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Graphical Abstract Angew. Chem. Int. Ed. 12005

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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:
D. Enders,* C. Grondal:
Direct Organocatalytic de novo Synthesis of Carbohydrates
T. Fink, H. Bruggesser, J.-L. Reymond*:
Virtual Exploration of the Small-Molecule Chemical Universe
Below 160 Daltons
S. Kobayashi,* K. Arai, H. Shimizu, Y. Ihori, H. Ishitani,
Y. Yamashita:
A Bimetallic Chiral Niobium Complex for Lewis Acid Catalyzed
Enantioselective Reactions: Design of a Tridentate Ligand and
Elucidation of the Catalyst Structure
H. Braunschweig,* K. Radacki, D. Rais, G. R. Whittell:
The First Boryl Bridged Complex: An Unprecedented
Coordination Mode of the BR2 Ligand
C. Whitehouse,* J. Fang, A. Aggeli, M. Bell, R. Brydson,
C. W. G. Fishwick, J. Henderson, C. M. Knobler, R. W. Owens,
N. H. Thomson, D. A. Smith, N. Boden*
Adsorption and Self-Assembly of Peptides on Mica Substrates
You Seok Seo, C. Lee, K. H. Lee, K. B. Yoon*
1:1 and 2:1 Charge-Transfer Interactions between Aromatic
Hydrocarbons and Dry Titanium Dioxide
News
F. Arnold Receives ACS Medal
22
B. Meunier Becomes President of the
CNRS
22
D. Kurth Accepts Position in Tsukuba 22
Dithiolene Chemistry
Kenneth D. Karlin, Edward I. Stiefel
reviewed by G. J. Leigh
23
Synthetic Metal-Containing Polymers
Ian Manners
reviewed by D. Bergbreiter
24
[4� Cycloadducts from Lewis Acid
Mediated Reactions of Acroleins with
Cyclopentadiene
Expect the unexpected: Classic organic
chemistry continues to hold surprises.
Cyclopentadiene and simple a-alkylated
acroleins, in the presence of AlCl3 and
Et2AlCl, furnish unconventional [4�
cycloadducts (see scheme). The ?expected? Diels?Alder adducts are intermediates in the reaction.
Homogeneous Catalysis
As good as gold: The activation and
selective oxygenation of inert CH bonds,
as in methane, is a demanding problem. It
is now shown that the combination of
gold as a catalyst and H2SeO4 as the
oxidant results in a 94 % selectivity for
CH3OSO3H at 28 % CH4 conversion (see
scheme). These results mean that gold
now claims its place alongside the other
noble metals as a methane oxidation
catalyst.
Books
Highlights
Cycloadditions
B. Niess, H. M. R. Hoffmann*
D. E. De Vos,* B. F. Sels
26 ? 29
30 ? 32
Gold Redox Catalysis for Selective
Oxidation of Methane to Methanol
8
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Angew. Chem. Int. Ed. 2005, 43, 8 ? 17
Angewandte
Chemie
Reviews
Protein Science
L. Wang, P. G. Schultz*
34 ? 66
Expanding the Genetic Code
Breaking the code: A large number of
novel amino acids have been incorporated
into the genetic codes of both prokaryotic
and eukaryotic organisms (see schematic
representation). These remove the limita-
tions imposed by the existing 20 amino
acid codes and should make it possible to
generate proteins and perhaps entire
organisms with new or enhanced properties.
Communications
Metalation Reactions
Mixed-metal chemical synergy is strikingly
exemplified by the clean, selective deprotonation of one benzene ring of bis(benzene)chromium by bimetallic (Na/Mg or
K/Mg) amide base mixtures. The bis(benzene)chromium moiety forms highyielding crystalline trimetallic products
(see picture) with the mixed bases, but it
is inert towards the non-synergic, parent
monometallic amides. Na/K red; Mg
green; Cr light blue; N yellow; C black.
E. Hevia, G. W. Honeyman, A. R. Kennedy,
R. E. Mulvey,* D. C. Sherrington 68 ? 72
Synergic Monodeprotonation of Bis(benzene)chromium by Using Mixed Alkali
Metal?Magnesium Amide Bases and
Structural Characterization of the
Heterotrimetallic Products
Packing them in: Based on zinc and
aromatic-rich dicarboxylic acids these new
coordination networks (see structure;
green Cl, red O, yellow Zn, blue N, gray C)
have hydrogen uptakes comparable to
those of the best carbon nanotubes and
metal?organic frameworks. The highly
interpenetrating nature of these networks
points to a new design strategy for
hydrogen-storage materials that employ
an entrapment mechanism.
For the USA and Canada:
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individuals who are personal members of a
www.angewandte.org
Functional Materials
B. Kesanli, Y. Cui, M. R. Smith,
E. W. Bittner, B. C. Bockrath,
W. Lin*
72 ? 75
Highly Interpenetrated Metal?Organic
Frameworks for Hydrogen Storage
national chemical society, or whose institution
already subscribes, or who are retired or selfemployed consultants, print only: US$ 394.00.
Postage and handling charges included. All
Wiley-VCH prices are exclusive VAT.
2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
9
Angewandte
Chemie
Crown-compound complexation through
secondary hypervalent I贩稯 bonding
interactions enables stabilization of an
aqua(hydroxy)(phenyl)iodonium ion. The
resulting aqua complex 1 is stable in the
solid state as well as in solution and
serves as a versatile oxidizing agent,
Coordination Chemistry
M. Ochiai,* K. Miyamoto, Y. Yokota,
T. Suefuji, M. Shiro
75 ? 78
especially in water. Tf = trifluoromethanesulfonyl.
Synthesis, Characterization, and Reaction
of Crown Ether Complexes of
Aqua(hydroxy)(aryl)iodonium Ions
Nanotechnology
L. Sheeney-Haj-Ichia, B. Basnar,
I. Willner*
78 ? 83
Efficient Generation of Photocurrents by
Using CdS/Carbon Nanotube Assemblies
on Electrodes
Electric light orchestra! Enhanced photocurrents are generated in an assembly
that consists of CdS nanoparticles linked
to a gold electrode by carbon nanotubes
(see picture, TEOA = triethanolamine).
The enhanced photocurrents are attribu-
ted to the effective transport of conduction-band electrons through the carbon
nanotube to the electrode, a process that
competes with electron?hole recombination in the CdS semiconductor nanoparticles.
Porphyrin Analogues
Four up, four down: Reductive alkylation
of cyclo[8]pyrrole and its derivatives gives
rise to the corresponding reduced per-Nalkylated products, a reaction unknown in
the case of porphyrins. These bowl-like
molecules are arranged with four substituents up and four substituents down in a
well-defined alternating fashion, as
observed from their crystal structures (see
picture; blue N).
Under lock and key: A molecular machine
based on the redox-coupled guest
T. KMhler, Z. Ou, J. T. Lee, D. Seidel,
V. Lynch, K. M. Kadish,*
J. L. Sessler*
83 ? 87
Reductive N Alkylation of Cyclo[8]pyrroles
exchange of a cucurbit[8]uril-stabilized
charge-transfer complex is reported. It
behaves as a molecular loop lock that
requires not only a key but also an
activation process to open (see graphic).
Host?Guest Chemistry
W. S. Jeon, E. Kim, Y. H. Ko, I. Hwang,
J. W. Lee, S.-Y. Kim, H.-J. Kim,
K. Kim*
87 ? 91
Molecular Loop Lock: A Redox-Driven
Molecular Machine Based on a HostStabilized Charge-Transfer Complex
Angew. Chem. Int. Ed. 2005, 43, 8 ? 17
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2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
11
Contents
Analytical Methods
S.-I. Nishimura,* K. Niikura,
M. Kurogochi, T. Matsushita, M. Fumoto,
H. Hinou, R. Kamitani, H. Nakagawa,
K. Deguchi, N. Miura, K. Monde,
H. Kondo
91 ? 96
High-Throughput Protein Glycomics:
Combined Use of Chemoselective
Glycoblotting and MALDI-TOF/TOF
Mass Spectrometry
Common oligosaccharides and aldehydeattached glycoproteins derived from
enzymatic modifications can be captured
by glycoblotting based on oxylamino-con-
C?C Coupling
taining polymers. The combination of this
glycoblotting and MALDI-TOF/TOF mass
spectrometry enabled a high-throughput
analytical method to be developed.
Able to be stable: The reaction of diethylzinc and bis(2-pyridylmethyl)amine yields
the title complex by C?C coupling and
deamination reactions. This complex is
dimeric in the solid state (see structure;
orange Zn, blue N, gray C). The pyridyl
substituents enable the formation of a
rare example of a bis(alkylzinc)imide.
M. Westerhausen,* A. N. Kneifel,
A. Kalisch
96 ? 98
(Z)-Bis(alkylzinc)imido-1,2-di(2-pyridyl)ethene: Intramolecular Stabilization of a
Bis(alkylzinc)imide
Lewis Acids in Organic Synthesis
A. Goeke,* D. Mertl, G. Brunner 99 ? 101
Alkyl Aluminum Halide Promoted Intramolecular Cyclization of w-Allyl-cycloalk-2enones: Access to Bridged Bi- and
Tricyclic Compounds
Cyclization makes the scent: A rearrangement of w-allyl cycloalkenones leads to
structurally complex bi- and tricyclic
ketones in good yields (see scheme). The
method allows efficient access to an
olfactorily interesting class of compounds.
The next generation: Diphosphinocarbene
(Arduengo carbene) and imidazol-2-ylidene (Bertrand carbene) are combined in
complex 2, which was prepared by reaction of the diphosphinoketenimine com-
plex 1 with propargylamine to form a new
type of P2C=CN2 electron-rich olefin,
which behaves as a strongly basic
diphosphine.
Hybrid Carbenes
J. Ruiz,* M. E. G. Mosquera, G. GarcOa,
F. MarquOnez, V. Riera
102 ? 105
Imidazoline-Functionalized Diphosphines: Models for N-Heterocyclic Carbene?
Diphosphinocarbene Coupling
12
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Angew. Chem. Int. Ed. 2005, 43, 8 ? 17
Angewandte
Chemie
Asymmetric Catalysis
H. Li, Y. Wang, L. Tang, F. Wu, X. Liu,
C. Guo, B. M. Foxman,
L. Deng*
105 ? 108
Not too close for comfort: Practical chiral
organocatalysts like that shown promote
Michael addition reactions of a wide range
of trisubstituted carbon nucleophiles to
various nitroalkenes, often with nearly
perfect stereoselectivity (> 99 % ee and
> 98:2 d.r.). In one step adjacent carbonor heteroatom-substituted quaternary and
tertiary stereocenters are generated from
readily available starting materials.
Stereocontrolled Creation of Adjacent
Quaternary and Tertiary Stereocenters by a
Catalytic Conjugate Addition
Organocatalysis
J. W. Yang, M. T. Hechavarria Fonseca,
N. Vignola, B. List*
108 ? 110
Selective reduction without metals: An
imidazolidinone salt effectively catalyzes
the highly enantioselective biomimetic
transfer hydrogenation of a,b-unsaturated
aldehydes to give the saturated analogues
using a synthetic dihydropyridine cofactor
(see scheme). Remarkably only one
enantiomer forms regardless of the configuration of the enal starting material.
The effect of pore size on the radiolytic
production of hydroxyl radicals has been
investigated in silica controlled pore
glasses (CPGs) by means of the HOCinduced conversion of coumarin into
7-hydroxycoumarin (7-OHC). Production
of 7-OHC decreases with decreasing pore
size (see plot). This effect is not attributed
to the capture of HOC at the water/silica
interface but to the modified diffusion
regime in such confined environments.
Spectrum of zirconium methylidene:
Reaction of laser-ablated zirconium with
CH4 in excess neon at 5 K forms [H2C=
ZrH2], the simplest carbene complex.
Density functional theory calculations
predict a C1 symmetry structure (see
picture) with agostic CH贩穁r bonding.
This structure is confirmed by the match
between calculated and observed IR frequencies. Methane activation by [H2C=
ZrH2] gives [(CH3)2ZrH2].
Angew. Chem. Int. Ed. 2005, 43, 8 ? 17
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Metal-Free, Organocatalytic Asymmetric
Transfer Hydrogenation of a,b-Unsaturated Aldehydes
Chemistry in Porous Materials
S. Foley, P. Rotureau, S. Pin,
G. Baldacchino, J.-P. Renault,*
J.-C. Mialocq
110 ? 112
Radiolysis of Confined Water: Production
and Reactivity of Hydroxyl Radicals
CH Activation
L. Andrews,* H.-G. Cho,
X. Wang
113 ? 116
[H2C=ZrH2]: The Simplest Carbene
Hydride Complex, Agostic Bonding,
and CH Activation of CH4 to Form
[(CH3)2ZrH2]
2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
13
Contents
Enzyme Inhibitors
Target-guided synthesis: Rather than
making and screening thousands of
compounds for lead discovery, in situ click
chemistry employs the biological target
itself to assemble its inhibitors by selectively binding and interconnecting
reagents within the confines of its binding
sites. Subnanomolar inhibitors of carbonic anhydrase II were produced by the
enzyme from simple azide and acetylene
precursors (see picture).
V. P. Mocharla, B. Colasson, L. V. Lee,
S. RMper, K. B. Sharpless, C.-H. Wong,
H. C. Kolb*
116 ? 120
In Situ Click Chemistry: Enzyme-Generated Inhibitors of Carbonic Anhydrase II
Synthetic Methods
O. L. Epstein, J. K. Cha*
121 ? 123
Rapid Access to the ?in,out?-Tetracyclic
Core of Ingenol
In ? out ? shake it all about! The
tetracyclic core of ingenol has been prepared in a convergent synthesis. The
pinacol-type rearrangement of an epoxy
alcohol provides a simple, expedient so-
lution to the challenging ?inside?outside?
intrabridgehead stereochemistry of ingenol (see scheme, TBS = tert-butyldimethylsilyl).
Differently sized and shaped nanocrystals
of water-soluble magnetite were prepared
by refluxing FeCl3�H2O in 2-pyrrolidone
for different periods of time. The picture
(scale bar: 100 nm) shows how first
spherical nanoparticles appear (1 h, a),
grow (10 h, b), and finally form cubic
particles (24 h, c). The mechanism leading to Fe3O4 nanocrystals is discussed.
Fischer carbene complexes have been
implied as intermediates in a catalytic
tandem process for the synthesis of cyclic
compounds, including eight-membered
carbocycles, in excellent yields from alky-
nols (see scheme). The method was
optimized to avoid the use of large
quantities of the metallic species, thus
overcoming one of the main limitations of
Fischer carbene complexes.
Several lines of evidence suggest that
reduction of the carbonyl group occurs
after epoxide-ring opening in the first
examples of catalytic, reductive coupling
of epoxides and aldehydes (see scheme).
The hydroxyether products are obtained
with > 95:5 regioselectivity in all cases,
independent of the steric and electronic
nature of R1 and R2.
Magnetic Nanoparticles
Z. Li, Q. Sun, M. Y. Gao*
123 ? 126
Preparation of Water-Soluble Magnetite
Nanocrystals from Hydrated Ferric Salts
in 2-Pyrrolidone: Mechanism Leading to
Fe3O4
Medium-Ring Compounds
J. Barluenga,* A. DiRguez, F. RodrOguez,
F. J. FaSanTs
126 ? 128
Tandem [W(CO)5]-Catalyzed
Cycloisomerization?Cyclopropanation
Reactions Directed toward the Synthesis
of Eight-Membered Carbocycles
Coupling Reactions
C. Molinaro, T. F. Jamison*
129 ? 132
Catalytic Reductive Coupling of Epoxides
and Aldehydes: Epoxide-Ring Opening
Precedes Carbonyl Reduction
14
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Angew. Chem. Int. Ed. 2005, 43, 8 ? 17
Angewandte
Chemie
Enediynes
A question of size: Two N-protected
macrocyclic enediynes have been synthesized by intramolecular N-alkylation. The
smaller 12-membered enediyne, upon
deprotection, yields a stable amine. In
contrast, the amine generated from the
13-membered enediyne forms the aminol,
which in turn undergoes a spontaneous
Bergman cyclization (see scheme).
A. Basak,* S. K. Roy,
S. Mandal
Activation of Macrocyclic Enediynes by
Transannular Cyclization
Natural Products Synthesis
The antiinflammatory drug halipeptin A
(1) is a 17-membered cyclic depsipeptide
made up of l-alanine, a-methylcysteine,
decanoic acid, and isoleucine residues.
Key steps in its total synthesis, which
helped to confirm the stereochemistry of
the natural product, include a boranemediated aldol reaction and an asymmetric aza-Claisen rearrangement.
S. Yu, X. Pan, X. Lin, D. Ma*
135 ? 138
Total Synthesis of Halipeptin A: A Potent
Antiinflammatory Cyclic Depsipeptide
A tip for surface scientists: Tip-enhanced
Raman spectroscopy (TERS) was used to
record surface Raman spectra of benzenethiol and pyridine-4-thiol adsorbed on
Au and Pt single-crystal surfaces (see
picture). The benzenethiol spectra on the
two surfaces are distinctly different. This
result illustrates the power of TERS as a
diagnostic tool with high spatial resolution for surface studies.
Diffusion or activation control: Free CN
ions are generally alkylated at carbon (see
picture). N-attack is only observable in
diffusion controlled reactions with carbocations. Since isonitrile formation in
reactions with [Ag(CN)2] is due to the
change of the nucleophile, the explanation
of these regioselectivities by the hard and
soft acids and bases principle has to be
abandoned.
Angew. Chem. Int. Ed. 2005, 43, 8 ? 17
132 ? 135
www.angewandte.org
Surface Analysis
B. Ren,* G. Picardi, B. Pettinger,*
R. Schuster, G. Ertl
139 ? 142
Tip-Enhanced Raman Spectroscopy of
Benzenethiol Adsorbed on Au and
Pt Single-Crystal Surfaces
Reaction Mechanisms
A. A. Tishkov, H. Mayr*
142 ? 145
Ambident Reactivity of the Cyanide Ion:
A Failure of the HSAB Principle
2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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Contents
Cubane Rearrangements
A. A. Fokin,* B. A. Tkachenko,
P. A. Gunchenko,
P. R. Schreiner*
146 ? 149
The Protonation of Cubane Revisited
Cubane?s proton affinity is now understood! Protonated cubane forms a structure with a protonated CC bond (see
scheme), which undergoes rearrangement along the most favorable reaction
path rapidly giving 1,8-dihydropentalene
as the final product. The results confirm
the experimentally determined proton
affinity of cubane.
Mild cationic reaction conditions are used
for the efficient desymmetrization of prochiral bishomoallylic alcohols in an intramolecular Heck reaction. This is the first
example of a group-selective Heck cyclization in which the enantiotopic alkene
moieties are not incorporated into a cyclic
and, therefore, rigid system (see scheme).
The high enantioselectivity is attributed to
the hydroxy group functioning as a catalyst-directing group, which could be a
novel feature in asymmetric Heck
chemistry.
Four bonds at one stroke and products
with intensive fluorescence result from a
domino sequence consisting of insertion,
coupling, isomerization, and Diels?Alder
steps (see scheme, Ts = tosyl). Alkynoyl
ortho-iodophenyl esters or N-(iodophenyl)alkynanilides 1 react with propargyl allyl
ethers 2 to furnish spirocycles 3.
Weapons of moss destruction: Previously
unknown lipoxygenase biosynthetic pathways in the moss Physcomitrella patens
transform arachidonic acid into metabolites typical of animals, plants, algae, and
mushrooms when the moss is damaged
(see scheme). In this way metabolic
themes from all these organisms are
combined uniquely.
Asymmetric Heck Reaction
M. Oestreich,* F. Sempere-Culler,
149 ? 152
A. B. Machotta
Catalytic Desymmetrizing Intramolecular
Heck Reaction: Evidence for an Unusual
Hydroxy-Directed Migratory Insertion
Domino Reactions
D. M. D?Souza, F. Rominger,
T. J. J. MVller*
153 ? 158
A Domino Sequence Consisting of Insertion, Coupling, Isomerization, and Diels?
Alder Steps Yields Highly Fluorescent
Spirocycles
Bioorganic Chemistry
T. Wichard, C. GMbel, I. Feussner,
G. Pohnert*
158 ? 161
Unprecedented Lipoxygenase/Hydroperoxide Lyase Pathways in the Moss
Physcomitrella patens
16
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Angew. Chem. Int. Ed. 2005, 43, 8 ? 17
Angewandte
Chemie
Service
Keywords
162
Authors
163
Angewandte?s Sister Journals
164
Vacancies
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