Liu C.,Wuhan University |
Liu D.,Wuhan University |
Lei A.,Wuhan University |
Lei A.,Jiangxi Normal University
Accounts of Chemical Research | Year: 2014
Oxidative cross-coupling reactions between two nucleophiles are a powerful synthetic strategy to synthesize various kinds of functional molecules. Along with the development of transition-metal-catalyzed oxidative cross-coupling reactions, chemists are applying more and more first-row transition metal salts (Fe, Co, etc.) as catalysts. Since first-row transition metals often can go through multiple chemical valence changes, those oxidative cross-couplings can involve single electron transfer processes. In the meantime, chemists have developed diverse mechanistic hypotheses of these types of reactions. However, none of these hypotheses have led to conclusive reaction pathways until now. From studying both our own work and that of others in this field, we believe that radical oxidative cross-coupling reactions can be classified into four models based on the final bond formations. In this Account, we categorize and summarize these models. In model I, one of the starting nucleophiles initially loses one electron to generate its corresponding radical under oxidative conditions. Then, bond formations between this radical and another nucleophile create a new radical, [Nu1-Nu2]•, followed by a further radical oxidation step to generate the cross-coupling product. The radical oxidative alkenylation with olefin, radical oxidative arylative-annulation, and radical oxidative amidation are examples of this model. In model II, one of the starting nucleophiles loses its two electrons via two steps of single-electron-transfer to generate an electrophilic intermediate, followed by a direct bond formation with the other nucleophile. For example, the oxidative C-O coupling of benzylic sp3 C-H bonds with carboxylic acids and oxidative C-N coupling of aldehydes with amides are members of this model group. For model III, both nucleophiles are oxidized to their corresponding radicals. Then, the radicals combine to form the final coupling product. The dioxygen-involved radical oxidative cross-couplings between sulfinic acids and olefins or alkynes belong to this bond formation model. Lastly, in model IV, one nucleophile loses two electrons to generate an electrophilic intermediate, while the other nucleophile loses one electron to generate a radical. Then, a bond forms between the cation and the radical to generate a cationic radical, followed by a one-electron reduction to afford the final coupling product. The oxidative coupling between arylboronic acids and simple ethers was classified in this model. At the current stage, there are only a few examples presented for models III and IV, but they represent two types of potentially important transformations. More and more examples of these two models will be developed in the future. (Chemical Equation Presented). © 2014 American Chemical Society.
Wu Q.,Jiangxi Normal University
Chaos (Woodbury, N.Y.) | Year: 2012
We explore the impact of awareness on epidemic spreading through a population represented by a scale-free network. Using a network mean-field approach, a mathematical model for epidemic spreading with awareness reactions is proposed and analyzed. We focus on the role of three forms of awareness including local, global, and contact awareness. By theoretical analysis and simulation, we show that the global awareness cannot decrease the likelihood of an epidemic outbreak while both the local awareness and the contact awareness can. Also, the influence degree of the local awareness on disease dynamics is closely related with the contact awareness.
Qiu G.,Fudan University |
Ding Q.,Jiangxi Normal University |
Wu J.,Fudan University
Chemical Society Reviews | Year: 2013
As valuable C1 building blocks, isocyanides represent an important class of reactive species and synthons. During the past decades, exhaustive efforts have been devoted to the discovery of highly efficient reactions involving isocyanide on the basis of the development of the Passerini and Ugi reactions. Several types of reactions involving isocyanides have been reported, such as nucleophilic attack, electrophilic addition, imidoylation reactions, and oxidation etc. In this review, recent progress in isocyanide insertion chemistry is presented. Among all isocyanide insertions, two catalytic systems have been developed, that is, Lewis (Brønsted) acid-catalyzed isocyanide insertions and transition-metal-enabled isocyanide insertions, respectively. This review is hence written in the sequence of Lewis (Brønsted) acid-catalyzed isocyanide insertion and transitional metal-enabled isocyanide insertion, where isocyanide insertion into heteroatom-hydrogen bonds, carbon-halogen bonds, carbon-hydrogen bonds, and metal carbenes are summarized. © 2013 The Royal Society of Chemistry.
Yuan C.L.,Jiangxi Normal University
Journal of Physical Chemistry C | Year: 2010
Ni/NiO core/shell nanoparticles embedded in an amorphous Al 2O3 matrix were fabricated by pulsed laser deposition. The core/shell nanoparticles consist of a single-crystal Ni core and polycrystalline NiO shell. High coercivity at room temperature was achieved in the sample with Ni/NiO nanoparticles, which can be attributed to the interfacial interaction between the ferromagnetic Ni core and the antiferromagnetic NiO shell. These results indicate that the formed Ni/NiO core/shell structure is favorable for the large coercivity application. Copyright © 2010 American Chemical Society.
Chen Y.,Jiangxi Normal University
International Journal of Theoretical Physics | Year: 2014
A bidirectional quantum controlled teleportation scheme by using a genuine six-qubit entangled state is proposed. In our scheme, such a six-qubit entangled state is employed as the quantum channel linking three legitimate participants. And Alice may transmit an arbitrary single qubit state of qubit A to Bob and Bob may transmit an arbitrary single qubit state of qubit B to Alice via the control of the supervisor Charlie. This bidirectional quantum controlled teleportation is deterministic. © 2014, Springer Science+Business Media New York.
Xu X.-X.,Jiangxi Normal University
Physical Review A - Atomic, Molecular, and Optical Physics | Year: 2015
I theoretically investigate how the entanglement properties of a two-mode squeezed vacuum state (TMSVS) can be enhanced by operating quantum-optical catalysis on each mode of the TMSVS. The quantum-optical catalysis is simply mixing one photon at the beam splitter and post-select the beam-splitter (BS) output based on detection of one photon, first proposed by Lvovsky and Mlynek [Phys. Rev. Lett. 88, 250401 (2002)PRLTAO0031-900710.1103/PhysRevLett.88.250401]. I find that there exists some enhancement in the entanglement properties (namely, entanglement entropy, second-order Einstein-Podolsky-Rosen correlation, and the fidelity of quantum teleportation) in certain parameter ranges spanned by the low transmissivities of the BSs and the small squeezing parameter of the input TMSVS. © 2015 American Physical Society. ©2015 American Physical Society.
Liu Y.,Jiangxi Normal University |
Wan J.-P.,Jiangxi Normal University
Organic and Biomolecular Chemistry | Year: 2011
Copper-catalyzed cross-coupling reactions which lead to the formation of C-N, C-O, C-S and C-C bonds have been recognized as one of the most useful strategies in synthetic organic chemistry. During past decades, important breakthroughs in the study of Cu-catalyzed coupling processes demonstrated that Cu-catalyzed reactions are broadly applicable to a variety of research fields related to organic synthesis. Representatively, employing these coupling transformations as key steps, a large number of tandem reactions have been developed for the construction of various heterocyclic compounds. These tactics share the advantages of high atom economics of tandem reactions as well as the broad tolerance of Cu-catalyst systems. Therefore, Cu-catalyzed C-X (X = N, O, S, C) coupling transformation-initiated tandem reactions were quickly recognized as a strategy with great potential for synthesizing heterocyclic compounds and gained worldwide attention. In this review, recent research progress in heterocycle syntheses using tandem reactions initiated by copper-catalyzed coupling transformations, including C-N, C-O, C-S as well as C-C coupling processes are summarized. © 2011 The Royal Society of Chemistry.
Yan A.,Jiangxi Normal University
International Journal of Theoretical Physics | Year: 2013
We present a scheme for bidirectional controlled teleportation by using a six-qubit cluster state as quantum channel. Based on the C-not operation and single qubit measurements, Alice may transmit an arbitrary single qubit state of qubit A to Bob and Bob may transmit an arbitrary single qubit state of qubit B to Alice via the control of the supervisor Charlie. © 2013 Springer Science+Business Media New York.
Liu L.-X.,Jiangxi Normal University
Current Organic Chemistry | Year: 2010
Iron catalysts are extensively used in organic reactions in recent years since iron is one of the most abundant metals on earth, consequently one of the most inexpensive, and environmentally friendly ones, and many iron salts and complexes are commercially available. This comprehensive review attempts to cover the advances of iron-catalyzed organic reactions in the literature from 2007 to Sept 2009, particularly focusing on the formation of carbon-carbon bond. Simultaneously, the iron-catalyzed formation of carbon-heteroatom and heteroatom-heteroatom bond also are commented briefly. © 2010 Bentham Science Publishers Ltd.
Zhang M.,Jiangxi Normal University
Applied Organometallic Chemistry | Year: 2010
The C-H functionalization strategyhas received substantial attention becauseof its economic, sustainableandenvironmentally benign features.Most reports are on palladium, rhodium or ruthenium catalysis, and reports on copper catalysis are relatively fewer. Recently, many reports on copper-catalyzed/ mediated C-H functionalization have been published. Copper salts bear properties of cheapness and relatively low toxicity. This review introduces an advance on copper-catalyzed/mediated aromatic C-H functionalization. The content includes aromatic ring C-H bond functionalization and heteroaromatic C-H bond functionalization forming new carbon-carbon or carbon-heteroatom bonds. Copyright © 2010 John Wiley & Sons, Ltd.