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Graphical Abstract (Angew. Chem. Int. Ed. Engl. 151997)

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A Journal of the
L J 1
Deutscher Chemiker
International Edition in English
Pages 1555- I662
The cover picture shows the bright orange-colored solution of a catalyst containing
the depicted phosphane-rhodium fragment (M = Rh) in pure compressed CO,. At
24"C, that is below the critical temperature, liquid and gaseous CO, are in a phase
equilibrium, and the catalyst dissolves in the liquid phase. At the critical point
( T = 31°C) the difference between gaseous and liquid phase disappears, and the
catalyst becomes distributed in the compressed medium. Above the critical point, at
36"C, a homogeneous, supercritical phase (scC0,) exists.The high solubility of the
catalysts in supercritical CO, is attributed to the F(CF,),(CH,), side chains (shown
as waved lines), Provided that a suitable substitution pattern is maintained at the
aromatic ring, these chains do not change the chemical and catalytic behavior of the
active center (dashed oval) in comparison to those of the unsubstituted fragment.
Thus, for the first time the well-known potential of arylphosphorus compounds as
ligands for homogeneous catalysis is available for applications in scC0,. More
about these findings is reported by W. Leitner et al. on pages 1628 ff.
Similar rhodium and iridium complexes, which can be applied in fluorous biphase
catalysis with CF,C,F,, as solvent, are described by I. T. Horvath, J. A. Gladysz
et al. on pages 1610ff. and 1612ff.
Although counterintuitive, the conjecture that high-symmetry, low-entropy truncated
icosahedron C,, spontaneously forms out of the chaos of condensing carbon vapor
proved to be true. The observation that the cluster of 60 carbon atoms is singularly
chemically unreactive, as exemplified by its flagpole prominence in mass spectra,
could be explained only by this hypothesis. This resulted in more conjectures, some
of which proved correct, whereas others relating C,, to diffuse interstellar bonds and
soot formation remain speculative. Even if of questionable validity, these speculations have played a useful role in driving chemists to think about the formation of
fullerenes and other carbon morphologies.
A n p w Chum. Inr Ed. Engl. 1997, 36, No. I5
VCH VerlagsgesellschaftmbH, D-69451 Weinheim,1997
R. F. Curl * . . . . . . . . . . . . . . . . 1566- 1576
Dawn of the Fullerenes: Conjecture and
Experiment (Nobel Lecture)
Basic research must continue to be supported! This is one of the conclusions clearly
evident from the story behind the discovery of the fullerenes. The questions to which
answers were originally sought would not have been posed within the current confines of programs aimed increasingly at applied research. This and the fascination
associated with C,, and other members of the fullerene family are the central messages in this Nobel lecture.
Bucky gets the p r i z w l e v e n years after the discovery of C,, in 1985, the realization
that carbon makes this truncated icosahedral molecule, and larger geodesic cages, all
by itself is honored with the Nobel Prize. Only with the development of laser-vaporization cluster beam methods did the particular significance of C,, become apparent. Indeed the discovery process with respect to fullerenes and the properties of
carbon is far from being complete.
H. Kroto . . . . . . . . . . . . . . . . . . 1578- 1593
Symmetry, Space, Stars, and C,, (Nobel
R. E. Smalley
. ... . . . . .
. . . . . 1594-1601
Discovering the Fullerenes (Nobel Lecture)
Very large, planar, polycyclic aromatic hydrocarbons such as “supernaphthalene” and “supertriphenylene” (1)
are easily constructed by a DielsAlder reaction and subsequent
V. S. Iyer, M. Wehmeier,
J. D. Brand, M. A. Keegstra,
K. Miillen* . . . . . .. . . . . . . . . . 1604-1607
From Hexa-peri-hexabenzocoronene
1: R = H, tBu
Quantitative skeletal rearrangements in the intramolecular cyclodehydrogenation of
oligophenylenes such as 1 lead to planar polycyclic aromatic compounds such as 2.
,c VCH Verlags~esellschaftmbH. 0-69451 Weinheim,1997
Polycyclic Aromatic Hydrocarbons by
Cyclodehydrogenation and Skeletal Rearrangement of Oligophenylenes
The “Teflon greaseball” [RhCl{P[CH,CH2(CF2),CF3]3}3](1) is highly soluble in
CF,C,F,, and catalyzes a variety of organic transformations. The products can be
extracted with organic solvents, and the solution of 1 reused. This environmentally
friendly protocol is showcased for hydroboration, in which the customary oxidative
workup destroys the metal catalyst. Catalyst loadings of only 0.01 -0.25 mol% are
effective under- mild conditions (25-40 “C, 1-40 h)and give turnover numbers as
high as 8500.
M. Miiller, V. S. Iyer, C. Kiibel,
V. Enkelmann, K. Mullen* . . . 1607-1610
J. J. J. Juliette, I. T. Horvath,*
J. A. Gladysz* . . . . . . . . . . . . . . 1610-1612
Transition Metal Catalysis in Fluorous
Media: Practical Application of a New
Immobilization Principle to RhodiumCatalyzed Hydroboration
057O-OS33j97!3615-155S$17.50+ .5OjO
Angew. Chem. Int. Ed. Engl. 1997, 36, N o . 15
M.-A. Guillevic, A. M. Arif, I. T. Horvath,*
J.A.Gladysz*. _ . . .. _ . .. . . . . 1612-1615
The most highly fluorinated aliphatic species crystallized to date is 1 an exceptionally interesting
molecule with regard to its structure and from a
mechanistic standpoint. Four of the fluoroalkyl
groups form raftlike domains, which pack back-toback in a motif that maximizes parallel chains (depicted on the right). Complex 1 and CH,I react by
a free radical chain mechanism in CF,C,F,, , as opposed to the polar pathway for Vaska’s complex in
organic solvents. Although 0, is highly soluble in
CF,C,F, , , its addition to 1 is slower than in common organic solvents.
Synthesis, Structure, and Oxidative Additions of a Fluorous Analog of Vaska’s
Reactivity in
Fluorocarbons and Implications for
Chemotherapy of malignant tumors is extremely problematic because of the low
selectivity of the available cytostatic agents. The now synthetically available ether
2-the first stable analogue of lactone 1, which was identified as the tumor-associated antigen-presents the possibility for an active immunization against cancer.
Thermal stability (up to 350°C) is one of the characteristics of the supramolecular mesogenic polyamide
formed by self-assembly during the complexation
between a phenylbenzoic acid and a nylon containing pyridyl units in its backbone. The probable
structure of the hydrogen-bonded complex is shown
schematically on the right.
L. F. Tietze,* H. Keim . . . . . . . 1615-1617
Synthesis of a Novel Stable GM,-Lactone
Analogue as Hapten for a Possible Immunization against Cancer
T. Kato,* Y. Kubota, T. Uryu,
S.Ujiie. ~. . . . . . . . . . . . . . . . . . 1617-1618
Self-Assembly of a Mesogenic Polyamide:
Induction and Significant Stabilization of a
Liquid-Crystalline Phase through Complexation of a Phenylbenzoic Acid with a
Polymer Backbone Derived from 2,6Bis(amin0)pyridine Units
Rectangular channels lined with methylene groups
characterize the structure of the title compound.
The framework is constructed from COO,octahedra
and COO, tetrahedra that are linked through
0 - P - 0 bonds (structure depicted on the right).
The hydrophobic channels appear suitable for the
uptake of flat guest molecules.
D. L. Lohse, S.C. Sevov*
. H,O: A Novel
Microporous Diphosphonate with an Inorganic Framework and Hydrocarbon-Lined
Hydrophobic Channels
Angen. Chem. Inr. Ed. EngI. 1997, 36. No. I S
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Weinheim. 1997
$ 17.SO+ 50’0
Generation of three stereogenic centers in the angular tetracyclic framework of 3 is
possible starting from enantiomerically pure naphthoquinone 1 and the substituted
racemic vinylcyclohexene 2. The product 3 is formed in a one-pot domino reaction
comprising Diels-Alder cycloaddition and pyrolytic elimination of the sulfoxide.
The key step is the kinetic resolution of the racemic diene.
M. C. Carreiio,* A. Urbano,
J. Fischer . . . . . . . . . . . . . . . . . . 1621-1623
Enantioselective Diels-Alder Approach
to Angucyclinones from (S)-2-(p-Tolylsulfinyl)-l,4-naphthoquinone and Substituted Racemic Vinylcyclohexenes
Zwitterionicspecies are most likely the intermediates for the formation of 1,l-dihalo2,3-diarylbutadienes by addition of dihalocarbenes to 1,2-diarylcyclopropenes
[Eq. (a)]. Bicyclobutanes can be ruled out as intermediates for the formation of
J. Weber, U. H. Brinker * . . . . . 1623- 1626
Evidence for a Stepwise Addition of Carbenes to Strained Double Bonds: Reactions
of Dihalocarbenes with Cyclopropenes
The presence of an aqua bridge in the active and
phosphate-bound reduced form of manganese-containing catalases is the key finding from magnetization studies on these compounds. In addition several
observations indicate that the phosphate group may
form a second bridge, which suggests that two syn
coordination sites of the active dimanganese center
are occupied by easily exchangeable ligands, namely .&NI'
water molecules. The proposed structures are deON
Mn \N/O
L. Jacquamet, I. Michaud-Soret,
N. Debaecker-Petit, V. V. Barynin,
J.-L. Zimmermann,
J.-M. Latour* . . . . . . . . . . . . . . 1626-1628
l N / 0
Magnetization Studies of the Reduced
Active Form of the Catalase from Thermus
picted on the right.
The solubility of complexes is one
decisive factor for their use as homogeneous catalysts in supercritical carbon dioxide (scC0,). Complexes with
perfluoroalkyl-substituted aryiphosphane ligands (shown schematically
on the right), which can be prepared
by a straightforward and variable
synthetic methodology, exhibit high
solubility in scC0, in contrast to unsubstituted parent compounds.
S. Kainz, D. Koch, W. Baumann,
W. Leitner* . . . . . . . . . . . . . . . . 1628-1630
sccoz 9p@
\ p<c=02
- _- _.....
Extremely bathochromically absorbing derivatives of the halobacterial membrane
protein bacteriorhodopsin (Amax = 570 nm) form upon incorporation of merocyanine dyes of the type shown below into the protein binding site. Upon covalent
attachment to the protein (through formation of a protonated Schiff base), these
compounds convert into hemicyanines in which the positive charge is distributed
over the entire 7~ system of the chromophore.
= 487 nrn
Perfluoroalkyl-Substituted Arylphosphanes
as Ligands for Homogeneous Catalysis in
Supercritical Carbon Dioxide
D. Hoischen, S. Steinmiiller,
W. GCrtner,* V. Buss,*
H.-D. Martin* . . . . . . . . . . . . . 1630-1633
Merocyanines as Extremely Bathochromically Absorbing Chromophores in the
Halobacterial Membrane Protein Bacteriorhodopsin
h,,, = 755 nm
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Angew. Chem. I n t . Ed. Engl. 1997,36, No. 15
The size and shape of the molecules of
the aliphatic hydrocarbon solvent
have a strong influence on the magnitude of the anomalous spectral
shift in the fluorescence maximum of
the charge transfer (CT) state of a
high-generation dendrimer (shown
schematically on the right). Its molecules no longer exist in an open extended form but exhibit a compact, globular structure, and the dipole moment of the
CT state in pentane is larger than in cyclohexane.
The molecular geometry is mirrored
in the macroscopically ordered patterns found in a series of stiff, phenylacetylene dendrimers 1. These compounds form hexagonal columnar
liquid crystalline phases with snowflake-like morphologies.
C. Devadoss, P. Bharathi,
J. %Moore* . . _ _ _. ... . . . _ _ 1633-1635
Anomalous Shift in the Fluorescence
Spectra of a High-Generation Dendrimer
in Nonpolar Solvents
D. J. Pesak, J. S. Moore* . . . . . 1636-1639
Columnar Liquid Crystals from ShapePersistent Dendritic Molecules
By immobilizing the cobalt complex 1 on the glycine-functionalized inner walls of
mesoporous silica (MCM41), an efficient heterogeneous catalyst for the selective
oxidation of cyclohexane to cyclohexanone with tert-butyl hydroperoxide is produced. The detailed atomic structure of the active site during catalysis was determined by in-situ X-ray absorption spectroscopy. The findings are important for the
design of new efficient oxidation catalysts.
T. Maschmeyer,* R. D. Oldroyd,
G. Sankar, J. M. Thomas,'
I. J. Shannon, J. A. Klepetko,
A. F. Masters, J. K. Beattie,
C. R. A. Catlow . . . . . . . . . . . . 1639- 1642
Designing a Solid Catalyst for the Selective
Low-Temperature Oxidation of Cyclohexane to Cyclohexanone
Clear confirmation of recent theoretical studies concerning the structure of the endohedral complexes
formed by La and C,, is provided by the NMR
spectroscopic investigations presented here. Complex La,(qC,, is present, and its structure is based
on the unstable "empty" Z,,isomer of C8,. The two
La atoms circulate inside this round cage even at
room temperature (shown schematically on the
T. Akasaka,* S. Nagase,* K. Kobayashi,
M. Walchli, K. Yamamoto,
H. Funasaka, M. Kako, T. Hoshino,
T. Erata . . . . . . . . . . . . . . . . . . . 1643- 1645
Novel reagents for olefin amination-A new class of manganese(v) nitrides containing Schiff bases as ligands was prepared from the corresponding Mn"' complexes
following a new mild oxidative procedure. Structures of examples of both the Mn"'
starting material and the Mn" product have been confrimed by X-ray crystallography. These Mn-N complexes such as 1 are potentially effective reagents for nitrogen-atom transfer, as could be demonstrated by the reaction with styrene.
J. Du Bois, C. S. Tomooka, J. Hong,
E. M. Carreira,* M. W. Day . . 1645-1647
AngeM. Chem. In1 Ed. EngI. 1997, 36, No. 15
0 VCH Verlagsgesellschafi mhH, D-69451 Weinheim, 1997
I3C and I3'La NMR Studies of La,@C,,:
First Evidence for Circular Motion of
Metal Atoms in Endohedral Dimetallofullerenes
Synthesis and Structure of Novel Mn"' and
MnV Complexes: Development of a New,
Mild Method for Forming Mn=N Bonds
/7.50+ SO 0
The differentiated recognition of Ag' and Hg" can be achieved with the pentaleno
crown ethers 1 both by variation of the cavity size and through the reversible trithiadiazapentalene-trithiotriuret redox system ( 1 s 2 ) . These compounds were obtained
in a one-pot reaction of trithiadiazapentalenes with diamino polyethers of different
chain lengths. n = 1-3, R = CH,, CH,C,H,.
%# L
H. Graubaum,* F. Tittelbach, G. Lutze,
K. Gloe,* M. Mackrodt, T. Kruger,
N. Krauss, A. Deege,
H. Hinrichs . . . . . . . . . . . . . . . . 1648- 1650
Novel Crown Ethers with a Trithiadiazapentalene-Trithiotriuret Redox System
v0qo2 vogo
Promising as a chelating agent and as a photosensitizer, hemiporphycene is the third porphyrin isomer
after porphycene and corrphycene with a central N,
coordination sphere. The stable octaethyl derivative
of hemiporphycene 1 was obtained by the combination of a McMurry reaction and a reductive CC
cleavage from a bis(tetrapyrroledia1dehyde). Like
its congeners, 1 possesses a planar ring skeleton.
\' - -
E. Vogel,* M. Broring, S. J. Weghorn,
P. Scholz, R. Deponte, J. Lex,
H. Schmickler, K. Schaffner,*
S. E. Braslavsky, M. Miiller, S. Porting,
C. J. Fowler, J. L. Sessler" . . . . 1651-1654
Octaethylhemiporphycene: Synthesis,
Molecular Structure, and Photophysics
* Author to whom correspondence should be addressed
Linus Pauling: A Life in Science and Politics - T. Goertzel, B. Goertzel
Force of Nature: The Life of Linus Pauling . T. Hager
Linus Pauling in His Own Words: Selections from His Writings, Speeches,
and Interviews B. Marinacci
G. B. Kauffman, L. M . Kauffman
Edward Frankland: Chemistry, Controversy and Conspiracy
in Victorian England C. A. Russell
Laser Techniques in Chemistry
. A. B. Meyer, T. R. Rizzo
$2 VCH VerlagsgesellschafimbH, 0-69451 Weinheim. 1997
H . Baumgartel . . . . . . . . . . . . . . . .. . 1658
German versions of all reviews, communications, and highlights in this issue appear
in the second July issue of Angewandte Chemie.The appropriate page numbers can be
found at the end of each article and are also included in the Author Index on p. 1661.
G. B. Kauffman, L. M . Kauffman . . 1655
Author Index
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Angew. Chem. Int. Ed. Engl. 1991, 36, No. 15
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