close

Вход

Забыли?

вход по аккаунту

?

Graphical Abstract Angew. Chem. Int. Ed. 142003

код для вставкиСкачать
Contents
News
Polymerization Catalysis:
S. Mecking honored
1562
Gas-phase Chemistry:
H. Schwarz recognized
1563
James P. Collman
reviewed by D. Lenoir
Mike Sargent, Chris Harrington,
Rita Harte
reviewed by K. G. Heumann
1562
Polymers: Staudinger Prize to
W. Kaminsky
1562
Books
Naturally Dangerous
Guidelines for Achieving High
Accuracy in Isotope Dilution Mass
Spectrometry
1564
Highlights
R
Advances in Sonogashira Reactions
R. R. Tykwinski*
X
1566 – 1568
Evolution in the Palladium-Catalyzed
Cross-Coupling of sp- and sp2-Hybridized
Carbon Atoms
Pd catalyst, CuI
solvent, base,
H–C≡C–R'
R
R'
X = Cl, Br, I, OTf
Palladium-catalyzed bond-formation
between alkynes and aryl halides and
triflates is as fascinating today as it was
nearly 30 years ago when such reactions
were introduced by Sonogashira (see
scheme; OTf = CF3SO3). More facile procedures, new acetylide coupling partners,
and more efficient catalysts and ligand
systems all combine to expand the limits
of this versatile reaction.
Molecular dynamics “on-the-fly” gives
new insights in chemical reactivity on very
short time scales. The pictures resulting
from the simulations offer a precise and
comprehensive view of chemical reactions
in three-dimensional space. Processes
such as the reaction between formaldehyde and two hydroxyl radicals shown
here, as well as very complex reaction
pathways, can be determined in this way.
The macrolamellar structure observed in
some highly ordered mesoporous materials (see left image: scale bar = 2 mm) has
been suggested by Professor Su et al. to
occur as a result of the ultramicrotoming
process. Further evidence is now put
forward by Professor Xu that attempts to
show that such structural characteristics
are, in fact, inherent to the ZSU-L material
(see right image: scale bar = 1.5 mm).
Molecular Dynamics Simulations
I. Frank*
1569 – 1571
Chemical Reactions “On the Fly”
Correspondence
Macrolamellar Structure?
Z.-Y. Yuan, M.-F. Six-Boulanger,
B.-L. Su*
1572 – 1573
Do Mesostructured Materials Have an
Unusual Macrolamellar Structure?
Microlamellar Structure?
A.-W. Xu*
1574 – 1575
Additional Proof for the Existence of
Microlamellar Structured ZSU-L
Templated from Silicone Surfactants
1554
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
Angew. Chem. Int. Ed. 2003, 42, 1554 – 1559
Angewandte
Chemie
Reviews
Organophosphorus Compounds
The great pretender: Phosphorus mimics
quite closely the chemistry of carbon in its
low coordination states (that is, one and
two). The picture illustrates some of the
molecules which highlight this analogy:
clockwise from the top: phosphaacetylene, phosphirane, phosphinine, the transient phosphinidene complex [HPW(CO)5], phosphaferrocene, phosphole,
and phosphaethene.
F. Mathey*
1578 – 1604
Phospha-Organic Chemistry:
Panorama and Perspectives
Communications
Long-Lived Luminescence
R. Passalacqua, F. Loiseau, S. Campagna,*
Y.-Q. Fang, G. S. Hanan*
1608 – 1611
Time trials: A ruthenium(ii) complex
based on tridentate polypyridine ligands
(see picture) featuring the longest luminescence lifetime (1.8 ms) ever reported is
described. This new species has been
obtained by applying the multichromo-
phore approach, in which the various
metal- and organic-based chromophores
are only weakly interacting, so that their
individual properties are essentially
maintained.
Inside knowledge: UV/Vis (absorption
spectrum depicted) and Raman data
reveal the stabilization of the trans-keto
tautomer of 2-(2-hydroxyphenyl)benzothiazole (HBT) inside the nanosized FAU
zeolite. The trans-keto tautomer exhibits
highly intensive fluorescence in the zeolite, as compared to the cis-keto tautomer,
which is formed in solution during the
excited-state intramolecular proton-transfer (ESIPT) process.
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 Meacham Ave., Elmont, NY 11003. Periodicals
Angew. Chem. Int. Ed. 2003, 42, 1554 – 1559
postage paid at Jamaica NY 11431. US POSTMASTER: send address changes to Angewandte
Chemie, Wiley-VCH, 111 River Street, Hoboken,
NJ 07030. Annual institutional subscription
price for institutions: Europe E 2998.00/
3148.00. Outside Europe US$ 3718.00/3904.00
(valid for print or electronic/print and electronic
www.angewandte.org
In Search of Ruthenium(ii) Complexes
Based on Tridentate Polypyridine Ligands
that Feature Long-lived Room-Temperature Luminescence: The Multichromophore Approach
Nanostructured Functional Materials
S. Mintova,* V. De Waele,
U. Schmidhammer, E. Riedle,*
T. Bein*
1611 – 1614
In Situ Incorporation of
2-(2-Hydroxyphenyl)benzothiazole within
FAU Colloidal Crystals
delivery); for individuals who are personal
members of a national chemical society, or
whose institution already subscribes, or who
are retired or self-employed consultants, print
only (including postage and handling charges):
Europe E 248.00/Outside Europe US$ 348.00.
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1555
Contents
Mixed-Valent Spin-Crossover System
Y. Sunatsuki, Y. Ikuta, N. Matsumoto,*
H. Ohta, M. Kojima, S. Iijima,
S. Hayami, Y. Maeda, S. Kaizaki,
F. Dahan, J.-P. Tuchagues
1614 – 1618
An Unprecedented Homochiral
Mixed-Valence Spin-Crossover
Compound
Spin doctoring: [FeIIH3L][FeIIIL](NO3)2,
where H3L is a hexadentate tripod ligand
bearing three imidazole groups, is formed
in a one-pot assembly reaction, and is
shown to be a homochiral mixed-valence
spin-crossover compound. The structure
consists of a 2D assembled sheet that is
held together by imidazole–imidazolate
hydrogen bonds between [FeIIH3L]2+ and
[FeIIIL] units (see picture). At least three
electronic states can be accessed by
temperature effects and photoirradiation.
Nanoparticle-Coated Electrodes
The hard cell! There have been numerous
reports highlighting the questionable
safety of lithium secondary batteries, an
example of which is shown here, where
exothermic reactions of LiCoO2 electrodes
have considerable fire and explosion
potential. The coating of such electrodes
with a layer of AlPO4 nanoparticles is
shown to reduce these risks significantly,
even where a short circuit of the cell was
observed.
J. Cho,* Y.-W. Kim, B. Kim, J.-G. Lee,
B. Park*
1618 – 1621
A Breakthrough in the Safety of Lithium
Secondary Batteries by Coating the
Cathode Material with AlPO4
Nanoparticles
Carbon Nanorings
T. Kawase,* Y. Seirai, H. R. Darabi,
M. Oda,* Y. Sarakai,
K. Tashiro*
1621 – 1624
All-Hydrocarbon Inclusion Complexes of
Carbon Nanorings: Cyclic [6]- and
[8]Paraphenyleneacetylenes
Ringing the changes: The belt-shaped
p-conjugated [6]- and [8]paraphenyleneacetylenes exhibit nanosized cavities
(see picture), and act as host molecules in
crystalline inclusion complexes with
hexamethylbenzene and toluene, respectively. The concave side of the cavities
appears to possess a negative electronic
potential.
Nanoring–Fullerene Complexes
T. Kawase,* K. Tanaka, N. Fujiwara,
H. R. Darabi, M. Oda*
1624 – 1628
Complexation of a Carbon Nanoring with
Fullerenes
Unusually stable complexes are formed
between [6]paraphenyleneacetylene
([6]CPPA, see picture) and fullerenes
(either C60 or bis(ethoxycarbonyl)methanofullerene). Crystallographic analysis
1556
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
reveals that a major driving force for the
formation of such complexes is the
existence of a novel concave–convex
p–p interaction (see structure).
Angew. Chem. Int. Ed. 2003, 42, 1554 – 1559
Angewandte
Chemie
~ ~
F
F
Weak Interactions in Polymerization
D
H/X
F
H
H
M
[Zr]
R/H
S. C. F. Kui, N. Zhu,
M. C. W. Chan*
P
H
H
weak so that the chain-propagation process is not perturbed, and “controversial”
hydrogen bonds with strong dispersive
character, such as CH···FC, are therefore
ideal in this role (see scheme).
Attracting attention! The existence of
attractive interactions between a functionalized ancillary ligand and a growing
alkyl chain is a highly novel concept in
olefin polymerization reactions (see
scheme). Such interactions must be very
1628 – 1632
Observation of Intramolecular CH···FC
Contacts in Non-Metallocene Polyolefin
Catalysts: Model for Weak Attractive
Interactions between Polymer Chain and
Noninnocent Ligand
C-H Bond Activation
S. NPckel, P. Burger*
low activation barrier is analyzed and
traced by DFT methods which provide
guidelines for the design of novel
systems, which would allow the activation
of methane under mild conditions.
Teaching an old dog a new trick: A novel
square-planar iridium(i) system undergoes facile thermal intermolecular CH
activation process at ambient temperature (see scheme). The observed unusual
F2
F2
F2
F2
F2
UV
Me
S Me
O
H
(P)-1a
S
S Me
Vis
O
H
O
H
*
S. Yamamoto, K. Matsuda,
M. Irie*
S
(R,R)-1b
O
Chirality from the crystal lattice: The
achiral diarylethene 1 a crystallizes in a
monoclinic chiral space group, that is, two
different kinds of crystals, (M)-1 a and
(P)-1 a, are obtained. Photoirradiation of
(P)-1 a furnished optically pure closed-ring
isomer (R,R)-1 b in the single crystal (see
scheme). The photochemical cycles can
be repeated by alternating UV and visible
photoirradiation.
Reversed Si¼C bond polarity is displayed
by the first isolable 2-silenolate.
[(TMS)2SiC(O)tBu]K+, which is thermally
stable at room temperature and structur-
ally characterized by X-ray crystallography,
contains a C¼O double bond and a SiC
single bond with a strongly pyramidal Si
center. These results in combination with
NMR spectroscopic and atomic-charge
data indicate that resonance structure II
domincates the electronic structure.
TMS = trimethylsilyl.
www.angewandte.org
1636 – 1639
Absolute Asymmetric Photocyclization of
a Photochromic Diarylethene Derivative in
Single Crystals
H
ee > 95%
Angew. Chem. Int. Ed. 2003, 42, 1554 – 1559
Transition-Metal Complexes with Sterically
Demanding Ligands: Facile Thermal
Intermolecular CH Bond Activation in a
Square-Planar IrI Complex
Photochemistry of Chiral Crystals
F2
Me
*
1632 – 1636
Stable Silenolates
T. Guliashvili, I. El-Sayed, A. Fischer,
H. Ottosson*
1640 – 1642
The First Isolable 2-Silenolate
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1557
Contents
O
Natural-Product Synthesis
O
H
O D
K. I. Booker-Milburn,* P. Hirst,
J. P. H. Charmant,
L. H. J. Taylor
1642 – 1644
A Rapid Stereocontrolled Entry to the
ABCD Tetracyclic Core of Neotuberostemonine
Single-Molecule Magnets on Gold
A. Cornia,* A. C. Fabretti, M. Pacchioni,
L. Zobbi, D. Bonacchi, A. Caneschi,
D. Gatteschi, R. Biagi, U. Del Pennino,
V. De Renzi, L. Gurevich,
H. S. J. Van der Zant
1645 – 1648
Direct Observation of Single-Molecule
Magnets Organized on Gold Surfaces
H
H
C
H H
A
N
H
H
B
1
O
H
O
O
H
E
O
H
O
H
CO2H
H
N
H
O
O
H
O
HH
H
O
O
O
2
Four out of the five rings of the alkaloid
neotuberostemonine (1) are present in
the advanced precursor 2. The tetracyclic
compound 2 has now been prepared in a
H
3
4
short, linear route via lactone acid 3. A key
step in the synthesis was the cupratemediated SN2’ ring-opening desymmetrization of the C2-symmetric bislactone 4.
Scanning tunneling microscopy can be
utilized to individually probe single-molecule magnets that have been deposited on
gold substrates (see schematic). Dilute
solutions (in THF/H2O/NH4OH) of a
dodecamanganese(iii,iv) cluster surrounded by acetyl-protected thiol groups,
[Mn12O12(L)16(H2O)4], have been used to
prepare Au(111) adsorbates that are a first
step towards ultra-high-density information storage using single-molecule magnets.
Macrolide Total Synthesis
X. Liao, Y. Wu,
J. K. De Brabander*
1648 – 1652
Total Synthesis and Absolute
Configuration of the Novel MicrotubuleStabilizing Agent Peloruside A
A unique configuration-dependent mechanistic switch, observed when epimeric
seco-acids are subjected to typical Mitsunobu lactonization conditions, is just one
of the many unexpected, yet insightful
Cation-Containing Zeolites
Photocatalytic fillings for cavities: A very
simple, yet highly efficient method to
introduce triphenylpyrylium (TPP) ions
into Y-zeolite cavities has been found (see
picture). It consists of simply stirring the
non-activated NaY-zeolite with an aqueous solution of triphenylpyrylium hydrogen sulfate at 40 8C, before drying the
doped support. The FTIR and elemental
analyses of the product (TPP-Y), as well as
the repeated and reproducible photocatalytic reactivity of the TPP-Y confirm the
presence of the TPP+ electron acceptor
inside the cavities of the support.
A. M. Amat,* A. Arques, S. H. Bossmann,
A. M. Braun,* S. GQb,
M. A. Miranda*
1653 – 1655
A “Camel through the Eye of a Needle”:
Direct Introduction of the TPP+ Ion inside
Y-Zeolites by Formal Ion Exchange in
Aqueous Medium
1558
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
surprises of a synthetic adventure culminating in the first enantioselective total
synthesis of the novel microtubule-stabilizing natural product peloruside A (1).
www.angewandte.org
Angew. Chem. Int. Ed. 2003, 42, 1554 – 1559
Angewandte
Chemie
Back to basis: Short DNA duplexes can be
packed with at least four hydrophobic,
not-hydrogen-bonding biphenyl base pairs
in the center of the sequence without
compromising stability. Recognition of
Bph occurrs by interstrand-stacking interactions as illustrated (X = biphenyl or
bipyridyl). This new zipperlike recognition
motif opens exciting possibilities for the
introduction of new function into doublehelical recognition systems based on the
DNA backbone.
DNA Recognition
C. Brotschi, C. J. Leumann* 1655 – 1658
DNA with Hydrophobic Base Substitutes:
A Stable, Zipperlike Recognition Motif
Based On Interstrand-Stacking
Interactions
Kinetics of Photoionization
Sacrificial offerings: N-Methylacridon
(MA) is a catalyst for the production of
hydrated electrons e
aq by a three-photon
process, with the surfactant sodium
dodecylsulfate acting as sacrificial
donor (Dsac ; see scheme).
M. Goez,*
B. H. M. Hussein
1659 – 1661
Generation of Hydrated Electrons by an
Acridone-Sensitized Three-Photon Cycle
Synthesis of Benzonitriles
M. Sundermeier, A. Zapf,
M. Beller*
A useful source of cyanide for the palladium-catalyzed cyanation of aryl halides is
acetone cyanohydrin (see scheme;
dpppe = 1,5-bis(diphenylphosphanyl)pentane, tmeda = N,N,N’,N’-tetramethylethylenediamine). The key to the success of
Communications labeled with
this symbol have been judged
by two referees as being “very
important papers”.
the reaction is the slow dosage of the
cyanation reagent to the reaction mixture
to prevent the deactivation of the
palladium catalyst caused by excess
cyanide ions in solution.
1661 – 1664
A Convenient Procedure for the
Palladium-Catalyzed Cyanation
of Aryl Halides
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.
Service
Angew. Chem. Int. Ed. 2003, 42, 1554 – 1559
www.angewandte.org
Keywords
1666
Authors
1667
Preview
1669
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1559
Документ
Категория
Без категории
Просмотров
0
Размер файла
489 Кб
Теги
abstract, int, angel, chem, 142003, graphical
1/--страниц
Пожаловаться на содержимое документа