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Graphical Abstract (Angew. Chem. Int. Ed. Engl. 111997)

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A Journal of the
- _____
International Edition in English
The cover picture shows the intense yellow luminescence that is triggered when
crystals of the trinuclear gold(1) complex [Au,(CH,=COCH,),] come in contact
with a drop of solvent. The prerequisite for this solvent-stimulated luminescence is
the prior irradiation with long-wavelength UV light. This luminescence was totally
unexpected, and was first discovered during the isolation of the complex when the
resulting crystals were filtered and subsequently washed. The two emission spectra
clearly reveal that the yellow luminescence (lower right spectrum) cannot arise from
the dissolved species (upper left spectrum). Investigations into the origins of this
phenomenon are reported by A. L. Balch et al. on pages 1179ff.
Incorporation of redox metals into the framework of zeolites and related molecular
sieves considerably extends their utility in organic synthesis. The structural diversity- --includingvariation of the redox metal as well as size and polarity of the micropores . providcs the possibility of designing tailor-made solid catalysts for liquidphase oxidations under mild conditions with O,, H,O,, and RO,H as oxidants.
Important considerations for designing o r choosing a suitable catalyst based on
molecular sieves can be derived from the numerous examples. some of which are
even in industrial use, of oxidation of synthetically interesting compounds (alkenes,
alcohols, aldehydes, amines, arenes) as well as the different methods for synthesizing
redox molecular sieves (incorporation of redox metal by ion exchange by substitution of framework atoms or encapsulating a metal complex).
Diversity and efficiency is offered by the method of converting ketones into cyclopentenes by sclcctive intramolecular insertion of alkenylidenes R,C=C: into C - H
bonds. The chain extension that converts an aldehyde into an alkyne can also be
achieved with these cdrbenes. These two possibilities are generalized in the equation
R'= alkyl
fi2R3' i 1 ~ i 3
R1= H.aryl
I. W. C. E. Arends, R. A. Sheldon,*
M. Wallau, U. Schuchardt*. . . 1144-1163
Oxidative Transformations of Organic
Compounds Mediated by Redox Molecular
W. Kirmse"
. . . . .. . . . .. . . .
. 1164-1170
Alkenylidenes in Organic Synthesis
Photochemical switches, energy storage devices, or
photochemical sensors are potential applications of
luminescent gold complexes The basis for this expectation is the spectacular discovery by Balch et a1 ,
who observed that a trinuclear gold complex (see
picture) gave rise to an intense emission upon dissolution in an organic solvent after previous irradiation with near-UV light (Angew Chem. Znt Ed
Engl 1997, 36, 1179)
L. H.Gade*
. .
“Hyt was of Gold, and
Bryghte . ’”
Some enzymes tolerate bases and transition metal catalysts at elevated temperatures--conditions which, for example, Williams et al. and Backvall et al. have
shown are suitable for racemizing secondary alcohols by Meerwein-Ponndorf
reduction/Oppenauer oxidation. Enzyme-catalyzed acylation under Meerwein Pondorf-Verley conditions facilitates dynamic kinetic resolutions of alcohols.
Shon so
R. Stiirmer* . . . . . . . . . . . . . . . 1173-1174
Enzymes and Transition Metal Complexes
in Tandem-A New Concept for Dynamic
Kinetic Resolution
In the presence of tertiary phosphanes, AgCl reacts readily with the reagent
Te(Ph)SiMe, to yield silver- tellurolate polynuclear complexes. In the case of PMe,,
the polymer [Ag,,(p3-TePh),,(PMe,),], (shown below) is formed, in which the TePh
ligands serve as both inter- and intracluster bridges.
J. F. Corrigan, D. Fenske,*
W. P. Power . . . . . . . . . . . . . . . . 1176- 1179
Striking yellow luminescence is observed upon addition of a drop of solvent to colorless crystals of
[Au,(CH,N=COCH,),] that were previously irradiated with near-visible light. The trigonal prismatic
stacking of individual molecules of the triangular
cluster in the solid state (shown on the right) sheds
light on the possible mechanisms for this luminescence.
J. C. Vickery, M. M. Olmstead, E. Y. Fung,
A. L. Balch* . . _ _. . . . _ . . . . 1179-1181
The bowl-shaped reaction environment created by the
Lewis acid aluminum tris(2,6-diphenylphenoxide)
has been utilized as an efficient template in intramolecular radical cyclizations. The pathway and
the stereoselectivity of the radical cyclization can be
altered by using this template. A schematic representation of the transition state of the templateassisted reaction is shown on the right.
T. Ooi, Y. Hokke,
K. Maruoka* . . . . . . . . . . . . . . 1181-1183
Success at last: The 1,4-allylation of a,P-unsaturated aldehydes with selectivities up to 95/5 and yields
of 83% has been achieved thanks to the newly
developed Lewis acidic receptor p-F-ATPH (L =
T. Ooi, Y Kondo,
K. Maruoka* . . . . . . . . . . . . . . 1183-1185
In addition to a coordination site for the aldehyde, this possesses a n appropriate coordination site for a reactive nucleophile, as
Silver-Tellurolate Polynuclear Complexes:
From Isolated Cluster Units to Extended
Polymer Chains
Solvent-Stimulated Luminescence from the
Supramolecular Aggregation of a Trinuclear Gold(1) Complex that Displays
Au.” Au
Remarkable Template Effect of a Lewis
Acidic Receptor in Intramolecular Radical
Conjugate Allylation to a,P-Unsaturated
Aldehydes with the New Chemzyme
shown schematically on the right.
C VCH VerlagsgesellschuffmhH, 0-69451 Weinheim.1997
0570-0833/9713611-1136 3 17 50+ 5010
Angew. Chem. I n f . Ed. Engl. 1997, 36, No. 11
Novel chelate ring-opening occurs when cytotoxic
bis(aminoet hylphosphanyl)platinum(rI) binds rapidly
to the N3 atom of the DNA base thymine (T) and
RNA base uracil (U) at pH 7 in the presence of
chloride ions (depicted on the right). This is in contrast to cisplatin, which shows little binding to
thymine or uracil under similar conditions, and thus
opens the possibility for base-specific attack on
DNA and RNA.
Prototype of a new aromatization
reaction: thermal rearrangement of
I ,3-hexadiene-5-yne (1) to benzene
(3) via isobenzene 2, a highly reactive
benzene isomer. Trapping experiments with styrene and the behavior
of arenes containing 1 as a subunit
indicate that this isomerization is also suitable for preparing condensed
arenes and fullerene fragments.
N. Margiotta, A. Habtemariam,
P. J. Sadler* . . . . . . . . . . . . . . . 1185-1187
Strong, Rapid Binding of a Platinum
Complex to Thymine and Uracil Under
Physiological Conditions
H. Hopf,* H. Berger, G. Zimmermann,*
U. Niichter, P. G. Jones,
I.Dix . . . . . . . . . . . . . . . . . . . . . 3187-1190
Formation of Isobenzenes by Thermal
Blue fluorescence is exhibited by the hexaazakekulene 1, the first fully aromatic heteroanalogue of
kekulene. It was synthesized in four steps from
formaldehyde and proflavine (3,6-diaminoacridine). Although 1 is insoluble in organic solvents, it
is slightly soluble in strong acids such as methanesulfonic or trifluoroacetic acid-probably due to
A. Tatibouet, R. Hancock,
M. Demeunynck,*
J. Lhomme . . . _ _ .._. ... . . . . 1190-1191
The orthogonally protected gylcosylated amino acid
building block 1 for the synthesis of peptidomimetics
was prepared by the coupling of an amino acid aldehyde with a glycosyl dianion of glucosamine. This
new C-glycosylated amino acid displays an improved metabolic stability and thus an improved
bioavailability because of the single carbon chain
between the sugar residue and the amino acid and
because of the C-C linkage at the anomeric center.
F. Burkhart, M. Hoffmann,
H. Kessler * . . . . . . . . . . . . . . . . 1191- 1192
A carbide carbon atom as a vertex stabilized by coordination to the Lewis acid TeBr, is a feature of the
cubdne-like clucter 1 shown on the right This complex, which I S indefinitely stable in the solid state but
dissolves only in DMSO-and then with rapid decomposition i s the ultimate product in the reaction
between [Te,Fe,(CO),] and CBr,
New lead compounds with promising biological activity are represented by CP225,917 and CP-263,114. An approach based on an intramolecular Diels-Alder
reaction for the total synthesis of these compounds is exemplified by the synthesis
of racemic bicyclo[4.3.1]dec-1(9),4-dienes2 a, b from triene 1.
\ 0
Angtw. Clwm. Inr. M EnRI 1997. 36, No I1
Stereoselective Synthesis of a C-Glycosidic
Analog of N-Glucoasparagine
J R Eveland,
K H Whitmire*
1193-1 194
Synthesis and Characterization of the
Carbide Cubane Cluster [Fe,(CO)gTe,(p,CTeBr,)] with an Unusual Tetrahedral
CTe, Unit
K. C. Nicolaou,* M. W. HHrter.
L. Boulton, B. Jandeleit . . . . . 1194-1 196
Synthesis of the Bicyclic Core of
CP-225,917 and CP-263,114 by an Intramolecular Diels-Alder Reaction
2a, b
,&; VCH Verlagsgesellschaft mhH, 0-69451 Weinheim, 1997
How does the catalytic set-up of a hydrolase activate H,O, for enzymatic oxidations?
The oxidizing species is a peracid, as these studies with the metal-free haloperoxidases CPO-Pand CPO-Tclearly show. The analogy between the hydrolase and haloperoxidase reactions is elucidated in the reactions below.
R’ / l o x R 2
Metal-Free Bacterial Haloperoxidases as
Unusual Hydrolases: Activation of H,O,
by the Formation of Peracetic Acid
M. Picard, J. Gross, E. Lubbert,
S. Tolzer, S. Krauss, K.-H. van Pke,
A. Berkessel* . . . . . . . . . . . . . . 1196-1199
Fast and simple: Rotaxanes and pseudorotaxanes are synthesized by simply melting
their wheel and axle components for one minute. The complementarity between the
cavity of the wheel and the spatial demands of the stopper groups was designed to
permit a temperature-controlled “slipping off’ process in solution.
A simple one-pot reaction with readily accessible compounds [Eq. (a)] provides a
route to high-valent molecular Fe’” complexes with a N/S/P coordination sphere.
The Fe’” character of the metal center, which is stabilized by n-donor bonds from
the lone pairs of electrons of the amide N and thiolate S donors, is confirmed by
spectroscopic and structural data of 1 (R = nPr). The L4- ligand is “innocent”!
Two new types of gold-gold interactions are described. Crystals of 1 contain polymeric chains with short contacts between cationic gold centers, while in 2 one gold atom
is coordinated nearly trigonally by three others.
M. Handel, M. Plevoets, S. Gestermann,
F. Vogtle* . . . . . . . . . . . . . . . . . 1199-1201
Synthesis of Rotaxanes by Brief Melting of
Wheel and Axle Components
D. Seilmann,* S. Emig, F. W. Heinemann,
F. Knoch . . . . . . . . . . . . . . . . . . 1201-1203
A Convenient Way to Novel Fe’” Complexes with Mixed N/S/P Coordination
Spheres and “Innocent” Ligands
J. Vicente,* M.-T. Chicote,*
M.-D. Abrisqueta, R. Guerrero,
P.G. Jones* . . . . . . . . . . . . . . . 1203-1205
New Motifs in Aurophilic Self-Assembly :
Synthesis and Structures of
[Au(NH=CMe,),]CF,SO, and
The trends in carbon-sulfur bond length for complexes of 1,4,7-trithiacyclononane
(9S3) provide compelling evidence that C-S o* orbitals accept n-electron density
from the metal. As the metal d-orbital energy and occupancy increase, this leads
ultimately to cleavage of the C-S bonds with concomitant release of ethene in the
Re and Tc complexes [Eq. (a)].
[M(9S3),]” + e
[M(9S3)(SCH2CH,SCH,CH,S)]+ + C,H, (M
Tc, Re)
VCH VPrlay.sye.sellschufI mhN. 0-49451 Wcinheini,1997
G. E. D. Mullen, M. J. Went,
S. Wocadlo, A. K. Powell,
P. J. Blower* . . . . . . . . . . . . . . . 1205-1207
Electron Transfer Induced C-S Bond
Cleavage in Rhenium and Technetium
Thioether Complexes: Structural and
Chemical Evidence for n Back-Donation to
C-S (T* Orbitals
0570-0833197/3611-11383 17.50+ .SO/O
Angen,. C l ~ mInt.
. Ed Enyi. 1997, 36. No. I 1
Biomimetic reduction of benzoylformate to mandelate with 97-99 % ee was achieved
with the diastereomeric, bridged NADH models (S,S)-1 and (R,S)-I. The
oligomcthylene bridge acts as an "enzyme wall" and hinders the approach of the
substrate from one side of the dihydropyridine ring. Isomers 1 were synthesized from
the corresponding bridged nicotinate precursor, which was prepared by the reaction
of formyl-substituted (viny1imino)phosphorane with methyl propiolate.
- ,LR,
A. L. E. Larsson, B. A. Person,
J.-E. BSickvall* . . . . . . . . . . . . . 1211-1212
Novoqm 435
- 1.5 (fB%Si),
- 6 NaCl
What lithiates what? In a reaction between Ph,NH and excess nBuLi the
aggregate 1 comprising nBuLi,
monolitiated amine. and doubly
lithiated amine units forms. Thc
structure (see picture) raises interesting questions about lithiation reaction mechanisms.
Enzymatic Resolution of Alcohols Coupled
with Ruthenium-Catalyzed Racemization
of the Substrate Alcohol
major product
minor product
Blue-black trisupersilyldigallanyl, a new metastable inorganic radical, forms in the
reaction of GaCI, with tBu,SiNa in pentane at room temperature according to
Equation (a). The X-ray structure analysis reveals that it contains a planar
Si,Ga"Ga' and a nearly linear Ga"GalSi framework; according to the ESR spectrum
the unpaired electron resides on both G a atoms. Surprisingly, the analogous reaction of AlCI, and /Bu,SiNa (A1 instead of G a in Equation (a)) does not lead to
trisupersilyldialanyl, but to red tetrasupersilyldiafane (zBu,Si),Al-Al(SirBu,), .
2 GSCI, + 6 tBu3SiNa
Highly Enantioselective Reduction with
Novel. Bridged NADH Models
n n
A specifically designed acyl donor, an
efficient enzyme, and a stable and reliable ruthenium catalyst are fundamental for the resolution of the
racemic alcohols described here (see
schemc on the right). For R ' = Ph
and R 2 = Me, 100% conversion into
the corresponding acetate was
achieved with greater than 99.5% r e .
N. Kanomata,* T. Nakata . . . 1207-121 1
N. Wiberg,* K. Amelunxen, H . Noth,
H. Schwenk, W. Kaim, A. Klein.
T. Scheiring . . . . . . . . . . . . . . . . 1213-1215
(tBu,Si),Ga,: A New Type of Compound
for a Heavy Group 13 Element
R. P. Davies, P. R . Raithby,
R.Snaith* . . . . . . . . . . . . . . . . . 1215-1217
Lithiation of a Simple Amine with a Large
Excess of n-Butyllithium: The Remarkable
(Ph,NLi) . IPh(C,H,Li)NLi], .
(nBuLi), . (Et,O),
( P h 2 N L i ) . [Ph(C,,H,Li)NLi], .
( r ~ B u L i ) ~( E t L O ) I I
* Author
10 whom
correspondence should hc addressed
Data Analysis for Chemists. Applications to QSAR and Chemical Products Design .
D. Livingstone
C. E. Wayne, R. P. Wayne
Electrochemical Phase Formation and Growth
E. Budevski, G. Staikov, W. J. Lorenz
The Chemistry of C-Glycosides
D. E. Levy, C. Tang
German versions of all reviews, communications, and highlights in this issue appear
in the first June 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. 1223.
VCH Verlagsgesehsehufrm h f f . 0-694Sl Wemherm. 1997
R. Fleischer ......................................
M . Oelgernoller ................................
K. E. Heusler ...................................
G. Lemanski .....................................
Author Index
8 17.80+.8O/O
Angen. Chem Inr. Ed. Engl. 1997, 36, No. 1 I
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abstract, int, angel, engl, chem, graphical, 111997
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