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Graphical Abstract Angew. Chem. Int. Ed. 222003

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Contents
News
Clusters: P. Braunstein
recognized
2444
Metal Catalysis: S. Gibson promotes
women scientists
Organic Chemistry:
Focus on small rings
Enzyme Kinetics
2445
Alejandro G. Marangoni
reviewed by M. Bertau
Organic Ion Radicals
2445
Zory V. Todres
reviewed by M. Schmittel
Drug Design
2446
Darren R. Flower
reviewed by H. Kubinyi
Concise Chemistry of the Elements
2447
Sławomir Siekierski, John Burgess
reviewed by T. M. Klaptke
Helical structures can be formed in different ways: In rigid molecules through
steric interactions and in flexible mole-
cules through intramolecular noncovalent
interactions or through supramolecular
associations.
Books
Highlights
Helical Molecules and Aggregates
C. Schmuck*
2448 – 2452
Molecules with Helical Structure: How To
Build a Molecular Spiral Staircase
Minireviews
DNA-Mediated Charge Transfer
H.-A. Wagenknecht*
2454 – 2460
Reductive Electron Transfer and Transport
of Excess Electrons in DNA
Checking the traps: The transport of
excess electrons in DNA has great potential for DNA chip technology. Radiolysis
studies, for example, with mitoxanton as
the electron acceptor and new photochemical assays (see scheme) have given
new insights into the mechanisms of
these processes.
Reviews
Protein–Protein Interactions
T. Berg*
Does size matter? Can a drug-like molecule efficiently modulate the interaction
between proteins in which the protein–
protein interface (as indicated in the
scheme) is many times larger than the
small molecule itself ? If so, how do you
identify such organic molecules? Answers
to these questions can be found in this
review on the current research aimed at
producing the next generation of drugs.
2462 – 2481
Modulation of Protein–Protein
Interactions with Small Organic
Molecules
2436
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
Angew. Chem. Int. Ed. 2003, 42, 2436 – 2443
Angewandte
Chemie
Communications
Tetraozonide of Phosphorus Oxide
They do indeed exist, but not as expected:
binary peroxide compounds of phosphorus. Whereas the peroxide P2O6 described
by Schenk in 1937 still remains a presumption, the reaction of phosphorus(iii)
oxide with ozone at low temperature has
led to the tetraozonide P4O18 (see picture),
the first defined binary peroxo compound
of phosphorus. This is the oxygen-richest
phosphorus compound known to date,
and possibly could be used as a source for
the generation of singlet oxygen under
very mild conditions.
A. Dimitrov, B. Ziemer, W.-D. Hunnius,
M. Meisel*
2484 – 2486
The First Ozonide of a Phosphorus
Oxide—Preparation, Characterization,
and Structure of P4O18
Epipodophyllotoxin Total Synthesis
U. Engelhardt, A. Sarkar,
T. Linker*
2487 – 2489
Efficient Enantioselective Total Synthesis
of ()-Epipodophyllotoxin
In only twelve steps the total synthesis of
()-epipodophyllotoxin (2) has been
completed starting from commercially
available piperonal (1). The first stereocenter was formed under auxilary control,
while the following epoxidation and radical cyclization proceeded with outstanding diastereoselectivity, which enabled the
target molecule to be isolated in an overall
yield of 30 % and with 97 % ee.
Regioselective Arene Alkylation
Methyl-substituted arenes can be synthesized with high regioselectivity in only two
steps through formal exchange of an
aromatic carboxylic acid function with an
alkyl substituent. The results obtained
with toluic acid illustrate that good to very
good yields can be obtained from inexpensive reagents (see scheme).
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Angew. Chem. Int. Ed. 2003, 42, 2436 – 2443
K. Vorndran, T. Linker*
2489 – 2491
Simple Two-Step ipso Substitution of
Aromatic Carboxylic Acids by Alkyl
Halides
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Europe E 248.00/Outside Europe US$ 348.00.
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2437
Contents
Polymer-Supported Synthesis
S. Weik, J. Rademann*
Smoothly linked: Polymer-supported
phosphorane 1 is a C-nucleophile that can
be acylated under mild reaction conditions. Diversely substituted a-ketocarbonyl and a-hydroxycarbonyl compounds
2 are furnished following to a reaction
sequence including oxidative cleavage of
the supported phosphoranes.
2491 – 2494
A Phosphorane as Supported Acylanion
Equivalent: Linker Reagents for Smooth
and Versatile CC Coupling Reactions
Organometallic Gelators
Stranded solvents: The aminocarbene
chromium complex shown forms fiberlike
aggregates of several mm length by selfassembly through noncovalent interactions. These strands allow an efficient
immobilization of organic solvents in the
form of a gel. The carbohydrate head
group may induce supramolecular chirality in the aggregates.
G. BLhler, M. C. Feiters, R. J. M. Nolte,
K. H. DMtz*
2494 – 2497
A Metal–Carbene Carbohydrate
Amphiphile as a Low-Molecular-Mass
Organometallic Gelator
Metal-Organic Zeolites
Unprecedented coordination polymers of
hexagonal tungsten bronze topology represent a new type of metal–organic zeolites: the compounds have a microporous
structure, they are thermally stable and
are capable of the reversible adsorption of
dichloromethane (see picture).
E. B. Rusanov, V. V. Ponomarova
V. V. Komarchuk, H. Stoeckli-Evans
E. Fernandez-IbaNez, F. Stoeckli
J. Sieler, K. V. Domasevitch* 2499 – 2501
A Topology Paradigm for Metal-Organic
Zeolites
Phototriggered Molecular Release
A. Okamoto, K. Tanabe, T. Inasaki,
I. Saito*
2502 – 2504
Phototriggered Drug Release from
Functionalized Oligonucleotides by a
Molecular Beacon Strategy
More than just a light switch: A phototriggered molecule-releasing system controlled through intramolecular triplet
quenching by using a molecular beacon
2438
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
strategy with photoactive probe oligodeoxynucleotides (ODNs) has been
developed (see picture).
Angew. Chem. Int. Ed. 2003, 42, 2436 – 2443
Angewandte
Chemie
Positive discrimination: Confocal microscopy analysis has shown that TentaGel
beads functionalized with unnatural carbohydrate-based ligands (2) can discriminate extremely well between carbohydrate-binding proteins labeled separately
with fluorescein and tetramethylrhodamine (blue ellipsoids and red triangles, respectively) that recognize the
Carbohydrate Recognition
A. Basu, D. Kahne*
Overcoming Degeneracy in Carbohydrate
Recognition
same natural carbohydrate ligands (1, see
schematic representation).
A highly fluorophilic environment comprising the HCaC¼O unit of Asn 98 in
the active site of thrombin was identified
by X-ray crystallography of a complex
formed between the enzyme and a synthetic inhibitor (see partial X-ray structure,
distances are in Angstroms). Short
CF···HCa and CF···C¼O contacts
involving HCaC¼O fragments were
also frequently observed in small-molecule X-ray crystal structures.
Mapping Enzyme Active Sites
The tubulin-bound structure of epothilone A (shown in green) differs substantially
from its free conformation (determined by
X-ray crystallography, shown in gray). The
new structural data correlate well with
results from chemical modification
experiments, giving a consistent picture of
the functionally important regions of
epothilone.
Structure of Bound Epothilone
C–C torsion angles in HC-CCH3 moieties
can be measured by a new NMR experiment based on the measurement of
CH–CH dipolar–dipolar cross-correlated
relaxation rates and is demonstrated on a
mixture of 13C-labeled epothilone (1) and
tubulin. The new pulse sequence is
broadly applicable to any HC-CCH3 moiety
and therefore to a number of amino acid
side chains in proteins.
Angew. Chem. Int. Ed. 2003, 42, 2436 – 2443
2504 – 2506
www.angewandte.org
J. A. Olsen, D. W. Banner,* P. Seiler,
U. Obst Sander, A. D’Arcy, M. Stihle,
K. MLller,* F. Diederich*
2507 – 2511
A Fluorine Scan of Thrombin Inhibitors to
Map the Fluorophilicity/Fluorophobicity
of an Enzyme Active Site: Evidence for
CF···C¼O Interactions
T. Carlomagno,* M. J. J. Blommers*
J. Meiler, W. Jahnke, T. Schupp
F. Petersen, D. Schinzer, K.-H. Altmann
C. Griesinger*
2511 – 2515
The High-Resolution Solution Structure of
Epothilone A Bound to Tubulin: An
Understanding of the Structure–Activity
Relationships for a Powerful Class of
Antitumor Agents
Torsion Angles of Epothilones
T. Carlomagno,* V. M. SQnchez,
M. J. J. Blommers,
C. Griesinger*
2515 – 2517
Derivation of Dihedral Angles from
CH–CH Dipolar–Dipolar Cross-Correlated
Relaxation Rates: A C–C Torsion Involving
a Quaternary Carbon Atom in
Epothilone A Bound to Tubulin
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2439
Contents
Antitumor Drugs
F. Yoshimura, A. Rivkin, A. E. Gabarda,
T.-C. Chou, H. Dong, G. Sukenick,
F. F. Morel, R. E. Taylor,
S. J. Danishefsky*
2518 – 2521
Synthesis and Conformational Analysis of
(E)-9,10-Dehydroepothilone B: A Suggestive Link between the Chemistry and
Biology of Epothilones
Solid-Phase Total Synthesis
R. I. Storer, T. Takemoto, P. S. Jackson,
S. V. Ley*
2521 – 2525
A Total Synthesis of Epothilones Using
Solid-Supported Reagents and
Scavengers
The most potent epothilone analogue
reported to date was obtained by incorporation of an E double bond at C9C10
in the epothilone B series (see picture).
Molecular modeling, NMR spectroscopic
analysis, and chemical observations were
used to rationalize the remarkable
potency-enhancing effect of the double
bond.
A total synthesis of epothilone C (1) with
concomitant formal synthesis of epothilone A is described, using immobilized
reagents and scavengers to effect multistep synthetic transformations and purifications.
Me H Me
N
N
Alkaloid Total Synthesis
L. E. Overman,*
E. A. Peterson
2525 – 2528
N
N
H H Me
Enantioselective Total Synthesis of the
Cyclotryptamine Alkaloid Idiospermuline
N
N
Me H Me
idiospermuline
Stereogenic quaternary carbons present
the primary challenge in the syntheses of
trispyrrolidinoindoline alkaloids such as
idiospermuline. In its synthesis the two
contiguous quaternary centers are expediently addressed by combining the lithium dienolate of a differentially protected
dihydroisoindigo with a tartrate-derived
electrophile. The third quaternary stereocenter is introduced by a catalytic asymmetric Heck reaction.
Alkaloid Total Synthesis
J. J. Kodanko,
L. E. Overman*
2528 – 2531
Enantioselective Total Syntheses of the
Cyclotryptamine Alkaloids Hodgkinsine
and Hodgkinsine B
A late-stage resolution of the meso-3a,3a’bispyrrolidinoindoline unit of rac-7 in a
catalytic asymmetric transformation earmarks the remarkably short, ten-step,
total syntheses of hodgkinsine and hodg-
2440
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
kinsine B. The enantioselective total synthesis of hodgkinsine B establishes the
relative and absolute configuration of this
trispyrrolidinoindoline alkaloid.
Angew. Chem. Int. Ed. 2003, 42, 2436 – 2443
Angewandte
Chemie
Chiral dyads of (S)-ketoprofen and (S)- or
(R)-tetrahydrofurfurylamine show diastereomeric differentiation in photoinduced
Photoinduced Hydrogen Abstraction
hydrogen abstractions, which could be
directly followed by time-resolved observation of the ketone triplet state. A unimolecular rate constant of
kH = 3.0 T 105 s1 was found for the
S,S diastereomer, while the S,R diastereomer reacts four times slower
(kH = 7.5 T 104 s1).
U. Pischel, S. Abad, L. R. Domingo,
F. BoscQ, M. A. Miranda*
2531 – 2534
Diastereomeric Differentiation in the
Quenching of Excited States by Hydrogen
Donors
Selective Benzoin Condensation
X. Linghu, J. S. Johnson*
2534 – 2536
Kinetic Control in Direct a-Silyloxy Ketone
Synthesis: A New Regiospecific Catalyzed
Cross Silyl Benzoin Reaction
Side-stepping thermodynamics. In contrast to the traditional benzoin reaction,
which can yield a mixture of homo and
mixed adducts, only one regioisomer was
obtained from the new cyanide-catalyzed
silyl benzoin reaction between acylsilanes
and aldehydes (see scheme).
OR'
HO
HO
HO
HO
O
Sialylglycopeptide Synthesis
O
O OH
O
OH
O
O
HO
O
HO
NHAc
O
HO
OH
O
HO
R
NHAc
CO2H
HO
HO
R' = HO
AcHN
O
O
HO
HO
O
HO
OH
O
HO
N. Yamamoto, Y. Ohmori, T. Sakakibara,
K. Sasaki, L. R. Juneja,
Y. Kajihara*
2537 – 2540
O
NHAc
HO
OR'
Egg yolk provided the starting disialylundecasaccharide for a highly efficient chemoenzymatic synthesis of a biantennary
complex-type glycopeptide (see picture).
Repetitive protection and deprotection
H
N
R'
H R
OH
PPh3, CCl4
reflux
Only nine steps away: PPh3/CCl4-mediated stereospecific rearrangement of a,adisubstituted indoline-2-methanol to
2,2,3-trisubstituted optically active tetrahydroquinoline (see scheme) has been
Angew. Chem. Int. Ed. 2003, 42, 2436 – 2443
steps required in oligosaccharide synthesis were thus avoided, and the desired
glycopeptide was rapidly assembled on a
solid phase (R = peptide).
H R
N
R'
Solid-Phase Synthesis of Sialylglycopeptides through Selective Esterification
of the Sialic Acid Residues of an AsnLinked Complex-Type Sialyloligosaccharide
Total Synthesis of Virantmycin
( )-virantmycin
Cl
developed. The reaction was applied to
the first total synthesis of natural virantmycin, in only nine steps from commercially available starting material.
www.angewandte.org
M. Ori, N. Toda, K. Takami, K. Tago,
H. Kogen*
2540 – 2543
Stereospecific Construction of Contiguous Quaternary and Tertiary Stereocenters
by Rearrangement from Indoline-2-methanol to 2,2,3-Trisubstituted Tetrahydroquinoline: Application to an Efficient Total
Synthesis of Natural Virantmycin
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2441
Contents
Cyclic Dodecasaccharide Structure
Two forms of a cyclic molecule, namely a
rhomb and a square, are observed for an
oligosaccharide, which has four repeating
units that consist only of amino sugars
(see picture). A relatively high water
content (ca. 34 %) can be discerned from
the crystals, which were formed from a
water/polyethylene glycol solution by utilizing a hanging-drop crystallization technique.
M. FUrnbUck, L. Eriksson, S. Senchenkova,
K. Zych, Y. A. Knirel, Z. Sidorczyk,
G. Widmalm*
2543 – 2546
Crystal Structure of a Cyclic
Enterobacterial Common Antigen
Pyrene Dimerization
I. Aprahamian, G. J. Bodwell, J. J. Fleming,
G. P. Manning, M. R. Mannion,
T. Sheradsky, R. J. Vermeij,
M. Rabinovitz*
2547 – 2550
Reductive Dimerization of Tethered
Pyrenes: Implications for the Reduction
of Polcyclic Aromatic Hydrocarbons
Pyrene reduction revisited: A reductive
dimerization process is observed for
strained pyrene derivatives, which occurs
through single-electron reduction with
lithium metal (see scheme). This process
has implications for the reduction of
pyrene itself. Various NMR methods can
be utilized to characterize the products
that result from such reactions.
Terminal alkenes act as dual nucleophiles
in a zirconocene-mediated, highly 1,4diastereoselective, tandem reduction–
allylation reaction of 1,4-diketones. A
zirconocene–alkene complex (in equili-
brium with an allyl–zirconocene–hydride
species) can deliver both hydride and an
allyl group to a diketone, with control of
the relative configuration of up to three
new stereogenic centers (see scheme).
Tandem Reduction–Allylation
K. Fujita, H. Shinokubo,
K. Oshima*
2550 – 2552
Highly Diastereoselective Tandem
Reduction–Allylation Reactions of
1,4-Diketones with Zirconocene–Olefin
Complexes
Communications labeled with this symbol have been judged by two referees as being “very important papers”.
The publication of Communications labeled with this symbol has been accelerated because of their topical or highly competitive
nature.
Service
Keywords
2554
Authors
2555
Vacancies
Preview
2442
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
A29
2557
Angew. Chem. Int. Ed. 2003, 42, 2436 – 2443
Angewandte
Chemie
Corrigenda
*
In the Communication "Enantioselective
CC Bond Formation with Titanium(iv)
Alkoxides—An Unusual Alkylation" by R.
Mahrwald in Angew. Chem. Int. Ed. 2002,
41, 1361–1363 the structures of the triols
1 a–c and 2 a–c described therein must be
revised. In fact 1 a–c and 2 a–c should be
substituted, meso-configured tetrahydro-
pyrans. Their identity was ascertained by
comparison with X-ray crystal structure
analyses of analogous compounds during
subsequent studies. The originally
accepted CH activation during this reaction with titanium(iv) alkoxides is apparently not involved in the real reaction
mechanism. Further addition of aldehydes
to alcohols, instead of to the corresponding titanium(iv) alkoxides, suggests that
an elimination–addition mechanism
analogous to a Prins reaction is involved.
All the results and their interpretation will
soon be published in a full paper. The
author apologizes to the readers and
referees for the mistakes in the publication.
In the Communication by J. M. Thomas
et al. in Angew. Chem. Int. Ed. 2003, 41,
1520–1523 misleading statements were
made in the first two sentences. The
correct version is:
extensive liberation of the greenhouse gas
N2O.[1, 2]”
using a homogeneous cobalt-containing
catalyst.”
This replaces the passage:
“The current, widely used and environmentally harmful industrial method of
producing adipic acid (2) first entails the
oxidation of cyclohexane in air, to a
mixture of cyclohexanol and cyclohexanone using a homogeneous cobalt-containing catalyst. This mixture is then
oxidized by nitric acid to adipic acid with
“The current, widely used and environmentally harmful industrial method of
producing adipic acid (2) first entails the
oxidation of cyclohexane by nitric acid
(with extensive liberation of the greenhouse gas N2O) to a mixture of cyclohexanol and cyclohexanone.[1, 2] This mixture is then rather inefficiently converted
to adipic acid (and some other products)
In the legend to the cover picture on
p. 2101 in Issue 19 of Angew. Chem. Int.
Ed. the following acknowledgment was
not included: “The authors thank B.
Lafleuriel (CURRI-Visualization, ULPStrasbourg) for generating the cover
Angew. Chem. Int. Ed. 2003, 42, 2436 – 2443
www.angewandte.org
It has been drawn to the authors’ attention (by Dr. J. H. Teles, BASF) that in
current industrial practice in the production of adipic acid using nitric acid as an
oxidant, the nitrous oxide liberated is
decomposed to oxygen and nitrogen prior
to release into the atmosphere, thereby
avoiding environmental damage from this
source.
picture illustration.” The editorial office
apologizes for this omission.
2003 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2443
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