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Graphical Abstract Angew. Chem. Int. Ed. 462003

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Contents
The following articles are already available online (in Wiley InterScience). You can find them at
www.angewandte.org, under Full Text, Early View.
R. Hoffmann,* D. J. Tantillo*:
Breaking Down Barriers: The Liaison Between Sigmatropic
Shifts, Electrocyclic Reactions, and Three-Center Cations
DOI: 10.1002/anie.200352853
Published online: November 19, 2003
F. W. Lichtenthaler,* K. Nakamura, J. Klotz:
( )-Daucic Acid: Revision of Configuration, Synthesis, and
Biosynthetic Implications
DOI: 10.1002/anie.200352718
Published online: November 18, 2003
Articles judged by the referees or the editor as being either very important or very urgent are immediately edited, proof-read, and electronically
published once the manuscript has arrived in the editorial office in final form. As long as there is no page number available these articles should be
cited in the following manner:
Author(s) Angew. Chem. Int. Ed., online publication date, DOI.
Web Sites
http://www.brenda.uni-koeln.de
5666
BRENDA: Everything You Always Wanted
To Know about Enzymes
C. Weise
Books
Handbook of Molecular Physics and
Quantum Chemistry
5667
reviewed by C. van Wllen
Stephen Wilson, Peter F. Bernath, Roy
McWeeny
Highlights
Functional Materials
T. Glaser*
5668 – 5670
Switching of a Spin-Crossover-Material
Incorporated in Metal–Organic Frameworks by a Reversible Ligand-Substitution
Reaction in the Crystalline State
A reversible ligand-substition reaction in
the crystal provides a possibility to switch
spin-crossover materials (see picture).
The merger of spin-crossover with the
nanoporosity of metal–organic frame-
works allows a dramatic variation of the
cooperative interactions between the spin
transition centers by sorption/desorption
of guest molecules.
Crystallized and elucidated: Our understanding of the basic functions of ion
channels—the selective guidance of ions
through cell membranes and the control
of this process by “gates”—is derived to a
large extent from the contributions of
Roderick MacKinnon, who was awarded a
Nobel Prize this year for his work. The
picture shows the X-ray crystal structure of
the prokaryotic potassium channel KcsA
(blue: K+ ions, red: carbonyl groups of the
peptide backbone and water molecules).
Angew. Chem. Int. Ed. 2003, 42, 5657 – 5663
www.angewandte.org
Ion Channels
D. Trauner*
5671 – 5675
Potassium Channels: Symmetric,
Selective, and Sensitive
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
5657
Contents
Minireviews
Conservation Techniques
H. Langhals,* D. Bathelt
5676 – 5681
The Restoration of the Largest Archaelogical Discovery—a Chemical Problem:
Conservation of the Polychromy of the
Chinese Terracotta Army in Lintong
The monomer of choice for the preservation of the lacquer base of the Chinese
terracotta warriors through polymeriza-
tion is hydroxyethyl methacrylate (1). The
treated artifacts (such as the shown
cuirass) remain unchanged for years.
Reviews
Single-Crystal Growth of Silicon
J. Evers,* P. KlEfers, R. Staudigl,*
P. Stallhofer
5684 – 5698
Czochralski’s Creative Mistake: A Milestone on the Way to the Gigabit Era
Purely by accident: Silicon chips for the
microelectronic industry are continually
being developed to improve performance.
We now live in the era of the 300-mm Si
wafer (see picture), with which the manufacture of one-gigabit chips began in
2001. The high-purity Si single crystals
used to make such wafers are prepared by
a method devised by Jan Czochralski,
which, as has only now been revealed, he
discovered through a failed experiment.
Communications
Macrocycles
“One ring to bind them”: The Borromean
link, which consists of three rings connected such that no two are concatenated,
is a challenging synthetic target. The
synthesis of an orthogonal two-ring
system that could be a precursor for such
a link was prepared from a polypyridine
template (see picture).
J. C. Loren, M. Yoshizawa,
R. F. Haldimann, A. Linden,
J. S. Siegel*
5702 – 5705
Synthetic Approaches to a Molecular
Borromean Link: Two-Ring Threading with
Polypyridine Templates
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5658
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Angew. Chem. Int. Ed. 2003, 42, 5657 – 5663
Angewandte
Chemie
What’s in the middle matters little! Differential conductance measurements
made on single-molecule rotaxanes and
their precursor dumbbells in transistors
with platinum electrodes reflect the molecule–electrode contacts rather than the
middle section of the molecules (see
diagram; the color reflects the conductance, with dark corresponding to zero
current). Interface states dominate electron transport. Molecular signatures are
masked and even constitutional asymmetry in the molecule is difficult to detect.
Molecular Electronics
H. Yu, Y. Luo, K. Beverly, J. F. Stoddart,
H.-R. Tseng, J. R. Heath*
5706 – 5711
The Molecule–Electrode Interface in
Single-Molecule Transistors
Multicomponent Asymmetric Catalysis
S. Takizawa, H. Somei, D. Jayaprakash,
H. Sasai*
5711 – 5714
Immobile without support: The first synthesis of chiral Al-bridged and Ti-bridged
polymers by a metal-mediated selfassembly of (R,R)-6,6’-bi(binol)
(binol = 1,1’-bi-2-naphthol), which bears
two pairs of phenolic hydroxy groups at
the opposite sides in the molecule, is
described (see scheme, X = OH or O).
The polymers are found to promote
asymmetric Michael reaction and carbonyl–ene reaction with high enantioselectivity and can be reused.
Metal-Bridged Polymers as Insoluble
Multicomponent Asymmetric Catalysts
with High Enantiocontrol: An Approach
for the Immobilization of Catalysts
without Using any Support
A trinuclear palladium(ii) chloride phosphane complex, [(PdCl2)3(PAr3)2], is
obtained in the reaction of a bowl-shaped
triarylphosphane with a deep cavity with
PdCl2 even when an excess amount of the
phosphane is employed. X-ray crystallography established the structure of the
complex: a trimer of PdCl2 is terminated
by two phosphane ligands (see picture).
Coordination Chemistry
Y. Ohzu, K. Goto,*
T. Kawashima*
5714 – 5717
A Bowl-Shaped Triarylphosphane with a
Large Cone Angle: Synthesis and
Crystallographic Analysis of a
[(PdX2)3(PR3)2]-Type Complex
Host–Guest Systems
J. M. C. A. Kerckhoffs,
F. W. B. van Leeuwen, A. L. Spek,
H. Kooijman, M. Crego-Calama,*
D. N. Reinhoudt*
5717 – 5722
Primitive similarities with regulatory
strategies of natural systems have been
mimicked by a synthetic self-assembled
receptor. The complexation of a hydrogenbonded trimer inside a hydrogen-bonded
Angew. Chem. Int. Ed. 2003, 42, 5657 – 5663
molecular cage triggers similar large conformational changes to the ones occurring
in enzymes upon complexation of a
specific substrate. Controlled release is
also achieved (see scheme).
www.angewandte.org
Regulatory Strategies in the Complexation
and Release of a Noncovalent Guest
Trimer by a Self-Assembled Molecular
Cage
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
5659
Contents
Crown Complexes
Crowning Glory: Twelve m2-sulfur donors
are located above and below an Ni6 ring to
form a double crown cluster (see picture).
This [12]metallacrown-6 nickel(ii) cluster
was synthesized by spontaneous selfassembly from 2-sulfanylethanol, carbon
bisulfide, NaOH, and NiSO4. The hydroxy
groups of 2-sulfanylethanol form strong
intermolecular hydrogen-bonding interactions, and thus help in sustaining the
metallacrown complex.
F.-F. Jian,* K. Jiao, Y. Li, P.-S. Zhao,
L.-D. Lu
5722 – 5724
[Ni6(SCH2CH2OH)12]: A Double Crown
[12]Metallacrown-6 Nickel(ii) Cluster
Metal–Alkene Complexes
I. Krossing,* A. Reisinger
5725 – 5728
A Stable Salt of the Tris(ethene)silver
Cation: Structure and Characterization of
[Ag(h2-C2H4)3]+[Al{OC(CF3)3}4]
More than 50 years after the proposal of
the Dewar–Chatt–Duncanson model for
the binding of olefins to transition-metal
atoms, the first structurally characterized
example of a silver–C2H4 complex ([Ag(h2C2H4)3]+, see picture) was obtained with
the help of the very weakly coordinating
[Al{OC(CF3)3}4] ion. By contrast, earlier
gas-phase investigations only suggested
the existence of [Ag(h2-C2H4)x]+ ions (x = 1
and 2).
Building butterflies: A carborane-supported {ReIrAu2} butterfly has been
assembled by stepwise addition of iridium
and then gold to a rhenium-monocarborane complex (see picture green = BH,
orange = B, black = CPh). The method of
preparation has considerable potential for
the synthesis of other new heteropolymetallic species.
Carborane Clusters
S. Du, J. A. Kautz, T. D. McGrath,
F. G. A. Stone*
5728 – 5730
Heterometallic Cluster Assembly on a
Rhenium–Monocarborane Substrate
Super Lewis Acid Catalyst
A. Hasegawa, K. Ishihara,*
H. Yamamoto*
5731 – 5733
Trimethylsilyl Pentafluorophenylbis(trifluoromethanesulfonyl)methide as a
Super Lewis Acid Catalyst for the
Condensation of Trimethylhydroquinone
with Isophytol
5660
Acid and vitamin E: Trimethylsilyl super
Lewis acids, such as [C6F5 C(Tf)2] Me3Si+
and Tf3CSiMe3, are extremely active and
highly effective catalysts for the regiose-
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
lective condensation of trimethylhydroquinone with isophthyol to afford
( )-a-tocopherol (vitamin E; see scheme,
Tf = CF3SO2.
Angew. Chem. Int. Ed. 2003, 42, 5657 – 5663
Angewandte
Chemie
Making DNA blink: A molecular machine
based on the DNA i-motif structure is
driven by changing pH (see picture). At
pH 5, oligonucleotide X* folds into the imotif (closed state), and complementary
strand Y adopts a random-coil structure.
At pH 8, X* unfolds and forms an
extended duplex with Y. This reversible
process can be monitored by means of a
rhodamine green label (green circle),
whose fluorescence is quenched by a
dabcyl moiety (gray circle) in the closed
but not in the open state.
Molecular Devices
D. Liu,
S. Balasubramanian*
5734 – 5736
A Proton-Fuelled DNA Nanomachine
Organometallic Chemistry
O. Baudoin,* A. Herrbach,
F. GuSritte
Palladacyclic intermediates effectively
lower the high energy barrier to cleavage
of a C(sp3) H bond. C H activation of
benzylic gem-dialkyl groups of bromo- and
The Palladium-Catalyzed C–H Activation
of Benzylic gem-Dialkyl Groups
iodobenzenes produces olefins and
cyclobutabenzenes, respectively, without
homocoupling (see scheme).
Biometallic Materials
Nucleoside–metallacarborane conjugates
(for example, TBEMC ; see picture with low
toxicity were synthesized and coupled as a
redox label to DNA oligonucleotide. The
labeled oligonucleotide acted as a primer
for Taq polymerase.
A. B. Olejniczak, J. Plešek, O. Křiž,
Z. J. Lesnikowski*
5740 – 5743
A Nucleoside Conjugate Containing a
Metallacarborane Group and Its Incorporation into a DNA Oligonucleotide
Micrometer-scale rodlike DNA architectures can be synthesized by one-step
molecular assembly using cross-linked
oligonucleotides with bismaleimide linkers and subsequent DNA ligation (see
scheme). Atomic force microscopy studies have shown that the flexibility of the
DNA structures in the parallel doublehelix structure is reduced.
Angew. Chem. Int. Ed. 2003, 42, 5657 – 5663
5736 – 5740
www.angewandte.org
DNA Structures
M. Endo, T. Majima*
5744 – 5747
Parallel, Double-Helix DNA Nanostructures Using Interstrand Cross-Linked Oligonucleotides with Bismaleimide Linkers
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
5661
Contents
Asymmetric Additions
Z. Xu, R. Wang,* J. Xu, C.-s. Da, W.-j. Yan,
C. Chen
5747 – 5749
Highly Enantioselective Addition of
Phenylacetylene to Aldehydes Catalyzed
by a b-Sulfonamide Alcohol–Titanium
Complex
Three simple steps were required to
prepare the b-sulfonamide alcohol ligand
(L*) from l-phenylalanine. Its titanium
complex efficiently catalyzes the asymmetric addition of phenylacetylene (2) to
aromatic aldehydes 1 to form enantiomerically pure propargyl alcohols 3.
Ts = p-toluenesulfonyl, R = substituted
phenyl or naphthyl group.
What a difference a ligand makes! The
reactivity of Pd0/trialkylphosphane complexes is of great interest because of their
unusual effectiveness as cross-coupling
catalysts for alkyl electrophiles [Eq. (1)].
This study sheds light on various aspects
of the critical oxidative-addition step of
the catalytic cycle.
Reaction Mechanisms
I. D. Hills, M. R. Netherton,
G. C. Fu*
5749 – 5752
Toward an Improved Understanding of the
Unusual Reactivity of Pd0/Trialkylphosphane Catalysts in Cross-Couplings of
Alkyl Electrophiles: Quantifying the
Factors That Determine the Rate of
Oxidative Addition
Cluster Compounds
C. P. G. Butcher, A. Dinca, P. J. Dyson,
B. F. G. Johnson,
P. R. R. Langridge-Smith,
J. S. McIndoe*
5752 – 5755
Facile generation of naked-metal particles
by stripping the ligands from transitionmetal–carbonyl clusters for gas-phase
studies by FTICR–MS is achieved by using
ESI combined with collision induced dissociation (see picture).
A Strategy for Generating Naked-Metal
Clusters for Gas-Phase Reactivity Studies
by FTICR–MS
Polycyclic Aromatic Hydrocarbons
P. R. Schreiner,* M. Prall,
V. Lutz
5757 – 5760
Fulvenes from Enediynes: Regioselective
Electrophilic Domino and Tandem
Cyclizations of Enynes and Oligoynes
5662
Complementary products: the electrophilic cyclizations of ortho-benzooligoynes
upon bromination give benzopentafulvenes with orthogonal, peripheral phenyl
groups. In contrast, the thermal cyclizations of the same starting materials give
naphthalene derivatives. This strategy was
used for the synthesis of anellated benzopentafulvenes in domino reactions.
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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Angew. Chem. Int. Ed. 2003, 42, 5657 – 5663
Angewandte
Chemie
Heterogeneous Catalysis
Rates ten times faster for the conversion
of ethylbenzene (EB) into styrene are
possible over unpromoted hematite catalysts if reduction to magnetite and coking
is prevented by adding traces of oxygen.
This finding results from measurements
made with the stagnation-point microflow
reactor shown (1: model catalyst, 2: cap,
3: diode laser).
O. Shekhah, W. Ranke,* A. SchEle,
G. Kolios, R. SchlUgl
5760 – 5763
Styrene Synthesis: High Conversion over
Unpromoted Iron Oxide Catalysts under
Practical Working Conditions
C–H Activation
N. Gommermann, C. Koradin, K. Polborn,
P. Knochel*
5763 – 5766
The one-pot reaction of alkynes, aldehydes, and secondary amines in the
presence of CuBr/quinap as the catalytic
system provides various enantiomerically
enriched propargylamines in good yields
(up to 99 %) and good selectivities (up to
96 % ee) [Eq. (1)].
Enantioselective, Copper(i)-Catalyzed
Three-Component Reaction for the
Preparation of Propargylamines
Highly-functionalized reagents can be
produced from gold nanoparticles containing up to seven different DNA oligonucleotide sequences (see picture). The
individual oligomers are orthogonally
addressable and reveal an efficient reactivity that is comparable to that of the
analogous monofunctional conjugates.
Nanotechnology
C. M. Niemeyer,* B. Ceyhan,
P. Hazarika
5766 – 5770
Oligofunctional DNA–Gold Nanoparticle
Conjugates
Communications labeled with this symbol have been judged by two referees as being “very important papers”.
The publication of Communications labeled with this symbol has been accelerated because of their topical or highly competitive
nature.
Service
Angew. Chem. Int. Ed. 2003, 42, 5657 – 5663
www.angewandte.org
Keywords
5772
Authors
5773
Preview
5775
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
5663
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