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Graphical Abstract (Angew. Chem. Int. Ed. Engl. 23241994)

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A Journal of the
Deutscher Chemiker
International Edition in English
Pages 2351 -2544
The cover picture shows Emil Fischer in his Berlin laboratory around 1910 and points
to the unifying theme of several articles in this issue- the 100th anniversary of
Fischer’s lock-and-key principle. To mark this occasion a symposium took place in
Mainz, Germany, last August with the title “Supramolecular Chemistry: 100 Years
Schloss-Schliissel-Prinzip. A. Eschenmoser’s introductory remarks from this conference. F. W. Lichtenthaler’s tribute to Emil Fischer, and D. E. Koshland’s lecture on
the extension of Fischer’s principle to the theory of induced fit are presented here.
Emil Fischer and supramolecular chemistry: The link between the discoverer of the
lock-and-key concept and major aspects of this new branch of chemistry is tracked
down by A. Eschenmoser in his introductory comments at a symposium in Mainz,
Germany. in August 1994. He also comments on the two fundamental selection
types postsynthesis selection and presynthesis selection, or in other words, discovery and design.
“To use a picture I would like to say that enzyme and glucoside have to fit together
like lock and key in order to exert a chemical effect on each other.” These words were
used in 1894 to describe what has become one of the most fertile concepts not only
in organic chemistry, but also in biology and medicine. To commemorate the
hundredth anniversary F. W. Lichtenthaler gives an account of how Emil Fischer
was led to this analogy and how avidly it was adopted by others, yet how cautiously
it was applied by its initiator.
A. Eschenmoser* ..............................
One Hundred Years Lock-and-Key Principle
F. W. Lichtenthaler* .............. 2364-2374
100 Years “Schliissel-Schloss-Prinzip”:
What Made Emil Fischer Use this Analogy?
As a glove changes shape when a hand slips into it, so an enzyme changes its conformation on binding a ligand. This theory of induced fit extends the lock-and-key
principle that Emil Fischer proposed exactly 100 years ago. The new theory proposed by D. E. Koshland. Jr. in 1958 allows one to explain regulation and cooperative effects. and adds some new specificity principles as well.
An almost forgotten method has turned into a creative answer to new questions in
synthesis. In the past few years the palladium-catalyzed coupling of aryl and alkenyl
halides with alkenes, known as the Heck reaction. and a series of related C-C bond
forming reactions have gained a secure position in the organic chemist's arsenal of
methods. These reactions can be conducted with chemo-, regio-, diastereo-. and even
enantioselectivity, and are pivotal components of modern cascade reactions. Openchain precursors such as 1 may thus be used to prepare impressively complex oligocycles like 2. R = C0,Me.
D. E. Koshland, Jr.* .............. 2475-2478
The Key-Lock Theory and the Induced Fit
A. de Meijere,*
F. E. Meyer ............................
2379-241 1
Fine Feathers Make Fine Birds: The Heck
Reaction in Modern Garb
Not just the size but also the multiplication of functions possible through branching
is at the forefront of dendrimer chemistry. Owing to the numerous recent key
publications by Newkome. Frechet, Moore, Majoral, Meijer, and others, this Highlight has the dimensions of a minireview.
J. Issberner, R. Moors,
F. Vogtle* .....................____.___. 2413-2420
Dendrimers: From Generations and Functional Groups to Functions
Palladacycles like 1 undergo spontaneous rupture of the C-C bond between the
aliphatic and aromatic parts of the norbornyl-phenyl ligand after selective metudialkylation of the arene ring through PdIV intermediates like 2. This reaction proceeds smoothly without a-H elimination with alkyl and benzyl halides RX.
+ 2RX
2421 -2422
Palladacycles as Intermediates for Selective
Dialkylation of Arenes and Subsequent
Very high yields and diastereoselectivities. mild reaction conditions. a straightforward experimental procedure, and cheap starting materials-- these are the advantages offered by the reaction of (E)-enamines 1 with iminium salts 2 to give the
Mannich bases 3. Since Mannich bases are important synthetic building blocks for
pharmaceuticals and natural products, this reaction will surely prove to be extremely
M. Catellani,*
M. C. Fagnola .......................
N. Risch,* M. Arend ...........__2422-2423
Diastereonierically Pure Mannich Bases
from the Addition of Enamines to Ternary
Iminium Salts
High molecular mass, uniform structure, and complete solubility characterize the
novel ladder polymers 1. The formation of dication 2 from a model analogue of 1
by oxidation with 2,3-dichloro-5,6-dicyanobenzoquinone(DDQ) and subsequent
dehydration with trifluoromethanesulfonic acid reveals that 1 is a potent precursor
for the preparation of heteroanalogous. ionic poly[n]acenes. R ' = p-C,H,n-C,,,H2,. RZ = p-C,H,rBu; counterion CF,SO;.
T. Freund. U . Scherf.
K. Mullen* ............................
Ladder Polymers with a Heteroacene Skeleton
Surprisingly low thermal stability in solution is displayed by the 2H-1.2-azaphosphirene tungsten complex 1 : acetylene derivatives and benzaldehyde were
used to trap an intermediate phosphanediyl tungsten complex formed from 1. The reaction of 1 with
benzaldehyde provides a new, diastereoselective
route to oxaphosphirane tungsten complexes.
How does the rate of electron transfer between
the quinone and porphyrin units in cyclophanes of type 1 vary with distance? H. A.
Staab et a]. report here on the synthesis and
properties of cyclophanes with benzene, naphthalene ( I ) , and anthracene spacers. which
were examined by spectroscopy, X-ray structure analysis, and molecular dynamics calculations.
Hydrogen shift and ring closure instead of deprotonation: Cycloheptatriene (2) does not show the photoreactivity expected from M O considerations, in
contrast with the dibenzo derivative 1. Semiempirical calculations trace this difference to the crossing
of states on relaxation of the excited state of 2.
Thermally Induced Ring Cleavage of a 2H1,2-Azaphosphirene Tungsten Complex
H. A. Staab.* A. Feurer,
R. Hauck ...............................
Porphyrin-Quinone Cyclophanes with
Gradually Varied Donor- Acceptor Distances
H.-M. Steuhl,
M. Klessinger* .....................
2431 -2433
Excited-State Carbon Acids: Theoretical
Studies of Suberene and Cycloheptatriene
Z . Xie. R. Bau,
C. A. Reed* ...........................
Ligand or solvate? This question is raised by the
arrangement of the cation and two p-xylene solvent
molecules in the crystal structure of 1 (shown on the
right) Complex I, which provides the first example
of a [Fe(tpp)]+cation not coordinated by the anion,
shows that this question cannot be answered definitively, and introduces a new strategy for preparing
weakly coordinating anions. tpp = tetraphenylporphyrinnte
How many metal atoms can coordinate to a C=C
unit? The answer for Co-A1 clusters 1 (R = Me)
and 2 ( R = Et), the first p-q2:q2-bridged dialuminjoethene clusters, is "four". The complexes are
formed in about 30% yield on treatment of
[C~+(q'-ethene)~Co](Cp' = C,Me,, C,Me,Et)
with AIEt,H.
R. Streubel,* A. Kusenberg,
J. Jeske, P. G . Jones ............... 2427-2428
"Free" [Fe(tpp)]+ Cation: A New Concept
in the Search for the Least Coordinating
1, 2
J. J. Schneider,* C. Kriiger,
M . Nolte, I. Abraham,
T. S. Ertel, H. Bertagnolli ...... 2435-2437
[ ~Cp*(q2-C,H,)CoA1(C,H,)i : Synthesis
and Structure of Unusual Co-AI Cluster
A water-soluble P-cyclodextrin bearing seven naphthoate chromophores
forms a very stable 1 : l inclusion
complex (shown right) with a merocyanine dye. which mimics the antenna effect in photosynthetic units. The
energy transfer from the naphthoate
chromophores to the merocyanine IS
shown to take place with 100% effciency.
L. Jullien, J. Canceill, B. Valeur,*
E. Bardez, J-M. Lehn* ... ...... 2438-2439
Antenna Effect
The silylene complexes 1 are stabilized by the electron-deficient metal fragment PtL,
rather than by a more usual electron-donating group. The base-stabilized silylene
complex 2 is formed in the reaction of [Fe(CO),{P(OEt),}] with HSi(NMe,), as a
result of an unprecedented exchange of OEt and NMe, ligand substituents.
U. Bodensieck, P. Braunstein.*
W. Deck. T. Faure, M . Knorr,
C. Stern .................................
Platinum- Iron Silylene Complexes and
Metal-Promoted Substituent Exchange between Si(NMe,), and P(OEt), Ligands
New evidence suggests that the monomeric aryl metal compounds 2,4,6-Ph3C,H,M
(M = Cu, Ag) may be mixtures of 2,4,6-Ph3C,H,M and 2,4,6-Ph3C,H,Br or merely
the aryl bromide. Although the aryl metal compounds appeared to be well characterized in 1988 by spectroscopic and X-ray crystallographic methods, doubts arising
from theoretical considerations - -in particular C -Cu and C- Ag distances of presumably the same length-led to reexamination of the X-ray data.
An intramolecular Pd-C coupling reaction yields the
oxapalladacycle 1. This is the first time that the
transmetalation intermediate in the Stille coupling
reaction has been isolated. Complexes of type 1 react readily with alkyl, allyl, benzyl, and acyl halides
to form aryl-carbon bonds. This reaction can be
extended to the preparation of substituted derivatives of 1 and the aza analogue 2.
The Crystal Structures of Base-Free.
Monomeric Arylcopper(1) and Arylsilver(1)
Compounds; Two Cases of Mistaken Identity?
D. J. Cirdenas, C. Mateo,
A. M. Echavarren * .._..___.
...... 2445-2447
Synthesis of O m - and Azapalladacycles
from Organostannanes
2 : X = NSOpMe
Selective reaction of one of two C-W bonds in 1 with octanal yields 2. The disilyl
compound 1 and also silylstannyl compounds, useful reagents in organic synthesis,
could be prepared regioselectively ( > 9 9 : 1) by hydride reduction of allylic
A. Haaland,* K. Rypdal, H. P. Verne,
W. Scherer. W. R. Thiel _.._......2443-2445
M. Lautens,*
P. H. M. Delanghe ................. 2448-2450
A Regioselective Palladium-Catalyzed
Reduction of 3.3-Heterobimetalated Allylic
Acetates Synthesis and Reactivity of Allylic Bimetallic Compounds
Reaction of cyclotrisilane 1 with lithium yields, depending on the reaction conditions,
either the trisilane 2 lithiated at the terminal positions or the vicinal dilithiodisilane
3. These silanes are the first examples of this class of compounds and the first to be
characterized by X-ray structure analysis. Ar = 2-(Me,NCH,)C,H,.
J. B e h e r , * U. Dehnert,
D. Stalke* .............................
Doubly Lithiated Oligosilanes: Synthesis
and Structure of the First Vicinal Dilithiodisilane
Lewis acid/Lewis base interactions and hydrogen
bonds account for the cooperative binding of two
molecules of benzylamine to the chiral diboronate 1 .
Exclusive formation of the 1 :2 complex of the Lewis
acid I and benzylamine is evident in the N M R
spectrum, which implies that the binding of the first
molecule provides a suitable binding site for the second amine molecule.
Nucleosides with appropriate isotopic labels are crucial for studies of nucleic acid structures, drug-binding phenomena. and related molecular recognition
processes. A mild and general approach for the introduction of ‘‘N at the 3-position of pyrimidine
nucleosides is illustrated by the conversion of AZT
to [3-’’N]-AZT 1 (* = isotopically labeled).
X. Ariza, V. Bou, J. Vilarrasa,*
V. Tereshko, J. L. Campos ..... 2454-2455
_ . _ 2456-2457
A Water-Soluble “Bear Trap” Exhibiting
Strong Anion Complexation Properties
S. S. Yoon, W. C. Still ........... 2458 -2460
Expeditious Synthesis of a Novel C,-Symmetric Receptor that Binds Peptides Sequence-Selectively
2460 - 2462
Single-Step Six-Electron Transfer in a Heptanuclear Complex: Isolation of Both Redox Forms
The guanine-specific cleavage of oligonucleotides is achieved with the conjugate 1,
which contains a fullerene tethered to a tetradecadeoxyribonucleotide Nu(pNu),.
This conjugate was able to form a duplex with a complementary oligonucleotide,
and triplexes with appropriate double-stranded oligonucleotides. Irradiation of the
complexes leads to site-specfic cleavage of the target sequences-probably through
the action of singlet oxygen.
C ~ I ~ i v r In/.
r . Ed. Enxl. 1994. 33. N o . 23/24
A Short Route to [3-’*N]-3’-Azido-3’-deoxythymidine (N3-Labeled AZT) via
J. W. Steed, R. K. Juneja,
J. L. Atwood*
A Chiral Lewis Acid with Two “Metal”
Centers: Cooperative Binding of Two
Amine Molecules to a Chiral Diboronic
J.-L. Fillaut, J. Linares,
D. Astruc* .......................
The cationic heptanuclear hexaferrocenyl compound 1 can be synthesized
efficiently (as the orange-red PF,
salt) by the FeCp+-induced hexaferrocenylalkylation of the hexamethylbenzene ligand of [FeCp(C,Me,)]PF,. The 6 e oxidation of 1
to the heptacation and the 1 e reduction to the neutral compound are
supported by cyclic voltammetry and
Mossbauer spectroscopy.
Complexation with (arene)ruthenium(n) units converts calixarenes into suitable host compounds for anions. The hexacation composed of calixarene 1 with four (p-cymene)Ru fragments bound to the phenyl groups can complex a BF, ion, as
demonstrated by X-ray structure analysis. The BF, ion is
found deep within the host cavity.
Over 50000 tripeptides in one go were tested for their
binding properties towards receptor 1 (R =
CO(CH 2)2C02Dye).The tripeptide library was synthesized on polystyrene beads (one compound per
bead). These were then mixed with the colored receptor. The few beads that changed color were selected for characterization. Considering its remarkably high sequence selectivity and straightforward
synthesis. I might well prove to be most useful in the
areas of’ separation and analysis.
K. Nozaki, M . Yoshida,
H. Takaya* ............................
A. S. Boutorine, H. Tokuyama,
M. Takasugi, H. Isobe,
E. Nakamura, C. HClene* ..... 2462-2465
Conjugates :
Photoinduced Sequence-Specific D N A
~ ~ r l u g . ~ g e . ~ e l l s cmhH,
h a f i 0-69451 Wijinheirn, 1994
0570-0833/94/2323-2357d 10.00 t .25!0
A bent metallocene with a side-on q3-boundtrimethylenemethane (tmm) ligand is observed in
the crystal structure of the title compound 1
(shown on the right). The Zr-C1 and ZrC 2 bond lengths indicate that two strong CJ
bonds link Zr to the terminal C atoms of the
tmin ligand. The distance between Zr and the
central atom C 3 is typical for a weak CJ bond.
Reactions of 1 with reagents that contain polar double bonds, for example methyl formate and tert-butyl isocyanate, yield insertion products with six-membered rings.
G E Herberich,* C Kreuder.
U Englert
A New
Mode of Bonding for the Trimethylenemethane Ligand
From the simple building block D-glucose, soraphen
I a (R = CH,) and the derivative I b (R = H) have
been prepared. Compound l a is the parent compound of a new class of eighteen-membered
macrolides with interesting biological properties.
One of the key steps of the total synthesis was the
selective methylation of 1 b yielding 1 a.
S. Abel, D. Faber, 0. Hiiter.
B. Giese* ...............................
Total Synthesis of Soraphen A,,
A novel membrane-bound cytochrome PdS,,
mimic (shown schematically below.
1 : a Rh"' complex, 2: a manganoporphyrin) catalyzes the epoxidation of alkenes
with dioxygen. The turnover numbers achieved with this catalyst are in the same
range as those obtained with the natural enzyme.
vesicle bilayer
A. P. H. J. Schenning, D. H. W. Hubert,
J. H. van Esch, M. C. Feiters,
R. J. M. Nolte* .............._____...
Novel Bimetallic Model System for CYtochrome P450:Effect of Membrane Ehvironment on the Catalytic Oxidation
. . . .
Nonconjugated diynes can also form diradicals by cyclization. Thermolysis of 1 (R
= iPr) initially yields 1.4-didehydrobutadiene 2, which reacts with a hydrogen donor
R'H (e.g. solvent) to give the trapping products 3 and 4.The reactivity of 1 is
explaiiied by the electronic activation of the alkyue units by the N atoms, a sufficiently small separation of the C atoms to be linked, and a gain in energy upon
formation of the CT and n: bonds.
1,4-Didehydrobutadiene: The Intermediate
in a New Class of Thermally Induced
Intramolecular Alkyne Couplings
R. Gleiter," A. Ritter ...__........2470-2472
4, x = R '
Which arene ligand coordinates? An intramolecular exchange previously unknown
for Rh' complexes in which the phenyl ether moieties bind alternately in an 7'
fashion to the Rh' center (in 1 and 1' on the right) is observed by two-dimensional
'HN M R exchange spectroscopy. This exchange of the aryl ether-phosphane ligands probably proceeds via intermediate 2 and therefore cannot be detected when
the 0 atoms are exchanged for CH, groups.
E. T. Singewald, C. A. Mirkin.*
A. D. Levy, C. L. Stern _.__.....
Novel Rh' Piano-Stool Complexes with
New Hemilabile Ligands Ligating through
Phosphane and Arene Groups: Synthesis.
Characterization, and Reactivity
Methyltrioxorhenium(vl1)-catalyzed oxidation of 2-methylnaphthalene (1) with hydrogen peroxide leads to vitamin K , (2) in good yield and high regioselectivity. The
currently employed industrial synthesis of 2 with chromic acid produces 18 kg of
chromium-containing waste per kg of product.
W. Adam,* W. A. Herrmann,
J. Lin, C. R. Saha-Moller,
R. W Fischer,
J. D . G. Correia .....................
Homogeneous Catalytic Oxidation of
Arenes and a New Synthesis of Vitamin K,
M. D. Shair, T. Yoon, T.-C. Chou,
S. J. Danishefsky* .................. 2477-2479
An intermediate in the total synthesis of dynemicin A,
quinone imine I can be used as a dienophile. But 1
is also a potent cytotoxic agent against human cancer cell lines since it is able to cleave D N A . In vitro
and in vivo studies showed that 1 is more effective
than two frequently applied antitumor drugs.
Quinone imine 1 was synthesized by the rapid oxidation of a fleeting hydroisoquinone intermediate.
Enediyne Quinone Imines: Truncated, Biologically Active Dynemicin Congeners
A chiral hydrophilic environment is created at either rim of calix[4]arene by the
synthesis of glycosyl derivatives such as the water-soluble tetragalactosyl calixarene
1. This derivative is potentially an attractive synthetic receptor for chiral recognition
of polar organic molecules.
A. Marrd, M.-C. Scherrmann,
A. Dondoni,* A. Casnati,
P. Minari, R. Ungaro* .......... 2479-2481
Sugar Calixarenes: Preparation of Calix[4]arenes Substituted at the Lower and Upper Rims with 0-Glycosyl Groups
A butterfly-shaped framework is observed for the
Ni2AI, unit in the title compound, which is synthesized from [(Cp*AI),] and [Cp,Ni] The planes of
the Cp* hgdnds are nearly perpendicular t o the
planes of the Ni,AI triangles The NiAl complex is
didmdgnetic, only slightly air- and moisture-sensitive, and remdrkably stable
The integration of two different metals in a twodimensional mesoscopic aggregate is possible by
dipping a multibilayer film first in a solution of
[Ni(CN),]'- arid then in a solution of C u 2 + . The
resulting aggregate, shown in an idealized structure
on the right, displays anisotropic orientation similar
to that of single crystals.
The saddle-shaped porphyrin with the largest deviation from planarity observed to
date is found in thecrystal structure of [H,obrtpp][CF,C0O],.0.5CHCl3 (H20brtpp
= octabromotetraphenylporphyrin) . The pyrrole rings in the porphyrin are twisted
by 62" with respect to each other, and the ,!l-pyrrole C atoms are displaced by over
1.5 8, from the mean plane of the porphyrin ring. This extreme distortion is caused
by the bulky peripheral substituents on the porphyrin ring and the four protons at
the core o f the structure.
C Dohnieier, H Kiautscheid,
H Schnockel*
2482 2483
[(CpNi),(Cp*AI),] Cp*AI as
Two-Electron Ligdnd
N. Kimizuka, T. Handa,
I. Ichinose, T. Kunitake* ....... 2483-2485
Mesoscopic Sheets of a Cyano-Bridged
Cu-Ni Coordination Complex: Template
Synthesis at the Interlayers of Cast Multibilayer Films
M . 0. Senge,* T. P. Forsyth.
L. T. Nguyen, K. M. Smith .... 2485-2487
Sterically Strained Porphyrins-Influence
of Core Protonation and Peripheral Substitution on the Conformation of Tetra-nzeso-,
Octa-B-, and Dodeca-Substituted Porphyrin Dications
Mn(C1O4),-6H,O, 2,2’-bipyridine, and NaN, were used to synthesize [Mn(N,),(bpy)] r . the crystal structure of which (shown below) is characterized by alternating
end-on and end-to-end bridging azido ligands. The existence of alternating ferroand antiferromagnetic interactions between the S = 512 ions, as found previously
only in copper(1r) complexes, is suggested.
R. Cortes, L. Lezama,
J. L. Pizarro, M . I. Arriortua.
X. Solans, T. Rojo* ............... 2488-2489
Tetraamide hosts not only complex
para-benzoquinone to form 1, they
also activate the guest towards electrochemical reduction. The structure
and redox properties of this system
bear close similarity to those of the
quinone binding domains of photosynthetic reaction centers.
P. A. Brooksby, C. A. Hunter.*
A. J. McQuillan,* D. H. Purvis.
A. E. Rowan, R . J. Shannon,
R . Walsh ................................
Almost rectangular cavities can be seen in the structure of the title compound (part of the crystal structure shown on the right), the first heteropolyoxotungstate with defined micropores. The compound
was prepared in a hydrothermal reaction with W,
WO,, H,PO,, H,O, and hexamethylenediamine.
Potential applications of this compound in catalytic
oxidations or as a support in shape-selective reactions must still be proven.
Alternating Ferro- and Antiferromagnetic
Interactions in a Mn” Chain with Alternating End-On and End-to-End Bridging
Azido Ligands
Supramolecular Activation of prim-Benzoquinone
M . Holscher, U. Englert. B. Zibrowius.
W. F. Holderich* ..._____..._........
2491 -2493
3 H,O,
Microporous Solid from Dawson Anions
and 1,6-Diaminohexane
- - * Author
to whom correspondence should he addresced
New Books
Author Index A-149
1994 Index of Reviews and Highlights 2499
Events 2361, 2362
Author Index 2503
Preview A-150
Subject Index 2515
The editorial staff and publishers express their thanks to all
readers, authors, referees, and advertisersfor their continued
interest and support over the past year and wish them a
prosperous 1995.
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abstract, int, angel, engl, chem, 23241994, graphical
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