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  • Tetrafluorination of Aromatic Azide Yields a Highly Efficient Staudinger Reaction: Kinetics and Biolabeling
    Chem. Asian J. (IF 4.083) Pub Date : 2018-05-01
    Yonghui Xie; Longhuai Cheng; Yasi Gao; Xuekang Cai; Xing Yang; Long Yi; Zhen Xi
    更新日期:2018-06-22
  • Directly Bridging Indoles to 3,3'‐Bisindolylmethanes Using Carboxylic Acids and Hydrosilanes under Mild Conditions
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-21
    Liang-Nian He; Chang Qiao; Xiao-Fang Liu; Hong-Chen Fu; Hao-Peng Yang; Zhi-Bo Zhang

    A straightforward Lewis acid‐promoted protocol for 3,3'‐bisindolylmethanes (BIMs) synthesis via reductive alkylation of indoles at C3 position with carboxylic acids in the presence of hydrosilane was developed for the first time. Instead of aldehydes, more readily available, stable, and facilely handling carboxylic acids have been employed as alternative alkylating agents. As an efficient organocatalyst, B(C6F5)3 enables the reductive alkylation of various substituted indole derivatives with carboxylic acids with up to 98% yield at room temperature and under neat conditions. This metal‐free strategy offers an alternative approach for the direct functionalization of indoles to BIMs with carboxylic acids and such protocol allows selective reduction of carboxylic acid to aldehyde in combination with C‐C bond formation.

    更新日期:2018-06-22
  • Unprecedented Acid‐Promoted Polymerization and Gelation of Acrylamide: A Serendipitous Discovery
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-20
    Siew Yin Chan; Shermin S. Goh; Qingqing Dou; Benjamin Qi Yu Chan; Wee Sim Choo; David James Young; Xian Jun Loh
    更新日期:2018-06-20
  • 更新日期:2018-06-20
  • 更新日期:2018-06-20
  • 更新日期:2018-06-20
  • Palladium‐Catalyzed Divergent Arylation of Triazolopyridines: A Computational Study
    Chem. Asian J. (IF 4.083) Pub Date : 2018-04-30
    Deyaa I. AbuSalim; Sungwoo Hong; Mu‐Hyun Baik
    更新日期:2018-06-20
  • Hyperporous Carbon Supported Nonprecious Metal Electrocatalysts for Oxygen Reduction Reaction
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-20
    Tian-Long Zhai; Cuijuan Xuan; Jincheng Xu; Li Ban; Zhiming Cheng; Shaolei Wang; Deli Wang; Bien Tan; Chun Zhang

    Highly porous carbonaceous nonprecious metal catalysts for oxygen reduction reaction are prepared by carbonization of low‐cost metalloporphyrin‐based hypercrosslinked polymers (MPH‐X). With high surface area (2768 m2 g‐1), hierarchical porous structure and high metal loading (9.97 wt %), the obtained hyperporous carbon MPH‐Fe/C catalyst exhibits high oxygen reduction reaction (ORR) activity with a half‐wave potential (0.816 V) that is comparable to the 0.819 V of commercial Pt/C. Stability tests reveal that MPH‐Fe/C also exhibits outstanding long‐term durability and methanol‐tolerance. Our findings may offer an alternative approach to produce nonprecious metal ORR catalysts in large‐scale due to the low‐cost MPH‐X precursors with diverse metal types.

    更新日期:2018-06-20
  • Multifunctional lanthanide‐based metal‐organic frameworks with polyheterotopic ligand: ytterbium(III)‐doped for luminescence enhancement and selective dye adsorption properties
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-20
    Wei Chen; Ruiqing Fan; Ping Wang; Yuwei Dong; Yulin Yang

    The chemistry of metal‐organic frameworks has been progressing fast as its exciting potential multifunctional applications. Herein, serials of three‐dimensional lanthanide‐based metal‐organic frameworks, {[Ln(HTPO)(NO3)‐(H2O)]·x(CH3CN)·y(H2O)}n (Ln = Eu 1, Tb 2, Gd 3, Sm 4, Dy 5, Nd 6), {[Eu(TPO)(HCOO)0.5]·(H3O)0.5}n (7), {[Eu(TPO)(DMF)]·(solv)x}n (8) and {[Eu(TPO)(DMA)]·(solv)x}n (9) were synthesized with semi‐rigid C3 symmetry ligand H3TPO. In these frameworks, ligand H3TPO presents totally different configuration, framework 1 exhibits good breathing properties for absorbing more guest molecules by solvent‐induced single‐crystal‐to‐single‐crystal (SC‐SC) transformation involving configuration transformation of organic linker in the framework. Ytterbium ion was firstly doped in 1 for improving luminescent performance (lifetime and quantum yield) of red europium emission. Among series of Eu1‐xYbxTPO samples, Eu0.88Yb0.12TPO shows enhanced luminescence intensity ( ~ 5.1 times of the pure europium system), and the lifetime increase from 1073.08 μs to 1236.57 μs. Moreover, the porosity of these frames allows them to efficiently adsorb dye molecules with highly selectivity and efficiency.

    更新日期:2018-06-20
  • Encapsulation of Ag‐nanoparticle in an Amine‐Functionalized Porphyrin MOF and its Use as a Heterogeneous Catalyst for CO2 Fixation under Atmospheric Pressure
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-20
    Srinivasan Natarajan; Gargi Dutta; Ajay Kumar Jana; M. Eswaramoorthy; Deeraj Kumar Singh

    A new porphyrin based compound, [Zn3(C40H24N8)(C20H8N2O4)2(DEF)2](DEF)3 (1) has been synthesized employing 5,10,15,20‐tetrakis(4‐pyridyl)porphyrin (H2TPyP), 1,2‐diamino‐3,6‐bis(4‐carboxyphenyl)benzene and Zn2+ salt at 100ºC under solvothermal condition. The structure, determined by single crystal X‐ray diffraction studies, is three dimensional with three‐fold interpenetration. The usefulness of free ‐NH2 groups in the ligand was exploited for anchoring Ag‐nanoparticles via a simple solution‐based route. The Ag‐loaded sample, Ag@1, was characterized by PXRD, EDS, HRTEM, SEM, XPS and ICP‐MS analysis which clearly indicate Ag‐nanoparticles with size of 3.83 nm were uniformly distributed within the MOF. The Ag@1 sample was evaluated for possible catalytic activity for the carboxylation of terminal alkyne employing CO2 under atmospheric pressure, which gave excellent results. The Ag@1 catalyst was found to be robust, active and recyclable. The present studies suggest that the porphyrin MOFs not only exhibit interesting structures but also show good heterogeneous catalytic activity towards fixation of CO2.

    更新日期:2018-06-20
  • The New Mode of Energy Transferring between Mn2+ and Eu2+ in Nitride Based Phosphor SrAlSi4N7 with Tunable Light and Excellent Thermal Stability
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-19
    Jianyan Ding; Takatoshi Seto; Yichao Wang; Yaxin Cao; Hua Li; YuHua Wang

    In this work, energy transfers reciprocally between Mn2+ and Eu2+ ions in nitride SrAlSi4N7 have been found and investigated in detailed. In contrast to Mn2+ and Eu2+ activated oxide based phosphors, the red light centering at 608 nm is ascribed to 4f‐5d transitions of Eu2+ ions and Mn2+ activated SrAlSi4N7 emits a cyan light peaked at 500 nm. Additionally, the special broad excitation band of SrAlSi4N7: Mn2+ centering at 362 nm has been covered by that of Eu2+ ions ranging from 300 to 550 nm. The overlap of energy level of Mn2+ and Eu2+ ions creates the condition for the energy transferring reciprocally between Eu2+ and Mn2+ ions. A series of SrAlSi4N7: 0.002Mn2+, xEu2+ (0 ≤x≤ 005) with tunable emission light have been synthesized and the decay curves of samples prove the happening of the energy transfer between Mn2+ and Eu2+ ions reciprocally. This mode of energy transfer not only prevents the loss of energy, but also improves the thermal stability and the intensity of SrAlSi4N7: Mn2+, Eu2+ at 150 °C is still beyond 92 % of the initial intensity. The results provide a new mode of energy transfer, which is expected to improve the drawback existing in energy transfer.

    更新日期:2018-06-20
  • E5M7+ (E=C–Pb, M=Li–Cs): A Source of Viable Star‐Shaped Clusters
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-19
    Alejandro Vásquez‐Espinal; Karen Palacio‐Rodríguez; Estefanía Ravell; Mesías Orozco‐Ic; Jorge Barroso; Sudip Pan; William Tiznado; Gabriel Merino
    更新日期:2018-06-20
  • Mussel‐Inspired Polydopamine Coating for Flexible Ternary Resistive Memory
    Chem. Asian J. (IF 4.083) Pub Date : 2018-05-14
    Yong‐Yan Zhao; Xue‐Feng Cheng; Wen Hu Qian; Jin Zhou; Wu‐Ji Sun; Xiang Hou; Jing‐Hui He; Hua Li; Qing‐Feng Xu; Na‐Jun Li; Dong‐Yun Chen; Jian‐Mei Lu
    更新日期:2018-06-20
  • Cancer‐Cell Imaging Using Copper‐Doped Zeolite Imidazole Framework‐8 Nanocrystals Exhibiting Oxidative Catalytic Activity
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-19
    Changjoon Keum; Sangwoo Park; Sang-Yup Lee

    Copper‐doped zeolite imidazole framework‐8 (Cu/ZIF‐8) is prepared and its peroxidase‐like oxidative catalytic activity is examined with a demonstration of its applicability for cancer cell imaging. Through simple solution chemistry at room temperature, Cu/ZIF‐8 nanocrystals are produced that catalytically oxidize an organic substrate of o‐phenylenediamine in the presence of H2O2. In a similar manner to peroxidase, the Cu/ZIF‐8 nanocrystals oxidize the substrate through a ping‐pong mechanism with an activation energy of 59.2 kJ·mol‐1. The doped Cu atoms work as active sites in which the active Cu intermediates are expected to be generated during the catalysis, whereas the undoped ZIF‐8 does not show any oxidative activity. Cu/ZIF‐8 nanocrystals exhibit low cell toxicity and display catalytic activity through interaction with H2O2 among various reactive oxygen species in a cancer cell. This oxidative activity in vitro allowed cancer‐cell imaging exploiting the photoluminescence emitted from the oxidized product of o‐phenylenediamine, which was insignificant in the absence of the Cu/ZIF‐8 nanocrystals. The results of this study imply that the Cu/ZIF‐8 nanocrystal is a promising catalyst for the analysis of the microbiological systems.

    更新日期:2018-06-20
  • Multi‐Protein Dynamic Combinatorial Chemistry: A Novel Strategy that Leads to Simultaneous Discovery of Subfamily‐Selective Inhibitors for Nucleic Acid Demethylases FTO and ALKBH3
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-19
    Mohua Das; Yang Tianming; Dong Jinghua; Fransisca Prasetya; Xie Yiming; Kendra Wong; Adeline Cheong; Esther C. Y. Woon

    Dynamic combinatorial chemistry (DCC) is a powerful supramolecular approach for discovering ligands for biomolecules. To date, most, if not all, biologically‐templated DCC employ only a single biomolecule in directing the self‐assembly process. To expand the scope and potential of DCC, herein, we developed a novel multi‐protein DCC strategy which combines the discriminatory power of zwitterionic 'thermal‐tag' with the sensitivity of differential scanning fluorimetry. This strategy enables the discovery of ligands against several proteins of interest concurrently. It is remarkably sensitive and could differentiate the binding of ligands to structurally‐similar subfamily members, which is extremely challenging to achieve. Through this approach, we were able to simultaneously identify subfamily‐selective probes against two clinically important epigenetic enzymes, FTO (7; IC₅₀ = 2.6 µM) and ALKBH3 (8; IC₅₀ = 3.7 µM). To our knowledge, this is the first report of a subfamily‐selective ALKBH3 inhibitor. The developed strategy could, in principle, be adapted to a broad range of proteins, thus it shall be of widespread scientific interest.

    更新日期:2018-06-20
  • Developing a self‐healing supramolecular nucleoside hydrogel based on guanosine and isoguanosine
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-19
    Fan Tang; Hui Feng; Hang Zhao; Hongxia Dan; Yuqi Du; Yandi Xiao; Qianming Chen

    Recently, supramolecular hydrogels have attracted increasing interest owing to their tunable stability and inherent biocompatibility. However, only few studies have been reported in the literature on self‐healing supramolecular nucleoside hydrogels, compared to self‐healing polymer hydrogels. In this work, we successfully developed a self‐healing supramolecular nucleoside hydrogel obtained by simply mixing equimolar amounts of guanosine (G) and isoguanosine (isoG) in the presence of K+. The gelation properties have been studied systematically by comparing different alkali metal ions as well as mixtures with different ratios of G and isoG. To this end, rheological and phase diagram experiments demonstrated that the co‐gel not only possessed good self‐healing properties and short recovery times (only 20 seconds) but also could be formed at very low concentrations of K+. Furthermore, nuclear magnetic resonance (NMR), powder X‐ray diffraction (PXRD), and circular dichroism (CD) spectroscopy suggested that possible G2isoG2‐quartet structures occurred in this self‐healing supramolecular nucleoside hydrogel. This co‐gel, to some extent, addressed the problem of isoguanosine gels for applications in vivo, which showed the potential to be a new type of drug delivery system for biomedical applications in the future.

    更新日期:2018-06-20
  • Calix[5]phyrin for Fluoride Ion Sensing with Visible and Near Infrared Optical Responses
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-19
    Tomohiro Higashino; Atsushi Kumagai; Hiroshi Imahori

    Fluoride (F‐) ion sensing is an important topic due to its roles in health, medical, and environmental sciences. In this regard, colorimetric sensors with a near infrared (NIR) optical response are useful in biological systems because they can avoid interference from endogenous chromophores. Although calix[n]phyrins are highly attractive as sensors with the NIR optical response, studies on calix[n]phyrins are still limited owing to their intrinsic instability against ambient light and air. In this study, we report the synthesis and characterization of a new calix[5]phyrin bearing one sp3‐hybridized carbon atom as a π‐expanded calix[n]phyrin. Upon addition of tetrabutylammonium fluoride, the calix[5]phyrin exhibited distinct NIR absorptions at 908 and 1064 nm as well as a visible color change. Importantly, it revealed an excellent selectivity for F‐ ion. These results demonstrate that calix[5]phyrins are promising colorimetric and NIR sensors of F‐ ion.

    更新日期:2018-06-20
  • Transition Metal Free Multicomponent approach to Stereo‐enriched Cyclopentyl‐isoxazoles via C−C Bond Cleavage
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-19
    Krishna Pillai Kaliappan; Parthasarathi Subramanian

    An efficient multicomponent reaction leading to the synthesis of stereo‐enriched cyclopentyl‐isoxazoles from camphor derived α‐oxime, alkynes and MeOH is reported. Our method involves a series of cascade transformations such as in situ generation of catalyst I(III) which catalyzes the addition MeOH into a sterically hindered ketone, oxime oxidation and α‐hydroxyiminium ion rearrangement to generate in situ nitrile oxide which upon [3+2]‐cycloaddition reaction with alkynes delivers regioselective products. The reaction is very selective to syn‐oxime. This multicomponent approach has also been extended for the synthesis of a novel glycoconjugate, camphoric ester‐isoxazole C‐galactoside.

    更新日期:2018-06-20
  • Polyoxometalate‐based metal‐organic framework hybridized with ketjenblack towards nonenzymatic H2O2 detection
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-19
    Cong Wang; Ming Zhou; Yuan-Yuan Ma; Hua-Qiao Tan; Yong-Hui Wang; Yang-Guang Li

    The rational design and development of efficient and affordable enzyme‐free electrocatalysts for electrochemical detection are of great significance for the large‐scale applications of sensing materials, and have aroused increasing research interests. In this paper, we report that a typical polyoxometalate (POM)‐based metal‐organic framework (NENU5) hybridized with ketjenblack (KB) is a highly efficient electrochemical sensing catalyst, which can be used for highly sensitive nonenzymatic H2O2 detection. The composite catalyst exhibited superb electrochemical detection performance towards H2O2, including a broad linear range from 10 μM to 50 mM, a low detection limit of 1.03 μM and a high sensitivity of 33.77 μA·mM‐1, as well as excellent selectivity and stability. The excellent electrocatalytic properties should be attributed to the unique redox activity of the POMs, the high specific surface area of the MOFs, the strong conductivity of KB, and the synergistic effect of the multiple components of composites during the H2O2 electrolysis. This work provides a new feasible pathway to explore nonenzymatic electrochemical sensors.

    更新日期:2018-06-19
  • Design of Single‐Site Photocatalysts by Using Metal–Organic Frameworks as a Matrix
    Chem. Asian J. (IF 4.083) Pub Date : 2018-05-14
    Meicheng Wen; Kohsuke Mori; Yasutaka Kuwahara; Taicheng An; Hiromi Yamashita
    更新日期:2018-06-18
  • 更新日期:2018-06-18
  • 更新日期:2018-06-18
  • Recent Advances in Ladder‐type Heteroarene‐based Organic Semiconductors
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-17
    Xugang Guo; Jianhua Chen; Kun Yang; Xin Zhou

    The fusion of heteroaromatic rings into ladder‐type heteroarenes can stabilize frontier molecular orbitals and lead to improved physicochemical properties, which are beneficial for applications in various optoelectronic devices. Hence, ladder‐type heteroarenes, which feature highly planar backbones and well delocalized π‐conjugation, recently have emerged as a type of promising organic semiconductors with excellent device performance in organic photovoltaics and organic field‐effect transistors. In this Focus Review, we summarize the recent advances in ladder‐type heteroarenes based organic semiconductors including hole‐transporting and electron‐transporting molecular semiconductors as well as fully ladder‐type conjugated polymers towards their applications in organic photovoltaics and field‐effect transistor. The use of ladder‐type small molecular acceptor materials has strikingly boosted the power conversion efficiency of fullerene‐free solar cells, recently, and the selected cases of latest developed ladder‐type fused ring electron acceptor (FREA) materials are also elaborated.

    更新日期:2018-06-18
  • Solvent Control over Supramolecular Gel Formation and Fluorescence for a Highly Crystalline π‐Conjugated Polymer
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-17
    Shotaro Hayashi; Atsushi Takigami; Toshio Koizumi

    In π‐conjugated polymers (πCPs), crystallinity and fluorescence typically exhibit a trade‐off relationship. Here, we have synthesised a highly crystalline and fluorescent π‐conjugated polymer with a simple alternating structure of 1,2,4,5‐tetrafluorophenylene and 3,3′‐dihexyl‐2,2′‐bithiophene units. In film, the polymer exhibited efficient red‐coloured fluorescence, an improved quantum yield (Φsol = 13% → Φfilm = 23%) and a crystalline structure. Interestingly, supramolecular gel formation occurred in appropriate solvents, and the macrostructure and fluorescence properties of the gel could be directly controlled by the choice of the solvent. The polymer self‐assembled into a spherical form that exhibited red fluorescence in non‐aromatic solvent (dichloroethane) and into a fibrous form that exhibited yellow fluorescence in aromatic solvent (mesitylene).

    更新日期:2018-06-18
  • Hyperbranched Polymers with Controllable Topologies for Drug Delivery
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-17
    Qingfu Ban; Wen Sun; Jie Kong; Si Wu

    Hyperbranched polymers (HPs) have been widely used for drug delivery due to their highly branched topology, which endows the HPs with a large amount of intramolecular cavities for drug encapsulation and terminal groups for drug conjugation. Additionally, the one‐pot and large‐scale preparation features enable the easy fabrication of HPs for biomedical applications. This review provides an overview of the synthesis of HPs and their application for drug delivery. First, we introduce the diversity of synthesis of HPs with controllable topologies. Subsequently, we discuss the drug encapsulation and drug conjugation using HPs. Finally, we highlight the use of HPs with controllable topologies for promising drug delivery.

    更新日期:2018-06-18
  • On‐surface synthesis of graphene nanoribbons catalyzed by Ni atoms
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-15
    Shuya Xing; Bing Liu; Wenquan Wang; Jiandong Guo; Weihua Wang

    Nanometer‐wide graphene nanoribbons can be synthesized from halogen aromatics through multistep on‐surface reactions, but the catalytic role of extrinsic transition‐metal atoms in these reactions are to be explored. Here by low‐temperature scanning tunnelling microscopy, we investigated the on‐surface synthesis of graphene nanoribbons from 10,10'‐dibromo‐9,9'‐bianthryl precursors in the presence of Ni atoms. Ni atoms not only act as catalysts in debromination and lead to the formation of an organometallic intermediate at 300 K, but also prompt the fusion reaction between graphene nanoribbons at 673 K. Our work demonstrates a more efficient way to fabricate fused graphene nanoribbons.

    更新日期:2018-06-15
  • Design and Synthesis of Quenched Activity‐based Probes for Diacylglycerol Lipase and α,β‐Hydrolase Domain Containing Protein 6
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-14
    E. J. van Rooden; M. Kohsiek; R. Kreekel; A. C. M. van Esbroeck; A. M. C. H. van den Nieuwendijk; A. P. A. Janssen; R. J. B. H. N. van den Berg; H. S. Overkleeft; M. van der Stelt
    更新日期:2018-06-14
  • 更新日期:2018-06-14
  • 更新日期:2018-06-14
  • Synthesis of Lead‐free CsGeI3 Perovskite Colloidal Nanocrystals and Electron Beam‐induced Transformations
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-14
    Xiaotong Wu; Weidong Song; Qian Li; Xixia Zhao; Dongsheng He; Zewei Quan
    更新日期:2018-06-14
  • Nickel‐Catalyzed Regioselective C(2)−H Difluoroalkylation of Indoles with Difluoroalkyl Bromides
    Chem. Asian J. (IF 4.083) Pub Date : 2018-05-03
    Vineeta Soni; Dipesh M. Sharma; Benudhar Punji
    更新日期:2018-06-14
  • The Recent Progress of Atom‐Economical Applications of Diaryliodonium Salt
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-14
    Ming Wang; Shihao Chen; Xuefeng Jiang

    Diaryliodonium salt as a stable and easily prepared reagent has been one of the most efficient arylation reagents in organic synthesis. In traditional methods, this reagent was generally applied as a single arylation source and the regenerated aryl iodide is a waste of resources. In the past five years, transition metal‐catalyzed both utilization of aryls in diaryliodonium salts were well demonstrated. The purpose of the present review is to focus on various atom‐economical applications of diaryliodonium salt methodologies, which were reported recently for the synthesis of functionalized molecules. The presentation is organized according to the structures of the diaryliodonium salts and the reaction components.

    更新日期:2018-06-14
  • Recent Advances in Transition Metal‐Catalysed Three‐Component Difunctionalization of Alkenes
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-13
    Tieqiao Chen; Ji-Shu Zhang; Long Liu; Li-Biao Han

    Three‐component reactions can directly convert three reactants into the products in one pot and thus greatly shorten the synthetic path. Recently, this strategy associated with transition metal catalysis has been applied in the difunctionalization of alkenes and a remarkable progress has been achieved, facilitating the construction of a wide range of functional molecules with high atom‐ and step‐economic efficiency. This focus review highlights the recent advances in this field.

    更新日期:2018-06-14
  • NHC‐Organocatalyzed Kinetic Resolutions, Dynamic Kinetic Resolutions and Desymmetrizations
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-13
    Zhongyao Wang; Dingwu Pan; Tingting Li; ZHICHAO JIN

    The last couple of decades have witnessed tremendous development within N‐heterocyclic carbene (abbreviated as NHC) organocatalysis. NHCs have been used as powerful organic catalysts in asymmetric synthesis. Although great achievements have been made in the asymmetric NHC catalysis, their applications in the kinetic resolution (abbreviated as KR), dynamic kinetic resolution (abbreviated as DKR) and desymmetrization processes have been relatively less developed. Moreover, limited activation modes have been involved in these processes. This review provides an overview of the NHC organocatalyzed KR, DKR and desymmetrization reactions in the preparation of chiral functional molecules. The aim is to highlight both of the importance and elegance of these methods in the construction of challenging chiral compounds and to provide our own perspective into the future development in this direction.

    更新日期:2018-06-14
  • 更新日期:2018-06-13
  • Down‐regulating Proteolysis to Enhance Anticancer Activity of Peptide Nanofibers
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-13
    Jie Li; Xuewen Du; Devon Powell; Rong Zhou; Junfeng Shi; Hongjian He; Zhaoqianqi Feng; Bing Xu

    Nanofibers of short peptides are emerging as a promising type of agents for inhibiting cancer cells. But the proteolysis of peptides decreases the anticancer efficacy of the peptide nanofibers. Here we show that decreasing the activity of proteasomes enhance the activity of peptide nanofibers for inhibiting cancer cells. Based on the structure of galactin‐3, we designed a heptapeptide, which self‐assembles to form nanofibers. The nanofibers of the heptapeptide exhibit moderate cytotoxicity to three representative cancer cell lines (HeLa, MCF‐7, and HepG2), largely due to the proteolysis of the peptides. Using a clinically approved proteasome inhibitor, bortezomib, to treat the cancer cells significantly decreases the proteolysis of the peptides and enhances the activity of the peptide nanofibers for inhibiting the cancer cells. This work illustrates a promising approach for enhancing the anticancer efficacy of peptide nanofibers by modulating intracellular protein degradation machinery, as well as provides insights for understanding the cytotoxicity of aberrant protein or peptide aggregates in complicated cellular environment.

    更新日期:2018-06-13
  • Visible‐Light‐Driven Hydrogen Production and Polymerization using Triarylboron‐Functionalized Iridium(III) Complexes
    Chem. Asian J. (IF 4.083) Pub Date : 2018-05-02
    Ling‐Xia Yang; Wan‐Fa Yang; Yong‐Jun Yuan; Yi‐Bing Su; Miao‐Miao Zhou; Xiao‐Le Liu; Guang‐Hui Chen; Xin Chen; Zhen‐Tao Yu; Zhi‐Gang Zou
    更新日期:2018-06-12
  • Palladium‐Catalyzed Mizoroki–Heck‐Type Alkenylation of Monoaryldialkylsulfoniums
    Chem. Asian J. (IF 4.083) Pub Date : 2018-05-04
    Daisuke Uno; Hiroko Minami; Shinya Otsuka; Keisuke Nogi; Hideki Yorimitsu
    更新日期:2018-06-12
  • Divergent Functionalization of N‐Alkyl‐2‐alkenylanilines: Efficient Synthesis of Substituted Indoles and Quinolines
    Chem. Asian J. (IF 4.083) Pub Date : 2018-04-26
    Jayanta Ghorai; Angula Chandra Shekar Reddy; Pazhamalai Anbarasan
    更新日期:2018-06-12
  • Colloidal synthesis of NiWSe nanosheets for efficient electrocatalytic hydrogen evolution reaction in alkaline media
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-11
    Wei Luo; Yuanmeng Zhao; Guixiang Mao; Yeshuang Du; Gongzhen Cheng

    Searching for efficient, low‐cost and durable electrocatalysts toward hydrogen evolution reaction (HER) is extremely urgent for the future energy conversion systems. Herein, we report a colloidal synthesis of two dimensional (2D) tungsten doped nickel selenides (NiWSe) nanosheets by using Ni(acac)2, W(CO)6 and selenium powder (Se) as precursors in oleylamine (OAm). We find that the introduction of W is essential for the formation of 2D nanosheets. As a result, by taking the advantage of the unique layered structure and strong synergistic electronic effect between Ni, W and Se, the as‐synthesized Ni0.54W0.26Se nanosheets exhibit the superior catalytic activity toward HER in alkaline media, with an overpotential of 162 mV (η10), which is much lower than those of NiSe2 (η10 of 330 mV) and WSe2 (η10 of 378 mV), and higher than most of the previously reported selenide‐based electrocatalysts.

    更新日期:2018-06-12
  • Photothermal heating and cooling of nanostructures
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-11
    Matthew Joseph Crane; Xuezhe Zhou; E. James Davis; Peter Pauzauskie

    A vast range of insulating, semiconducting, and metallic nanomaterials have been studied over the past several decades with the aim of understanding how continuous‐wave or pulsed laser radiation can influence their chemical functionality and local environment. Many fascinating observations have been made during laser irradiation including, but not limited to, the superheating of solvents, mass‐transport‐mediated morphology evolution, photodynamic therapy, morphology dependent resonances, and a range of phase transformations. In addition to laser heating, recent experiments have demonstrated the laser cooling of nanoscale materials through the emission of upconverted, anti‐Stokes photons by trivalent rare‐earth ions. This focus review outlines the analytical modeling of photothermal heat transport with an emphasis on the experimental validation of anti‐Stokes laser cooling. This general methodology can be applied to a wide range of photothermal applications, including nanomedicine, photocatalysis, and the synthesis of new materials. The review concludes with an overview of recent advances and future directions for anti‐Stokes cooling.

    更新日期:2018-06-12
  • Controllable Synthesis of a Highly Ordered Polymeric Structure Assembled from Cobalt‐Cluster‐based Racemic Supramolecules
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-10
    Hyojong Yoo; Hien Duy Mai; Inme Lee

    Metallosupramolecule‐based polymeric platforms with high degrees of hierarchy and tailorable functionalities are of great interest because of their unique morphologies and potential applications. Herein, the controllable synthesis of a highly‐ordered polymeric structure, {[M,P‐Co₈(PDA)₆(HIP)₃(DMF)₅(H₂O)]₃‐[Co(DMF)(H₂O)₂]} (1) (PDA = 2,6‐pyridinedicarboxylate, HIP = 5‐hydroxyisophthalate, DMF = dimethylformamide) with unique topology is reported. The solid‐state structure of 1 reveals that it is alternately and periodically assembled from racemic supramolecular monomers to form a zigzag‐shaped polymeric strand. Discrete racemic supramolecules (2) with topologies similar to those of monomeric species of 1 are also controllably synthesized in a separate reaction. Formation of intermolecular hydrogen bonds between supramolecules associated with hydroxyl groups of HIPs are critical for the unique solid‐state packing geometries of 1 and 2.

    更新日期:2018-06-11
  • Gem‐dinitromethyl substituted energetic metal‐organic framework based on 1,2,3‐triazole from in‐situ controllable synthesis
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-10
    Hao Gu; Qing Ma; Shiliang Huang; Zhenqi Zhang; Qi Zhang; Guangbin Cheng; Hongwei Yang; Guijuan Fan

    Synthesizing energetic metal‐organic frameworks at ambient temperature and pressure has been always a challenge in the research area of energetic materials. In this work, through in‐situ controllable synthesis, energetic metal‐organic framework gem‐dinitromethyl substituted dipotassium 4,5‐bis(dinitromethyl)‐1,2,3‐triazole with "cage‐like" crystal packing was obtained and characterized. Most importantly, for the first time we found that it could be successfully afforded with the catalytic effect of trifluoroacetic acid. This new compound exhibited its high density (2.04 g cm‐3) at ambient temperature, superior detonation velocity (8715 m s‐1) to that of lead azide (5877 m s‐1) and comparable to that of RDX (8748 m s‐1). Its detonation products are mainly N2 (48.1 %), suggesting it is also a green energetic material. The above‐mentioned performance indicates its potential applications in detonator devices as lead‐free primary explosive.

    更新日期:2018-06-11
  • Ruthenium Pincer‐Catalyzed Hydrogenation of Lactams to Aminoalcohols
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-10
    Tao Tu; Jiangbo Chen; Jiaquan Wang

    By using commercial available ruthenium pincer complex (Ru‐MACHO‐BH) as a catalyst, the challenging direct hydrogenation of lactams and analogues has been accomplished to successfully delivery corresponding value‐added aminoalcohols in good to excellent yields under mild reaction conditions. Remarkably, besides N‐protected lactams, unprotected ones could also be readily reduced in the presence of a catalytic amount of weak base or even under neutral reaction conditions, further highlighting broad substrate scopes and the protocol efficiency.

    更新日期:2018-06-11
  • 更新日期:2018-06-08
  • Embedding Carbon Nitride into a Covalent Organic Framework with Enhanced Photocatalysis Performance
    Chem. Asian J. (IF 4.083) Pub Date : 2018-04-30
    Junquan Pan; Liping Guo; Siquan Zhang; Ning Wang; Shangbin Jin; Bien Tan
    更新日期:2018-06-08
  • An aldehyde‐terminal peptide‐based supramolecular hydrogel for controlled delivery of amine drugs
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-07
    Youzhi Wang; Yiming Zhang; Xinxin Li; Can Li; Zhimou Yang; Ling Wang

    Supramolecular hydrogels hold great promise for controlled drug delivery. Herein we reported on a supramolecular hydrogel based on an aldehyde‐terminal peptide. The hydrogel was prepared via the enzyme instructed self‐assembly (EISA) process, and the resulting hydrogels showed an ultra‐stable property in highly acidic or basic aqueous solutions. The hydrogelator could form Schiff base with amine drugs. Due to the pH‐responsive property of Schiff base, the hydrogels could be applied for controlled release of encapsulated amine drugs. Our study provides a novel peptide‐based hydrogel that may be applied for controlled delivery of amine containing therapeutics.

    更新日期:2018-06-08
  • Enantiospecific Suzuki–Miyaura Coupling of Nonbenzylic α‐(Acylamino)alkylboronic Acid Derivatives
    Chem. Asian J. (IF 4.083) Pub Date : 2018-05-07
    Toshimichi Ohmura; Kyoko Miwa; Tomotsugu Awano; Michinori Suginome
    更新日期:2018-06-07
  • Charge Separation in Multifunctionalized Framework of Hydrogen‐Bonded Periodic Mesoporous Organosilica
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-07
    Norihiro Mizoshita; Shinji Inagaki

    Integration of functional molecular parts into nanoporous materials in a state that allows intermolecular charge or energy transfer is one of the key approaches to the development of photofunctional and electroactive materials. Here we report charge separation in a functionalized framework of a periodic mesoporous organosilica (PMO) self‐assembled by hydrogen bonds. Electroactive π‐conjugated organic species with different electron‐donating and electron‐accepting properties are selectively fixed onto the external surface of a nanoparticulate PMO, within the pore wall, and onto the surface of the internal mesopore. UV irradiation of the modified PMO results in photoinduced electron transfer and charge separation from the external surface to the pore wall and from the pore wall to the surface of the internal mesopores. These results suggest the high potential of multifunctionalized PMOs for the construction of photocatalytic reaction fields.

    更新日期:2018-06-07
  • Synthesis, Isolation and Structure of Trifluoromethylated Fullerene D2‐C76, C76(1)(CF3)10‐18
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-06
    Nadezhda B. Tamm; Daria V. Ignat'eva; Leonid A. Aslanov; Sergey Troyanov

    High‐temperature trifluoromethylation of fullerene C76 chlorination products followed by HPLC separation of C76(CF3)n derivatives resulted in the isolation and X‐ray structural characterization of thirteen C76(1)(CF3)n compounds including nine new isomers such as one isomer of C76(1)(CF3)10, two C76(1)(CF3)12, three C76(1)(CF3)14, one C76(1)(CF3)16, and two isomers of C76(1)(CF3)18. Dependent on their addition patterns, C76(1)(CF3)n isomers are divided into three subgroups and discussed in terms of trifluoromethylation pathways and relative formation energies.

    更新日期:2018-06-07
  • Selective hydrosilylation of alkynes with octaspherosilicate (HSiMe2O)8Si8O12
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-06
    Kinga Stefanowska; Adrian Franczyk; Jakub Szyling; Mikolaj Pyziak; Piotr Pawluc; Jedrzej Walkowiak

    Comprehensive studies on platinum‐catalyzed hydrosilylation of a wide spectrum of the terminal and internal alkynes with spherosilicate (HSiMe2O)8Si8O12 (1a) were investigated. The influence of the reaction parameters, and the types of reagents and catalysts on the efficiency of the process, which enabled the creation of a versatile and selective method to synthesize olefin octafunctionalized octaspherosilicates, was studied in detail. Within this work, twenty novel 1,2‐(E)‐disubstituted and 1,1,2‐(E)‐trisubstituted alkenyl‐octaspherosilicates (3a‐m, 6n‐t) were selectively obtained with high yields, and fully characterized (1H, 13C, 29Si NMR, FT‐IR, MALDI TOF or TOF MS ES+). Moreover, the molecular structure of the compound (Me3Si(H)C=C(H)SiMe2O)8Si8O12 (3a) was determined by X‐ray crystallography for the first time. The developed procedures are the first, which allowed selective hydrosilylation of terminal silyl, germyl, aryl and alkyl alkynes with 1a, as well as the direct introduction of sixteen functional groups into the 1a structure by the hydrosilylation of internal alkynes. This method constituted a powerful tool for the synthesis of hyperbranched compounds with a Si‐O based cubic core. The resulting products, due to their unique structure and physicochemical properties, are considered novel, multifunctional, hybrid and nanometric building blocks, intended for the synthesis of star‐shaped molecules or macromolecules, as well as nanofillers and polymer modifiers. In the presented syntheses, commercially available reagents and catalysts were used, so these methods can be easily repeated, rapidly scaled up and widely applied.

    更新日期:2018-06-07
  • Light‐Induced Bending of Needle‐Like Crystals of Naphthylvinylbenzoxazole Triggered by trans–cis Isomerization
    Chem. Asian J. (IF 4.083) Pub Date : 2018-04-20
    Jiang Peng; Jinyu Zhao; Kaiqi Ye; Hongqiang Gao; Jingbo Sun; Ran Lu
    更新日期:2018-06-06
  • Amorphous porous organic polymers based on Schiff‐base chemistry for high efficient iodine capture
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-05
    Zongxia Guo; Panli Sun; Jianbin Lin; Tong Shi; Shaofeng Liu; Abin Sun; Zhibo Li

    Porous organic polymers (POPs) have been considered as prominent adsorbents for volatile iodine. So far, both crystalline and amorphous POPs have accomplished excellent Iodine capture capability. Considering the difficulty and challenging in preparing perfect crystalline POPs, it needs more explorations in developing versatile amorphous POPs. Herein, amorphous POPs based on Schiff‐base reaction were designed and synthesized for volatile iodine removal. Four amorphous POPs products named as NDB‐H, NDB‐S, ADB‐HS and ADB‐S obtained under different solvothermal conditions were investigated in morphologies, porosity and their iodine enrichment performance in details. It is noteworthy that excellent efficiency for removing iodine vapor was acquired for NDB‐S (~425 wt%), ADB‐HS (~345 wt%) and ADB‐S (~342 wt%). Remarkably, NDB‐H exhibited an iodine capture capacity up to ~443 wt%. Excellent reusability was obtained as well. Amorphous NDB‐H has accomplished such high iodine capture performance illustrating the infinite chance to exploit versatile amorphous POPs for iodine enrichment and removal based on Schiff‐base chemistry.

    更新日期:2018-06-06
  • Designing bifunctional solid catalyst for organic reactions in water: Simultaneous anchoring of acetylacetone ligand and amphiphilic ionic liquid tag using a dihydropyran as linker
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-05
    Bingbing Lai; Fuming Mei; Yanlong Gu

    Using a solid catalyst to promote organic reactions in water often encountered an inherently difficult problem, poor mass transfer efficiency of organic substance in water, which is responsible, in many cases, for insufficient reaction and low yield. To solve this problem, the solid surface can be designed to be amphiphilic. But it is not easy to introduce a surfactant‐like moiety onto the surface of silica‐based materials, which are often used in immobilization of homogeneous catalysts. By using an easily accessible dihydropyran derivative as grafting linker, a surfactant‐combined bifunctional silica‐based solid catalyst, which possesses both an ionic liquid tail and a metal acetylacetonate moiety, has been successfully prepared through a mild Lewis acid‐catalyzed ring‐opening reaction of the dihydropyran with a thiol‐functionalized silica. These obtained materials were characterized by many physicochemical methods including FT‐IR, EA, FSEM, EDX, XPS, BET and TG. Three referential catalysts with or without integration of the ionic liquid were also prepared. In many reactions, the surfactant‐combined silica‐supported metal acetylacetone catalysts displayed superior catalytic activity in pure water than the referential catalysts. The surfactant‐combined solid catalysts were proved to be recyclable, and can be reused for several times without significant loss of their activities.

    更新日期:2018-06-06
  • C−H Alkenylation of Pyrroles by Electronically Matching Ligand Control
    Chem. Asian J. (IF 4.083) Pub Date : 2018-04-30
    Hyun Tae Kim; Woohyeong Lee; Eunmin Kim; Jung Min Joo
    更新日期:2018-06-05
  • Organocatalytic Strategies for the Synthesis of Cyclopenta‐Fused Arenes and Heteroarenes
    Chem. Asian J. (IF 4.083) Pub Date : 2018-04-19
    Bishnupada Satpathi; Atanu Mondal; S. S. V. Ramasastry
    更新日期:2018-06-05
  • 更新日期:2018-06-05
  • Kinetics of Spontaneous Bimetallization between Silver and Noble Metal Nanoparticles
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-05
    Kazutaka Hirakawa; Tetsuya Kaneko; Naoki Toshima

    A physical mixture of polymer‐protected Ag nanoparticles and Rh, Pd, or Pt nanoparticles spontaneously formed Ag‐core bimetallic nanoparticles. The formed nanoparticles were smaller than the parent Ag nanoparticles. In the initial process of this reaction, the surface plasmon absorption of Ag nanoparticles diminished and then almost ceased within one hour. Within several minutes, the decrement of Ag surface plasmon absorption could be analyzed by second‐order reaction. This reaction was accelerated with an increase of temperature and the energy gap in the Fermi level between Ag and the other metals. The activation energy (Ea) of this reaction could be determined. An electron transfer reaction from Ag to other metal nanoparticles was proposed as the initial interaction between these metal nanoparticles because the Fermi level of Ag is relatively high, and the electron transfer is possible in terms of energy. The Marcus plot between the rate constant and the driving force, roughly estimated from the work function of metals, and the observed Ea values reasonably explained the proposed electron transfer mechanism.

    更新日期:2018-06-05
  • A Non‐Templated Route to Macrocyclic Dibridgehead Diphosphorus Compounds: Crystallographic Characterization of a "Crossed Chain" Variant of in/out Stereoisomers
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-05
    John A. Gladysz; Sugam Kharel; Tiezheng Jia; Nattamai Bhuvanesh; Joseph Reibenspies; Janet Blümel

    Reactions of (O=)PH(OCH2CH3)2 and BrMg(CH2)mCH=CH2 (4.9‐3.2 equiv; m = a/4, b/5, c/6) give the dialkylphosphine oxides (O=)PH((CH2)mCH=CH2)2 (2a‐c; 77‐81% after workups), which are treated with NaH and then α,ω‐dibromides Br(CH2)nBr (0.49‐0.32 equiv; n = a'/8, b'/10, c'/12, d'/14) to yield the bis(trialkylphosphine oxides) (H2C=CH(CH2)m)2P(=O)‐(CH2)n(O=)P((CH2)mCH=CH2)2 (3ab', 3bc', 3cd', 3ca'; 79‐84%). Reactions of 3bc' and 3ca' with Grubbs' first generation catalyst and then H2/PtO2 afford the dibridgehead diphosphine di‐oxides O=)P(CH2)n((CH2)n')2P(=O) (4bc', 4ca'; 14‐19%, n' = 2m + 2); 31P NMR spectra show two stereoisomeric species (ca. 70:30). Crystal structures of two isomers of the latter are obtain‐ed, out,out‐4ca' and a conformer of in,out‐4ca' that features crossed chains, such that the (O=)P vectors appear out,out. While 4bc' resists crystallization, a byproduct derived from an alternative metathesis mode, (CH2)12P(=O)(CH2)12(O=)P(CH2)12, as well as 3ab' and 3bc', are structurally characterized. The efficiencies of other routes to dibridgehead diphosphorus compounds are compared.

    更新日期:2018-06-05
  • Cp*Co(III)‐catalyzed Efficient Dehydrogenation of Secondary Alcohols
    Chem. Asian J. (IF 4.083) Pub Date : 2018-06-04
    Manoj Kumar Gangwar; Pardeep Dahiya; Balakumar Emayavaramban; Basker Sundararaju

    A novel, well‐defined molecular Cp*Co(III) complex was isolated and structurally characterized for the first time. The efficiency of this cobalt catalyst was demonstrated in alcohol dehydrogenation and dehydrative coupling of secondary alcohols under mild conditions into ketones and ethers, respectively.

    更新日期:2018-06-05
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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