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Graphical Abstract Angew. Chem. Int. Ed. 62003

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Contents
News
Simulations: Max Planck Award to
van Gunsteren
600
Asymmetric Synthesis: Kagan Receives
Noyori Prize
600
Chemistry in Europe: B‰ckvall Leads
the Way
600
James Clark and Duncan Macquarrie
Reviewed by: J¸rgen O. Metzger
Books
Handbook of Green Chemistry and
Technology
601 ± 602
Highlights
O
Caffeine
S. R. Waldvogel*
H 3C
604 ± 605
O
Caffeine–A Drug with a Surprise
N
CH3
N
N
N
CH3
1
Over 180 years after its isolation caffeine
(1) still has some surprises in store: As a
repellent for snails and slugs, as a stimulating agent with a molecular mode of
action, for enhancing performance, its
habituation, and as an artificial receptor.
Keywords:
alkaloids ¥ heterocycles ¥ natural products ¥
reaction mechanisms
Coded Amino Acid No. 22
C. Fenske, G. J. Palm,
W. Hinrichs*
Sometimes, less is more. The genetic
code seems to be reduced and was
probably optimized during evolution. This
idea is supported by the newly discovered
amino acid pyrrolysine (see scheme,
X = Me, NH2, OH) as an essential side
chain in the active site of a methyl transferase in Archaea. The chemical and
structural properties of pyrrolysine, which
is directly encoded by redefining a stop
codon, are discussed with regard to the
™universality∫ of the genetic code.
606 ± 610
How Unique Is the Genetic Code?
Keywords:
amino acids ¥ enzymes ¥ genetic code ¥
pyrrolysine ¥ RNA
Correspondence
Duality Principle and Chirality
A. Rassat*
611 ± 613
Application of the Duality Principle to
Chiral Icosahedral Metal Complexes
Keywords:
cage compounds ¥ chirality ¥ duality ¥
symmetry
592
By application of the duality principle, the
type of chirality recently reported in icosahedral barium, strontium, or lanthanum
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complexes can be found in a tetrafluorododecahedrane of the same T symmetry
(see scheme).
Angew. Chem. Int. Ed. 2003, 42, No. 6
Angewandte
Chemie
Reviews
Biomineralization
E. B‰uerlein*
614 ± 641
Biomineralization of Unicellular Organisms: An Unusual Membrane Biochemistry for the Production of Inorganic Nanoand Microstructures
Long seen as difficult to determine, the
mechanisms of the biomineralization of
species-specific nanostructures of magnetic bacteria, calcareous algae (a), and
diatoms (b) are now within reach. Modern
methods in molecular biology have in the
last few years provided much insight into
these biomineralization processes.
Keywords:
biomineralization ¥ magnetosomes ¥
unicellular organisms ¥ vesicles
Communications
Despite the presence of 55 nonequivalent
atoms the structure of the layered nickel
succinate [Ni7(C4H4O4)4(OH)6(H2O)3]¥7 H2O was solved by ab initio methods
from powder-diffraction data. The structure contains unprecedented Ni6 units
(blue in the picture) linked by further Nicentered octahedra (green) and succinate
ions (yellow).
Microporous Nickel Succinate
N. Guillou,* C. Livage, W. van Beek,
M. Noguõs, G. Fÿrey
644 ± 647
A Layered Nickel Succinate with Unprecedented Hexanickel Units: Structure
Elucidation from Powder-Diffraction Data,
and Magnetic and Sorption Properties
Keywords:
carboxylate ligands ¥ hydrothermal
synthesis ¥ magnetic properties ¥
microporous materials ¥ nickel ¥ X-ray
powder diffraction
Colorimetric Isomer Probes
F. SancenÛn, R. MartÌnez-MµÊez,*
M. A. Miranda, M.-J. SeguÌ,
J. Soto
647 ± 650
Discrimination of isomeric anions: The
selective, shape-controlled colorimetric
sensing of dicarboxylate ions has been
achieved and represents a development in
the ™naked-eye∫ detection of certain organic isomers. The photograph shows the
diverse colors of solutions of a 1,3,5triarylpent-2-en-1,5-dione in dioxane/water solution (70:30 v/v) at approximately
pH 6, in the presence of either maleate (cis
isomer, magenta) or fumarate (trans isomer, yellow) ions.
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ANGEWANDTE CHEMIE International
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(valid for print or electronic/print and electronic
Angew. Chem. Int. Ed. 2003, 42, 592 ± 598
¹ 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Towards the Development of Colorimetric
Probes to Discriminate between Isomeric
Dicarboxylates
Keywords:
carboxylate ligands ¥ hydrogen bonding ¥
ion±molecule reactions ¥ receptors ¥
sensors
delivery); for individuals who are personal
members of a national chemical society, or
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are retired or self-employed consultants, print
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1433-7851/03/4206-0593 $ 20.00+.50/0
593
Contents
Porphyrin-Containing [3]Rotaxanes
R. G. E. Coumans, J. A. A. W. Elemans,
P. Thordarson, R. J. M. Nolte,
A. E. Rowan*
650 ± 654
Synthesis of Porphyrin-Containing
[3]Rotaxanes by Olefin Metathesis
Keywords:
host±guest systems ¥ metathesis ¥
porphyrinoids ¥ ring-opening
polymerization ¥ rotaxanes
A ruthenium-carbene-stoppered [2]rotaxane acts an intermediate in the synthesis
of porphyrin-containing [3]rotaxanes by an
olefin-metathesis protocol. The thread of
these [3]rotaxanes can be extended to a
polybutadiene strand by using them as
chain-transfer agents in the ring-openingmetathesis polymerization of cyclooctadiene to give macromolecular porphyrin
rotaxanes (see picture).
Crown-Shaped Ln Polyoxometalates
K. Fukaya, T. Yamase*
654 ± 658
Eu
As
Alkali-Metal-Controlled Self-Assembly of
Crown-Shaped Ring Complexes of
Lanthanide/[a-AsW9O33]9 : [K{Eu(H2O)2(a-AsW9O33)}6]35 and [Cs{Eu(H2O)2(a-AsW9O33)}4]23
Keywords:
host±guest systems ¥ lanthanides ¥
polyoxometalates ¥ self-assembly ¥
tungsten
Conducting Polymers
H. Meng, D. F. Perepichka,
F. Wudl*
658 ± 661
Facile Solid-State Synthesis of Highly
Conducting Poly(ethylenedioxythiophene)
Keywords:
CC coupling ¥ conducting materials ¥
polymerization ¥ polythiophenes ¥ solidstate reactions
594
W
K
Cs
Crowning glory: The L-shaped
[Ln(H2O)2(a-AsW9O33)]6 (Ln = lanthanide) building unit provides an elegant
approach to develop crown-shaped structures of [{Ln(H2O)2(a-AsW9O33)}n]6n
(n = even number of 4) which can
encapsulate a cation. The watermill-propeller structure, left, is a K+ ion encapsulated by six [a-AsW9O33]9 ligands, whereas the windmill structure, right, is a Cs+
ion encapsulated by four [a-AsW9O33]9
ligands.
Gentle heating of crystalline 2,5-dibromo3,4-ethylenedioxythiophene affords a
highly conducting, bromine-doped
poly(3,4-ethylenedioxythiophene)
(PEDOT). The conductivity of the polymer
can be further increased by doping with
iodine. By using this approach, thin films
of PEDOT with a conductivity as high as
20 S cm1 can be easily fabricated on
insulating plastic surfaces (see picture).
¹ 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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Angew. Chem. Int. Ed. 2003, 42, No. 6
Angewandte
Chemie
Asymmetric Michael Addition
N. Halland, P. S. Aburel,
K. A. J˘rgensen*
661 ± 665
Highly Enantioselective Organocatalytic
Conjugate Addition of Malonates to Acyclic a,b-Unsaturated Enones
An imidazolidine easily prepared from
phenylalanine is the catalyst for the highly
enantioselective Michael addition shown.
A great diversity of a,b-unsaturated
enones was transformed with excellent
enantioselectivities. The scope of the
reaction is further demonstrated by the
synthesis of two optically active compounds, a d-ketoester and a tetrahydroquinoline (see scheme).
Keywords:
asymmetric catalysis ¥ enones ¥
ketoesters ¥ malonates ¥
tetrahydroquinolines
Structural Memory Reporters
M. Ziegler, A. V. Davis, D. W. Johnson,
K. N. Raymond*
665 ± 668
Supramolecular Chirality: A Reporter of
Structural Memory
Non-tetrahedron-forming L2 ligands insert
into a resolved DDDD-[Ga4L16]12 tetrahedral assembly of labile metal and ligand
components without compromising its
supramolecular structure (see scheme).
Preservation of the chirality of the initial
architecture verifies its structural memory.
Keywords:
chiral memory ¥ circular dichroism ¥
self-assembly ¥ structural memory ¥
supramolecular chemistry
Fluctuating Skeletal Bonds
Y. Sahin, C. Pr‰sang, P. Amseis,
M. Hofmann, G. Geiseler, W. Massa,
A. Berndt*
669 ± 671
A distorted triboratetrahedrane anion, 2,
is proposed as the transition state of the
fluctuation of the skeletal bonds of triboracyclobutanide 1, a two-electron aro-
Angew. Chem. Int. Ed. 2003, 42, 592 ± 598
matic compound, B3LYP/6-31G* computations support this suggestion
(R = SiMe3, Dur = 2,3,5,6-tetramethylphenyl).
¹ 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Triboracyclobutanides: Four-Membered
Two-Electron Aromatic Compounds with
Fluctuating Skeletal Bonds
Keywords:
boron ¥ density functional calculations ¥
enantiomerization ¥ ring inversion ¥ small
ring systems
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595
Contents
Boron-Containing Rings
Y. Sahin, C. Pr‰sang, M. Hofmann,
G. Subramanian, G. Geiseler, W. Massa,
A. Berndt*
671 ± 674
A Diboracyclopropane with a PlanarTetracoordinate Carbon Atom and a
Triborabicyclobutane
Keywords:
anti-van©t-Hoff/Le Bel compounds ¥
boron ¥ density functional calculations ¥
multicenter bonds ¥ small ring systems
Four-coordinate in a three-membered ring
and thereby planar: The chemical shift of
the skeletal carbon atom of 1, which was
generated and spectroscopically characterized at 90 8C, agrees very well with
that computed for the model 2, but differs
by 70 ppm from that of the similarly
substituted, but distorted-tetrahedral carbon atom in 3. R = SiMe3, Dur = 2,3,5,6tetramethylphenyl.
Getting the message across: Strong electronic coupling over a distance of 1.3 nm
is observed for the RuIV;III
state of the
2
complex 1n (n = + ). The fully delocalized
system 1+ is distinguished by an extremely intense intervalence chargetransfer (IVCT) band and a single intense
vibrational band.
Long-Range Electronic Coupling
Y. Hoshino,* S. Higuchi, J. Fiedler, C.-Y. Su,
A. Knˆdler, B. Schwederski, B. Sarkar,
H. Hartmann, W. Kaim*
674 ± 677
Long-Range Electronic Coupling in Various Oxidation States of a C4-Linked Tris(bdiketonato)ruthenium Dimer
Keywords:
alkynyl ligands ¥ mixed-valent compounds ¥
ruthenium ¥ spectroelectrochemistry
Peptides Composed of d-Amino Acids
The chemoenzymatic synthesis of all-dpolypeptides such as the all-d version of
the WW domain of hPin1 (1) was achieved
by applying the substrate mimetics strategy and clostripain as the biocatalyst.
Ironically all-d-peptides are better synthesis targets for proteases than their all-l
analogues, although nature designed
these enzymes for the cleavage of all-lpeptides.
N. Wehofsky, S. Thust, J. Burmeister,
S. Klussmann, F. Bordusa*
677 ± 679
all-d-Polypeptides: Novel Targets for
Semisynthesis
Keywords:
clostripain ¥ peptides ¥ proteases ¥
semisynthesis ¥ substrate mimetics
596
¹ 2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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Angew. Chem. Int. Ed. 2003, 42, No. 6
Angewandte
Chemie
Electron Transfer in Rotaxanes
N. Watanabe, N. Kihara, Y. Furusho,
T. Takata,* Y. Araki, O. Ito*
681 ± 683
Photoinduced Intrarotaxane Electron
Transfer between Zinc Porphyrin and
[60]Fullerene in Benzonitrile
A through-space superexchange mechanism appears to be responsible for charge
recombination (CR) following photoexcitation and charge separation (CS) in
rotaxanes containing zinc porphyrin and
C60 moieties (see picture), as suggested
by the low activation energy of this
process. Furthermore, the charge-separated state is relatively long-lived.
Keywords:
charge transfer ¥ fluorescence ¥ fullerenes ¥
porphyrinoids ¥ rotaxanes
New Form of Isomerism
A. Shivanyuk, J. Rebek, Jr.*
684 ± 686
Isomeric Constellations of Encapsulation
Complexes Store Information on the
Nanometer Scale
The limited mobilities of two different
guests present during the self-assembly of
a cylindrical capsule give rise to a new
form of isomerism (see scheme).
A [3þ3] modular self-assembly gives rise
to the formation of a molecular bowl or
crown with syn,syn,syn conformation (see
picture). These structures are analogues
of calix[3]arenes and can function as anion
receptors. Interestingly, an NO3 ion is
found to distort from a trigonal plane into
a trigonal pyramid when binding to the
bottom of the molecular bowl.
Keywords:
data storage ¥ encapsulation ¥ isomerism ¥
nanostructures ¥ self-assembly
Modular-Assembled Bowls and Crowns
S.-Y. Yu,* H. Huang, H.-B. Liu, Z.-N. Chen,
R. Zhang, M. Fujita
686 ± 690
Modular Cavity-Tunable Self-Assembly of
Molecular Bowls and Crowns as Structural
Analogues of Calix[3]arenes
Keywords:
metallacycles ¥ palladium ¥ platinum ¥ selfassembly ¥ supramolecular chemistry
Angew. Chem. Int. Ed. 2003, 42, 592 ± 598
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597
Contents
Supported Gold Catalysts
J. Guzman, B. C. Gates*
690 ± 693
Structure and Reactivity of a Mononuclear
Gold-Complex Catalyst Supported on
Magnesium Oxide
Keywords:
cluster compounds ¥ EXAFS spectroscopy ¥
gold ¥ hydrogenation ¥ supported catalysts
A golden age of catalysis? A structural
model of a MgO-supported complex
[AuIII(CH3)2{OMg}2] (where the MgO ligands are part of the MgO support) has
been established based on distances and
coordination numbers determined by
EXAFS spectroscopy (see picture). This
compound is the precursor of a mononuclear gold complex that catalyzes
ethene hydrogenation. For comparison, a
family of supported gold clusters was also
prepared.
Spiro Alkaloids
Me
Me
C. Meyers, E. M. Carreira*
O
O
694 ± 696
HN
Total Synthesis of ()-Spirotryprostatin B
N
H
1
O
N
O
N
HN
N
N
H
O
Me
2
TIPS
Me
TIPS
3
spirotryprostatin B (4)
Keywords:
alkaloids ¥ Julia±Kociensky reaction ¥ ring
expansion ¥ spiro compounds ¥ total
synthesis
Rapid assembly of the backbone of spirotryprostatin B (4) was achieved by employing a MgI2-catalyzed ring-expansion
reaction of spiro[cyclopropane-1,3’-oxindole] 1 and alkynyl imine 2 to yield
advanced intermediate 3. Introduction of
Communications labeled with
this symbol have been judged
by two referees as being ™very
important papers∫.
the prenyl side chain was accomplished by
aldehyde olefination through a Julia±
Kociensky reaction, a transformation that
greatly facilitates late-stage derivatization
for biological studies. TIPS = triisopropylsilyl.
The publication of
Communications labeled with
this symbol has been
accelerated because of their
topical or highly competitive
nature.
Supporting information for
articles labeled with this symbol
can be found at
www.angewandte.org or
www.interscience.wiley.com.
The issues for January 2003 appeared online on the following dates:
Issue 1: January 14. ¥ Issue 2: January 16. ¥ Issue 3: January 20. ¥ Issue 4: January 28
Service
598
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Keywords
698
Authors
699
Preview
701
Events
702
Angew. Chem. Int. Ed. 2003, 42, No. 6
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