Angewandte Chemie International Edition in English

Cover image for Vol. 27 Issue 2

February 1988

Volume 27, Issue 2

Pages 207–308

Currently known as: Angewandte Chemie International Edition

    1. Cover Picture (Angew. Chem. Int. Ed. Engl. 2/1988)

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198802071

      Thumbnail image of graphical abstract

      The cover shows the principle of a purely organic molecular light converter. The excitation spectra of the compound shown clearly reveal that the emission intensity of the tetraphenylporphyrinyl (TPP) terminal group at 665 nm (carmine red) depends on the wavelength of excitation and exhibits a maximum upon excitation with 256-nm light; the absorption maximum of the anthryl moiety is found at this wavelength. No TPP emission occurs upon excitation in the region of polyene absorption. Following selective excitation of the anthryl moiety with UV light, energy is transferred through the polyene chain and reemitted by the TPP moiety. It is hoped that such studies will afford insight into the mechanisms of energy transfer in biological and abiological systems. Further details are given by F. Effenberger, H. C. Wolf et al. on p. 281 ff. Cover design: Illustration & Design, Mannheim.

    2. Graphical Abstract (Angew. Chem. Int. Ed. Engl. 2/1988)

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198802072

  1. Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    1. Pharmaceutical Proteins (pages 207–225)

      Dr. Dietmar Blohm, Dr. Claus Bollschweiler and Dr. Heinz Hillen

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198802073

      The use of hormones, serum proteins, and enzymes as therapeutic agents has become firmly established since the commercial introduction of insulin (1923), thyroid hormone (1934), Factor VIII (1948), and calcitonin (1970). However, the term pharmaceutical protein is not limited to therapeutic agents, but also includes diagnostic agents (enzymes, monoclonal antibodies) and, recently, even vaccines (based on defined single proteins and oligopeptides). This area owes its rapid development to genetic engineering and biotechnology, which have contributed to the discovery and modification of new proteins and made it possible to produce them on a preparative scale.

    2. Zeolites: Catalysts for Organic Syntheses (pages 226–246)

      Dr. Wolfgang Hölderich, Dr. Michael Hesse and Dr. Fritz Näumann

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198802261

      As catalysts, zeolites display many useful properties—particularly, shape selectivity, thermal stability, and acidity. These aluminosilicates are not only employed as catalysts in petrochemistry and in oil processing, but have also been used recently for directed, highly specific preparations of synthetic intermediates and fine chemicals. The types of reactions that may be catalyzed with zeolites include electro- and nucleophilic substitution, double-bond and skeletal isomerizations, additions, eliminations, and hydrogenations.

    3. Structure Elucidation and Artificial Intelligence (pages 247–260)

      Dr. Wolfgang Bremser

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198802471

      Interaction between the chemist and the computer, which, while not as creative, has a much better memory and works astoundingly fast, can help to channel the flood of data produced in spectroscopy laboratories, some of them completely automated. In many cases, “intelligent” computer systems already exist which allow automatic elucidation of the structures of organic compounds. Yesterday's dream has become in part today's reality.

  2. Communications

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    1. [{Hg3Co(C4H6NO)6}(NO3) 2]n: A Macrobicyclic Bimetallic Chain Polymer Incorporating Deprotonated 2-Pyrrolidone Bridges (pages 261–262)

      Dr. David M. L. Goodgame, Dr. David J. Williams and Richard E. P. Winpenny

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198802611

      Thumbnail image of graphical abstract

      Sixteen-membered macrocycles with Hg(C4H6NO)2 central struts linking adjacent Co atoms characterize the structure of the title complex shown (NOmath image ions omitted). This complex might exhibit ion-exchange properties.

    2. B6H14, a Dimeric B3H7? (pages 262–263)

      Dr. Bernd Brellochs and Prof. Dr. Herbert Binder

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198802621

      Thumbnail image of graphical abstract

      “B3H7” is formed in situ upon oxidation of B3Hmath image and upon Cl abstraction from B3H7Cl. The NMR data indicate that the dimeric form B6H14 is most likely present and has the probable valence structures A[BOND]C, since the reactivity of B6H14 suggests that the original B3H7 units are intact.

    3. A New Type of Unsaturated triangulo Transition-Metal Cluster and Homogeneous Catalyst (pages 263–264)

      Prof. Dr. Hans-Jürgen Haupt, Dr. Peter Balsaa and Dr. Ulrich Flörke

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198802631

      Thumbnail image of graphical abstract

      The three Re[BOND]Re bonds of nearly identical length in 1 indicate that the four π electrons are delocalized in the Re three-membered ring of this cluster, which contains 44 valence electrons. Complex 1 closes the gap between clusters with 48 and 46 valence electrons and those with 42. In addition, the complex has proved to be a homogeneous hydrogenation catalyst.

    4. Tris(2,2′-bipyridyl-5-sulfonic acid)rhodium(III), an Improved Redox Catalyst for the Light-Induced and the Electrochemically Initiated Enzymatic Reduction of Carbonyl Compounds (pages 265–267)

      Dipl.-Chem. Marlene Franke and Prof. Dr. Eberhard Steckhan

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198802651

      Unchanged activity after 36 hours is displayed by the light-induced redox system consisting of nitrilotriethanol, NAD, horse liver alcohol dehydrogenase, cyclohexanone, and [Ru(bpy)3]2⊕, with the title compound [Rh(L3)]3⊕ as electron relay. The electrochemically initiated enzymatic reduction of cyclohexanone in an analogous system also takes place with [Rh(L3)]3⊕ as redox catalyst without the formation of inactive (NAD)2. Since the reduced form of [Rh(L3)]3⊕ does not reduce carbonyl compounds, it is also possible to exploit fully the stereospecificity of the enzyme with the system described here.

    5. The Copper Salt of 2-Iodo-5-methyl-N,N′-dicyanoquinonediimine—a Radical Anion Salt Exhibiting Metallic Conductivity down to Low Temperatures (pages 267–268)

      Dipl.-Chem. Peter Erk, Prof. Dr. Siegfried Hünig, Dr. Jost Ulrich von Schütz, Dipl.-Phys. Hans-Peter Werner and Hans Christoph Wolf

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198802671

      Thumbnail image of graphical abstract

      The title compound 1b is a radical anion salt whose conductivity increases continuously down to 1.2 K. This property is surprising since similar highly conductive salts of the type 1, X = Me, Cl, Br; M = Cu, Ag, alkali metal (exception: 1a), undergo a transition to a semiconducting state between 300 and 100 K.

    6. A New Route to trans-Substituted γ-Lactones (pages 268–270)

      Dipl.-Chem. Thomas Kunz and Prof. Dr. Hans-Ulrich Reissig

      Article first published online: 22 DEC 2003 | DOI: 10.1002/anie.198802681

      Thumbnail image of graphical abstract

      trans-Substituted γ-lactones are formed with high diastereoselectivity according to Equation (a), especially when cuprates are used as organometallic reagents. For allyltrimethylsilane/TiCl4, the selectivity is only large when R1 is a bulky group. The γ-lactones thus obtained are valuable synthetic intermediates, and their formation is of mechanistic interest since they can be used to test the validity of the Felkin–Ahn model (R1 = Me, iPr, Ph; R2 = Me, nBu, allyl).

    7. How High is the Activation Barrier to Helix Inversion of 1,4,5,8-Tetrasubstituted Phenanthrenes? (pages 270–271)

      Prof. Dr. Albrecht Mannschreck, Dipl.-Chem. Erich Gmahl, Dr. Thomas Burgemeister, Fritz Kastner and Dr. Volker Sinnwell

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802701

      Thumbnail image of graphical abstract

      Lower than earlier assumed! The ΔG values for the helix inversion according to (a) were determined by 1H-NMR spectroscopy and/or by “on-line racemization” for several tetrasubstituted phenanthrenes. They are approximately 80 kJ mol−1, corresponding to a half-time of only a few seconds. Earlier, for the compounds with R = CH2CO2H, ΔG values of up to ca. 100 kJ mol−1 and thus t0.5 values of up to ca. 4 h had been estimated (R = CH2CO2H, CH2OH, CH(Me)OH, CH(CMe3)OH).

    8. Reactivity of Tri-tert-butylazete (pages 272–274)

      Dr. Uwe Josef Vogelbacher, Dipl.-Chem. Martin Ledermann, Dipl.-Chem. Thomas Schach, Dr. Gisbert Michels, Dipl.-Chem. Udo Hees and Prof. Dr. Manfred Regitz

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802721

      Thumbnail image of graphical abstract

      The first kinetically stabilized azete, the title compound 1, is sensitive toward oxidation (→ formation of the dioxetane 2) and undergoes hydrolysis to the β-imino ketone 3. Sterically nondemanding cycloaddition partners such as cyclopentadiene or diazomethane (CH2N2) (→ formation of the adduct 4) attack at C-2/C-3, whereas those with bulky groups such as acetylenedicarboxylate esters or tert-butylphosphaacetylene (P[TRIPLE BOND]CtBu) (→ formation of the bicyclic compound 5) react at N-1/C-4.

    9. Amino Acid Methyl Esters as Chiral Auxiliaries in Aza–Diels-Alder Reactions in Aqueous Solution (pages 274–275)

      Dr. Herbert Waldmann

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802741

      Thumbnail image of graphical abstract

      Diastereoselectivities of up to 93 : 7 are attained at a reaction temperature of 0 to 25°C when (S) or (R) amino acid ester hydrochlorides and formaldehyde (formation of a chiral Schiff base) are allowed to react with dienes. Cleavage of the chiral auxiliary group was successfully carried out for phenylglycine and serine derivatives. Thus, phenylglycine and cyclopentadiene afforded the bicyclic aza compound 1 in enantiomerically pure form, while isoprene and serine afforded the didehydropiperidine 2.

    10. Heterogeneous, Bimetallic Metathesis Catalysts by Reaction of Fischer-type Carbene Complexes with Reduced Phillips Catalyst (pages 275–277)

      Dr. Karin Weiss, Wilfried Guthmann and Sergio Maisuls

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802751

      Catalytic metathesis reactions with carbene complexes are possible when these complexes are fixed on inorganic supports. Binding of Mo or W carbene complexes to the very efficient polymerization catalyst for the Phillips procedure, “SiO2/Cr”, resulted in their transformation to good metathesis catalysts. Cr carbene complexes, in contrast, gave rise to a system that is active neither for polymerization nor for metathesis.

    11. New Complex Cations of Aluminum(III) and Gallium(III) (pages 277–278)

      Prof. Dr. Alan H. Cowley, Prof. Dr. Carl J. Carrano, Dr. Rolf L. Geerts, Prof. Dr. Richard A. Jones and Dr. Christine M. Nunn

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802771

      Thumbnail image of graphical abstract

      Tris(3,5-dimethyl-1-pyrazolyl)hydridoborate [HB(pz*)3], formally a cyclopentadienide analogue, reacted with AlCl3 and GaCl3 to afford the cations [{HB(pz*)3}2M]1, but with InCl3 to give the neutral [HB(pz*)3]InCl2. 1, M = Ga, has two parallel N3 planes–in agreement with the expectation that [(C5H5)2Ga] should be a sandwich compound with parallel rings.

    12. Asymmetric Induction in the [2,3] Wittig Rearrangement by Chiral Substituents in the Allyl Moiety (pages 278–280)

      Dr. Reinhard Brückner and Henning Priepke

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802781

      Thumbnail image of graphical abstract

      A stereoselective route to homoallyl alcohols is provided by the title reaction, which proceeds via allyloxy carbanions. The diastereoselectivity in the transformation 1 → 2 (ds > 90%) is higher than for the analogous Claisen rearrangement.

    13. On the Pentaphosphacyclopentadienide Ion, Pmath image (pages 280–281)

      Prof. Dr. Marianne Baudler, Stilianos Akpapoglou, Dimitrios Ouzounis, Prof. Dr. Fritz Wasgestian, Bernd Meinigke, Prof. Dr. Herbert Budzikiewicz and Helmut Münster

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802801

      Thumbnail image of graphical abstract

      The aromatic character of the recently reported pentaphosphacyclopentadienide ion 1 was supported by spectroscopic and chemical findings. 1 is the first homocyclic aromatic system not containing carbon. Reaction of LiP5 and LiC5Me5 with FeCl2 allows direct synthesis of the mixed sandwich complex [(η5-P5)Fe(η5-C5Me5)].

    14. Synthesis and Optical Properties of Terminally Substituted Conjugated Polyenes (pages 281–284)

      Prof. Dr. Franz Effenberger, Dipl.-Chem. Hubert Schlosser, Dr. Peter Bäuerle, Dipl.-Phys. Stefan Maier, Dr. Helmut Port and Prof. Dr. Hans Christoph Wolf

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802811

      Thumbnail image of graphical abstract

      Long-chain, conjugated polyenes can function as molecular wires. This is shown by the photophysical properties of polyenes containing naphthyl, anthryl, and tetraphenylporphyrinyl (TPP) terminal groups. When the anthryl group in 1, which is obtainable by a sequence of Wittig reactions, is selectively excited, strong TPP emission is observed.

    15. Formation of Cycloheptatriene/Norcaradiene Systems in the Decomposition of Diaryldiazomethanes in Benzene (pages 284–285)

      Dr. Klaus Hannemann

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802841

      Thumbnail image of graphical abstract

      Working at high dilution was the prerequisite for the successful carbene addition of diphenyldiazomethane 1a and its methyl derivative 1b to benzene. Whereas only about 35% of norcaradiene was present in equilibrium in the case of the diphenylcarbene adduct 2a/3a, the presence of the ortho methyl group results in a nearly complete shift of the equilibrium to the side of the norcaradiene 3b (a, R [DOUBLE BOND] H; b, R [DOUBLE BOND] CH3).

    16. C5 Building Blocks for Terpene Syntheses: γ-Acetoxylation of (E)-2-Methyl-2-butenals (pages 285–287)

      Dr. Rolf H. Fischer, Dr. Heinz Krapf and Joachim Paust

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802851

      Thumbnail image of graphical abstract

      The title compounds 3, R [DOUBLE BOND] H or OAc, are of industrial importance for the preparation of terpenes, e.g., vitamin A. A new and simple route to these compounds is provided by the oxidation of the dienyl acetate 2 with environmentally acceptable oxidizing agents such as oxygen and peracetic acid. Compounds 2 can be prepared by acetylation of the aldehydes 1.

    17. Synthesis and Structure of an Azastibacubane (pages 287–288)

      Dipl.-Chem. Walter Neubert, Dr. Hans Pritzkow and Prof. Dr. Hans P. Latscha

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802871

      Thumbnail image of graphical abstract

      An unexpectedly simple structure was found for the product of the reaction of antimony pentachloride and methylbis(trimethylsilyl)amine. It contains the first cubane-like framework composed exclusively of antimony and nitrogen atoms.

    18. A Conjugated Bis(tetrathiafulvalene) System with Tetrathia-s-indacene Structure (pages 288–289)

      Dipl.-Chem. Peter Wolf, Dr. Herbert Naarmann and Prof. Dr. Klaus Müllen

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802881

      Thumbnail image of graphical abstract

      The title compound 1, a new donor for CT complexes, contains two tetrathiafulvalene (TTF) moieties, joined through an annelated benzene ring. Compound 1 is soluble in organic solvents. Initial studies show that, among other things, 1 reacts with dichlorodicyano-p-benzoquinone (DDQ) to form CT complexes containing separated donor and acceptor stacks. The powder electrical conductivity of 1 · DDQ is only 10−8 δ−1 cm−1. This is possibly an indication that the bulky substituents R result in increased separation of the layers compared with TTF · DDQ (R = 3,5-di-tert-butylbenzyloxy).

    19. Photochemical Reaction of [(CO)4Co(SiEt3)] with Ethylene: Implications for Cobaltcarbonyl-Catalyzed Hydrosilation of Alkenes (pages 289–291)

      Dr. Friedrich Seitz and Prof. Dr. Mark S. Wrighton

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802891

      The insertion of a nonactivated alkene into the M[BOND]Si bond of a catalytically active transition-metal complex has been demonstrated for the first time. Furthermore, the formation of CH4 instead of SiMe4 in the reaction of [(CO)4Co[BOND]Me] with Me3SiH is clearly inconsistent with the traditional Chalk–Harrod mechanism for the transition-metal-catalyzed hydrosilation of olefins. Both reactions are key steps in a new proposal for the mechanism of this reaction.

    20. CD Spectroelectrochemistry, a Method for the Characterization of Chiral Electron Transfer Reagents and Chiral Reaction Intermediates (pages 291–293)

      Prof. Dr. Jörg Daub, Dipl.-Chem. Josef Salbeck and Dipl.-Chem. Irmgard Aurbach

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802911

      Thumbnail image of graphical abstract

      New information on the properties of electron-transfer compounds should become available through the combination of chiroptic and electrochemical measurement. This approach was tested on bianthraquinone 1. The CD spectra of the two enantiomers of 12(⊙⊖) were thereby obtained. Comparison of the electronic spectrum of 12(⊙⊖) with those of the 9,10-anthraquinone radical anion and dianion revealed that 12(⊙⊖) should be formulated as a bisradical anion (R = CO2CH3).

    21. [TiSCl4]2⊖ and [Ti3O(S2)3Cl6]2⊖, a Multinuclear Complex with a Structure Typical for Clusters (pages 293–294)

      Prof. Dr. Ulrich Müller and Dipl.-Chem. Volker Krug

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802931

      Thumbnail image of graphical abstract

      In the presence of traces of oxygen, the title reaction of TiCl4 with S(SiMe3)2 affords [Ti3O(S2)3Cl4] in addition to TiSCl2. Both compounds can be converted into salts by reaction with Cl ions. The X-ray structural analyses of these salts revealed that [TiSCl4]2⊖ is square-pyramidal and [Ti3O(S2)3Cl6]2⊖ has the clusterlike structure shown despite the predicted absence of metal–metal bonds.

    22. The Structures of 1H-Cyclopropabenzene and Its 1,1-Bis(triisopropylsilyl) Derivative (pages 294–295)

      Prof. Dr. Richard Neidlein, Dr. Detlev Christen, Dr. Volker Poignée, Dr. Roland Boese, Dipl.-Ing. Dieter Bläser, Prof. Dr. Alfred Gieren, Dr. Catalina Ruiz-Pérez and Dr. Thomas Hübner

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802941

      Thumbnail image of graphical abstract

      π-Delocalization in a benzene ring despite the presence of an annelated cyclopropene ring is supported by the X-ray structure analyses of the title compounds 1a and 1b. Furthermore, despite the very bulky substituents in 1b, the two compounds have nearly the same bond lengths and bond angles. The cyclopropabenzene framework in both compounds is nonplanar; for steric reasons, however, the kind of symmetry reduction differs in 1a and 1b.

    23. Nitrogen Fixation by Borabenzene (pages 295–296)

      Prof. Dr. Günther Maier, Dr. Hans Peter Reisenauer, Dr. Jochem Henkelmann and Christine Kliche

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802951

      Thumbnail image of graphical abstract

      Borabenzene is stabilized in an extremely mild fashion in the matrix-isolated borabenzene–nitrogen adduct 4, which was identified by IR spectroscopy. In general, boraarenes and boraethenes can only be isolated when the electron deficiency on boron is satisfied by a donor. Compound 4 is formed via 3 upon flash pyrolysis of 1 in N2 as carrier gas.

    24. The Central Propellane Bond as Polymerizable CC Single Bond: Poly(tricyclo[4.2.0.02,7]octane-1,7-diyl)—a “Poly([1.1.1]propellane)” (pages 296–298)

      Dr. Arnulf-Dieter Schlüter

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802961

      Thumbnail image of graphical abstract

      The polymers 2 (R = tBu, Ph; x > 18) have a rigid rodlike structure. These “poly[1.1.1]propellanes” are obtainable by anion-initiated (tBuLi, PhLi) ring-opening polymerization, during which the central CC single bond in the corresponding [1.1.1]propellane 1 is broken. Of particular value in the structural proofs were the CP MAS 13C-NMR spectra.

    25. Synthesis of all-cis-1,4,7,10-Cyclododecatetraene (pages 298–299)

      Dr. Martin Brudermüller and Prof. Dr. Hans Musso

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802981

      Thumbnail image of graphical abstract

      The title compound 2 is a simple, previously unknown hydrocarbon. It was synthesized in a multistep reaction sequence, the last step of which is the McMurry reaction of the dialdehyde 1. The all-cis isomer 2 and the trans-cis isomer 3 are thereby formed and could be separated by preparative gas chromatography. The cyclooctatetraene homologue is of interest in terms of its cycloaddition and complexation behavior.

    26. 1,3-Dihydro-1,3-diborafulvene Derivatives (pages 299–300)

      Volker Schäfer, Dr. Hans Pritzkow and Prof. Dr. Walter Siebert

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198802991

      Thumbnail image of graphical abstract

      The first 1,3-dihydro-1,3-diborafulvene 1, which is stable to 100°C, was synthesized according to reaction (a). Compound 1 reacts with Mo(CO)6 to give the Mo(CO)4 complex of 1, in which the fulvene ligand is nonplanar and the Mo atom is coordinated in a distorted octahedral fashion (R1 = Me, R2 = Et).

    27. A New Route to Nitrile Oxides via α-Nitrosodiazo Derivatives (pages 301–302)

      Ghislaine Sicard, Dr. Antoine Baceiredo, Dr. Guy Crocco and Dr. Guy Bertrand

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198803011

      Thumbnail image of graphical abstract

      The analogy between a 1,2-bis(carbenoid) species and a species containing a triple bond, |[BOND]C[BOND]N[DOUBLE BOND]O↔[BOND]C[TRIPLE BOND]N→O|, was the basis for the method shown below for the synthesis of nitrile oxides. Noteworthy is the direct introduction of the NO group. Compound 1 is also the first nitrile oxide containing a P-bound CNO group (R = iPr2N).

    28. [Os(η2-PHS)(CO)2(PPh3)2], a Stable η2-Thioxophosphane(H[BOND]P[DOUBLE BOND]S)-Metal Complex (pages 302–304)

      D. Scott Bohle, Dr. Clifton E. F. Rickard and Prof. Dr. Warren R. Roper

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198803021

      Thumbnail image of graphical abstract

      The title compound 1 is formed by cleavage of acetic acid from 1. Compound 2 is unusual in that it reacts reversibly with alcohol + acid to give 3. Good yields in the reaction 1 → 2 were only obtained if the CH3CO2 group is first transformed into the CF3CO2 group. The selenium analogue of 2 was also synthesized (R = Me, Et; L = PPh3).

    29. Structures and Deformation Electron Densities of 1,2-Dihydrocyclobutabenzene and 1,2,4,5-Tetrahydrodicyclobuta[a,d]benzene (pages 304–305)

      Dr. Roland Boese and Dipl.-Ing. Dieter Bläser

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198803041

      Thumbnail image of graphical abstract

      The bond angles and not the bond lengths are significantly influenced by the annelation of four-membered rings (1 and 2). The deformation electron density map of 1 clearly shows the bent bonds in the four-membered ring as well as their effect on the electron densities in the bonds of the benzene ring.

  3. Book Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    1. Book Review: Practical Protein Chemistry—a Handbook. Edited by A. Darbre (page 306)

      Bernd Gutte

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198803061

    2. Book Review: Protein Engineering. Edited by M. Inouye and R. Sarma (page 306)

      Bernd Gutte

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198803062

    3. Book Review: Aromaticity. By P. J. Garratt (pages 306–307)

      Dieter Hasselmann

      Article first published online: 30 DEC 2003 | DOI: 10.1002/anie.198803063

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