Chemistry LettersVol.43 No.1 CMLTAGJanuary, 2014 ISSN 0366-7022

Copyright © 2014 The Chemical Society of Japan

Highlight Review

The Chelation-controlled Mukaiyama AldolReaction of Chiral α- and β-Alkoxy AldehydesGheorghe-Doru Roiban, Adriana Ilie, and Manfred T. Reetz*

The concept of treating chiral α- and β-alkoxy aldehydes with bicoordinate Lewis acids such as TiCl4, SnCl4, or MgBr2 followed by the additionof carbon nucleophiles for achieving chelation control with 1,2- and 1,3-asymmetric induction, respectively, was introduced three decades ago andhas since evolved into a general method. In the case of enol silanes, the chelation-controlled Mukaiyama aldol reaction is involved, which hasbeen used in recent natural products syntheses.

R1

BnO O

H

OSiMe3

R2+

bicoordinate

Lewis acid R1

BnO OHO

R2

bicoordinate

Lewis acidOBn

R1

H

O OSiMe3

R2+

OBn

R1

OH O

R2

Chem. Lett. 2014, 43 2-10 doi:10.1246/cl.130920

Highlight Review

Flexizymes-facilitated Genetic CodeReprogramming Leading to the Discoveryof Drug-like PeptidesNaohiro Terasaka and Hiroaki Suga*

Flexizymes are a family of aminoacylation ribozymes devised by in vitro selectionin our research group. They charge a wide variety of nonproteinogenic amino acidsonto virtually any kinds of tRNAs, enabling us to reprogram the genetic code in acustom-made cell-free translation system. This genetic code reprogramming methodwas integrated with a mRNA display method, which not only express nonstandardpeptides such as macrocyclic peptides but also select ligands specifically binding totarget proteins. This system is referred to as random nonstandard peptide integrateddiscovery (RaPID) system, which has yielded inhibitors against disease-relatedtarget proteins. In this review, we summarize the evolutionary history and recentapplications of the flexizymes and RaPID system.

Chem. Lett. 2014, 43 11-19 doi:10.1246/cl.130910

Highlight Review

Insights into Protein Allostery in the CsoR/RcnRFamily of Transcriptional RepressorsKhadine A. Higgins* and David Giedroc*

CsoR/RcnR transcriptional repressors adopt a disc-shaped, all α-helical dimer ofdimers tetrameric architecture, with a four-helix bundle the key structural feature ofthe dimer. Individual members of this large family of repressors coordinate Cu(I) orNi(II)/Co(II) or perform cysteine sulfur chemistry in mitigating the effects of metalor metabolite toxicity, respectively. Here we highlight recent insights into thefunctional diversity of this fascinating family of repressors.

Chem. Lett. 2014, 43 20-25 doi:10.1246/cl.130965

Highlight Review

Ionic versus Electronic Ferroelectricityin Donor­Acceptor Molecular SequencesSachio Horiuchi,* Kensuke Kobayashi,Reiji Kumai, and Shoji Ishibashi*

While the displacement of a static charge provides a good picture of theferroelectric polarization for the spin-Peierls-type transition in an ioniccomplex of tetrathiafulvalene (TTF) and p-bromanil (BA), it completely failsto explain both the magnitude and direction of the observed spontaneouspolarization in the neutral­ionic transition of TTF­p-chloranil (CA). Recentexperimental and theoretical research has highlighted the strong effects ofdynamical electrons traveling in the intermolecular space of TTF­CA.

Chem. Lett. 2014, 43 26-35 doi:10.1246/cl.130840

Chemistry Letters Vol.43, No.1 (2014)C-2

© 2014 The Chemical Society of Japan

Highlight Review

Layer-by-layer Nanoarchitectonics:Invention, Innovation, and EvolutionKatsuhiko Ariga,* Yusuke Yamauchi,* Gaulthier Rydzek,Qingmin Ji, Yusuke Yonamine, Kevin C.-W. Wu, and Jonathan P. Hill

In this highlight review, we focus on nanoarchitectonics combined with LbLassembly. Following an introduction of the invention and a brief history of the LbLassembly, innovations and evolution of the LbL assembly technique are describedbased on recent examples. These examples are categorized into two sections:(i) development in methodology (technical, material, and phenomenological aspectswith expansion of concept) and (ii) progress in application (physical, chemical,biochemical, and biomedical applications).

Chem. Lett. 2014, 43 36-68 doi:10.1246/cl.130987

Highlight Review

Recent Progress in MMX-Chain Complexes:Unique Electronic States and CharacteristicsDeveloped by Introducing Binary CountercationsHiroaki Iguchi,* Shinya Takaishi, and Masahiro Yamashita*

MMX-type quasi-one-dimensional iodide-bridged diplatinum complexes (MMX chains) provide various electronic states andattractive 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 Pt­I­Pt distance and robust frameworks, form a newelectronic state and show the water-vapor-induced reversible switching of electronic states and electrical conductivity. Theirrelatively high electrical conductivity enables us to investigate the nonlinear conduction and electrochemical characteristics in thesolid state for the first time in MMX chains.

Chem. Lett. 2014, 43 69-79 doi:10.1246/cl.130961

Chemistry Letters Vol.43, No.1 (2014) C-3

© 2014 The Chemical Society of Japan

AVisible-light-responsive Photocatalyst of Nitrogen-doped Solid-acid HNb3O8-N Studied by Ultrahigh-field1HMASNMR and 1H­93Nb/1H­15N HETCOR NMR in Solids

Tadashi Shimizu,* Toshihito Nakai, Kenzo Deguchi, Kazuhiko Yamada, Bing Yue, and Jinhua Ye

Chem. Lett. 2014, 43 80-82 doi:10.1246/cl.130784

A Facile Hydrothermal Synthesis of a MnCo2O4@Reduced Graphene Oxide Nanocomposite for Application inSupercapacitors

Yuan Yuan, Huiping Bi, Guangyu He,* Junwu Zhu, and Haiqun Chen*

MnCo2O4 nanoparticles with an average size of 12 nm were densely dispersedon RGO sheets by a one-step hydrothermal route with low cost and easyoperation. The prepared nanocomposite MnCo2O4@RGO exhibited highspecific capacitance of 334 F g¹1 at a large current density of 1Ag¹1 withexcellent cycle stability (98% after 2000 cycles).

Chem. Lett. 2014, 43 83-85 doi:10.1246/cl.130815

Expandability of Ultralong C­C Bonds: Largely Different C1­C2 Bond Lengths Determined by Low-temperature X-rayStructural Analyses on Pseudopolymorphs of 1,1-Bis(4-fluorophenyl)-2,2-bis(4-methoxyphenyl)pyracene

Takanori Suzuki,* Yasuto Uchimura, Fumika Nagasawa, Takashi Takeda, Hidetoshi Kawai, Ryo Katoono, Kenshu Fujiwara,Kei Murakoshi, Takanori Fukushima, Aiichiro Nagaki, and Jun-ichi Yoshida

The ultralong C1­C2 bond in the title moleculecan be elongated/shortened very easily, thusadopting a quite different bond length [1.700(6)­1.739(6)¡] in its pseudopolymorphs containinga variety of solvent molecules.

Chem. Lett. 2014, 43 86-88 doi:10.1246/cl.130872

Preparation and Characterization of Oligo(9,9¤-di-p-tolyl-3,3¤-bicarbazyl) and Its Application to Transparent ConductingMaterials

Youngwoong Kim, Takuya Tokuda, Fumitoshi Yagishita, Hyuma Masu, Minako Kubo, Katsuyuki Murashiro, and KatsuyoshiHoshino*

Preparation and characterization of conducting oligo-carbazole (OCz) hybrid films with a colorless trans-parency are described. The hybrid films were preparedby applying solutions obtained by the reaction ofmetals (tin, aluminum, or zinc) with an anion-dopedgreen-colored OCz.

Chem. Lett. 2014, 43 89-91 doi:10.1246/cl.130826

Chemistry Letters Vol.43, No.1 (2014)C-4

© 2014 The Chemical Society of Japan

Synthesis and Chiral Recognition Ability of Chitosan Derivatives with Different 4-Chlorophenylcarbamate­UreaStructures

Lili Zhang, Jun Shen, Wenli Zuo, and Yoshio Okamoto*

2

ROO

OH

NH2HO

n

ClR =

NCO

Chitosan

OO

OCONHR

NHCONHRRHNOCO

n1

OO

OCONHR

NHCONRRHNOCO

n

CNHR

OO

OCONHR

NCONHRRHNOCO

n

CNHR

biuretA

biuretB

O

O

OO

OCONR

NHCONHRRNOCO

n

CNHRO

RHNC O

allophanate

Chitosan derivatives bearing different 4-chlorophenyl-carbamate­urea structures were synthesized, and theirchiral recognition abilities were evaluated as chiralstationary phases (CSPs) for high-performance liquidchromatography (HPLC). These CSPs coated on silicagel exhibited different recognition ability depending ontheir structures and could be used with a few prohibitedsolvents as eluent, which efficiently improved theresolution for some racemates.

Chem. Lett. 2014, 43 92-94 doi:10.1246/cl.130834

Unique Synthetic Approach toward a Phosphaalkene: Synthesis of a Selenium-substituted Phosphaalkene with BulkySubstituents

Koh Sugamata, Takahiro Sasamori,* and Norihiro Tokitoh*

CSeTrpMe3Si

Me3SiC P

ClMe3Si

Me3SiTsi P

Cl

SeTrp AlCl3

–ClSiMe3

Tsi = C(SiMe3)3

Trp =

TrpSeLi

P

SeC

P A selenium-substituted phosphaalkene, (Me3Si)2C=PSeTrp (Trp: 9-triptycyl)), was synthesized by twomethods, substitution reaction of (Me3Si)2C=PCl withTrpSeLi, and treatment of TsiP(Cl)SeTrp (Tsi:C(SiMe3)3) with a catalytic amount of AlCl3. Thenewly obtained phosphaalkene was characterized indetail.

Chem. Lett. 2014, 43 95-96 doi:10.1246/cl.130862

Ni-Catalyzed Three-component Coupling Reaction of Conjugated Enyne, Carbonyls, and Dimethylzinc to ConstructAllenyl Alcohols

Yasuyuki Mori, Gen Onodera, and Masanari Kimura*

R1R2

R3CHOcat. Ni(0)

Me2Zn• R3

OHR2

R1

Me

Chem. Lett. 2014, 43 97-99 doi:10.1246/cl.130865

Transparent and Superhydrophobic Co3O4 Microfiber Films

Jindi Li, Jiansheng Xu, Ben Wang, and Zhiguang Guo*

The transparent films with the similar wax-gourd-like structure based on asmart two-step synthesis of one-dimensional (1D) Co3O4 nanofibresdirectly are fabricated on various substrates.

Chem. Lett. 2014, 43 100-101 doi:10.1246/cl.130854

Chemistry Letters Vol.43, No.1 (2014) C-5

© 2014 The Chemical Society of Japan

Aqueous Dispersion of Carbon Nanotubes Using Self-aggregating Peptides

Dukeun Kim, Toshiki Sawada, and Takeshi Serizawa*

A novel method to disperse single-walled carbonnanotubes (SWNTs) in aqueous phases by using self-aggregating peptides was demonstrated. SWNT dis-persion was performed by addition of water to solidmixtures of SWNTs and the peptides, and thesubsequent sonication proceses. Our method success-fully disentangled and dispersed larger amounts ofSWNTs with more excellent stability as compared toconventional methods.

Chem. Lett. 2014, 43 102-104 doi:10.1246/cl.130863 Editor's Choice

Introduction of an Arylethynyl Group onto an Anthracene Bisimide Core for Molecular Design of New π-ConjugatedCompounds

Tetsuo Iwanaga,* Ryo Tanaka, and Shinji Toyota*

Novel ethynylated anthracene bisimide (ABI) derivatives were synthesized by Sonogashira and Stille couplings. Theelectronic spectral data of the ABI with a 9-anthrylethynyl group suggested weak electronic interactions between theanthracene unit as the donor and the ABI unit as the acceptor.

N N

O

O O

O

R R

N N

O

O O

O

R R N N

O

O O

O

N N

O

O O

O

R R

R R

ABI unitAnthracene

donor

Extended π-conjugationby arylethynyl group

Chem. Lett. 2014, 43 105-107 doi:10.1246/cl.130842 Editor's Choice

Crystal Structure and Solid-state Ionic Conductivity of Cyclic Sulfonylamide Salts with Cyano-substituted QuaternaryAmmonium Cations

Makoto Moriya,* Takaaki Watanabe, Shohei Nabeno, Wataru Sakamoto, and Toshinobu Yogo*

Novel organic ionic plastic crystals were synthesizedfrom a cyclic perfluorosulfonylamide anion, {N(SO2-CF2)2CF2} (CPFSA), and cyano-functionalized qua-ternary ammonium cations. Solid-state ionic conduc-tivities and the phase-transition behavior underthermal conditions were measured for the obtainedcompounds. The crystal structure of [N(CH3)2-(CH2CN)2][CPFSA] was determined.

Chem. Lett. 2014, 43 108-110 doi:10.1246/cl.130874

Synthesis of Urchin-like Bi2Te3 Nanorods by a Microwave­Solvothermal Method

Ya Jiang,* Wei Zeng, and Yi Fang

(a) (b)Nanocrystalline Bi2Te3 with sphere and urchin-like morphologies has been successfully syn-thesized by microwave­solvothermal methodin PEG without reductant or surfactant. Themicrowave oven could automatically adjustmicrowave power and record the pressure 1.2MPa. Urchin-like crystalline Bi2Te3 was stableat temperature below 250 °C, and the decom-posing temperature was not influenced by thekind of gas atmosphere.

Chem. Lett. 2014, 43 111-112 doi:10.1246/cl.130833

Chemistry Letters Vol.43, No.1 (2014)C-6

© 2014 The Chemical Society of Japan

AVegetable Garden-like Zinc Dendritic Patterning by Electrodeposition

Isao Shitanda,* Ryohei Ichikawa, Yoshinao Hoshi, and Masayuki Itagaki

A highly regular zinc-dendric-patterned sheet was fabricated by electrodeposition.

Chem. Lett. 2014, 43 113-115 doi:10.1246/cl.130921

Generation of Arynes Triggered by Sulfoxide­Metal Exchange Reaction of ortho-Sulfinylaryl Triflates

Suguru Yoshida, Keisuke Uchida, and Takamitsu Hosoya*

Arynes were efficiently generated from readily available ortho-sulfinylaryl triflates by the treatment with phenylmagnesium bromidein tetrahydrofuran at ¹78 °C. Aryne generation was initiated by a rapid sulfoxide­metal exchange reaction, followed by theimmediate elimination of the ortho-OTf group. Various arynophiles efficiently reacted with arynes generated by this method within10min, providing the corresponding adducts in high yields.

S

OTf

R'

ORS RS RS

NN

N

Ph

PhMgBrN3CH2Ph

Sulfoxide–MetalExchange

+ isomerTHF

–78 °C, 10 min

Chem. Lett. 2014, 43 116-118 doi:10.1246/cl.130899

Morphology Analysis for Effect of the Polymer Cluster Produced from Adamantyl-bearing TrifunctionalMonomer on theStability of Liquid Crystal Alignment

Masanobu Mizusaki* and Kimiaki Nakamura

O

O

O

OO

O

O

O

O

O

+

1,3,5-TAOAd 4,4’-DAOBPh

SEM AFM

Effect on stability of liquid crystal (LC) alignment due to formation ofpolymer clusters on an alignment film was investigated. Morphologyanalysis with using SEM and AFM techniques revealed that the satbility ofthe LC alignment was increased by forming the polymer clusters producedfrom a copolymer of 1,3,5-triacryloyloxyadamantane (1,3,5-TAOAd) and4,4¤-diacryloyloxybiphenyl (4,4¤-DAOBPh).

Chem. Lett. 2014, 43 119-121 doi:10.1246/cl.130859

MnO2­Au Composite Electrodes for Supercapacitors

Yuming Dai, Shaochun Tang, Xiaoyu Wang, Xiang Huang, Chao Zhu, Zusheng Hang, and Xiangkang Meng*

The MnO2 nanorod­Au nanoparticle composites have been fabricated.The composites have a specific capacitance of 406.8 F g¹1 at 50mV s¹1,which is almost five times that of the pure MnO2 nanorods. Thecomposites have 91.3% capacitance retention over 2000 charge­dischargecycles at 5A g¹1, which is much better than that of pure MnO2 nanorods(74.6%).

Chem. Lett. 2014, 43 122-124 doi:10.1246/cl.130819

Chemistry Letters Vol.43, No.1 (2014) C-7

© 2014 The Chemical Society of Japan

Energy Transfer Dynamics of CdTe Quantum Dots on Epitaxial Graphene Prepared by Si Sublimation of 4H-SiC(0001)

Takuya Hirose, Hidefumi Shigemasa, Yasunori Kutsuma, Tadaaki Kaneko, and Naoto Tamai*

CdTeQDs

Graphene

Energy Transfer

hνν

Energy transfer from CdTe QDs to graphene.

Chem. Lett. 2014, 43 125-127 doi:10.1246/cl.130824

Cesium-adsorbent Geopolymer Foams Based on Silica from Rice Husk and Metakaolin

Francisco J. López, Satoshi Sugita, and Takaomi Kobayashi*

SEM observations of (a) GP-2.5, (b) GP-5, and (c) GP-10 cross-section.

Chem. Lett. 2014, 43 128-130 doi:10.1246/cl.130851

Imaging Mass Spectrometry of Intravenously Injected Gold Nanorods in Mice

Masanori Fujii, Naotoshi Nakashima, Takuro Niidome, and Yasuro Niidome*

Laser-induced desorption and ionization (LDI) of gold ions (Aun+: n = 1­3) were observed from gold nanorods in a liver section (thickness:10¯m). Organic molecules in the tissue did not inhibit the LDI processes of gold. The distribution of gold in the liver was determined byimaging mass spectrometry.

Chem. Lett. 2014, 43 131-133 doi:10.1246/cl.130864

Facile One-pot Synthesis of Some Novel Thiazolylpyrazole Derivatives with Antifungal Activity

Ya-Li Song, Tao Yang, Yun-Fang Dong, Fan Wu, and Geng-Liang Yang*

Chem. Lett. 2014, 43 134-136 doi:10.1246/cl.130908

Chemistry Letters Vol.43, No.1 (2014)C-8

© 2014 The Chemical Society of Japan

Enantioselective Fluorination of β-Ketoesters Catalyzed by Chiral Sodium Phosphate: Remarkable Enhancement ofReactivity by Simultaneous Utilization of Metal Enolate and Metal Phosphate

Keiji Mori, Ayaka Miyake, and Takahiko Akiyama*

X

O

CO2Me

1e (10 mol%)

SNPh

S

FPh

O O O O

Benzene X

O

CO2Me

FNa2CO3 (1.1 equiv) O

OP

O

OH

up to 92% ee

R R

(1.5 equiv)

1e

A chiral sodium phosphate-catalyzed highlyenantioselective fluorination of β-ketoesters wasachieved. In this process, the simultaneousformation of sodium enolate and sodiumphosphate under basic conditions is the key toachieving excellent selectivity. Indanone deriv-atives as well as benzofuranone derivativescould be employed in this reaction to afford thefluorinated adducts in good yields with good toexcellent enantioselectivities.

Chem. Lett. 2014, 43 137-139 doi:10.1246/cl.130934

Stabilization and Modification of Gold Nanocube Surfaces with Layered Silicate

Miharu Eguchi,* Masae Ito, and Taka-aki Ishibashi

Metal nanoparticles

Surfactant bilayer

Layered silicate The surface stability of metal nanoparticleswas enhanced by adsorption of layered silicateon metal nanocubes whose surface wasprotected by a surfactant. The obtained hybridexhibited high dispersibility even in concen-trated NaCl(aq). Furthermore, the surface ofthe negatively charged hybrids was demon-strated to be modifilable with cationic mole-cules.

Chem. Lett. 2014, 43 140-142 doi:10.1246/cl.130922

Comparative Study on the Photocatalytic Oxidation of Glycerol Using ZnO and TiO2

Natanael A. Hermes, André Corsetti, and Marla A. Lansarin*

Retention time/min

Gly

cero

l

Scheme illustrating the different selectivity of ZnOand TiO2 on the photocatalytic oxidation of glycerol.Abbreviations: glyceraldehyde (GAD), dihydroxyace-tone (DHA), glycolaldehyde (GCOL), and formalde-hyde (FORM).

Chem. Lett. 2014, 43 143-145 doi:10.1246/cl.130798

Chemistry Letters Vol.43, No.1 (2014) C-9

© 2014 The Chemical Society of Japan