactant. Hexamethylenetetramine was introduced as a structure directing and assembling agent to the synthesis of NiCo2O4 nanowires. NiCo2O4 nanowires with an average size of 80×10 nm2 are uniformly and densely dispersed on the graphene sheets. Cyclic voltammetry and galvanostatic charge–discharge measurements on NiCo2O4@RGO indicated a high specific capacitance of 737 F g−1 at a current density of 1 A g−1 and only 6% loss of the initial specific capacitance after 3000 charge/discharge cycles at 4 A g−1 in 2 M KOH electrolyte, which is valuable for practical application in supercapacitors.
    No preview · Article · May 2013 · Materials Letters
  • Guangyu He · Weifeng Liu · Xiaoqiang Sun · Qun Chen · Xin Wang · Haiqun Chen
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    ABSTRACT: We reported a facile co-precipitation method to prepare a highly active Fe3O4@graphene oxide (Fe3O4@GO) composite catalyst, which was fully characterized by means of X-ray diffraction (XRD), Fourier transformed infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and N2 adsorption–desorption measurements. The results demonstrated that the Fe3O4 nanoparticles (Fe3O4 NPs) with a small diameter of around 12 nm were densely and evenly deposited on the graphene oxide (GO) sheets. The as-prepared Fe3O4@GO composite was explored as a catalyst to reduce a series of nitroarenes for the first time, which exhibited a great activity with a turnover frequency (TOF) of 3.63 min−1, forty five times that of the commercial Fe3O4 NPs. The dosages of catalyst and hydrazine hydrate are both less than those reported. Furthermore, the composite catalyst can be easily recovered due to its magnetic separability and high stability.
    No preview · Article · May 2013 · Materials Research Bulletin
  • Guangyu He · Haiqing Wu · Kai Ma · Lin Wang · Xiaoqiang Sun · Haiqun Chen · Xin Wang
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    ABSTRACT: Multiple valence silver nanoparticles with irregular shape were anchored on reduced graphene oxide sheets by light irradiation. The characterization analysis revealed silver nanoparticles with different valences were uniformly attached on the surface of reduced graphene oxide sheets and mostly in the size of 30 nm. The antibacterial activities of the as-obtained nanocomposite against gram-negative bacteria E. coli and gram-positive bacteria S. aureus were investigated. Moreover, stability of the nanocomposite was measured by silver ion release. It was found that the nanocomposite has enhanced antibacterial activity and outstanding stability, which makes it a potential antibacterial agent.
    No preview · Article · Apr 2013 · Synthesis and Reactivity in Inorganic Metal-Organic and Nano-Metal Chemistry
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    ABSTRACT: Nucleophilic phosphine catalysis has proven to be a practical and powerful synthetic strategy in organic chemistry, which can provide easy access to five-, six-, seven-, and eight-membered nitrogen heterocyclic compounds. The reaction topologies can be controlled by a proper choice of the phosphine catalysts, as well as the functionalization of the reaction substrates. In many cases, the reactions take place smoothly at room temperature, with high efficiency and atom economy. This mini-review presents the recent advances in nucleophilic phosphine catalysis for the synthesis of drug-like nitrogen heterocylic compounds. The nitrogen heterocyclic compounds with significant biological activities derived from the library based on nucleophilic phosphine-catalyzed annulation reactions are also highlighted.
    No preview · Article · Apr 2013 · Mini Reviews in Medicinal Chemistry

Publication Stats

700 Citations
123.10 Total Impact Points

Institutions

  • 2010-2015
    • Changzhou University
      Wujin, Jiangsu Sheng, China
  • 2008-2010
    • Jiangsu University
      • School of Chemistry and Chemical Engineering
      Chenkiang, Jiangsu Sheng, China
  • 2003-2010
    • Jiangsu Polytechnic university
      Wujin, Jiangsu Sheng, China
  • 2000-2003
    • Jiangsu Institute of petrochemical Technology
      Wujin, Jiangsu Sheng, China