Angewandte Chemie International Edition in English

Cover image for Vol. 26 Issue 4

April 1987

Volume 26, Issue 4

Pages 275–370

Currently known as: Angewandte Chemie International Edition

    1. Cover Picture (Angew. Chem. Int. Ed. Engl. 4/1987)

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198702751

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      The cover shows a space-filling model (drawn with the SCHAKAL program) of a tris(arene) gallium complex with a novel mode of coordination: gallium(I) is enclosed in the cavity formed by the three benzene rings of [2.2.2]paracyclophane. This is the first example of a metal complex containing three centrically bound neutral arene ligands. The central atom has no less than 19 atoms in its first coordination sphere—18 C atoms of the benzene rings and one Br atom of the anion GaBrmath image, which forms a weak contact. Further details are reported by H. Schmidbaur et al. on page 338 ff.

  1. Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Corrigenda
    1. The Development of a Carbene-like Chemistry with Terminal Phosphinidene Complexes (pages 275–286)

      Prof. Dr. François Mathey

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198702753

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      The formal analogy between the species R2C:, R2Si:, RN:, and RP: should not be taken to imply similar reactivity. In fact, the species RP: do not react at all with, for example, olefins. The electrophilicity of RP: can be increased, however, by complexation, and the rich variety of chemical reactions observed for [RP[DOUBLE BOND]M(CO)5] frequently corresponds to the behavior observed for singlet carbenes.

    2. Control of the Electronic Structure of Organic Conductors as Exemplified by [NMP][TCNQ] Charge-Transfer Complexes (pages 287–293)

      Dr. Joel S. Miller and Prof. Arthur J. Epstein

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198702871

      A complete series of one-dimensional organic conductors differing stepwise in their physical properties is still a dream; however, the first steps in this direction have already been taken. The exchange of the N-methylphenazinium (NMP) ions in an [NMP][TCNQ] salt (TCNQ = tetracyanoquinodimethane) for phenazine makes it possible to specifically adjust the electronic structure from the quarter- to the half-filled band case.

    3. Synthesis of Glycopeptides, Partial Structures of Biological Recognition Components [New Synthetic Methods (67)] (pages 294–308)

      Prof. Dr. Horst Kunz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198702941

      Glycopeptides are characterized by their great biological importance and their extremely difficult syntheses. These substances are made up of sugars that are linked to peptides, usually through the OH group of serine or threonine. The protecting group strategies now available allow the carbohydrate and peptide moieties to be linked stereoselectively. After removal of the protecting groups, glycopeptides found in tumor-associated antigen structures can be bound to bovine serum albumin without the use of a spacer.

    4. Emission of Microparticles from Automotive Sources—X-ray Photoelectron Spectroscopy in Environmental Analysis (pages 309–319)

      Dr. R. Schlögl, G. Indlekofer and Priv.-Doz. Dr. P. Oelhafen

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703091

      A dispassionate discussion of the recent forest damage and of the use of 3-way catalysts to clean automobile exhaust requires objective data. XPS (or ESCA) measurements are of particular value for studying the surfaces of microparticles as well as for investigating related problems of environmental importance.

    5. Allylamine Derivatives—a New Class of Active Substances in Antifungal Chemotherapy (pages 320–328)

      Dr. Anton Stütz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703201

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      There is a critical need for drugs to treat fungal infections (mycoses), which are encountered worldwide. Terbinafin, 1, which was systematically derived from an initial structure discovered by chance, is a very promising antimycotic agent. The novel allylamines are potent and selective inhibitors of fungal squalene epoxidase.

  2. Communications

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Corrigenda
    1. Apparently Nonstereospecific Dihalocarbene Addition—an Explanation (pages 329–330)

      Prof. Dr. Eckehard V. Dehmlow and Dipl.-Chem. Thomas Stiehm

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703291

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      Reversible formation of :CX2 from :CXmath image under phase-transfer-catalysis conditions could explain the nonstereospecific carbene addition observed for 1. Reversible nucleophilic addition of :CXmath image results in the isomerization of 1 to 2; the subsequent carbene addition to 1 and 2 to give 3 and 4, respectively, occurs stereospecifically, as expected (X = C1, Br).

    2. Titanium Hydride Formation through Hydrogen Transfer from 2-Methylpyridine to a Titanium Fulvene Compound; the First Structurally Characterized Terminal Titanium Hydride (pages 330–331)

      Dr. Johannes W. Pattiasina, Fré van Bolhuis and Dr. Jan H. Teuben

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703301

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      An unusual structure and a unique route of formation characterize the title compound 1. It is formed from the fulvene-titanium compound [Cp*(C5Me4CH2)Ti] and 2-methylpyridine in ether. H-6 of the pyridine derivative migrates to Ti, and the fulvene ligand is transformed by CC bond formation into a functionalized cyclopentadienyl ligand (Cp*5Me5).

    3. Sequential Configuration Analysis of Peptides (pages 331–332)

      Thomas Bolte, Dahai Yu, Hans-Thomas Stüwe and Prof. Dr. Wilfried A. König

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703311

      The determination of the degree of racemization of the amino acids at each position of a peptide is possible by means of a new procedure. The peptide is first treated with tert-butyl isocyanate; the N-terminal amino acid of the resulting N-tert-butylcarbamoylpeptide is then cleaved off as the ester 1 with iPrOH/HCl. This step is repeated until the peptide has been fully degraded. The degree of racemization of 1 can be determined by enantioselective gas chromatography (or HPLC).

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    4. Benzene and Linearly Annelated Arenes as Dienophiles in Diels–Alder Reactions with Inverse Electron Demand (pages 332–334)

      Prof. Dr. Gunther Seitz, Apotheker Reinhard Hoferichter and Dr. Rolf Mohr

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703321

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      Benzene 1 reacts in a very untypical manner with the extremely electron-poor diazadiene 2. The initial product of this Diels-Alder reaction is presumably 3, which could be stabilized by a [4 + 2] cycloreversion followed by oxidation to 4. Simple donor–substituted benzenes react analogously.

    5. Formation of Oxazolidinones and Oxazinanones by Reaction of Allylamines and of Homoallylamines with Carbon Dioxide and Iodine via Intramolecular Cyclization (pages 334–335)

      Prof. Dr. Takashi Toda and Dr. Yoshinori Kitagawa

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703341

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      “CO2 fixation” has been achieved, under normal pressure at room temperature without a catalyst, by means of the title reaction. The five- and six-membered heterocycles 1 and 2, respectively, are formed in 40–70% yield. Longer reaction time and the addition of Cs2CO3 increases the yields to 60–90% (R1 = H, alkyl, aryl; R2 = H, alkyl; R3 = H, CH2Aryl).

    6. Synthesis and Properties of 1-Cycloheptatrienylidene-2-cyclopentadienylidene-ethylene Derivatives (pages 335–336)

      Prof. Dr. Takashi Toda, Dr. Norihiko Shimazaki and Prof. Dr. Toshio Mukai

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703351

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      How important is the resonance formula 1′ for describing the properties of 1? The influence of the aryl substituents of the five-membered ring on the position of the stretching vibration of the cumulene bond and the 13C-NMR spectrum indicate that 1′ has some, but not all too great, importance. The derivatives of 1, which were obtained in acceptable yields, moreover, show very seldomly observed emission from an S2 state.

    7. Mycoloylpeptides and Other Lipopeptide Adjuvants from Higher Aldoketene Dimers (pages 336–338)

      Dipl.-Chem. Jörg Metzger and Prof. Dr. Günther Jung

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703361

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      Aldoketene dimers 1, obtained from fatty acid halides and tertiary amines, react with amino acid esters 2 to give lipoamino acids 3. These can be transformed into two- and three-chain mycoloyl compounds, some of which are effective B-cell mitogens (R = long-chain alkyl group; R′ = amino acid moiety).

    8. Arene Complexes with Weak Interactions: A Macrocyclic Tris(arene) Complex of Gallium(I) with η18 Coordination (pages 338–340)

      Prof. Dr. Hubert Schmidbaur, Rudolf Hager, Dipl.-Chem. Brigitte Huber and Dr. Gerhard Müller

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703381

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      Ga+ fits exactly into the cavity of [2.2.2]paracyclophane; the cation 1 is the first tris(arene) complex with neutral arene moieties. All 18 ring C atoms are bound nearly identically to Ga+, as revealed by the bond lengths (2.911–3.079 Å). In addition, a weak contact exists with a bromine atom of the counterion GaBrmath image. The compound 1·GaBrmath image forms colorless, only slightly air-sensitive crystals.

    9. The Fluorometric Determination of Thymine Glycol as Criterion of the Treatment of Foodstuffs (Biological Material) with Ionizing Radiation (pages 340–341)

      Prof. Dr. Konrad Pfeilsticker and Dipl.-Oecotroph. Jürgen Lucas

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703401

      The conservation of foodstuffs by means of ionizing radiation is not permitted in the Federal Republic of Germany. Until now, radiative treatment has been detectable within limits only for dried substances, in particular spices. This communication describes the principle of a new method that is suitable for water-containing foodstuffs. Thymine glycol (TG) is known to be formed upon irradiation of DNA. When (TG-containing) DNA is allowed to react with o-aminobenzaldehyde, TG is converted into 3-hydroxyquinaldine, which can be detected fluorimetrically. The fluorescence intensity can be correlated with the radiation dose, thereby allowing not only the irradiation to be detected but also its amount to be estimated.

    10. Photoisomerization of Stilbazolium Chromophores with Potential Nonlinear Optical Applications (pages 341–342)

      Dr. George L. Gaines Jr.

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703411

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      Why is 1 photostable? Many other stilbazolium compounds, including protonated 1, undergo isomerization to the cis form upon irradiation. This isomerization is forestalled, however, when a quinoid resonance structure of type 1a is favored. The cisoid conformer of 1a is thermodynamically unstable compared with 1a (transoid).

    11. 1,2-Diselenete and 1,2-Thiaselenete (pages 343–344)

      Frank Diehl and Prof. Dr. Armin Schweig

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703431

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      Two new unsubstituted, small-ring heterocycles, the title compounds 2a and 2b, have been generated by pyrolysis of the educts 1a and 1b and identified by PE and IR spectroscopy (in an argon matrix). The spectra are very similar to those of 1,2-dithiete.

    12. s-Tetrazine as Ligand for Monomeric and Bridged Macrocyclic Metal Complexes (pages 344–345)

      Dr. Uwe Keppeler, Dr. Sonja Deger, Dipl.-Chem. Armin Lange and Prof. Dr. Michael Hanack

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703441

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      Good semiconductor properties are exhibited by stable bridged metal complexes containing s-tetrazine as an N-donor ligand. Square-planar metal complexes, for example, phthalocyaninatoruthenium(II) and 2,3-naphthalocyaninatoiron(II), may be bridged. The structure of this hexcoordinated bridged polymer is indicated in formula 1.

    13. First ENDOR Investigations of Biologically Relevant Organic Radicals in Reversed Micelles (pages 345–347)

      Dipl.-Biochem. Norbert Bretz, Ingrid Mastalsky, Dipl.-Chem. Martin Elsner and Prof. Dr. Harry Kurreck

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703451

      Reversed micelles as problem solvers: They stabilize enzymes with respect to hydrophobic interactions, suppress possibly undesired properties of modified cofactors such as aggregate formation, and now make possible, among other things, EPR and ENDOR spectroscopy of the radical anions of riboflavin, flavin mononucleotide (FMN), and flavin adenine dinucleotide (FAD) in aqueous media, without water being the actual solvent. In this way, problems arising from high microwave dielectric loss can be avoided.

    14. P8iPr4—the First Tricyclo[,4]octaphosphane (pages 347–348)

      Prof. Dr. Marianne Baudler, Dr. Bernhard Koll, Dr. Christoph Adamek and Prof. Dr. Rolf Gleiter

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703471

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      An octaphosphahomonorbornene skeleton characterizes the new P8iPr4 isomer 1, which is formed upon thermolysis of various bi- and tricyclic isopropylphosphanes. Compound 1 is more stable than the isomer having a bisnoradamantane structure, even though its skeleton 2 is an important structural group of Hittorf's phosphorus. The structure of 1 was derived from the 13P-NMR parameters (R = iPr).

    15. P8tBu6O6—a Highly Oxidized Cyclophosphane with Intact P Framework (pages 348–349)

      Prof. Dr. Marianne Baudler and Dr. Joachim Germeshausen

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703481

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      The title compound 1 contains exclusively exocyclically bonded oxygen. It was obtained by reaction of the corresponding octaphosphane with cumene hydroperoxide at room temperature and was isolated by HPLC. Reaction of the octaphosphane with molecular oxygen, on the other hand, resulted in ring cleavage with preferential formation of the diphosphane derivative H(tBu)(O)P[BOND]P(O)(tBu)H. Compound 1 is the first multiply oxidized organocyclophosphane (R = tBu).

    16. Raman Spectrum of the Tetrasilatetrahedrane Anion Simath image (pages 349–351)

      Dr. Gerhard Kliche, Dr. Martin Schwarz and Prof. Dr. Hans-Georg von Schnering

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703491

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      All three fundamental vibrations of the tetra-silatetrahedrane anion Simath image have been observed for the first time. The synthesis of the red, transparent metal silicides CsSi, K3LiSi4, and K7LiSi8, which was achieved recently, made possible the measurement of the Raman (and IR) spectrum of Simath image.

    17. Enantioselective Synthesis of α-Trialkylsilyl Ketones and Aldehydes (pages 351–352)

      Prof. Dr. Dieter Enders and Dr. Braj Bhushan Lohray

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703511

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      α-Silylated carbonyl compounds (R)-1 with ≥96% ee are obtainable, as shown below, using SAMP as a chiral auxiliary. Compounds 1 constitute some of the most versatile synthetic building blocks. Analogously, RAMP affords (S)-1. SAMP is (S)-([BOND])-1-amino-2-(methoxymethyl)pyrrolidine; RAMP is the (R)-(+) isomer.

    18. “Two-Electron Reduction” of Phosphane-substituted Tricobalt Clusters—Evidence for a 17-Electron Intermediate in the Dissociative ETC Ligand Substitution (pages 352–354)

      Dipl.-Chem. Klaus Hinkelmann, Falko Mahlendorf, Priv.-Doz. Dr. Jürgen Heinze, Dipl.-Chem. Hans-Thomas Schacht, Dr. John S. Field and Prof. Dr. Heinrich Vahrenkamp

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703521

      Reduction and ligand elimination result in reversible transformation of the μ3-alkylidyne complex 1 into the 17-electron species 2⊙⊖. This was confirmed by cyclic voltammetry and multisweep experiments with 1 as well as by trapping of the released phosphane ligand. The further reduction to 22⊖ is also reversible. The radical anion 2⊙⊖, which is an essential 17-electron intermediate for the ETC ligand exchange, is the first such species to be unequivocally detected.

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    19. Thermolysis of NH4HCO3—A Simple Route to the Formation of Free Carbonic Acid (H2CO3) in the Gas Phase (pages 354–355)

      Dr. Johan K. Terlouw, Dr. Carlito B. Lebrilla and Prof. Dr. Helmut Schwarz

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703541

      “Carbonic acid cannot exist in the free state.” Now, a surprisingly simple experiment has shown that this statement is wrong. Thermolysis of NH4HCO3 affords, among other products, H2CO3, which is stable as both the neutral molecule and the radical cation. This finding also confirms the results of detailed ab initio and semiempirical calculations, which show that H2CO3 should be stable in the gas phase because the activation energy for its decomposition is large.

    20. Azoalkane-Nitrene Cleavage on an Fe3-Cluster (pages 355–356)

      Dr. Edward J. Wucherer and Prof. Dr. Heinrich Vahrenkamp

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703551

      The transformation of the μ3 ligand EtN[DOUBLE BOND]NEt into two μ3 ligands :NEt occurs upon heating the Fe3 complex 1 to 120°C. In addition to ca. 5% of decomposition products, ca. 75% of 2 and ca. 20% of 1 are obtained. The reaction 1[RIGHTWARDS ARROW] 2 is the simplest example so far of a cluster-induced fragmentation of a ligand. The overall composition of the complex does not change as a result of the NN cleavage.

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    21. Gas-Inclusion Crystals of Tetra-tert-butyltetrahedrane and Its Deformation Density (pages 356–357)

      Prof. Dr. Hermann Irngartinger, Dr. Reiner Jahn, Prof. Dr. Günther Maier and Dr. Rolf Emrich

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703561

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      Low-temperature X-ray diffraction measurements performed on tetra-tert-butyltetrahedrane revealed the existence of clathrates in crystals without hydrogen bonds. Both N2 and Ar are entrapped. The deformation density determined for the Ar clathrate revealed that the tetrahedral bonds are bent outward from the C[BOND]C bond vector by 26°. (M = center of the line joining the two other C atoms of the tetrahedron.)

    22. Trimethylenemethane Complexes of Cr, Mo, and W by Novel Methylenation of Allenes with Carbene Complexes; Cyclopentanes by [3+2] Cycloaddition of Trimethylenemethane Complexes to Allenes (pages 357–359)

      Prof. Dr. Rudolf Aumann and Jürgen Uphoff

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703571

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      The trimethylenemethane complexes 3, M[DOUBLE BOND]Cr, Mo, W, are new C3 building blocks for syntheses involving [3+2] cycloadditions. They are obtained as diastereomeric mixtures from the carbene complexes 1 and the allene 2. Complex 3, M[DOUBLE BOND]Cr, and its diastereomer react with further 2 to give the cyclopentane derivative 4; furthermore, the cyclopentenone 5 is formed in high yield from 2 and CO (via the reaction 1 + 2 [RIGHTWARDS ARROW] 3).

    23. Glycosyl Isocyanide Dichlorides—Novel Synthetic Building Blocks in Sugar Chemistry (pages 359–360)

      Dr. Tillmann Hassel and Dr. Hanns Peter Müller

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703591

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      Per-O-acetylglycosyl isocyanide dichlorides of type 1 expand the armamentarium of preparative carbohydrate chemistry. Compounds 1 are readily accessible by chlorination of the corresponding isothiocyanates. Their synthetic potential is exemplified by the transformation of the glucose derivative 1 into the glucosylamino oxadiazole 2.

    24. The Influence of Substituents on Double-Bond Localization, e.g. in s-Indacene (pages 360–362)

      Prof. Dr. Edgar Heilbronner and Prof. Dr. Zhong-Zhi Yang

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703601

      In a molecule with conjugated π bonds, which substituents favor localized double bonds? Heuristic rules to answer this question qualitatively have been derived in the framework of the Hückel model. Only the maximum eigenvalue of the unperturbed system is required along with the atomic orbital coefficients of the HOMO and LUMO and their energies.

    25. Total Synthesis of the Enantiomerically Pure Lichen Macrolide (+)-Aspicilin (pages 362–364)

      Prof. Dr. Gerhard Quinkert, Dipl.-Chem. Nona Heim, Dr. Jürgen Glenneberg, Dr. Uta-Maria Billhardt, Dipl.-Chem. Volker Autze, Dr. Jan W. Bats and Dr. Gerd Dürner

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703621

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      The title compound 1 contains an 18-membered lactone ring, four centers of chirality, and a CC double bond. It was synthesized in enantiomerically pure form starting from the inexpensive chemicals phenol, azelaic acid, and the ethyl ester of (S)-lactic acid. The key step of the synthesis is a (presumably broadly applicable) photochemical reaction.—It is remarkable how far information can be transferred from the center of chirality already present (C-17) to the new center of chirality (C-6).

    26. Bond Stretch Isomerism in Bicyclo[1.1.0]tetrasilanes. Contrasts Between Strained Silicon and Carbon Ring Systems (pages 364–366)

      Prof. Dr. Paul von Ragué Schleyer, Dr. Alexander F. Sax, Dr. Josef Kalcher and Prof. Dr. Rudolf Janoschek

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703641

      Is bicyclotetrasilane expected to exhibit a markedly short or a markedly long central Si[BOND]Si bond? Ab initio calculations at different levels of accuracy all gave two potential minima. The corresponding structures differ in the length of the central bond (by about 0.5 Å), the interflap angle (120 and 140°), and the H[BOND]Si[BOND]Si angle at the bridgehead atoms (140 and 90°). In all calculations, the structure with the long Si[BOND]Si bond proved to be lower in energy. This order can be reversed, however, in derivatives with bulky substituents at the bridgehead atoms.

  3. Book Reviews

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Corrigenda
  4. Corrigenda

    1. Top of page
    2. Reviews
    3. Communications
    4. Book Reviews
    5. Corrigenda
    1. You have free access to this content
      Corrigendum (page 370)

      Version of Record online: 22 DEC 2003 | DOI: 10.1002/anie.198703702