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Graphical Abstract Angew. Chem. Int. Ed. 252006

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Contents
The following Communications have been judged by at least two referees to be “very
important papers” and will be published online at www.angewandte.org soon:
A. Narayanaswamy, H. Xu, N. Pradhan, X. Peng*
Single-Crystal Nanoflowers with Different Chemical
Compositions and Physical Properties Grown by Limited
Ligand Protection
J. L. Alonso,* E. Cocinero, A. Lesarri, M. E. Sanz, J. L$pez
The Glycine–Water Complex
A. Tao, P. Sinsermsuksakul, P. Yang*
Polyhedral Silver Nanocrystals with Distinct Scattering
Signatures
J. van Bokhoven*, C. Louis, J. Miller, M. Tromp, O. Safonova,
P. Glatzel
Activation of Oxygen on Gold–Alumina Catalysts: In situ
High-Energy Resolution Fluorescence and Time-Resolved X-ray
Spectroscopy
M. Brynda, R. Herber,* P. Hitchcock, M. Lappert,* I. Nowik,
P. Power,* A. Protchenko, A. Ruzicka, J. Steiner
Higher Nuclearity Group 14 Metalloid Clusters:
[Sn9{Sn(NRR’)}6] (R = 2,6-iPr2C6H3 ; R’ = SiMe3 or SiMe2Ph)
O. Guill0n-Villafuerte, G. Garc3a, B. Anula, E. Pastor, M. Blanco,
M. A L$pez-Quintela, A. Hern5ndez-Creus, G. Planes*
Assembly of Subnanometric 2D Pt Nanoislands in Parallel Rows
on Au(111) by Self-Assembly of Pt Clusters
News
Biochemistry:
R. R. Breaker honored
4052
Organic Chemistry:
D. W. C. MacMillan awarded
4052
Biochemistry:
Prize to J. K. Barton
4052
reviewed by B. Friedrich
4053
Books
Master Mind
Daniel Charles
Highlights
Ionizing radiation (UV, X-rays, etc.) induces DNA damage not merely from the
primary impact of high-energy quanta but,
to a large extent, from secondary particles.
Among these, low-energy electrons (see
scheme) play an important role. Gasphase studies that use crossed-molecular
and monochromatic electron beams have
provided new fundamental insight into
the mechanism of radiation damage in
DNA.
Radiation Damage
P. Swiderek*
4056 – 4059
Fundamental Processes in Radiation
Damage of DNA
Correspondence
Borates
T. Delahaye, F. Boucher, M. Paris,
O. Joubert, M. Caldes,
Y. Piffard*
4060 – 4062
Some Experimental Evidence that
Zn4O(BO3)2 is Zn6O(OH)(BO3)3
4040
A combination of techniques show that
the so-called zincoborate “Zn4O(BO3)2” is
in fact a zinc oxyhydroxyborate. The presence of hydrogen in the structure
explains the constriction of the
O(3)···O(3) distance through it being
straddled by an OH···O bridge and rules
out the hypothesis of oxygen vacancies in
the environment of boron.
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2006, 45, 4040 – 4049
Angewandte
Chemie
Reviews
Folding
Present day biomolecular modeling is
limited in its application by four main
problems: 1) the force-field problem,
2) the search problem, 3) the ensemble
problem, and 4) the experimental problem. These four problems are discussed
in this Review by using practical examples,
and perspectives are outlined for overcoming the limitations of biomolecular
modeling.
folded/native
Membrane or Micelle Formation
denatured
Complexation
bound
micelle
mixture
Partitioning
unbound
in membrane
in water in mixtures
Molecular Dynamics
W. F. van Gunsteren,* D. Bakowies,
R. Baron, I. Chandrasekhar, M. Christen,
X. Daura, P. Gee, D. P. Geerke, A. Gl@ttli,
P. H. HAnenberger, M. A. Kastenholz,
C. Oostenbrink, M. Schenk, D. Trzesniak,
N. F. A. van der Vegt,
H. B. Yu
4064 – 4092
Biomolecular Modeling: Goals, Problems,
Perspectives
Communications
UV300
Visible light
UV254
Membranes
A. Nayak, H. Liu, G. Belfort* 4094 – 4098
UV254
Vis
Lighting the way: Through the combination of a UV-grafting process with the
photoresponsive properties of spiropyran
molecules, an optically reversible switching membrane surface was developed.
This process can be used in preference to
inducing physical movement of longchain SAMs toward an electrode and as a
result improve many industrial opportunities including those dependent on surface wettability and molecular adhesion.
Dynamic Chemistry
The fellowship of the rings: Circular
dichroism measurements reveal that
chirality is transferred from 12 stereogenic
centers to 6 octahedral zinc(II) centers
(see picture) in two enantiomeric pairs of
chiral Borromeates, one of which has been
found to be wholly asymmetric in the solid
state by X-ray crystallography.
For the USA and Canada:
ANGEWANDTE CHEMIE International
Edition (ISSN 1433-7851) is published weekly
by Wiley-VCH PO Box 191161, D 69451 Weinheim, Germany. Air freight and mailing in the
USA by Publications Expediting Inc. 200
Angew. Chem. Int. Ed. 2006, 45, 4040 – 4049
An Optically Reversible Switching
Membrane Surface
C. D. Pentecost, A. J. Peters, K. S. Chichak,
G. W. V. Cave, S. J. Cantrill,
J. F. Stoddart*
4099 – 4104
Chiral Borromeates
Meacham Ave., Elmont, NY 11003. Periodicals
postage paid at Jamaica NY 11431. US POSTMASTER: send address changes to Angewandte
Chemie, Wiley-VCH, 111 River Street, Hoboken,
NJ 07030. Annual subscription price for institutions: US$ 5685/5168 (valid for print and
electronic / print or electronic delivery); for
individuals who are personal members of a
national chemical society prices are available
on request. Postage and handling charges
included. All prices are subject to local VAT/
sales tax.
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
4041
Angewandte
Chemie
Software developed in house in combination with a recently developed method
of MALDI-TOF MS enable not only the
elucidation of individual chain structures
of poly(lactide-co-glycolide), a polymer
used extensively in the medical sector, but
a full characterization of this copolymer
including even its chemical composition
and topology (random, gradient, block
(see figure), or alternating).
Polymer Chemistry
Noncovalent interactions are used to
generate a polymeric supramolecular
chiral catalyst (see picture). This heterogeneous catalyst, which is based on
Feringa’s MonoPhos/RhI system, is
formed by orthogonal self-assembly of
recognition motifs through hydrogen
bonding and ligand-to-metal coordination
interactions. It shows excellent asymmetric induction and reusability in the catalysis of the asymmetric hydrogenation of
dehydro-a-amino acid and enamide derivatives.
Heterogeneous Catalysis
S. Huijser, B. B. P. Staal, J. Huang,
R. Duchateau,* C. E. Koning 4104 – 4108
Chemical Composition and Topology of
Poly(lactide-co-glycolide) Revealed by
Pushing MALDI-TOF MS to Its Limit
L. Shi, X. Wang, C. A. Sandoval, M. Li,
Q. Qi, Z. Li, K. Ding*
4108 – 4112
Engineering a Polymeric Chiral Catalyst
by Using Hydrogen Bonding and
Coordination Interactions
Polymerization
Get into the groove: Porous coordination
polymers with basic interaction sites
catalyze the fast and stereoselective polymerization of acetylene derivatives. The
reactions take place in the one-dimensional nanochannels of the coordination
polymer (see picture).
T. Uemura, R. Kitaura, Y. Ohta,
M. Nagaoka, S. Kitagawa* 4112 – 4116
Nanochannel-Promoted Polymerization
of Substituted Acetylenes in Porous
Coordination Polymers
Glycoproteins
The missing link: Reiterative ligations
based on non-cysteine and cysteine-based
acyl acceptors have been used to prepare
synthetic polypeptides and proteins with
multiple sites of glycosylation. Highly
Angew. Chem. Int. Ed. 2006, 45, 4040 – 4049
complex positionally defined glycopolypeptides corresponding to single glycoforms can be formed from simple components.
B. Wu, J. Chen, J. D. Warren, G. Chen,
Z. Hua, S. J. Danishefsky*
4116 – 4125
Building Complex Glycopeptides:
Development of a Cysteine-Free Native
Chemical Ligation Protocol
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
4043
Contents
Alkaloids
Naturally radical: The microwave-induced
rearrangement of sceptrin to natural products ageliferin and nagelamide E results
in approximately the same ratio as they
are isolated from natural sources. Computational investigations show that the
vinylcyclobutane–cyclohexene rearrangement occurs via diradical intermediates
and support the involvement of this
rearrangement in the biosynthesis of the
natural products.
B. H. Northrop, D. P. O’Malley,
A. L. Zografos, P. S. Baran,*
K. N. Houk*
4126 – 4130
Mechanism of the Vinylcyclobutane
Rearrangement of Sceptrin to Ageliferin
and Nagelamide E
Zwitterions
X. Kong, I.-A. Tsai, S. Sabu, C.-C. Han,
Y. T. Lee, H.-C. Chang,* S.-Y. Tu,
A. H. Kung, C.-C. Wu
4130 – 4134
Progressive Stabilization of Zwitterionic
Structures in [H(Ser)2–8]+ Studied by
Infrared Photodissociation Spectroscopy
Magnetic Clusters
T. C. Stamatatos, K. A. Abboud,
W. Wernsdorfer,
G. Christou*
4134 – 4137
High-Nuclearity, High-Symmetry, HighSpin Molecules: A Mixed-Valence Mn10
Cage Possessing Rare T symmetry and an
S = 22 Ground State
Does (Ser)2 have a neutral structure? How
does the zwitterion evolve with an
increasing cluster size of serine (Ser)?
Infrared spectroscopic and mass-spectrometric analysis of [H(Ser)n]+ (n = 2–8)
shows progressive stabilization of the
zwitterion with increasing cluster size,
and the results of ab initio calculations
based on density functional theory of
[H(Ser)2]+ are also given (picture: a
neutral structure; red O, blue N, gray C,
white H).
Taking the high road: The unification of
azide and hmp (hmpH = 2-(hydroxymethyl)pyridine) ligands has provided a
route to two salts of a new Mn10 cation
with an aesthetically pleasing, high-symmetry structure. The cation (see excerpt of
structure; MnII yellow, MnIII blue, O red,
N green, C gray) is completely ferromagnetically coupled and possesses an S = 22
ground state, one of the highest values
ever reported.
Iridium Complexes
N.-M. Hsu, W.-R. Li*
4138 – 4142
Accelerated Discovery of RedPhosphorescent Emitters through
Combinatorial Organometallic Synthesis
and Screening
4044
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2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Seeing red dots: A parallel solid-phase
synthetic protocol was developed in the
search for red-phosphorescent iridium
complexes. Direct screening of resinbound chloro-bridged dimers and leads
was performed and validated (see picture), and two hits were identified. Their
electroluminescent devices exhibited very
high external quantum efficiencies.
Angew. Chem. Int. Ed. 2006, 45, 4040 – 4049
Angewandte
Chemie
Chiral Assemblies
A. Tanaka, K. Inoue, I. Hisaki, N. Tohnai,
M. Miyata,* A. Matsumoto 4142 – 4145
Something out of nothing: Chiral layered
crystals are obtained from achiral 4methylbenzylammonium myristate and
pentadecanoate. The molecular chirality
within a single molecule in these systems
arises from the fixation of the conformation. It then spreads over the 2D layers
and finally over the 3D crystal to generate
supramolecular chirality by parallel
assembly (see picture).
Supramolecular Chirality in Layered
Crystals of Achiral Ammonium Salts and
Fatty Acids: A Hierarchical Interpretation
Microreactors
P. He, P. Watts, F. Marken,
S. J. Haswell*
Currently coupled: A clean microreactorbased electrosyntheses in the absence of
supporting electrolyte is demonstrated
and shown to feature very simple cell
geometries. As exemplified for the coupling reaction of various olefins with
benzyl bromides, the height of the microfluidic cell and the flow rate are crucial for
the minimization of unwanted side products and optimization of yields (see
picture).
4146 – 4149
Self-Supported and Clean One-Step
Cathodic Coupling of Activated Olefins
with Benzyl Bromide Derivatives in a
Micro Flow Reactor
Asymmetric Synthesis
A. Joncour, A. DScor, S. Thoret, A. Chiaroni,
O. Baudoin*
4149 – 4152
Return to sender: A biaryl configuration
that is controlled by a benzylic stereocenter in an atropo-selective Suzuki coupling
in turn controls the stereocenter configuration in an SN1-type dehydrative cycli-
No salt please: Halide scavengers AgOTf
and TlOAc are not required for the Heck
coupling of electron-rich olefins with aryl
bromides and chlorides. Using ammonium additives, these reactions can be
carried out in either an imidazolium ionic
liquid or a common molecular solvent,
thus furnishing 1,1’-disubstituted olefins
in high yields with excellent regioselectivities.
Angew. Chem. Int. Ed. 2006, 45, 4040 – 4049
zation performed at low temperature.
Promising antimicrotubule biaryls of high
optical purity are obtained in this manner.
TFA = trifluoroacetic acid, pin = pinacolato.
Biaryl Axis as a Stereochemical Relay for
the Enantioselective Synthesis of
Antimicrotubule Agents
Homogeneous Catalysis
J. Mo, J. Xiao*
4152 – 4157
The Heck Reaction of Electron-Rich
Olefins with Regiocontrol by HydrogenBond Donors
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
4045
Contents
Silyllithium Compounds
D. Bravo-Zhivotovskii,* I. Ruderfer,
S. Melamed, M. Botoshansky, A. Schmidt,
Y. Apeloig*
4157 – 4159
[{(tBu2Me)2Si}3Li4]2 : An Aggregated
Dianion of a 1,1-Dilithiosilane with a
Unique Structural Motif
Analytical Methods
S. Lacombe,* F. Bournel, C. Laffon,
P. Parent
4159 – 4163
Radical Photochemistry in OxygenLoaded Ices
An anionic dilithium compound: The
dianion [(R2Si)3Li4]2 (R = tBu2MeSi) as
salt 2 was synthesized as the first of its
kind by dissolving 1 in THF. The structure
of 2 was solved by X-ray crystallography
and studied by solid-state and solution
NMR spectroscopy. Compound 2 reacts
as a dilithiosilane.
Ice to see you all: The photoproducts
formed by irradiation of water and molecular oxygen ices are strongly dependent
on the chemical composition of the
medium. The observation of all the transient species (radicals and molecules, see
picture) simultaneously will have applications in different fields such as astrochemistry and radiobiology.
Cumulene Synthesis
Y.-H. Liu,* H.-J. Gao,
S.-L. Zhou
4163 – 4167
Highly Stereoselective Synthesis of TMS-,
Alkyl-, or Aryl-Substituted cis[3]Cumulenols via a-Alkynylated
Zirconacyclopentenes
Double bonds come in threes: A highly
stereoselective and potentially general
method for the synthesis of tetrasubstituted cis-[3]cumulenes through zirconiummediated coupling of 1,3-butadiynes with
Oligosaccharide Analysis
A. Lohse, R. Martins, M. R. Jørgensen,
O. Hindsgaul*
4167 – 4172
Solid-Phase Oligosaccharide Tagging
(SPOT): Validation on Glycolipid-Derived
Structures
4046
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2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
aldehydes or ketones is described (see
scheme). Remarkably, the reaction occurs
with completely different chemoselectivity
to that usually observed with alkyl- or arylsubstituted zirconacyclopentenes.
SPOT check: A simple technique for
labeling oligosaccharides consists of
capturing the sugars on beads functionalized with hydroxylamine groups bearing
cleavable linkers. After sequential pipetting in and out of reagents, tagged sugars
are released into solution (see picture;
PEGA = polyethylene glycol–polyacrylamide resin) for analysis by electrophoresis or mass spectrometry.
Angew. Chem. Int. Ed. 2006, 45, 4040 – 4049
Angewandte
Chemie
Cycloaddition Reactions
P. Wipf,* M. A. A. Walczak
4172 – 4175
Pericyclic Cascade Reactions of
(Bicyclo[1.1.0]butylmethyl)amines
Direct access: Phase-transfer N-allylation
and N-propargylation of (bicyclo[1.1.0]butylmethyl)amines initiate diastereoselective pericyclic cascade reactions
that culminate in novel spirocyclic and
tricyclic pyrrolidine heterocycles through
formal ene or [2þ2] pathways.
Asymmetric Catalysis
J. G. Kim, P. J. Walsh*
Stop that achiral catalyst! Chiral Lewis
acid catalyzed aryl additions to aldehydes
that originate from aryl halides generate
products with very low ee values (see
scheme, left), because the achiral metal
halide by-products are much more effi-
cient catalysts than those derived from
chiral amino alcohols. A LiCl-selective
inhibitor is introduced that enables a
highly enantioselective one-pot arylation
of aldehydes that begins with aryl bromides (right).
4175 – 4178
From Aryl Bromides to Enantioenriched
Benzylic Alcohols in a Single Flask:
Catalytic Asymmetric Arylation of
Aldehydes
Liquid Crystals
Precious particles: Dicyanoargentate(I)
and dicyanoaurate(I) salts of an
imidazolium cation form both crystalline
(see structure and enlargement of the
cation and anion) and smectic-A phases.
Electrodeposition from the ionic liquid
crystals provides a novel route to silver
particles and gold nanoparticles.
W. Dobbs, J.-M. Suisse, L. Douce,*
R. Welter
4179 – 4182
Electrodeposition of Silver Particles and
Gold Nanoparticles from Ionic LiquidCrystal Precursors
P4 Activation
D. Yakhvarov,* P. Barbaro, L. Gonsalvi,
S. MaWas Carpio, S. Midollini,*
A. Orlandini, M. Peruzzini,* O. Sinyashin,
F. Zanobini
4182 – 4185
P’s in a pod: White phosphorus reacts
with [M(dppm)2]OTf (M = Rh, Ir;
dppm = PPh2CH2PPh2) to give [M(dppm)(Ph2PCH2PPh2PPPP)]OTf whereby a trihapto “P5” ligand is assembled through
PP bond formation between one dppm
Angew. Chem. Int. Ed. 2006, 45, 4040 – 4049
PPh2 group and an activated P4 molecule
(see scheme; P green, M red, C white,
phenyl groups omitted). A bimetallic
reaction pathway leading to the final
product is proposed, as based on in situ
31
P NMR studies.
A Snapshot of P4 Tetrahedron Opening:
Rh- and Ir-Mediated Activation of White
Phosphorus
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
4047
Contents
Surfaces
J.-J. Benattar,* M. Nedyalkov, F. K. Lee,
O. K. C. Tsui
4186 – 4188
Adhesion of a Free-Standing Newton
Black Film onto a Solid Substrate
Arsenic Ligands
L. J. Gregoriades, H. Krauss, J. Wachter,
A. V. Virovets, M. Sierka,
M. Scheer*
4189 – 4192
The Potential of a cyclo-As3-Ligand
Complex in Supramolecular Chemistry
Film transfer: A new method is presented
to transfer free-standing Newton black
films of surfactant onto a solid substrate
(see picture). X-ray reflectivity and atomic
force microscopy reveal that the
deposited films have a high degree of
molecular organization and good
adhesion.
As3 makes the connection:
[Cp*Mo(CO)2(h3-As3)] reacts with
Ag[Al{OC(CF3)3}4] to yield a novel dimeric
complex featuring the cyclo-As3 ligand in
an unusual face-bridging coordination
mode. Analytical data and DFT calculations support the existence of a monomer–dimer equilibrium in solution (see
scheme). [Cp*Mo(CO)2(h3-As3)] also
reacts with CuX (X = Cl, Br, I) to yield
insoluble dimers consisting of planar
Cu2X2 moieties.
Organocatalysis
S. Mayer, B. List*
4193 – 4195
Asymmetric Counteranion-Directed
Catalysis
Exceedingly high enantioselectivity in a
catalytic reaction can be realized even
when the chirality resides only in the
counteranion of the catalyst. A salt (1)
composed of an achiral ammonium
cation and a chiral phosphate counteran-
ion catalyzes asymmetric transfer hydrogenations of aromatic and aliphatic a,bunsaturated aldehydes with a Hantzsch
ester in excellent enantioselectivities (see
scheme).
Not a catalyst killer: In the reaction of 2
with B(C6F5)3, a nucleophilic aromatic
substitution with CF bond cleavage
leads to the unexpected difluoride 1.
Although the formation of ZrF species
during olefin polymerization by
[Cp’2ZrR]+[RB(C6F5)3] (Cp’ = substituted
or unsubstituted h5-cyclopentadienyl;
R = Me, H) catalysts is often described as
a deactivation, the catalyst precursor 2
can be regenerated from 1 through
treatment with iBu2AlH.
CF Activation
P. Arndt,* U. J@ger-Fiedler, M. Klahn,
W. Baumann, A. Spannenberg,
V. V. Burlakov, U. Rosenthal* 4195 – 4198
Formation of Zirconocene Fluoro
Complexes: No Deactivation in the
Polymerization of Olefins by the ContactIon-Pair Catalysts [Cp’2ZrR]+[RB(C6F5)3]
4048
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2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2006, 45, 4040 – 4049
Angewandte
Chemie
Protein Modification
C. J@ckel, M. Salwiczek,
B. Koksch*
4198 – 4203
Fluorine in a Native Protein
Environment—How the Spatial Demand
and Polarity of Fluoroalkyl Groups Affect
Protein Folding
Give and take: The influence of fluoro
substitution of amino acid side chains on
their interaction profile in a native polypeptide environment was studied sys-
tematically. The fluorination of alkyl
groups has opposing electrostatic and
steric consequences for the stability of
hydrophobic protein cores.
Functional Materials
Octopolar tris[(phenyl)ethynyl]benzenes
with high second-order nonlinear optical
(NLO) activity form discotic liquid-crystalline mesophases whose properties
depend on the length of the alkoxy chains.
The molecules self-organize in a noncentrosymmetric fashion in the bulk
phase which enables the construction of a
simple, efficient, NLO device (see picture).
G. Hennrich,* A. Omenat, I. Asselberghs,
S. Foerier, K. Clays, T. Verbiest,*
J. L. Serrano*
4203 – 4206
Liquid Crystals from C3-Symmetric
Mesogens for Second-Order Nonlinear
Optics
Blocked up: Amphiphilic DNA-block
copolymers were prepared in a fully automated single process by using a DNA
synthesizer. These materials formed
micelles in aqueous solution which were
applied as a scaffold for DNA-templated
organic reactions (see picture, red and
green balls = reactants, yellow bar = new
bond). For a novel fluorogenic reaction,
the DNA-templated conversions were
detected by fluorescence spectroscopy.
DNA-Templated Synthesis
F. E. Alemdaroglu, K. Ding, R. Berger,
A. Herrmann*
4206 – 4210
DNA-Templated Synthesis in Three
Dimensions: Introducing a Micellar
Scaffold for Organic Reactions
The issues for June 2006 appeared online on the following dates
Issue 21: May 10. · Issue 22: May 18. · Issue 23: May 24. · Issue 24: June 1
Service
Keywords
4214
Authors
4215
Angewandte’s
Sister Journals
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Angew. Chem. Int. Ed. 2006, 45, 4040 – 4049
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
4212 – 4213
4217
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