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Graphical Abstract (Angew. Chem. Int. Ed. Engl. 71994)

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International Edition in English
A Journal of the
Deutscher Chemiker
Pages 699-792
The cover picture shows in the foreground the oxygen-bridged binuclear iron(rv)
complex p-oxo-bis[ (octaethylcorrolato)iron(~v)]( N = green, 0 = blue, Fe = pink,
ethyl substituents have been omitted), which may bring about a renaissance of the
metallocorroles. The fact that corroles stabilize metals in unusual oxidation states BS
trianionic ligands has now been proven by E. Vogel et al.-see pp. 731 -735-with
some iron(iv) corrole complexes, formed from the stable, diiron complex shown,
which crystallizes as black rhombuses. The question mark in the background emphasizcs the uncertainty associated with the unequivocal assignment of the oxidation state to the metal center in complexes with “non-innocent” ligands such as
Wild mixtures of stereoisotners are usually formed in the synthesis of oligo(nucleoside phosphorothioate)s owing to the stereogenic phosphorus centers. Is the
preparation of isomers with defined configuration at each phosphorus atom feasible,
and if so. how far off is the stereoselective synthesis? In this review the problems of
the stereoselective preparation of these compounds are outlined, and new synthetic
methods are discussed. Oligo(nuc1eoside phosphorothioate)s have potential as “antisense therapeutics” for treatment of viral infections, cancer, and possibly even
AIDS. But medical applications require stereochemically uniform compounds.
W. J. Stec,* A. Wilk ................... 709- 722
Stereocontrolled Synthesis of Oligo(nucleoside phosphorothioate)s
Readout of an entire protein sequence from a mass spectrum, a high sample throughput, and the possibility of sequencing modified peptides or peptides containing
unusual amino acids are the advantages of the combination of Edman degradation
and mass spectrometry (MS). Fully automated sequencers based on this ladder
sequencing technique would provide viable alternatives to the standard sequencers
equippcd with on-line HPLC. This technique shows the potential of novel ionization
and MS techniques for future protein analysis.
J. W. Metzger* ...........................
Ladder Sequencing of Peptides and
Proteins-A Combination of Edman
Degradation and Mass Spectrometry
Like a complicated puzzle containing pieces that do
not belong, the determination of the structure of the
active site of photosystem 11presents several intricacies. The picture on the right shows a new model for
the 0x0- and carboxylato-bridged Mn, cluster.
which also considers the coordinated cofactors
Ca' + and C I ~The
, concept is based on spectroscopic
data (ESR, EXAFS) from years of research.
K . Wieghardt* ...........................
A Structural Model for the Water-Oxidizing Manganese Cluster in Photosystem I1
Will optical resolution by HPLC with chiral columns become obsolete? With a new
technique, which should be amenable to upscaling, suspensions of crystalline host
compounds such as 1 and 2 in hexane or water form 1 : I complexes with the one
enantiomer of a racemic alcohol or ether such as 3 and 4 that fits best into its lattice.
The two enantiomers can then be separated by vacuum distillation.
G. Kaupp* ................................
Resolution of Racemates by Distillation
with Inclusion Compounds
The unusual oxidation state + I V for iron centers can
be stabilized by porphyrin-like corrole ligands in
such a way that the compounds 1 (R = CI, Ph, OFecorrole) can be isolated at room temperature. The
oxygen-bridged binuclear iron(1v) corrole, which
can be readily converted into the mononuclear
ironfrv) corrole, forms as the only defined product
from the reaction of the ligand with [Fe,(CO),J followed by workup in air. In contrast, only a few
iron(rv) porphyrins are known so far, and these are
too unstable to be isolated as solids.
Far-reaching analogies between p-oxodiiron(iii) complexes of porphycenes and porphyrins with regard to
physical. chemical. and structural properties are revealed by investigations of the new metalloporphycenes 1 (R = nPr, t B u ) . These are obtained by
using standard methods for porphyrin chemistry.
The Fe-0-Fe angle in 1 (R = nPr) differs widely
(145 ) from those of the metalloporphyrins (1 61
180') and that of 1 (R = t B u ; 179") as a result of
reduced steric interactions.
E. Vogel,* S. Will, A. Schulze Tilling,
L. Neumann, J. Lex, E. Bill,
A. X. Trautwein,
K . Wieghardt .............................
731 -735
Metallocorroles with Formally Tetravalent
R -
M. Lausmann, I. Zimmer,
J. Lex, H. Lueken,
K. Wieghardt, E. Vogel* ........... 736-739
p-Oxodiiron(rr1) Complexes of Porphycenes
Neither in the solid state, nor in solution-proof of
the existence of indigoid compounds such as I with
thioxo instead of 0x0 groups remains elusive. The
oxidation of leucoindigoid precursors does not lead
to 1 in any example examined, but rather to the
valence isomeric 1.2-dithiines 2 o r to niacrocyclic
bisdisulfides, depending on the heteroatom X (S.
NCH,, NH. 0).
* xg?
W. Schroth,* E. Hintzsche,
M. Felicetti, R. Spitzner,
J. Sieler, R . Kempe ....................
\ /
Concerning the Questionable Existence of
Thioxoindigoid Compounds
Coordination with participation of manganese distinguishes complexes 1 and 2. The
P-Mn bond in 1 remains intact, whereas in 2 the bond is cleaved and the P atoms
are subject to electrophilic attack.
L. Brunet. F. Mercier,
L. Ricard, F. Mathey* ............... 742-745
The Reactivity of Phosphacymantrenes
towards Palladium(n) and Palladium(o)
Compounds: Synthesis, Structure, and
Chemistry of Pd,Mn, and Pd,Mn, Arrays
Me Me
The synthesis of new, medium-sized copper clusters with unusual structures and a
successful combination of experiment and theoretical calculation- this is offered by
the present communication. The reaction of CuAc with PR,R' (R, R' = Et, Ph) and
E(SiMe,), (E = S , Se) leads to the clusters 1-4. Several of these might be intermediates in the synthesis of larger cluster complexes. The structure of [Cu,,Se,(PH,),]
calculated by ab initio methods agrees with the structure of 1 within the limits of the
Vertex-sharing BO, and PO, tetrahedra form the framework of the title compounds.
Ca[BPO,] and Sr[BPO,] crystallize in the stillwellite structural type and contain
tetrahedral chain anions k[BPO:-]. which can be described as loop-branched
"dreier" single chains. In Ba,[BP,O,,] the :,tetrahedral anions form "zweifach"
open "vierer" single chains. Given these results and the known linking modes of
tetrahedral units, it is expected that borophosphates with layered and framework
structures. as well as microporous structures, can be found.
In a one-pot reaction, aldononitriles can be synthesized smoothly from glycosyl
azides by successive treatment with N-bromosuccinimide (NBS) and activated
metals M* [Eq. (a)]. By the correct choice of the reducing agent, the intermediate
alcoholate can be trapped with electrophiles.
The determination of the structures of molecules in solution is a challenge. Now the
relative configuration, and to a certain extent, the preferred conformation of a
flexible chiral compound can be determined by calculations employing data obtained from NMR cross-relaxation experiments. Force field parameters and conformational preferences need not be specified.
A look behind hydrogenation catalysts: How is the hydrogen molecule bound to the
metal atom of a carbonyl complex in the intermediate? Which positions of a substrate molecule are attacked as a result? The course of a photochemical hydrogenation [Eq. (a)] could now be followed for the first time by NMR spectroscopy through
nuclear spin polarization effects.
hv, p-H,
hv, P-H,
I co
(M = Cr)
- co
(M = Mo)
S. Dehnen, A. SchCfer.
D. Fenske,*
R. Ahlrichs ................................
New Sulfur- and Selenium-Bridged Copper
Clusters; Ah Initio Calculations on
[Cu,,Se,(PH,),] Clusters
R. Kniep," G . Gozel, B. Eisenmann,
C. Rohr, M. Asbrand,
M. Kizilyalli ..............................
Borophosphates- .A Neglected Class of
Compounds: Crystal Structures of
Mn"[BPO,] (MI' = Ca, Sr) and Ba,[BP,O,,]
A. Furstner,*
J.-P. Praly * __.........___._________._......
751 -753
Conversion of Glycosyl Azides via
N-Bromoglycosylimines to Aldononitriles
M. Reggelin,* M. Kock,
K. Conde-Frieboes,
D. Mierke .................................
Determination of the Relative Configuration by Distance Geometry Calculations
with Proton-Proton
Distances from
NOESY Spectra
A. Thomas, M. Haake,
E-W. Grevels, J. Bargon* .......... 755-757
In Situ NMR Investigations of Photocatalyzed Hydrogenations with Parahydrogen
in the Presence of Metal Carbonvl
Compounds of Group 6
Simply heating a suspension of
[Ph,P][VO,CI,] and tBuPO,H, in
acetonitrile in a sealed tube to
100°C gave the first of the three
title compounds as dark green crystals. The structure of this compound (shown on the right) could
not have a more pleasing simplicity. Relatively minor changes in
the starting materials led to other,
more complicated products.
J. Salta. Q. Chen.
Y.-D. Chang, J. Zubieta* ........... 757-760
Neutral molecules are encapsulated in the cluster anions in the title, which were
produced by solvothermal reactions of [nBu,N],[H,V,,O,,]
and PhAsO,H, in
CH,OHiH,O (99 : 1) with and without Et,NCI. The structures are shown schematically below.
The Oxovanadium- Organophosphonate
System: Complex Cluster Structures
[(VO),jPhP(O),OP(O),Ph~ 4C1]-, and
Encapsulated Chloride Anions Prepared
from Simple Precursors
M. I. Khan, J. Zubieta . . . _ _ _ . _ _760-762
The Oxovanadium-Organoarsonate
System: [2CH,OH c VI20,,(0H),(phAsO,),,,l"- and [ 2 H z 0 = VlZ0,2(OH)2-
Clusters with Nanometer Dimensions and
Cavities for Neutral Molecules
Carbon rods 1-5 up to five nanometers long are formed by oxidative polymerization
of trans-bis(triisopropylsily1)-protected tetraethynylethene with phenylacetylene as
end-capping reagent. The X-ray crystal structures of 1 and 2 show perfectly planar,
conjugated carbon frames. Compounds 1 - 5 are readily reduced; the number of
reversible one-electron reductions equals the number of tetraethynylethene moieties
in each molecular rod. TIPS = triisopropylsilyl.
J. Anthony, C. Boudon,
F. Diederich," J.-P. Gisselbrecht.
V. Gramlich, M. Gross,
M . Hobi. P. Seiler _.._.__...._.__._..___
Stable Soluble Conjugated Carbon Rods
with a Persilylethynylated Polytriacetylene
In solution, in an organic glass, and in an argon matrix-the irradiation of the bisdiazo compound 1 always leads to the silirene 2 as the main product. The latter was
characterized both directly by IR spectroscopy and by its products of trapping
experiments. Compound 2 is the first silirene without substituents at the double
\ /
M. Trommer, W. Sander,*
C. Marquard .............................
1,l -Dimethyl-1H-silirene
More than three PR,Au ligands were coordinated for
the first time to an element of the sixth main group:
the p4-S atom of the title compound occupies the
apical position in the tetragonal pyramidal framework (shown on the right); its four Au atoms are
arranged in a butterfly form with a hinge angle of
30 ’.
F. Canales, M. C. Gimeno,
P. G. Jones, A. Laguna* ........... 769-770
Discrete metal clusters in quasi-solid solution are
present in amorphous sulfides of the transition
metals in the intermediate oxidation states. A
“chemical” possibility for their characterization is
cyanolgsis. In this way the title compound I was
“extruded” from amorphous Re$, , which is built
up of tetranuclear clusters. The Re:” Re:” cluster
arises through oxidation of the hypothetical “intermediate” [Re,(t‘z-S),(~u,-S),(CN)
, O ] s -.
A. Mullet-,* E. Krickemeyer,
H. Bogge, H. Ratajczak,
A. Armatage ..............................
Aurophilicity at Sulfur Centers : Synthesis
and Structure of the Tetragold(1) Species
[(Ph3PA~),S](CF,S0,), . 2CH,CI2
A Building Principle of Amorphous
Chalcogenides of Transition Metals: The
“Extrusion” of the Electron-Rich Cluster
[Re,S,(S0,),(CN),0]8~ from a-Re,&
Kinetically inert and yet catalytically active is
the lanthanum complex 1, whereas the
analogous Eu and Dy complexes catalyze neither cleavage of R N A oligomers nor transesterification of a phosphate diester. A possible
explanation for the different behavior is the
size of the La3+ ion. which enables an expansion of the coordination sphere from nine to
S. Amin, J. R. Morrow,*
C. H. Lake,
M. R. Churchill .........................
773 -77s
Lanthanide(II1) Tetraamide Macrocyclic
Complexes as Synthetic Ribonucleases:
Structure and Catalytic Properties of
+ 3 CF,SO; + EtOH
S.-H. Jang, P. Gopalan,
J. E. Jackson,* B. Kahr* ........... 775-777
The structure of the peroxides 1, which arise
on oxidation of the corresponding triarylmethyl radicals in air, remained unrecognized
for a long time. The false assumption that
triarylmethyl radicals are linked methylto-methyl on peroxidation parallels the earlier misconception that triphenylmethyl dinier
was hexaphenylethane. R = H, OCH,.
Dithiiranes were hitherto considered unstable and
were only discussed as elusive intermediates. The
dithiirane 1, in contrast, can be readily isolated, purified. and characterized by spectroscopy and X-ray
diffraction as well as by a series of chemical reactions.
Jacobson and Heintschel Peroxides
The First Isolable Dithiirane by Oxidation
of a Dithietane
Exchange of a P-methine unit for an N atom of a
pyrrole ring of a porphyrin leads to a new type of
porphyriin isomer, which is formed by condensation
of pyrrole grid p-tolylaldehyde. Ni” ions are surprisingly coordinated by 1 as tetradentate ligand, that is
through the three N atoms and the C atom of the
inner cycle. The framework of the green metalloporhyrin is planar.
A. Ishii, T. Akazawa,
T. Maruta, J. Nakayama,*
M. Hoshino, M . Shiro ............... 777-779
P. J. Chmielewski,
L. Latos-Graiynski.*
K. Rachlewicz,
T. Glowiak .................................
Tetra-p-tolylporphyrin with an Inverted
Pyrrole Ring: A Novel Isomer of Porphyrin
C n n ten t c
Within reach appears to be the total synthesis of dynemicin A now that after the
preparation of the endiyne moiety, the synthesis of the pentacyclic anthraquinone
skeleton has been achieved. Starting from 1, the key steps of the reaction sequence
are two ortho metalations at quinoline which furnish the ketone 2 after quenching
with the appropriate electrophile, cyclization, and oxidation. The ketone is probably
a suitable precursor for the totai synthesis of this cystostatic and antibiotic agent.
K. C. Nicolaou,*
J. L. Gross, M. A. Kerr.
R. H. Lemus, K . Ikeda,
K. Ohe .......................................
781 -783
Synthesis of the Anthraquinone Framework of Dynemicin A
AgBF, assists chloride abstraction, and the HBF, formed as intermediate acts as
catalyst for the ligand exchange in the simple synthesis of homo- and heteroleptic
monomeric platinum complexes according to Equation (a). Z, Z' = H, Me.
A. D. Ryabov,*
R. van Eldik* ............................
An Easy Route to Homo- and Heteroleptic
Biscycloplatinated Complexes without
Recourse to Organohthium Compounds
Highly reactive and sparingly soluble, the first tetraaminophosphoniurn salt P(NH,),I (crystal structure of the cation shown on the right) is accessible
from phosphorothionic triamide. For the acid- base
pair H,PN,f/PN:- the structures could be compared over eight dissociation steps for the first time.
W. Schnick.* S. Horstniann,
A. Schmidpeter ..........................
Synthesis and Crystal Structure of the First
Tetraaminophosphonium Salt P(NH,),I
The same compound, 1,2,3,4-Cb0H,
( l ) , is both the major kinetic product
of the reaction of C,, or C,,H, with
BH, and the thermodynamically
most stable isomer of C,,H,. This
was predicted by ab initio calculations and confirmed by experiment.
C. C. Henderson,
C. M. Rohlfing, R. A. Assink,
P. A. Cahill* ..............................
The ionizing power of liquid SO, is sufficient to induce reactions between acetals or
SKI-active alkyl chlorides with allylsilanes without additional Lewis acids [Eq. (a),
X = OCH,, R = PhCH(OCH,), n-C,H,,CH(OCH,), etc.; X = CI, R = Ph,C, PhMe,C, etc.]. Reactions in liquid SO, are economical and ecologically advantageous.
An additional benefit: they are extremely simple to perform!
+ CH,=CH-CH,-SiMe,
a me ,SIX
, R-CH2-CH=CH,
C,,H,: Kinetics and Thermodynamics of
Multiple Addition to C,,
H. Mayr,* G. Gorath, B. Bauer
Liquid Sulfur Dioxide as a Lewis-Acidic
Solvent for the Alkylation and Alkoxyalkylation of Allylsilanes
* Author
whom correspondence should be addressed
Coordination Chemistry of Aluminum
Biosensors. Theory and Applications
G. H. Robinson
. D. G. Buerk
The Organic Chemistry of Drug Design and Drug Action
R. B. Silverman
u! Uld ...............................................
U. Bilitewski ......................................
J. D. Dohertx .....................................
Author Index A-29
Preview A-30
The Best Cover Picture in 1993
Many thanks to all readers in Germany and overseas who took the trouble to tell us their favorite
cover pictures from last year. We were glad that every cover appealed to someone; nevertheless,
some were streaks ahead of others. The clear favorite as first choice was the April cover, showing
the spectral “landscape” of the fluorescence excitation spectra of single perylene molecules in a
polyethylene film. This was followed by the February cover (a copper- tellurium cluster), and the
third most frequently quoted in first place were the January and March issues (an eleven-component supercomplex and a tetraethynyltetradehydro[l2]annulene,respectively). Most often mentioned (that is, as first, second, or third choice) was the October cover (atomic force microscopy
image of DNA), followed by September (dendrimer-the largest characterized hydrocarbon) and
April (see above) in that order.
How are the cover pictures conceived? Most often they are thanks to the creativity of our authors
who send a cover picture suggestion along with their manuscript. That is most welcome. Of
course, in some cases the stimulus for the picture comes from the editors.
The winners of a year’s subscription to Angewandte C/ or VCH books to the value of
DM 300.- are S. Kazarian, Nottingham; J. Gross, Darinstadt ; D. Klostermeyer, Munich;
E. Lattmann, Hannover; F. Starck, Erlangen; C. Steuckart, Gottingen.
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abstract, int, angel, engl, chem, graphical, 71994
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