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Graphical Abstract Angew. Chem. Int. Ed. 72006

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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:
H. Kiyohara, Y. Nakamura, R. Matsubara, S. Kobayashi*
Catalytic Asymmetric Allylation of Iminoesters and
Iminophosphonates with a Variety of Allylsilanes Leading to
Enantiomerically Enriched Allylglycine Derivatives
J. J. La Clair*
Total Syntheses of Hexacyclinol, 5-epi-Hexacyclinol, and
Desoxohexacyclinol Unveils an Antimalarial Prodrug Motif
H. Katagiri, T. Miyagawa, Y. Furusho,* E. Yashima*
Synthesis and Optical Resolution of a Double Helicate
Consisting of ortho-Linked Hexaphenol Strands Bridged by
Spiroborates
D. Belder,* M. Ludwig, Li-Wen Wang, M. T. Reetz*
Enantioselective Catalysis and Analysis on a Chip
P. Cheung, A. Bhan, G. J. Sunley, E. Iglesia*
Selective Carbonylation of Dimethyl Ether to Methyl Acetate
Catalyzed by Acidic Zeolites
W. Richtering,* I. Berndt, J. S. Pedersen
Temperature-Sensitive Core–Shell Microgel Particles with Dense
Shells
Obituary
George S. Hammond (1921–2005)
N. J. Turro, H. Gray
1018
Books
Modern Physical Organic Chemistry
Eric V. Anslyn, Dennis A. Dougherty
reviewed by C. Schmuck
1019
Posttranslational Modification of Proteins
Christopher T. Walsh
reviewed by A. G. Beck-Sickinger,
K. M rl
1020
Highlights
Bioorganic Chemistry
J. Spencer,* T. R. Walsh*
Plan of attack: b-Lactam antibiotics
remain at the forefront of the battle with
pathogenic bacteria, particularly of Gramnegative strains that cause hospitalacquired infections. Metallo-b-lactamases, enzymes that confer resistance to
almost all b-lactams, are spreading in
these organisms. A new class of irreversible metallo-b-lactamase inhibitor (OPS;
see picture) offers hope for the development of countermeasures to this growing
clinical problem.
1022 – 1026
A New Approach to the Inhibition of
Metallo-b-lactamases
Essays
Philosophy behind Imaging
M. Hampe*
1028 – 1031
Visual Essences, Readable Signs, Means
of Construction: On the Relevance of
Images in Science
1006
Seeing is believing, but images in science
are often based on mathematical and
philosophical presuppositions. Computation and imaging, which once seemed to
be in conflict, have become interconver-
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
tible. It seems that pictures will become
more and more important in science. This
should not lead to new illusions about
supposedly direct insights into the
essence of things.
Angew. Chem. Int. Ed. 2006, 45, 1006 – 1015
Angewandte
Chemie
Reviews
Natural Products Synthesis
Diverse structures and biological activities are shown by polyyne natural products (such as the compounds shown,
isolated fron Anacyclus pyrethrum).
Although some polyynes can be assembled with relative ease, most present a
considerable synthetic challenge because
of either a highly conjugated and unstable
framework or stereochemical considerations. Recent strategies for the synthesis
of these fascinating molecules are
discussed.
A. L. K. Shi Shun,
R. R. Tykwinski*
1034 – 1057
Synthesis of Naturally Occurring Polyynes
Communications
Distance determination: A double electron electron resonance (DEER) measurement of a distance of 6.1 nm (green
lines) between singly nitroxide-labeled
human von Willebrand Factor A domains
demonstrates oligomerization of this
domain in dilute solution (see structure);
probably in an arrangement similar to that
observed in the crystal structure. The
DEER technique should be generally
applicable for characterizing noncovalent
interactions between macromolecules in
solution.
EPR Spectroscopy
J. E. Banham, C. R. Timmel,
R. J. M. Abbott, S. M. Lea,
G. Jeschke*
1058 – 1061
The Characterization of Weak Protein–
Protein Interactions: Evidence from DEER
for the Trimerization of a von Willebrand
Factor A Domain in Solution
Coal Liquefaction
M. W. Haenel,* J. Narangerel,
U.-B. Richter, A. Rufińska
1061 – 1066
In view of escalating oil prices, new
processes are needed for the conversion
of coal to liquid fuels. The first “real” coal
hydrogenation in the sense of hydrogen
addition to unsaturated C C bonds
enables the liquefaction of high-rank
bituminous coals, which up to now could
be processed only by combustion or
gasification.
The First Liquefaction of High-Rank
Bituminous Coals by Preceding
Hydrogenation with Homogeneous
Borane or Iodine Catalysts
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Angew. Chem. Int. Ed. 2006, 45, 1006 – 1015
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
1007
Angewandte
Chemie
Borylene Complexes
Naked boron: Reaction of the bromoborylene complex [(h5-C5Me5)(OC)Fe(m-CO)(m-BBr)Pt(PCy3)Br] with [M(PCy3)2]
(M = Pd, Pt) leads to complexes featuring
the unprecedented coordination of one
boron atom to three transition-metal
centers (see picture). According to structural and DFT studies, the new compounds are best described as metalloborylene complexes stabilized by transition-metal bases.
H. Braunschweig,* K. Radacki, D. Rais,
F. Seeler
1066 – 1069
Boron in the Coordination Spheres of
Three Transition-Metal Atoms: Syntheses
and Structures of Metalloborylenes
Stabilized by a Transition-Metal Base
Inhibitors
Designed inhibitors (like 1) of IspF, a key
enzyme in the non-mevalonate pathway
for terpene biosynthesis and a potential
antimalarial target, were synthesized and
evaluated. Since fluorescent probes were
introduced in these ligands, their affinity
towards IspF from E. coli could be determined by fluorescence titrations. The
binding modes of two ligands in ternary
complexes with IspF and a ZnII ion were
clarified by X-ray analysis.
C. M. Crane, J. Kaiser, N. L. Ramsden,
S. Lauw, F. Rohdich, W. Eisenreich,
W. N. Hunter,* A. Bacher,*
F. Diederich*
1069 – 1074
Fluorescent Inhibitors for IspF, an
Enzyme in the Non-Mevalonate Pathway
for Isoprenoid Biosynthesis and a
Potential Target for Antimalarial Therapy
Partial protolysis of GaCp* with [H(OEt2)2]+[BArF] afforded the GaI compound [Ga2Cp*]+[BArF] (see structure).
Experimental and computational studies
confirm the mainly ionic structure of the
cation, in which the Ga+ ions are only
weakly covalently stabilized by a bridging
Cp* ligand. Initial experiments point to
the interesting synthetic potential of this
compound as a source for Ga+ in solution.
Organogallium Complexes
B. Buchin, C. Gemel, T. Cadenbach,
R. Schmid, R. A. Fischer*
1074 – 1076
The [Ga2(C5Me5)]+ Ion: Bipyramidal
Double-Cone Structure and Weakly
Coordinated, Monovalent Ga+
Photochemical Syntheses
C. M. Kaneshiro,
K. Michael*
1077 – 1081
A Convergent Synthesis of
N-Glycopeptides
Two birds are killed with one stone when
N-glycopeptides are synthesized by condensation of photoreactive peptides with
glycosylamines. Firstly, the aspartic acid
side chain is protected as an amide with a
nitroindoline moiety, which is then con-
Angew. Chem. Int. Ed. 2006, 45, 1006 – 1015
verted into a powerful acylating agent by
UV light. Secondly, photoacylation is carried out under base-free conditions, which
minimizes an undesired side reaction, the
formation of aspartimide.
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
1009
Contents
Core–Shell Particles
I. Berndt, C. Popescu, F.-J. Wortmann,
W. Richtering*
1081 – 1085
Mechanics versus Thermodynamics:
Swelling in Multiple-TemperatureSensitive Core–Shell Microgels
Borane Chemistry
D. Joosten, I. Pantenburg,
L. Wesemann*
1085 – 1087
Distanna-closo-dodecaborate
The thermal transition of a thermoresponsive microgel of poly-N-isopropylacrylamide (PNIPAM; transition temperature = 34 8C) is shifted to higher temperatures when it is embedded in a shell
of temperature-sensitive poly-N-isopropylmethacrylamide (PNIPMAM; transition temperature = 44 8C). The magnitude
of the shift depends on the shell/core
mass ratio. A thick shell induces a third
transition arising from strong mechanical
forces exerted on the core.
Hybrid clusters: Reductive cleavage of a
novel dimeric closo-heteroborate (see picture; Sn blue, B green, H white), which
was characterized by NMR spectroscopy
and X-ray crystallography, provides a route
to 1,2-distanna-closo-dodecaborate.
Enzyme Models
M. Kujime, H. Fujii*
1089 – 1092
Spectroscopic Characterization of
Reaction Intermediates in a Model for
Copper Nitrite Reductase
A nitrous acid complex was identified by
spectroscopic and kinetic analyses under
stopped-flow conditions as an intermediate in the reaction of copper(i) nitrite
complex 1 with trifluoroacetic acid (see
scheme). A reaction mechanism was
proposed in which two protons are transferred in a stepwise manner to the nitrite
anion. Intramolecular electron transfer
from copper to the nitrite ligand occurs in
the second protonation step.
Split and run: A study of the asymmetric
hydrogenolysis of an aryl-carbon–bromine
bond in a naphthalene chromiumtricarbonyl complex shows the use of a new
bulky phosphoramidite ligand to yield the
product in highly enantiomerically enriched form (see scheme).
Asymmetric Synthesis
E. P. KNndig,* P. D. Chaudhuri, D. House,
G. Bernardinelli
1092 – 1095
Catalytic Enantioselective Hydrogenolysis
of [Cr(CO)3(5,8-Dibromonaphthalene)]
1010
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2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2006, 45, 1006 – 1015
Angewandte
Chemie
Actinide Chemistry
Intermediates in theory and experiment:
Different approaches of the density functional theory were used to obtain a close
description of the reaction mechanisms of
the title reactions. They supplied the
minima 1–3 for U+ and 4–6 for U2+. The
theoretical results are compared with
experimental data.
M. d. C. Michelini, N. Russo,*
E. Sicilia
1095 – 1099
How Can Uranium Ions (U+, U2+) Activate
the O H Bond of Water in the Gas Phase?
Splitting the amine! The Ugi four-component reaction (Ugi 4CR) relies on the
presence of a component with a primary
amino group. This protocol has been
modified by “splitting” the primary amine
into two secondary amines. The resulting
variant of the Ugi 4CR proceeds with good
to excellent yield and widens the versatility
of the original multicomponent reaction
by enabling variation of the molecular
backbone.
Contracted out: Quantum mechanical
calculations and classical molecular
dynamics simulations have been used to
Multicomponent Reactions
G. B. Giovenzana,* G. C. Tron,*
S. Di Paola, I. G. Menegotto,
T. Pirali
1099 – 1102
A Mimicry of Primary Amines by
Bis-Secondary Diamines as Components
in the Ugi Four-Component Reaction
investigate the actuation mechanism of a
substituted poly(calix[4]arene quaterthiophene). The results show that electrostatic repulsions between the charged
atoms of the calix[4]arene scaffolds in the
oxidized-deprotonated species induce a
drastic contraction of the electrochemically activated polymer molecules.
Calculations
J. Casanovas,* D. Zanuy,
C. AlemPn*
1103 – 1105
Conducting Polymer Actuator Mechanism
Based on the Conformational Flexibility of
Calix[4]arene
Cyclization
C. Ferrer, A. M. Echavarren* 1105 – 1109
Going for gold: Cationic gold(i) complexes favor formation of six- and sevenmembered rings by 6-endo-dig, 6-exo-dig,
and 7-exo-dig cyclizations of alkynyl
Angew. Chem. Int. Ed. 2006, 45, 1006 – 1015
indoles, whereas indoloazocines are
favored with AuCl3 as catalyst (see
scheme). Allenes are also formed by a
fragmentation process.
Gold-Catalyzed Intramolecular Reaction
of Indoles with Alkynes: Facile Formation
of Eight-Membered Rings and an
Unexpected Allenylation
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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1011
Contents
Cluster Chemistry
R. D. Adams,* B. Captain,
M. D. Smith
Give and take: The compounds
[PtRe2(CO)9(PtBu3)(m-H)2] and
[Pt2Re2(CO)7(PtBu3)2(m-H)2] (1) are
obtained from the reaction of [Pt(PtBu3)2]
with [Re3(CO)12(m-H)3]. Compound 1 adds
hydrogen at 25 8C to yield the tetrahydrido
complex [Pt2Re2(CO)7(PtBu3)2(m-H)4] (2;
see structure, red H, blue Pt, green Re,
silver C, gold O, yellow P). When heated
and also when irradiated, compound 2
eliminates one equivalent of H2 to regenerate 1 in high yield.
1109 – 1112
A Highly Unsaturated Platinum–Rhenium
Cluster Complex Activates Hydrogen
Reversibly
Catalytic Hydrogenation
J. Zhang, G. Leitus, Y. Ben-David,
D. Milstein*
1113 – 1115
Efficient Homogeneous Catalytic
Hydrogenation of Esters to Alcohols
With open arms: A ruthenium PNN complex (see scheme) catalyzes the hydrogenation of esters in high yields under
neutral conditions. The analogous PNP
complex is less active. A mechanism is
Nanostructures
J. Zhang, J. Du, B. Han,* Z. Liu, T. Jiang,
Z. Zhang
1116 – 1119
Sonochemical Formation of SingleCrystalline Gold Nanobelts
Nanoparticles
E. Ye, H. Tan, S. Li,
W. Y. Fan*
1120 – 1123
Self-Organization of Spherical, Core–Shell
Palladium Aggregates by Laser-Induced
and Thermal Decomposition of
[Pd(PPh3)4]
1012
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2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
proposed based on the hemilabile nature
of the PNN ligand which allows a vacant
site to be created by decoordination of the
CH2NEt2 arm.
Benign belts: Single-crystalline gold
nanobelts (see SEM image) can be synthesized by ultrasound irradiation of an
aqueous solution of HAuCl4 containing ad-glucose as a biological directing agent.
The gold nanobelts are typically 30–50 nm
wide and several micrometers long. The
method is simple, rapid, and avoids
hazardous substances.
Metal in the middle: Uniform, spherical,
core–shell aggregates (100 20 nm; see
picture) are obtained by photodecomposition of [Pd(PPh3)4] to form the metal
core, followed by aggregation of smaller
Pd nanocrystals and free phosphanes,
produced by thermal decomposition of
the remaining precursor, around this core.
Prolonged irradiation or thermal decomposition alone yields only the core structure or the shell structure, respectively.
This enables the nanoparticle structure to
be tuned.
Angew. Chem. Int. Ed. 2006, 45, 1006 – 1015
Angewandte
Chemie
Ionic Liquids
The polar domains within model ionic
liquids are assessed by intermolecular
NOE interaction studies. The cation–
cation distances in pure ionic liquids 1butyl-3-methylimidazolium (see picture)
and 1-butyl-2,3-dimethylimidazolium tetrafluoroborate are obtained and used to
provide models of the local structure of
the liquids.
A. Mele,* G. RomanR, M. Giannone,
E. Ragg, G. Fronza, G. Raos,
V. Marcon
1123 – 1126
The Local Structure of Ionic Liquids:
Cation–Cation NOE Interactions and
Internuclear Distances in Neat
[BMIM][BF4] and [BDMIM][BF4]
Vitamin E
C. GrNtter, E. Alonso, A. Chougnet,
W.-D. Woggon*
1126 – 1130
A Biomimetic Chromanol Cyclization
Leading to a-Tocopherol
Vitamin E synthesis: Covalently linked
dipeptides serve as readily removable and
recyclable chiral auxiliaries in the diastereoselective cyclization of phytylhydroqui-
nones. Depending on the chirality of the
handle, (2R)- or (2S)-a-tocopherol (vitamin E) can be produced with a diastereomeric excess of up to 80 % (see scheme).
Efficient communication: The first porphyrin-photosensitizer-containing biomimetic model for the active site of Feonly hydrogenases has been synthesized
and structurally characterized (see picture). Its fluorescence spectrum reveals
that an efficient electronic communication occurs between the porphyrin unit
and the covalently linked diiron–azadithiolate moiety.
Circular or columnar orientations of
mesoporous silica can be selectively prepared by tuning the silica-to-surfactant
ratio and the humidity during the synthesis of the mesoporous material within
the regular larger channels of anodic
alumina membranes. The transmission
electron microscopy image shows the
circular orientation of these highly
ordered hexagonal mesostructures.
Angew. Chem. Int. Ed. 2006, 45, 1006 – 1015
Enzyme Models
L.-C. Song,* M.-Y. Tang, F.-H. Su,
1130 – 1133
Q.-M. Hu
A Biomimetic Model for the Active Site of
Iron-Only Hydrogenases Covalently
Bonded to a Porphyrin Photosensitizer
Mesoporous Materials
B. Platschek, N. Petkov,
T. Bein*
1134 – 1138
Tuning the Structure and Orientation of
Hexagonally Ordered Mesoporous
Channels in Anodic Alumina Membrane
Hosts: A 2D Small-Angle X-ray Scattering
Study
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
1013
Contents
Bioinorganic Chemistry
M. E. Helton, D. Maiti, L. N. Zakharov,
A. L. Rheingold, J. A. Porco, Jr.,
K. D. Karlin*
1138 – 1141
A m-h2 :h2-Disulfide Dicopper(ii) Complex
from Reaction of S8 with a Copper(i)
Precursor: Reactivity of the Bound
Disulfur Moiety
Side on: Elemental sulfur (S8) reacts with
a tridentate chelate (MePY2)Me2N copper(i) compound, generating a side on
m-h2 :h2-disulfido bridged complex [{CuII(MePY2)Me2N}2(S22 )]2+ (see structure:
Helical Structures
yellow S, green Cu, blue N, gray C); its
reactivity towards PPh3, RNC, CO, O2,
PhCH2Br, and a tetradentate chelating
ligand are described.
ality during the coassembly of gel-forming
p-conjugated molecules by inverted helicity results in the formation of longitudinally fused M and P helices. This “sergeants and soldiers” approach to coassembly under stereomutation has been
confirmed by CD and AFM techniques
(see picture).
A. Ajayaghosh,* R. Varghese, S. J. George,
C. Vijayakumar
1141 – 1144
Transcription and Amplification of
Molecular Chirality to Oppositely Biased
Supramolecular p Helices
Let’s twist again: Transcription of molecular chirality from common stereogenic
centers to amplified supramolecular chir-
Computational Chemistry
R. Iftimie,*
M. E. Tuckerman*
1144 – 1147
The Molecular Origin of the “Continuous”
Infrared Absorption in Aqueous Solutions
of Acids: A Computational Approach
The origin of the continuum region
(ñ = 1000–3000 cm 1) in the IR absorption spectra of solutions of strong acids is
well understood, but in weak acids, it has
remained a mystery until now. An ab initio
molecular dynamics approach is used to
explain the molecular origin of this continuum for aqueous solutions of the weak
acid HF and identify the structure and
chemical nature of the dominant species
(see picture).
Cinchona alkaloids are employed in an
organocatalyzed asymmetric Friedel–
Crafts amination reaction of 2-naphthols.
These amination reactions proceed in
high yields with up to 98 % ee and have led
to a new class of non-biaryl atropisomer.
The rotation barriers of the chiral aminated 2-naphthols have been investigated by
experimental and computational methods.
Organocatalysis
S. Brandes, M. Bella,* A. Kjærsgaard,
K. A. Jørgensen*
1147 – 1151
Chirally Aminated 2-Naphthols—
Organocatalytic Synthesis of Non-Biaryl
Atropisomers by Asymmetric Friedel–
Crafts Amination
1014
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2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2006, 45, 1006 – 1015
Angewandte
Chemie
Highly sensitive: The hyper-Rayleigh
Scattering (HRS) technique has been
used to achieve the ultrasensitive detection of single base-pair mismatches in
oligonucleotide strands without any
modification of DNA. A very distinct HRS
intensity change is observed after hybridization even at the concentration of 10nanomolar probe single-stranded DNA.
Oriented assembly of zeolite crystals on a
porous support followed by secondary
growth leads to continuous, thin, uniformly oriented zeolite films (see picture
for a cross-sectional SEM image) of MFI
with the 5.1 Y 5.5-Z zigzag channels perpendicular to the support. These a-oriented films along with their previously
reported b-oriented counterparts are the
first set of thin molecular-sieve membranes with uniform but drastically different orientations.
DNA Structures
1151 – 1154
P. C. Ray*
Diagnostics of Single Base-Mismatch
DNA Hybridization on Gold
Nanoparticles by Using the HyperRayleigh Scattering Technique
Zeolite Films
J. Choi, S. Ghosh, Z. Lai,
M. Tsapatsis*
1154 – 1158
Uniformly a-Oriented MFI Zeolite Films
by Secondary Growth
Service
Keywords
1160
Authors
1161
Angewandte’s
Sister Journals
Preview
1162 – 1163
1165
For more information on
ChemMedChem see
www.chemmedchem.org
Angew. Chem. Int. Ed. 2006, 45, 1006 – 1015
2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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