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Graphical Abstract Angew. Chem. Int. Ed. 202004

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The following Communications are available online (in Wiley InterScience). You can find them, as
well as forthcoming Reviews, Highlights, and Essays, at, under Early View.
W. U. Dittmer, A. Reuter, F. C. Simmel*:
A DNA-Based Machine That Can Cyclically Bind and Release
DOI: 10.1002/anie.200353537
Published online: April 28, 2004
D. H. Paik, D.-S. Yang, I-R. Lee, A. H. Zewail*:
The Transition State of Thermal Organic Reactions: Direct
Observation in Real Time
DOI: 10.1002/anie.200453962
Published online: April 28, 2004
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 its 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
EPA Environmental Science Database:
Not Only for Americans
K. W. Fried, D. Lenoir
Peter Schwerdtfeger
reviewed by L. Gagliardi
Hans-Ulrich Blaser, Elke Schmidt
reviewed by R. Strmer
Can a hollow catalyst process a polymeric
substrate by “threading the needle?”
Nature’s DNA-processing enzymes
effortlessly use this pseudorotaxane
mechanism, but until recently this topology has not been realized in a synthetic
supramolecular system. However, there is
now compelling evidence that a toroidal
metallopophyrin does just that in the
epoxidation of polybutadiene (see picture).
Submonolayer sensitivity, spatial resolutions of 0.02 @, and time resolutions of
less than 1 ps are key features of the latest
developments in electron crystallography,
a method that allows the determination of
the structures of solid surfaces (see
picture). The road to this powerful technique and a comparison with complementary structure-determination techniques are discussed.
Relativistic Electronic Structure
Asymmetric Catalysis on Industrial
Supramolecular Chemistry
P. R. Carlier*
2602 – 2605
Threading the Needle:
Mimicking Natural Toroidal Catalysts
Electron Crystallography
J. M. Thomas*
2606 – 2610
Ultrafast Electron Crystallography:
The Dawn of a New Era
2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2004, 43, 2588 – 2594
Hindsight is a wonderful thing: Controversies are always difficult to characterize
while they are in progress; however, as
shown for the cases of stereochemistry
and bond-stretch isomerization, it is
much easier once all the evidence has
been amassed. These two examples have
demonstrated how important it is to
Structure Elucidation
consider all the experimental results
before coming to a conclusion. The
second example shows above all that
some evidence is more equal than
others—crystal-structure analysis was
considered at all stages to be the most
J. A. Labinger,*
S. J. Weininger*
2612 – 2619
Controversy in Chemistry: What Counts as
Evidence?—Two Studies in Molecular
Matrix Techniques
Helium droplets as a matrix: Helium
droplets (see picture) have unusual
properties that are very useful in
spectroscopy and in the study of chemical
reactions of molecules and complexes.
Single molecules (e.g. OSC; S yellow,
C black, O red) can be embedded, and
homo- and heteronuclear clusters can be
formed in their interiors. This unique
matrix technique opens the way for a
variety of new possible applications in
chemistry and physics.
J. P. Toennies,* A. F. Vilesov 2622 – 2648
Superfluid Helium Droplets: A Uniquely
Cold Nanomatrix for Molecules and
Molecular Complexes
Feats of clay: Molecular simulations are
used to study the mechanism of clayswelling hysteresis. A free-energy barrier
separating stable layered hydrates is
found to be the origin of this hysteresis.
The simulations are also used to predict
that changing the external pressure on a
clay mineral layer can induce hysteresis
(see picture).
Clay Minerals
T. J. Tambach,* P. G. Bolhuis,
B. Smit
2650 – 2652
A Molecular Mechanism of Hysteresis in
Clay Swelling
Cyanohydrin Anions
An enantiopure (salen)aluminum alkoxide
complex catalyzes the asymmetric coupling of acylsilanes and cyanoformate
esters [Eq. (1) , R = Bn, Et]. The reactions
afford unsymmetrical, fully protected
malonic acid derivatives that may be
elaborated to nonnatural b-amino acid
derivatives, and represent the first asymmetric catalytic reactions involving protected cyanohydrin anions.
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Angew. Chem. Int. Ed. 2004, 43, 2588 – 2594
D. A. Nicewicz, C. M. Yates,
J. S. Johnson*
2652 – 2655
Catalytic Asymmetric Acylation of
(Silyloxy)nitrile Anions
individuals who are personal members of a
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2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Low-Coordinate Species
S. Hino, M. Brynda, A. D. Phillips,
P. P. Power*
2655 – 2658
Synthesis and Characterization of a
Quasi-One-Coordinate Lead Cation
Easily lead: The demethylation of
[PbMe(2,6-Trip2C6H3)] (Trip = 2,4,6iPr3C6H2) with tris(perfluorophenyl)borane in toluene affords [Pb(2,6Trip2C6H3)·(h2-MeC6H5)][B(Me)(C6F5)3]
(see picture), in which the lead center is
singly bound to the 2,6-Trip2C6H3 moiety
and also weakly solvated by toluene.
Natural Product Synthesis
S. Kodama, Y. Hamashima, K. Nishide,
M. Node*
2659 – 2661
Total Synthesis of ()-Galanthamine by
Remote Asymmetric Induction
A pivotal intramolecular Michael addition
to form a fused 5,7,5 ring system and the
skeleton of ()-galanthamine (1) was
completely controlled by a remote chiral
imidazolidinone auxiliary derived from d-
phenylalanine (see scheme). This total
synthesis of the allylic alcohol 1 avoids the
corresponding enone narwedine, a highly
allergenic intermediate in previous syntheses of 1.
A turn on! A lockable photodriven molecular shuttle is based on a [2]rotaxane that
consists of an a-cyclodextrin threaded by
a stilbene derivative. The fluorescent
signals originate from the naphthalimide
stopper and indicate the position of the
shuttle. Once unlocked, the device can be
turned on by irradiation at 335 nm and
turned off by irradiation at 280 nm. The
shuttle can be locked or unlocked by the
addition acid or alkali, respectively (see
Excellent enantioselectivities (up to
99 % ee) and turnover numbers (up to
48 000) were attained in the hetero-Diels–
Alder reaction of a diverse range of
aldehydes and activated dienes catalyzed
by [Rh2(S-bptpi)4] (see scheme).
Molecular Devices
Q.-C. Wang, D.-H. Qu, J. Ren, K. Chen,
2661 – 2665
H. Tian*
A Lockable Light-Driven Molecular Shuttle
with a Fluorescent Signal
M. Anada, T. Washio, N. Shimada,
S. Kitagaki, M. Nakajima, M. Shiro,
S. Hashimoto*
2665 – 2668
A New Dirhodium(ii) Carboxamidate
Complex as a Chiral Lewis Acid Catalyst
for Enantioselective Hetero-Diels–Alder
2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2004, 43, 2588 – 2594
Cyclopropane Reagents
V. K. Yadav,* V. Sriramurthy
Push–pull substitution of cyclopropanes
can make these compounds synthetic
equivalents of 1,3-dipolar synthons 2,
suitable for formal [3þ2] addition reactions with aryl acetylenes. Upon treatment
with TiCl4, tert-butyldiphenylsilylmethylsubstituted cyclopropyl ketones 1 reacted
with aryl acetylenes to furnish cyclopentene derivatives 3 regio- and stereoselectively. R = nBu, tBu, Ph.
Thousands of kinase assays at one stroke
are possible by using high-content peptide microarrays. Such experiments
deliver information regarding peptidic
kinase substrates and accelerate the
development of high-throughput screening assays. Moreover, knowledge-based
selection of human sequences allows the
reliable detection of downstream targets
of protein kinases, as demonstrated for 3phosphoinositide-dependent protein
Formal [3þ2] Addition of AcceptorSubstituted Cyclopropylmethylsilanes
with Aryl Acetylenes
Automated Synthesis
M. Schutkowski,* U. Reimer, S. Panse,
L. Dong, J. M. Lizcano, D. R. Alessi,
J. Schneider-Mergener*
2671 – 2674
High-Content Peptide Microarrays for
Deciphering Kinase Specificity and
Natural Product Synthesis
Microwave-induced magic: There is a
widely held conviction that the antiviral
marine alkaloid ageliferin 1 arises biosynthetically from a Diels–Alder reaction
which, although possible, has yet to
materialize in the laboratory. A total synthesis of 1 from sceptrin is now reported
that has led to a new hypothesis for how 1
and other dimeric pyrrole-imidazole alkaloids might be formed in nature.
P. S. Baran,* D. P. O’Malley,
A. L. Zografos
2674 – 2677
Sceptrin as a Potential Biosynthetic Precursor to Complex Pyrrole–Imidazole
Alkaloids: The Total Synthesis of
Golden balls! Relativistic quantum chemical theory suggests the existence of an
interesting and surprising gold cluster.
The all-gold fullerene Au32 (see picture) is
structurally very similar to the familiar
buckminsterfullerene C60, as it is approximately the same size and hollow. Au32 is
stabilized by relativistic effects and
spherical aromaticity; the magnetic
shielding at the center of the fullerene has
the highest predicted value.
Angew. Chem. Int. Ed. 2004, 43, 2588 – 2594
2669 – 2671
Gold Fullerenes
M. P. Johansson,* D. Sundholm,
J. Vaara
2678 – 2681
Au32 : A 24-Carat Golden Fullerene
2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Intramolecular Cyclization
N. Bremeyer, S. C. Smith, S. V. Ley,
M. J. Gaunt*
2681 – 2684
An Intramolecular Organocatalytic
Cyclopropanation Reaction
Nucleophilic tertiary amines catalyze an
intramolecular cyclopropanation reaction
to give [n.1.0]bicycloalkanes in good yield
(see scheme). The reaction is tolerant of a
wide range of functional groups and is
highly diastereoselective. Furthermore,
Crystal Engineering
Wall decoration: Coordinatively unsaturated metal centers (CuII, CoII, and NiII)
can be embedded in the pore wall of a
microporous coordination polymer containing Schiff base type metalloligands
[M(salphdc)]2 (H4salphdc = N,N’-o-phenylenebis(salicylideneimine-5,5’-dicarboxylic acid)). These coordination polymers
possess large 1D channels with dimensions of approximately 14 S 14 @2 (see
R. Kitaura, G. Onoyama, H. Sakamoto,
R. Matsuda, S.-i. Noro,
S. Kitagawa*
2684 – 2687
Immobilization of a Metallo Schiff Base
into a Microporous Coordination Polymer
Helical Structures
N. E. Shepherd, G. Abbenante,
D. P. Fairlie*
2687 – 2690
Consecutive Cyclic Pentapeptide Modules
Form Short a-Helices that are Very Stable
to Water and Denaturants
Supramolecular Chemistry
Y. Liu,* H. Wang, P. Liang,
H.-Y. Zhang
2690 – 2694
Water-Soluble Supramolecular Fullerene
Assembly Mediated by Metallobridged
when a catalytic amount of a chiral
cinchona alkaloid derivative is used the
reaction produces cyclopropanes with
enantiomeric excess of 94 %. EWG =
electron withdrawing group.
A generic approach to mimicking a-helices has been achieved by using sequences
of consecutive macrocyclic pentapeptides
(for example, cyclo(1!5)-Ac-[KARAD]nNH2) to form 3-turn (see picture) and 4turn a-helices, which have high conformational stability in water and are resistant to protein-denaturing conditions
(65 8C, 8 m guanidine·HCl, trypsin digestion).
A coordinated metal center aids water
solubility of a supramolecular fullerene
assembly. Two cyclodextrins rings are
bridged back-to-back in one unit, and
these units form an end-to-end intermolecular inclusion complex with fullerene to
produce an intermolecular polyfullerene
(see picture). Under the right conditions
the assembly acts as an efficient photodriven DNA-cleavage reagent.
2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2004, 43, 2588 – 2594
Structure Elucidation
Blink and you will miss it! The structure of
carbasalatum calcicum (CC) has been
determined by synchrotron powder diffractometry. By scrutinizing crystal dissolution and nucleation, it was found that
the degradation of CC in water involves
acetylsalicylatum calcicum (AC) as a furtive species that quickly exchanges its
acetylsalicylic acid (ASA) ligands with
water (see scheme). The crystal structure
of AC is also reported.
Dissolution of nanosized crystallites may
be inhibited and even suppressed due to
their small size. Nanoparticles with size
distribution similar to that of critical
dissolution pits (see picture) can be
kinetically stabilized against further dissolution even in undersaturated solutions. In biological systems, this behavior
confers remarkable self-preservation on
biominerals in the fluctuating milieu.
Direct Evidence for a Furtive State in the
Degradation of Carbasalatum Calcicum
R. Tang, L. Wang, C. A. Orme, T. Bonstein,
P. J. Bush, G. H. Nancollas* 2697 – 2701
Dissolution at the Nanoscale:
Self-Preservation of Biominerals
Hybrid Materials
Amphiphilic pore walls facilitate reversible
sorption of short-chain alcohols by the 1D
microporous organic–inorganic hybrid
[1-Na]3[PW12O40] assembled from calix[4]arene–Na+ complex 1-Na+ (R1 = R2 = H)
and the polyoxotungstate anion
[PW12O40]3. The analogous assembly
formed with 2-Na+ (R1 = tBu,
R2 = CH2CO2Et) has a 3D microporous
Y. Ishii, Y. Takenaka,
K. Konishi*
2702 – 2705
Porous Organic–Inorganic Assemblies
Constructed from Keggin Polyoxometalate
Anions and Calix[4]arene–Na+
Complexes: Structures and
Guest-Sorption Profiles
Electron Diffraction
A formidable contender to X-ray diffraction is ultrafast electron crystallography.
Whereas the former is more suited to
investigate the bulk of the substrate, the
time, length, and sensitivity scales of
electron crystallography provide powerful
and complementary information on
atomic-scale structural dynamics at the
surface (see diffraction image of GaAs
Angew. Chem. Int. Ed. 2004, 43, 2588 – 2594
P. Ochsenbein,* M. Bonin, O. Masson,
D. Loyaux, G. Chapuis,
K. J. Schenk
2694 – 2697
F. Vigliotti, S. Chen, C.-Y. Ruan,
V. A. Lobastov,
A. H. Zewail*
2705 – 2709
Ultrafast Electron Crystallography of
Surface Structural Dynamics with
Atomic-Scale Resolution
2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Fluorescent Probes
R. Reents, M. Wagner, J. Kuhlmann,*
H. Waldmann*
2711 – 2714
Synthesis and Application of
Fluorescence-Labeled Ras-Proteins for
Live-Cell Imaging
Stereoselective Polymerization
S. Harder*
2714 – 2718
The Chemistry of CaII and YbII :
Astoundingly Similar But Not Equal!
Seeing is believing! Semisynthetic Rasproteins with a fluorophore introduced at
an appropriate site have been developed
as probes for live-cell imaging experiments. They are processed by the cellular
machinery, and their intracellular location
can then be determined by confocal laser
fluorescence microscopy.
Not a red/green stereographic, but a plot
showing the striking similarity between a
Ca and Yb complex. The molecular structures, and the NMR and IR spectra of
these Ca/Yb benzyl complexes are nearly
identical. However, their reactivity in styrene polymerization is completely different: an internally coordinated dibenzylytterbium(ii) complex produces polystyrene
of high syndiotacticity (r = 94.9 %,
rr = 90.0 %).
Electron Density Studies
The transfer of multipole parameters from
theoretically calculated pseudoatoms
(invarioms) allows the derivation of nonspherical electron densities and related
properties even from low-resolution X-ray
data, the electrostatic potential of
tri(l-valine) is obtained in this way (see
B. Dittrich,* T. KoritsVnszky,
P. Luger
2718 – 2721
A Simple Approach to Nonspherical
Electron Densities by Using Invarioms
Communications labeled with this symbol have been judged by two referees as being “very important papers”.
2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
A33, 2726
Angew. Chem. Int. Ed. 2004, 43, 2588 – 2594
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abstract, int, angel, 202004, chem, graphical
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