Chemistry Letters
Online ISSN : 1348-0715
Print ISSN : 0366-7022
ISSN-L : 0366-7022
Volume 43 , Issue 1
Showing 1-29 articles out of 29 articles from the selected issue
Highlight Review
  • Gheorghe-Doru Roiban, Adriana Ilie, Manfred T. Reetz
    2014 Volume 43 Issue 1 Pages 2-10
    Published: January 05, 2014
    Released: January 05, 2014
    [Advance publication] Released: October 23, 2013
    JOURNALS FREE ACCESS
    The concept of treating chiral α- and β-alkoxy aldehydes with bicoordinate Lewis acids such as TiCl4, SnCl4, or MgBr2 followed by the addition of carbon nucleophiles for achieving chelation control with 1,2- and 1,3-asymmetric induction, respectively, was introduced three decades ago and has since evolved into a general method. In the case of enol silanes, the chelation-controlled Mukaiyama aldol reaction is involved, which has been used in recent natural products syntheses.
     
  • Naohiro Terasaka, Hiroaki Suga
    2014 Volume 43 Issue 1 Pages 11-19
    Published: January 05, 2014
    Released: January 05, 2014
    [Advance publication] Released: October 24, 2013
    JOURNALS FREE ACCESS
    Flexizymes are a family of aminoacylation ribozymes devised by in vitro selection in our research group. They charge a wide variety of nonproteinogenic amino acids onto virtually any kind of tRNAs, enabling us to reprogram the genetic code in a custom-made cell-free translation system. This genetic code reprogramming method was integrated with a mRNA display method, which not only expresses nonstandard peptides such as macrocyclic peptides but also selects ligands specifically binding to target proteins. This system is referred to as random nonstandard peptide integrated discovery (RaPID) system, which has yielded inhibitors against disease-related target proteins. In this review, we summarize the evolutionary history and recent applications of the flexizymes and RaPID system.
    Flexizymes are a family of aminoacylation ribozymes devised by in vitro selection in our research group. They charge a wide variety of nonproteinogenic amino acids onto virtually any kinds of tRNAs, enabling us to reprogram the genetic code in a custom-made cell-free translation system. This genetic code reprogramming method was integrated with a mRNA display method, which not only express nonstandard peptides such as macrocyclic peptides but also select ligands specifically binding to target proteins. This system is referred to as random nonstandard peptide integrated discovery (RaPID) system, which has yielded inhibitors against disease-related target proteins. In this review, we summarize the evolutionary history and recent applications of the flexizymes and RaPID system. Fullsize Image
     
  • Khadine A. Higgins, David Giedroc
    2014 Volume 43 Issue 1 Pages 20-25
    Published: January 05, 2014
    Released: January 05, 2014
    [Advance publication] Released: November 01, 2013
    JOURNALS FREE ACCESS
    CsoR/RcnR transcriptional repressors adopt a disc-shaped, all α-helical dimer of dimers tetrameric architecture, with a four-helix bundle the key structural feature of the dimer. Individual members of this large family of repressors coordinate Cu(I) or Ni(II)/Co(II) or perform cysteine sulfur chemistry in mitigating the effects of metal or metabolite toxicity, respectively. Here we highlight recent insights into the functional diversity of this fascinating family of repressors.
     
  • Sachio Horiuchi, Kensuke Kobayashi, Reiji Kumai, Shoji Ishibashi
    2014 Volume 43 Issue 1 Pages 26-35
    Published: January 05, 2014
    Released: January 05, 2014
    [Advance publication] Released: November 02, 2013
    JOURNALS FREE ACCESS
    Molecular displacement in an alternating chain of donors and acceptors triggers ferroelectric switching of large electric polarization with a low electric field in some charge-transfer complexes. While the displacement of a point charge (i.e., static charge) provides a good picture of the polarization for spin-Peierls-type transition in an ionic complex of tetrathiafulvalene (TTF) and p-bromanil (BA), it completely fails to explain both the magnitude and direction of the observed spontaneous polarization in the neutral-ionic transition of TTF–p-chloranil (CA). The most spectacular behavior is that the TTF cations are displaced toward the anode and the CA anions toward the cathode. Recent experimental and theoretical research has highlighted the strong effects of dynamic electrons traveling in the intermolecular space of TTF–CA. The new “electronic ferroelectricity” mechanism can also be envisioned as a powerful guide for guaranteeing high-performance dielectric and related electronic functionalities, especially for organic molecular systems.
    While the displacement of a static charge provides a good picture of the ferroelectric polarization for the spin-Peierls-type transition in an ionic complex of tetrathiafulvalene (TTF) and p-bromanil (BA), it completely fails to explain both the magnitude and direction of the observed spontaneous polarization in the neutral–ionic transition of TTF–p-chloranil (CA). Recent experimental and theoretical research has highlighted the strong effects of dynamical electrons traveling in the intermolecular space of TTF–CA. Fullsize Image
     
  • Katsuhiko Ariga, Yusuke Yamauchi, Gaulthier Rydzek, Qingmin Ji, Yusuke ...
    2014 Volume 43 Issue 1 Pages 36-68
    Published: January 05, 2014
    Released: January 05, 2014
    [Advance publication] Released: November 13, 2013
    JOURNALS FREE ACCESS
    Materials fabrication with nanoscale structural precision based on bottom-up-type self-assembly has become more important in various current disciplines in chemistry including materials chemistry, organic chemistry, physical chemistry, analytical chemistry, biochemistry, colloid and surface chemistry, and supramolecular chemistry. Although the design of new materials based on nanoscale self-assembly is anticipated as a key concept, preparing complete three-dimensional structures at nanoscale precision remains a difficult target using current technologies. Rather, dimension-reduced approaches such as layering of two-dimensional nanostructures into precisely controlled lamellar nanomaterials are currently achievable. In particular, layer-by-layer (LbL) assembly is known as a highly versatile method for fabrication of controlled layered structures from various kinds of component materials using very simple, inexpensive, and rapid procedures. Therefore, fabrication of multilayer films through the LbL deposition process has attracted growing interest from various research communities. The high versatility and flexibility of LbL assembly is continuously creating new concepts, new materials, new procedures, and new applications. In this highlight review, we focus on nanoarchitectonics by LbL assembly. After an initial introduction on the invention and a brief history of the LbL assembly technique, innovations and the evolution of the technique are described based mainly on recent examples, which are categorized into two sections: (i) developments in methodology (technical, material, and phenomenological aspects with expansion of concept) and (ii) progress in applications (physical, chemical/biochemical, and biomedical applications).
    In this highlight review, we focus on nanoarchitectonics combined with LbL assembly. Following an introduction of the invention and a brief history of the LbL assembly, innovations and evolution of the LbL assembly technique are described based on recent examples. These examples are categorized into two sections: (i) development in methodology (technical, material, and phenomenological aspects with expansion of concept) and (ii) progress in application (physical, chemical, biochemical, and biomedical applications). Fullsize Image
     
  • Hiroaki Iguchi, Shinya Takaishi, Masahiro Yamashita
    2014 Volume 43 Issue 1 Pages 69-79
    Published: January 05, 2014
    Released: January 05, 2014
    JOURNALS FREE ACCESS
    MMX-Type quasi-one-dimensional iodide-bridged diplatinum complexes (MMX chains) provide various electronic states and attractive physical properties. In this review, we summarize the recent progress in MMX chains consisting of pyrophosphite (pop) ligands. The MMX chains with binary countercations, which have short Pt–I–Pt distance and robust frameworks, form a new electronic state. They show reversible dehydration–rehydration accompanied by the change of electronic states and electrical conductivity. Relatively high electrical conductivity in the MMX chains with binary countercations enables us to investigate the negative differential resistance (NDR) and electrochemical characteristics in the solid state for the first time in MMX chains.
    MMX-type quasi-one-dimensional iodide-bridged diplatinum complexes (MMX chains) provide various electronic states and attractive physical properties. In this review, we summarize the recent progress in MMX chains consisting of pyrophosphite (pop) ligands. The MMX chains with binary countercations, which have short Pt–I–Pt distance and robust frameworks, form a new electronic state and show the water-vapor-induced reversible switching of electronic states and electrical conductivity. Their relatively high electrical conductivity enables us to investigate the nonlinear conduction and electrochemical characteristics in the solid state for the first time in MMX chains. Fullsize Image
     
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