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Graphical Abstract (Angew. Chem. Int. Ed. Engl. 201997)

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E
A Journal of the
Gesellschaft
Deutscher Chemiker
1997
International Edition in English
36120
Pages 2137-2256
COVER PICTURE
The cover picture shows a model for the selective incorporation and localization of
lipopeptides and lipid-modified proteins in the plasma membrane of cells. The
lipopeptides were introduced into the cell by microinjection or membrane fusion.
According to this model, peptides and proteins which contain S-farnesylated cysteine residues can diffuse freely between different subcellular membranes until they
are additionally S-acylated in a membrane compartment. The now doubly lipidmodified peptide/protein can no longer be transferred between different membranes
and is localized in the membrane where S-acylation takes place, here the plasma
membrane. More on this proposed mechanism and how it was approached by a
combination of techniques from organic synthesis, biophysics, and cell biology
can be found on pages 2238ff in the contribution from the groups of Waldmann,
Wittinghofer, and Silvius.
REVIEWS
Contents
The first growth factors revealed to be involuntary helpers of cancer were hormones.
Synthetic modification of the decapeptide hormone LHRH gave about 5000
analogues, which are superagonists or antagonists. After the sequence determination
of the human LHRH receptor and models derived from it, characterization of the
substances and a search for new lead structures by high-throughput screening have
become possible. The first peptidomimetics and the growing understanding of the
three-dimensional structure of the receptor raises hopes of a new generation of
clinically active LHRH antagonists.
B. Kutscher,* M. Bernd, T. Beckers,
E. E. Polymeropoulos,
J. Engel . . . . . . . . . . . . . . . . . . . 2148 -2161
An important role in organometallic chemistry is predicted for N-heterocyclic carbenes, which are no longer laboratory curiosities but have developed into an industrially interesting class of compounds. They are readily accessible from azolium salts,
can combine with a large variety of metals in different oxidation states, and form
highly active and stable catalysts.
W. A. Herrmann,*
C. Kocher . . . . . . . . . . . . . . . . . 2162-2187
Angew,. Chrm. I n f . Ed. Engl. 1997, 36, No. 20
0 WILEY-VCH Verlag GmbH, D-69451 Weinheim,
1997
Chemistry and Molecular Biology in the
Search for New LHRH Antagonists
N-Heterocylic Carbenes
0570-OS33/97/3620-2139 $ 17.50+ .50/0
2139
HIGHLIGHTS
Contents
Among the diverse range of polyhedra seen for structures of boron clusters, the icosahedron is of particular importance. An unusual icosahedral boron
cluster, in which both closo-borate and selenoborate
substructures are present, was recently synthesized
by Krebs et al. from cesium selenide, boron, and
selenium (see schematic representation on the right,
o = B, 0 = Se).
L. Wesemann*
. . . . . . . . . . . . . 2189-2190
The Direct Synthesis of a closo-Borate from
Elemental Boron
Taxol, a true “evergreen” in natural product chemistry! Owing to the limited supply
of this successful antitumor agent in the bark of yew trees, alternative sources are
being sought. Crucial information on its unusual and complex biosynthesis (shown
below) has been obtained, and some enzymes responsible have been identified. The
long-term goal is the efficient, biotechnological production of taxol (1) by fungi or
plant tissue cultures.
J. Rohr* . . . . . . . . . . . . . . . . . . . 2190-2195
Biosynthesis of Taxol
OH
[U-’ 3Cd glucose
phenylalanine
COMMUNICATIONS
A combination of biotechnology and material science
enables the immobilization of DNA on carbon
nanotubes. After labeling with the heavy atoms platinum and iodine, the double-stranded DNA can be
visualized by high-resolution transmission electron
microscopy. In the picture the arrow highlights the
DNA layer.
S. C. Tsang, Z. Guo, Y K. Chen,
M. L. H. Green, H. A. 0. Hill,
T. W. Hambley, P. J. Sadler* . . 2198-2200
Immobilization of Platinated and Iodinated
Oligonucleotides on Carbon Nanotubes
S. Kammermeier, P. G. Jones,
R. Herges* . . . . . . . . . . . . . . . . 2200-2202
A substructure of a (5,5)-armchair nanotube was
obtained by metathesis reactions with tetradehydrodianthracene. The C-C bonds in the product are all
unsaturated and form a fully conjugated, beltlike
system. A set of molecular building blocks can be
used to synthesize other sections of nanotubes as
well.
2140
0 WILEY-VCH Verlag GmbH, D-69451 Weinheim,
Beltlike Aromatic Hydrocarbons by
Metathesis Reaction with Tetradehydrodianthracene
1997
0570-0833/97/3620-2140$17.50+ .50/0
Angen. Chem. Inr. Ed. Engl. 1997, 36, No. 20
Contents
Small variations in the reaction conditions and the choice of starting materials lead to a diverse range of novel
indium siloxane :structures. These
compounds can serve as model compounds for zeolite:;. The framework
of one of the indium siloxanes is depicted on the right.
A. Voigt, M. G. Walawalkar,
R. Murugavel, H. W. Roesky,*
E. Parisini, P. Lubini . . . . . . . . 2203-2205
Why does the benzene nucleus have a structure similar to cyclohexatriene in the ground state 1, and a
virtually D,,-symmetrical structure in the x + x*
excited state 2? A simple model based on the distortive propensity of the R electrons in the ground
state and their opposite tendency in the excited state
predicts this behavior, and more.
A. Shurki, S. Shaik* . . . . . . . . 2205-2208
Organic-Soluble Neutral and Ionic Indium
Siloxane Cages: Potential Precursors for
Indium-Containing Silicates
The Distortive Tendency of Benzene
n Electrons: How Is It Related to
Structural Observables?
1
2
The aerobic copper-catalyzed oxidation of alcohols such as 1 [Eq. (l)] functions even
in the absence of oxygen. Non-benzylic and secondary alcohols are further suitable
substrates. A key role in this reaction is played by azocarboxylates, which not only
serve as complex ligands but also as hydride acceptors; bulky R groups such as
terr-butyl are particularly suitable.
0"""
ROOCN=N-COOR, Cu'
I. E. Marko,* M. Tsukazaki, P. R. Giles,
S. M. Brown, C. J. Urch . . . . . 2208-2210
Anaerobic Copper-Catalyzed Oxidation of
Alcohols to Aldehydes and Ketones
oCHO
1
Why are there so few exceptions to the fact that pR/pF= I is positive? A straightforward theoretical basis is provided for the interpretation of the dediazoniation of
benzenediazonium ions, one of the most prominent examples of the few reactions for
which the reaction constants pR and pF [Eq. (I)] have opposite signs. The results
support the model that describes C-N bonding as synergistic N + C o dative and
C + N .n backdarive bonding. The analysis furnishes details about the electronic
structure that cannot be deduced from physical-organic studies alone.
lg(k,Y/kO)
=
CFoF
+ "RPR
Electron-Density Relaxation and Oppositely
Signed Reaction Constants in Dual
Substituent Parameter Relationships in
Dediazoniation Reactions
(1)
The incorporation of pyrrole units was the key to stabilizing the largest annulene
from Sondheimer et al., [30]annulene. Of the new aromatic [30]porphyrins 1-3, the
16-phenyl derivative 2 i s the most stable.
Angew. Chem. Inr. Ed Engl. 1997, 36, No.20
R. Glaser,* C. J. Horan,
H. Zollinger* . . . . . . . . . . . . . . 2210-2213
Q WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1997
C. Eickmeier, B. Franck*
. . . . 2213-2215
Hexavinylogous Porphyrins with Aromatic
30 x-Electron Systems
0570-0833/97/3620-2141 $17.50+ SO10
2141
Contents
The simplest nitrogen heterocycle,
aziridine,a very toxic and potentially
explosive liquid at room temperature, forms endless chains with an
ABCABC motif by hydrogen bonding in the solid state. The results of
the crystal structure analysis at
145 K do not suggest any deformations of the molecular skeleton on
going from the gas phase to the solid
state.
N. W. Mitzel,* J. Riede,
C. Kiener . . . . . . . . . . . . . . . . . . 2215-2216
The Crystal Structure of Aziridine
X
Optical activity due only to restricted rotation about the S-N bond in a sulfenamide
is demonstrated for the first time. Selective inversion recovery experiments were
utilized to measure the rate of interconversion of the enantiomers (shown below)
that were seperated by using HPLC.
M. B. D. Blanca, E. Maimon,
D. Kost* . . . . . . . . . . . . . . . . . . 2216-2219
The Chiral S-N Axis in Sulfenamides:
Enantiomeric Resolution, Direct Demonstration of Optical Activity, and Kinetics of
In terconversion
The first stable derivative of the hypothetical Te: iorr-the triiodide-analogous [Mes,Te,]+ ion (partial structure depicted on the right; Mes = 2,4,6trimethylpheny1)-is obtained by addition of the
nucleophile Mes,Te to the iodine-like electrophilic
ion [Mes,Te,]+. This reaction provides the first experimental proof of the close relationship between
the formation of hypervalent nonclassical Te, units
and that of triiodide from I, and I-.
J. Jeske, W. W. du Mont,*
P. G. Jones . . . . . . . . . . . . . . . . 2219-2221
Two molecules of water inserted between two dinuclear Mn: species as p3-hydroxo bridges are
evident in the manganese-oxygen core of
[(Mn:'(L)(OH)(thf)),].2THF (structure shown on
the right). This discrete complex is thus an appealing functional model of the Mn, core of the oxygenevolving center in photosystem I1 at an early S state.
LH, = 1,5-bis(3,5-dinitrosalicylideneamino)pentan3-01); solid unmarked ellipsoids: N ; open unmarked
ellipsoids : 0.
L. Stelzig, B. Donnadieu,
J. P. Tuchagues * . . . . . . . . . . . . 2221 -2222
The deep cavity in the calix[6]arene framework provides a sterically shielded environment for the SeOH
group of the selenenic acid 1. Thanks to this shielding the compound is extraordinarily stable-no decomposition was observed even after heating at
120°C for 5 h in CDCl,CDCl,-although the functional group is still reactive.
T. Saiki, K. Goto,
R.Okazaki* . . . . . . . . . . . . . . . 2223-2224
2142
0 WILEY-VCH Verlag GmbH, D-69451 Weinheim,
Synthesis of a Triiodide-Like Pentamesityltritellurium Cation by Addition of
Dimesityltelluride to the Remarkably
Electrophilic Trimesitylditelluronium Ion
The First Di-p3-hydroxo-Bridged Tetramanganese@) Complex
Isolation and X-ray Crystallographic
Analysis of a Stable Selenenic Acid
1997
0570-083319713620-2142'$17.50+ .SO/O
Angew. Chem. Inr.
Ed. Eng/. 1997,36, No. 20
~
Contents
Not the Markovnikov product 4, but the anti-Markovnikov product 3 is obtained by
the oxidative amination of styrenes 1 with secondary amines 2. The oxidant in this
rhodium-catalyzed reaction is the olefin itself, which is reduced to the ethylarene 5 .
Ar = aryl, R = alkyl, aryl.
2
1
3
4
M. Beller,* M. Eichberger,
H. Trauthwein . . . . . . . . . . . . . 2225-2221
Anti-Markovnikov Functionalization of
Olefins: Rhodium-Catalyzed Oxidative
Aminations of Styrenes
5
A precursor for Cu/Ru mixed-metal catalysts? This is one of the potential
applications of the title cluster (structure of the Ru,,Cu,Cl, framework shown
below), which can be isolated as the nBu,N+ salt from the reaction of
[ (Ph,P),N],[Ru loH,(CO),,] with nBu,NOH/H,O, [Cu(MeCN),], and (Ph,P),NCl.
M. A. Beswick, J. Lewis,
P. R. Raithby,*
M. C. Ramirez de Arellano
..
. 2227-2228
[Ru,,H,Cu,Cl,(CO),,]4-:
A New High
Nuclearity Copper - Ruthenium Cluster
M. D. Wasczcak, C. Lee,
I. H. Hall,* P. J. Carroll,
L. G. Sneddon * . . . . . . . . . . . . 2228 -2230
A cationic ferratricarbadecaboranyl
analogue of the ferrocenium cation
was synthesized and ,;tructurally
characterized (structure shown on
the right). Cytotoxicity and topoisomerase I1 inhibition studies of
the AsF, and SbF; salts strongly
suggest that tricarbadecaboranyl
analogues of other metallocene antitumor agents will exhibit significant
and selective antic:ancer activities.
Cationic Metallatricarbadecaboranyl Analogues of Metallocene Antitumor Agents:
Synthesis, Structure, and Antineoplastic
Activity of [l-(q5-C,H,)Fe-2-Me-2,3,4C,B,H,]+[X]- Salts (X- = AsF;, SbF;)
Borane complexation at the heteroatom increases the gas-phase C-H acidities of
dimethyl sulfide, trimethylamine, and trimethylphosphane by up to 20 kcal mol- '.
Deprotonation of the volatile Lewis acid- base complexes in the gas phase produces
dipole-stablized carbanions (see below) that do not rearrange to the more stable
borate isomers. The complexation also enhances the reactivity of pendant methyl
and ethyl groups toward substitution and elimination reactions.
J. Ren, D. B. Workman,
R. R. Squires* . . . . . . . . . . . . . 2230-2232
Enhanced a-CH Acidity and Reactivity of
Lewis Acid-Base Complexes in the Gas
Phase
BH3-
I
Not germa-, stanna-, and plumbaethenes, but ylidic
carbene adducts (depicted on the right) are obtained
with bis(diisopropy1amino)cyclopropenylidenes. The
first main group metal complexes with this nucleophilic carbene are interesting alternatives to the
intensively studied imidazol-2-ylidenes.
Angeu, Chem. In[. Ed Engi. 1997, 36, No. 20
NfPr2
0E.c:
R'
\R
4
H. Schumann,* M. Glanz, F. Girgsdies,
F. E. Hahn, M. Tamm,*
A. Grzegorzewski . . . . . . . . . . . 2232-2234
NiPr2
E = Ge. Sn. Pb
0 WILEY-VCH Verlag GrnbH. D-69451 Weinheirn, 1997
Cyclopropenylidene Adducts of Divalent
Germanium, Tin, and Lead
0570-0833/97/3620-2143 $17.50+ .50/0
2143
Contents
A nucleophilic rather than a radical mechanism was recently proposed for the
McMurry reaction. Quantum chemical density functional calculations support this
hypothesis. An intramolecular and an intermolecular pathway for the C-C coupling
step are discussed, and the pinacolate complexes 1 and 2 are identified as central
intermediates.
The reaction of RSbCI, with magnesium in tetrahydrofuran provides, in addition to Sb,R, and
Sb,R,, the title compound 1. The X-ray structure
analysis of the yellow crystals of 1 shows that the
Sb, cage corresponds to the P, section of the structure of Hittorfs phosphorus and is structurally
related to realgar (As,S,).
R
I
R-Sb
\'Sb-iSb
'b-h
Sb-Sb,
I
Sb-R
M. Stahl, U. Pidun,
G. Frenking* . . . . . . . . . . . . . . 2234-2237
On the Mechanism of the McMurry
Reaction
H. J. Breunig,* R. Rosler,
E.Lork . . . . . . . _ . . . . . . . . . . .2237-2238
SbSR,, R = (Me,Si),CH-A
Organostibane
Polycyclic
R
1, R = (Me&CH
Very small regions determine where lipoproteins accumulate in the cell. S-Farnesylated and S-palmitoylated N-Ras lipopeptides 1 accumulate specifically in the plasma membrane, as determined by investigations on fibroblast cells with fluorescence
microscopy. (In the structure below the shaded circle symbolizes a fluorescent label.)
Peptides that were only S-farnesylated do not accumulate in the plasma membrane.
H. Waldmann,* M. Schelhaas, E. Nagele,
J. Kuhlmann, A. Wittinghofer,*
H. Schroeder, J. R. Silvius* . . 2238-2241
Chemoenzymatic Synthesis of Fluorescent
N-Ras Lipopeptides and Their Use in
Membrane Localization Studies In Vivo
1
A new hydrogenation catalyst is formed by
thermolysis of the anionic carbonyl cluster
[A~,RLI,,C,(CO),,C~]~
- anchored to the mesoporous silicate MCM-41. The cluster was isolated
and characterized in MCM-41 both before and after
thermal treatment. The picture on the right shows a
model, based in particular on EXAFS analysis, of
the active bimetallic particle. The distribution of the
Ag/Ru particles in the MCM-41 cavities was determined by electron microscopy.
D. S. Shephard, T. Maschmeyer,
B. F. G. Johnson,* J. M. Thomas,*
G. Sankar, D. Ozkaya, W Zhou,
R. D. Oldroyd, R. G. Bell . . . . 2242-2245
Bimetallic Nanoparticle Catalysts Anchored
Inside Mesoporous Silica
* Author to whom correspondence should be addressed
2144
0 WILEY-VCH Verlag GmbH, D-69451 Weinheim, 1997
0570-0833/97/3620-2144 $17.50+ .50/0
Angew. Chem. Int. Ed. Engl. 1997, 36, No. 20
Contents
BOOKS
-
R.Riede1 . . . . . . _ _ . . . . . _ . _ . . . . .2241
..
- W. S. Rees Jr.
R . A . Fischer.. . . . . . . . . . . . . . . . . . . 2241
The Chemistry of Ceramics H. Yanagida, K. Kuomoto, M. Miyayama
CVD of Nonmetals
Introduction to glass science and technology
Chemistry of Powder Production
Hydrocarbon Resins
*
U. Schubert . . . . . . . . . . . .
J. E. Shelby
2248
R. Riedel . . . . . . . . . . . . . . . . . . . . . . . 2249
I! Arai
R . Miilhaupt
R. Mildenberg, M. Zander, G. Collin
Chemometrics in Environmental Analysis
. . .. ... .
......
....
,
. . . . . . . . . 2249
. J. W. Einax, H. W. Zwanziger, S. Geiss
C. Zwiener . . . . . . . . . . . . . . . . . . . . . 2250
- T. W. Swaddle
S . Hasenzahl . . . . . . . . . . . . . . . . . . . . 2250
Inorganic Chemistry. An Industrial and Environmental Perspective
C. Griesinger . . . . . . . . . . . . , . . . . . . . 2251
NMR Data Processing * J. C. Hoch, A. S. Stern
Handbook of Palladium-Catalyzed Reactions * J.-L. Malleron, J.-C. Fiaud,
J.-Y. Lagros
Database of Palladium Chemsitry. Reactions, Catalytic Cyles and
Chemical Parameters on CD-ROM * J.-L. Malleron, A. Juin
Protein and Peptide Analysis by Mass Spectrometry
- J. R. Chapman
German versions o f all reviews, communications, and highlights in this issue appear
in the second October issue of Angeivandte Chemie.The appropriate page numbers can
be found at the end of each article and are also included in the Author Index on
p. 2255.
U. Kazmaier . . . . . . . . . . . . . . . . . . . . 2252
E Zumpe
.
. . . .. . . .. . . .. . . . . . . . . .
2252
J. K Metzger . . . . , . . . . . . . . . . . . . . 2253
SERVICES
Events
2195
2254
0
Author Index
2255
2256
Amen'. C k m Inf Ed Ejlgf 1997, 36,No. 20
0 WILEY-VCH Verlag GmbH. D-69451 Welnhejm. 1997
0570-0833/97/3620-2145 S 17.50+.50,,0
2145
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