bluuebunny/crossref_metadata_2025 huggingface dataset:
NMR Spectroscopic Investigation of Intercalation Compounds of Organic Molecules and Sheet Silicates—p‐Xylene‐Hectorite and Related Systems
Authors: Fyfe Colin A. , Thomas John M. , Lyerla James R.
Published: December 2003

p‐Xylene and γ‐butyrolactone, taken up in the interlamellar spaces of the sheet silicate hectorite, were used to examine the possibilities offered by NMR spectroscopy as a method of studying such intercalation compounds. Using a pulsed FT‐NMR spectrometer, the degree of molecular freedom of an intercalated organic compound, the composition of mixtures, and even ketoenol equilibrium positions, can be determined.
Irritant and Defense Substances of Higher Plants—A Chemical Herbarium
Authors: Schildknecht Hermann
Published: December 2003

All living organisms respond to stimulation, reacting more or less sensitively and more or less typically to a wide variety of energy forms such as light, heat, gravity, pressure (sound), electricity—and chemicals. A living organism responds to an irritation by releasing irritants which—as potential defense substances—are directed against the attacker or assist the organism endogenously in an intrinsic defense reaction. Often very small energy changes perceived by the plant are enough to induce a series of physiological processes ultimately manifested as a glandular reaction or even movement. The irritants involved in these processes act on membranes as defense substances in the presence of an attacker, or as endogenous factors in their own cellular environment. These chemically very diverse low‐molecular active principles have been found in many parts of plants and in many plant families. For this reason alone we could speak of a chemical herbarium, but the case is even stronger because, in this botanical documentation, not only the individual chemicals are considered in context but also whole sets of interacting substances, since it is only in these sets that optimal activity is found (just as one considers not only the parts of a plant but also the whole plant in botany).
Elimination and Addition at the Phosphorus‐Carbon pπ‐pπ Bond
Authors: Appel Rolf , Maier Günther , Reisenauer Hans Peter , Westerhaus Axel
Published: December 2003

A novel compound with PC triple bond, phenylmethylidynephosphane (2), was produced by pyrolysis and trapped at −196 °C. The educt (1) decomposes almost quantitatively into (2) and Me3SiCl in a Hg‐diffusion pump vacuum at 700 °C; the educt (3), on the other hand, only yields (2) at 800 °C. Solutions of (2) are stable only at low temperatures; at 0 °C the half‐life is 7 min.
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Trinuclear Clusters from HCo(CO)4 Solutions
Authors: Fachinetti Giuseppe , Balocchi Laura , Secco Fernando , Venturini Marcella
Published: December 2003

HCo3(CO)9 (3) is the first isolable hydrido‐carbonyl cluster, which can be obtained using HCo(CO)4 (1) as starting compound. The trinuclear, electronically unsaturated cluster is formed by thermal decomposition of (1) together with the expected Co2(CO)8 (2). Lower nuclear clusters such as (3) are discussed as catalysts, e.g. in homogeneous hydroformylation or CO reduction.
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“Magnetochemical Series” for Lanthanoid Compounds
Authors: Urland Werner
Published: December 2003

“Magnetochcmical series”, not only for ligands but also for central ions, can be drawn up in the case of alkali‐metal lanthanoid oxides or halides. To explain the magnetic behavior of these compounds use was made, inter alia, of the Angular Overlap (AO) model. The AO parameter e0(R) could be determined for some series of compounds (from susceptibility measurements). Taking into account the (calculated) overlap integrals S(R) and additional relationships afforded magnetochemical series of the ligands I−< Br−< Cl−< F− ≈ O2− and of the lanthanoids. The sequence of the latter series Corresponds to the pattern of lanthanoid contraction.
Target Directed Drug Synthesis: The Aminoacyl‐tRNA Synthetases as Possible Targets
Authors: von der Haar Friedrich , Gabius Hans‐Joachim , Cramer Friedrich
Published: December 2003

The “tailor‐made” pharmaceutical has been an old dream ever since Paracelsus' days. His saying “Dosis sola facit venenum” is still valid. The ideal pharmacon should inhibit the pathological process or the parasitical organism to a maximum while causing as little harm as possible to the human organism. In order to achieve this goal one must try to make use of metabolic differences between the metabolism of the pathological organism and normal human metabolism in a rational way. With today's improved knowledge of enzymatic processes this seems to be a possible and highly promising approach. The pharmaceutical should act upon a process of central importance, such as the process of protein biosynthesis, where the required highly accurate construction of the macromolecules is achieved by a “proofreading” process. It is shown that this “proofreading” mechanism exhibits specific difference in different species.
Half a Century of Polystyrene—A Survey of the Chemistry and Physics of a Pioneering Material
Authors: Echte Adolf , Haaf Franz , Hambrecht Jürgen
Published: December 2003

Hermann Staudinger, the founder of polymer chemistry, would have been 100 years old this year. One of the key materials with which he elucidated the structure of high polymers was polystyrene.—Polystyrene, one of the most important thermoplastics, has now been manufactured industrially for some 50 years. Not only has it simplified our daily lives in a variety of ways, it has also been a model substance for the development and expansion of polymer chemistry and polymer physics, and it was the pioneering material for handling polymer solutions and melts. This article surveys the development and present state of knowledge of the polymerization of styrene and of the relationships between structure and properties.
Polymers with Metal‐Like Conductivity—A Review of their Synthesis, Structure and Properties
Authors: Wegner Gerhard
Published: December 2003

Polymers such as polyacetylene, which have an extended π‐electron system in their backbone, or like poly(p‐phenylene) consist of a sequence of aromatic rings are excellent insulators in their native state and can be transformed by oxidation or reduction in the solid state into conductive CT‐complexes which exhibit metal‐like conduction characteristics. The chemical and physical processes involved and the reasons for the observed quasimetallic conductivity are not yet fully understood. The real structure of these materials in chemical and physical terms, i. e. their complicated morphology and texture, as well as the results available on the structure‐property relationships of the “organic metals” must be considered when discussing their properties. In other words, a discussion of conductive polymers should be based on what is known of the highly conducting CT‐complexes of low‐molecular weight compounds. The discovery of the highly conducting polymer complexes has opened up a new interdisciplinary field of research which borders on polymer science, solid‐state and semiconductor physics and on organic solid‐state chemistry. It is hoped that this area will lead to numerous novel materials and technical applications.
Photochemical Formation of and Ligand Exchange in a Cationic Dithiolatonickel Complex
Authors: Vogler Arnd , Kunkely Horst
Published: December 2003

The first cationic transition metal complex containing a 1,2‐dithiolato ligand, (1), was generated photochemically from the neutral complex in chlorinated solvents. (1) is stable at low temperature; at room temperature an unusual ligand‐exchange takes place.
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Structure and Bonding in Cyclic Sulfur‐Nitrogen Compounds—Molecular Orbital Considerations
Authors: Gleiter Rolf
Published: December 2003

The molecular structures of monocyclic sulfur‐nitrogen ring systems, such as S2N2, S3N, S4N and S5N, can be considered as examples of electron rich (4n + 2)π systems. The structures of S4N4, S4N, P4S4, As4S4 and the bicyclic structures S4N, S4N as well as S5N6 can be rationalized on the basis of a planar tetrasulfur tetranitride with 12π electrons.
Methods of Fluorination in Organic Chemistry
Authors: Gerstenberger Michael R. C. , Haas Alois
Published: December 2003

Since the days of the “Manhattan Project” our knowledge of the chemistry of fluorine‐con‐taining compounds has increased tremendously. At first only considered out of curiosity, this area of research bordering between inorganic and organic chemistry has developed from modest beginnings to such a complexity of interesting ramifications that it would be very difficult to review all aspects in detail. The motivating force behind the developments in this field were, above all, the unusual properties the numerous compounds acquire on introduction of fluorine substituents. The spectrum of unusual modes of behavior extend from extreme stabilization in fluorine‐containing polymers and blood‐substitutes to drastic increases in reactivity in pharmacologically and phytomedicinally active substances and in dyes. Moreover, one physical peculiarity of the fluorine atom, its magnetic moment, opens a new route to the decyphering of metabolic processes.—Parallel to the ever increasing number of fluorinated compounds there has been a concomitant increase in the variety of methods of synthesis and reagents, which is frequently difficult to overview in entirety, even for the specialists. Older, simple methods such as halogen metathesis with metal fluorides and electrofluorination are being refined as far as higher selectivity is concerned, and completely new, very reactive substances such as hypofluorites and noble‐gas fluorides enable fascinating reactions on complex substrates,e. g.steroids and nucleobases. The present review is an attempted documentation and classification of the methods as well as a critical appraisal, not least from the standpoint of efficiency and economic aspects.
Periodated Cyclosilanes
Authors: Hengge Edwin , Kovar Dieter
Published: December 2003

The first cyclic silicon‐iodine compounds (SiI2)n, n = 4, 5, 6, are accessible from the corresponding phenyl derivatives by reaction with HI in the presence of A1I3 catalyst. The catalyst must be free of water and iodine. The products are yellow and extremely sensitive to moisture.
Trichloro(methyl)silane/Sodium Iodide, A New Regioselective Reagent for the Cleavage of Ethers
Authors: Olah George A. , Husain Altaf , Gupta B. G. Balaram , Narang Subhash C.
Published: December 2003

More than a dozen examples verify that ethers are cleaved regioselectively in very good yields by MeSiCl3/NaI in acetonitrile; primary and secondary methyl‐, benzyl‐, trityl‐ and tetrahydropyranyl ethers directly afford the primary and secondary alcohols. In the case of tert‐alkylmethyl ethers only the tert‐alkyl iodides are formed.
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Chemistry and Biochemistry of Microbial α‐Glucosidase Inhibitors
Authors: Truscheit Ernst , Frommer Werner , Junge Bodo , Müller Lutz , Schmidt Delf D. , Wingender Winfried
Published: December 2003

α‐Glucosidases are among the most important carbohydrate‐splitting enzymes. They catalyze the hydrolysis of α‐glucosidic linkages. Their substrates are—depending on their specificity—oligo‐ and polysaccharides. Microbial inhibitors of α‐amylases and other mammalian intestinal carbohydrate‐splitting enzymes studied during the last few years have aroused medical interest in the treatment of metabolic diseases such as diabetes. Moreover, they extend the spectrum of microbial secondary metabolites which comprises an enormous variety of structures. They also contribute considerably to a better understanding of the mechanism of action of α‐glucosidases. These inhibitors belong to different classes of substances. Those studied most thoroughly are microbial α‐glucosidase inhibitors which are members of a homologous series of pseudooligosaccharides of the general formula (4). They all have a core in common which is essential for their inhibitory action, a pseudodisaccharide residue consisting of an unsaturated cyclitol unit, and a 4‐amino‐4,6‐dideoxy‐ glucose unit. The—in many respects—most interesting representative of this homologous series is acarbose (5), a pseudotetrasaccharide exhibiting a very pronounced inhibitory effect on intestinal α‐glucosidases such as sucrase, maltase and glucoamylase. The present paper will review this new field of microbial α‐glucosidase inhibitors which has been studied with particular intensity during the past ten years.
4‐Aryldihydropyridines, a New Class of Highly Active Calcium Antagonists
Authors: Bossert Friedrich , Meyer Horst , Wehinger Egbert
Published: December 2003

The aryldihydropyridines first prepared by Hantzsch almost 100 years ago have recently been found to be highly effective calcium antagonists with suitable pharmacological profiles. An illustrative example is dimethyl‐l,4‐dihydro‐2,6‐dimethyl‐4‐(o‐nitrophenyl)pyridine‐3,5‐dicarboxylate (Nifedipine) which is already employed therapeutically. This substance lowers the frequency of attack of angina pectoris and reduces blood pressure. The discovery of the therapeutic activity of this class of substances initiated renewed investigation of the Hantzsch condensation and the synthesis of numerous 4‐aryldihydropyridines and related compounds. Qualitative and quantitative structure/activity relationships of these substances can be deduced from their biological data.
Preparation and Structure of Iodocuprates(I) with Tetrahedral Face‐to‐Face Coupling
Authors: Hartl Hans , Mahdjour‐Hassan‐Abadi Farbod
Published: December 2003

Very short Cu‐Cu distances occur in the triiododicuprates (1) and (2), which can be prepared in organic solvents from copper and ammonium iodides. The cations of the crystalline complexes are distinguished by the fact that the Cul4‐tetrahedra are alternately linked via common edges and faces.
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Analysis of Low Molecular Weight Homologues of Fiber‐Forming Polycondensates
Authors: Rossbach V.
Published: December 2003

Oligomers belong to the gray area between low molecular weight chemistry and macromolecular chemistry. Although they represent an undesirable “natural impurity” in fiber‐forming polycondensates, they serve as useful model compounds for the corresponding polymers in fundamental research. Whereas for many years new classes of oligomers were being made preparatively accessible and the isolation of higher oligomers in pure form was being pursued, at the present time the emphasis is on analysis. By a combination of classical chemical and instrumental methods of analysis from polymer and organic chemistry, the identification of oligomers of unknown structure, the analytical control of their synthesis and the determination of their content in technical polymers has meanwhile become a routine task.
The Critical Screening and Assessment of Scientific Results without Loss of Information—Possible or Not?
Authors: Luckenbach Reiner , Ecker Reinhard , Sunkel Josef
Published: December 2003

The critical assessment of information as a means of screening and selecting scientific results, leading to a procedure for condensing the flood of data from the primary literature into the secondary literature, is reviewed (here, exemplified for organic chemistry). The criteria for critical assessment without loss of content, developed and tested by the Beilstein Institute on the basis of a hundred years' experience, are presented. The possible extent to which data can thus be reduced is demonstrated for a number of examples.
Replication and Evolution in Inorganic Systems
Authors: Weiss Armin
Published: December 2003

Using layer silicates as models, the principle of replication, i.e. the spontaneous self‐multiplication of a carrier of information, can be shown to be a general property of certain macromolecular systems. Errors in replication and feedback together with environmental influences may lead to mutants with higher or lower replication rates, thus enabling evolution. In the light of these findings, the question of whether or not chemical evolution resulted directly in the nucleic acid/protein system, i.e. the genetic principle common to all living systems known up to now, has to be answered. It seems conceivable that as a first step a much simpler replicating system was formed: such a system might then have undergone an evolution of replicating systems, resulting in the final nucleic acid/protein system.
On the Structure of the Helical N‐Terminus in Alamethicin—α‐Helix or 310‐Helix?
Authors: Butters Thomas , Hütter Peter , Jung Günther , Pauls Norbert , Schmitt Heribert , Sheldrick George M. , Winter Werner
Published: December 2003

The crystal structure of the helical undecapeptide (1), a model of the N‐terminal alamethicin helix, suggests that no 310‐ but an α‐helix conformation is most probably present in the antibiotics alamethicin, trichotoxin, and suzukacillin. The nine N‐terminal amino acids of (1) are part of an α‐helix.
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Hybrid Orbitals and Their Applications in Structural Chemistry
Authors: Bingel Werner A. , Lüttke Wolfgang
Published: December 2003

A uniform, systematic, and complete review is given on s‐p hybrid orbitals with which a central atom Z enters into σ bonds with two to four ligands L. All possible cases of symmetry are treated: in four‐coordination from Td symmetry in ZL4 molecules to the asymmetric case of four different ligands; in three‐coordination from D3h symmetry in ZL3 molecules to Cs symmetry for ZLL′L″ molecules. For some cases the formulas are given for the first time. In this connection it is shown that the most general sp3 and sp2 hybrids still contain three and two free parameters, respectively. The appearance of hybrid orbitals on changing from a “delocalized” to a “localized” description of the bonding situation is illustrated with examples. Finally, possible applications in the description of the bonding relationships of molecules and the interpretation of the results of spectroscopic methods for the determination of molecular structure are indicated and likewise illustrated by examples.
Transition Metal Thiometalates: Properties and Significance in Complex and Bioinorganic Chemistry
Authors: Müller Achim , Diemann Ekkehard , Jostes Rainer , Bögge Hartmut
Published: December 2003

In their highest oxidation states the early transition metals V, Nb, Ta, Mo, W, and Re form tetrahedral, strongly colored thioanions endowed with some remarkable properties. Thiometalates can be formed by solid‐state reactions or in solution from the oxometalates. Poly‐thiometalates with mixed valences can be produced by new types of intramolecular condensation‐redox reactions from thioanions. The metal‐sulfur bonds can react either nucleophilically or electrophilically, and in the case of the Mo–S bonds this is of biochemical interest. It is important to mention the applications of thiometalates as ligands in complex chemistry (generation of multi‐metal complexes, versatile coordination behavior, unique electronic properties of the ligands), in which thiometalato complexes with a variety of electron populations can exist because of the marked electron delocalization. Apart from this, MoS has a significance in bioinorganic problems, e.g. the nitrogenase problem and CuMo antagonism.
A New Onium Salt: Synthesis and Characterization of the Difluorophosphonium Ion, PH2 F
Authors: Roesky Herbert W. , Weber Karl‐Liudwig , Schimkowiak Jürgen
Published: December 2003

Unlike salts of NH2F, which decompose explosively at room temperature, PH2F AsF( 1) is surprisingly stable. The fine crystalline, colorless (1) can be stored for several days at room temperature in polyethylene vessels; it decomposes with loss of HF and formation of red phosphorus, only on warming.
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Synthesis of Dithiophosphinato Complexes with Bis(diorganothiophilosphoryl)disulfanes: Mo3S7‐Cluster Dithiophosphinates
Authors: Keck Helmut , Kuclhen Wilhelm , Mathow Jürgen , Meyer Beate , Mootz Dietrich , Wunderlich Hartmut
Published: December 2003

Molybdenum‐sulfur clusters are of topical interest as model substances in bio‐inorganic chemistry. The readily soluble Mo3S7‐cluster chelates (1) and (2) have been synthesized for the first time from Mo(CO)6 and R2P(S)–S2–P(S)R2, R= Et or nPr. An X‐ray structure analysis of (1), a 1 :1 electrolyte, has been carried out. Further functionalization via suitable sub‐stituents R would seem to be possible.
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CH3SFSbF, a “Sulfuranonium” Salt
Authors: Kleemann Gert , Seppelt Konrad
Published: December 2003

Methyl‐ and ethylsulfur pentafluoride readily react at low temperatures with AsF5 or SbF5. An NMR spectroscopic investigation of the system H3CSbF5/SbF5, in SO2 showed that primarily the title compound is formed at −70°C; it rapidly decomposes on heating. H3CSFSbF and H5C2SFSbF could find use as strong alkylating agents.
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Determination of the Structure of New Tetrathiomolybdato Complexes of FeII, CuI and AgI by the Resonance Raman Effect: Textbook Examples for its Application in Coordination Chemistry
Authors: Müller Achim , Dommröse Anne‐Marie , Jaegermann Wolfram , Krickemeyer Erich , Sarkar Sabyasachi
Published: December 2003

Precursors with a high Fe content, such as (1), are especially suitable for the construction of the MoFe cofactor of nitrogenase. Reaction of AgNO3, (NH4)2MoS4 and PPh3 affords the symmetrical trinuclear complex (2). The structures of (1) and (2) and related compounds were determined by the Resonance‐Raman‐Effect method; the influence of the nearest and next nearest neighbors on the vibrations of the ligand chromophore is investigated.
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Thermal Conversion of 1,3‐Cyclooctadien‐5‐yne into Benzocyclobutene—A Novel Isomerization on the C8H8 Hypersurface
Authors: Meier Herbert , Hanold Norbert , Kolshorn Heinz
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 85. DOI:10.1002/anie.198200850
[(CH3)5C5Sn(C5H5N)]+: Synthesis, Structure and Bonding
Authors: Jutzi Peter , Kohl Franz , Krüger Carl , Wolmershäuser Gotthelf , Hofmann Peter , Stauffert Peter
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 25. DOI:10.1002/anie.198200250
Synthesis of Linear and Branched Cellotetraoses
Authors: Schmidt Richard R. , Michel Josef
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 78. DOI:10.1002/anie.198200780
Triferrocenylamine, NFc3
Authors: Herberhold Max , Ellinger Max , Thewalt Ulf , Stollmaier Friederike
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 98. DOI:10.1002/anie.198200980
Preparation of an Ethylene(hydrido)tungsten Complex by Photo‐Induced β‐Elimination
Authors: Alt Helmut Guido , Eichner Manfred Erwin
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 121. DOI:10.1002/anie.198201210
Carbonylcyclopropanes(Cyclopropylidenemethanones): Preparation and Steric Course of Cyclodimerization to Dispiro[2.1.2.1]octane‐4,8‐diones
Authors: Hoffmann H. M. R. , Wulff Jan Michael , Kütz Angela , Wartchow Rudolf
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 17. DOI:10.1002/anie.198200170
Problems of Economic Exploitation of Basic Research Findings (Discoveries, Inventions, Patents, Licenses)
Authors: Beier Friedrich‐Karl
Published: December 2003

In spite of high expenditures for basic research and its indisputable significance for technological development, the knowledge so gained seldom finds its way into industrial practice without difficulty and undue delay. Even without changing the aims of basic research, more commercially exploitable research results will be obtained in the future. It is in the interests of the public and the scientists themselves that such results, not only broaden scientific knowledge, but also be transferred in the best possible way into innovative practice. An intensified patent and license policy for scientists inventions is a more appropriate solution to this effect than any independent legal protection for scientific discoveries.
Organometallic Aspects of the Fischer‐Tropsch Synthesis
Authors: Herrmann Wolfgang A.
Published: December 2003

The Fischer‐Tropsch Synthesis counts among the industrial‐scale processes having a versatile and broad product range, and has for decades offered the most attractive possibility for the use of coal as a source of heating oil and fuels. This conceivably simple reaction, the catalytic hydrogenation of carbon monoxide, generally leads to simple hydrocarbons as well (i.e. short chain olefins) that have been sought as chemical feedstocks since the oil crisis of the seventies, but fails to provide the large‐scale, economic process required, due in large part to the minimal selectivity of traditional Fischer‐Tropsch processes. In an effort to solve this problem current research in this sector is concerned not only with the optimization of old and the development of new catalytic systems, but also increasingly with the elucidation of numerous relevant reaction mechanisms. This article will discuss, from the viewpoint of an organometallic chemist, the significance of typical model reactions, both with regard to some fundamental aspects of synthesis gas chemistry, and in comparison with previous views concerning the mechanism of the Fischer‐Tropsch Synthesis. The importance of various unique classes of complexes that have been studied in the context of Fischer‐Tropsch chemistry is also evaluated with regard to their importance in the synthesis of hydrocarbons from carbon monoxide and hydrogen. It emerges that the primary steps of the reductive oligomerization of carbon monoxide are best described by the carbide/methylene mechanism, as originally proposed by Hans Fischer and Franz Tropsch.
Stereoselectivity and Relative Reactivity in the Reaction of Organotitanium and ‐zirconium Reagents with Carbonyl Compounds
Authors: Reetz Manfred T. , Steinbach Rainer , Westermann Jürgen , Urz Ralf , Wenderoth Bernd , Peter Roland
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 257. DOI:10.1002/anie.198202570
Optically Active Glycerol Derivatives from 1,3(R) : 4,6(R)‐Di‐O‐benzylidene‐D‐mannitol— The First Structural Analogues of Moenomycin A
Authors: Schubert Thomas , Welzel Peter
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 361. DOI:10.1002/anie.198203610
Electorn Transfer by Grignard Reagents: Direct Evidence for Organomagnesium Radical Complexes
Authors: Kaim Wolfgang
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 289. DOI:10.1002/anie.198202890
From a Formyl to a Methyl Complex
Authors: Berke Heinz , Weiler Gertrud
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 214. DOI:10.1002/anie.198202140
Synthesis and Reactivity of Metal Complexes with the Zwitterionic Et3P—CS2 Ligand. Structure of the Dithiocarbonato Complex [(triphos)Co(S2CO)]
Authors: Bianchini Claudio , Meli Andrea , Orlandini Annabella
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 471. DOI:10.1002/anie.198204710
Dipolar Intermediates in the [2,3]Sigmatropic Rearrangement of Ammoniomethanides
Authors: Gompper Rudolf , Kohl Bernhard
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 398. DOI:10.1002/anie.198203980
Dialkylmagnesium Compounds from Magnesium, Hydrogen, and 1‐Alkenes
Authors: Bogdanović Borislav , Schwickardi Manfred , Sikorsky Peter
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 457. DOI:10.1002/anie.198204570
Reaction of Acyliminomalonic Esters with C‐Nucleophiles, an Umpolung in the Acylaminomalonic Ester Synthesis of α‐Amino Acids
Authors: Kober Reiner , Hammes Willi , Steglich Wolfgang
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 542. DOI:10.1002/anie.198205420
Doubly Metalated Carbon by Metal‐Induced Vinyl‐Ethylidene Rearrangement
Authors: Aumann Rudolf , Henkel Gerald , Krebs Bernt
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 506. DOI:10.1002/anie.198205060
Macrocycles of D‐ and L‐Proline Residues
Authors: Rothe Manfred , Mästle Werner
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 533. DOI:10.1002/anie.198205330
1,4‐Dialkylgermabenzenes‐Generation and Detection in the Gas Phase
Authors: Märkl Gottfried , Rudnick Dieter , Schulz Reinhard , Schweig Armin
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 523. DOI:10.1002/anie.198205230
Novel Synthesis of Octaalkyl‐ and Octaisoalkylporphyrins
Authors: Callot Henry Jacques , Louati Abderrazak , Gross Maurice
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 718. DOI:10.1002/anie.198207180
Cross‐Conjugated Trienes by Thermal Isomerization of Alkynes
Authors: Priebe Hanno , Hopf Henning
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 640. DOI:10.1002/anie.198206400
Orbital Symmetry Analysis of Triplet‐Singlet Spin‐Flip during Thermal Isomerization of Tetrahedral to Planar Nickel(II) Complexes
Authors: Halevi E. Amitai , Knorr Rudolf
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 622. DOI:10.1002/anie.198206220
A Stable Diazasilacyclopropane
Authors: Hluchy Johann , Klingebiel Uwe
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 750. DOI:10.1002/anie.198207500
A Stereocontrolled Synthesis of the Pheromone 4‐Methyl‐3‐heptanol: Novel and Selective CC‐Linking Reactions
Authors: Schlosser Manfred , Fujita Katsuramaru
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 646. DOI:10.1002/anie.198206460
Unsymmetrical Transfer of Allyl Groups in the Reaction of [(η3‐C3H5)2M] (M = Pd, Ni) with Bis(diphenylphosphino)maleic Anhydride
Authors: Fenske Dieter , Stock Petra
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 862. DOI:10.1002/anie.198208620
7‐Deazaguanosine‐3′,5′‐phosphate—An Isosteric cGMP Analogue with High Affinity for Cyclonucleotide Phosphodiesterase
Authors: Tran‐Thi Quynh‐Hoa , Franzen Doris , Seela Frank
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 945. DOI:10.1002/anie.198209450
Reversible Double Deprotonation of Hexamethylbenzene on Ruthenium: Formation of a Fluxional η3‐Benzyl Compound by Protonation of an o‐Quinodimethane Complex of Ruthenium(0)
Authors: Bennett Martin A. , McMahon Ian J. , Turney Terence W.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 853. DOI:10.1002/anie.198208530
The Hydrophobic and Metal‐Ion Coordinating Properties of α‐Lipoic Acid—An Example of Intramolecular Equilibria in Metal‐Ion Complexes
Authors: Sigel Helmut
Published: December 2003

Hydrophobic interactions as structure determining factors for macromolecules are well‐known in biochemistry. Considerably less recognized is the fact that these law‐energy interactions may also determine the structure of low‐molecular species. The same applies for weak ligand‐metal ion interactions. That both these factors may lead to intramolecular, contraction‐independent equilibria between isomeric metal‐ion complexes is demostrated with α‐lipoic acid as ligand. This cofactor affers metal ions two different binding sites: the carboxylate group and the disulfide linkage. The carboxylate group dominates the coordinating properties of this ligand towards the biologically important metal ions, but a disulfide‐metal ion interaction is still possible and under sterically favourable conditions may becomevery important; this could also be true under enzymic conditions here the carboxyl group is no longer free but amide‐liked to the protein. Furthermore, due to the valeric acid side chain, the lipoyl moiety is ideally suited to undergo hydrophobic ligand‐ligand interactions in mixed‐ligand complexes. Such hydrophobic interactions seem to be ideal to allwe migration, e.g., of the 14 Å long lipoyllysyl moiety, and also to caciliutate the correct ‘fixation’ at the surface of the enzyme.
Structure of the Octabismuth(2+) Cluster in Crystalline Bi8(AlCl4)2
Authors: Krebs Bernt , Hucke Marita , Brendel Claus Jörg
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1108. DOI:10.1002/anie.198211080
1,3‐Dipolar Cycloadditions to Dialkyl‐germanones and ‐germathiones
Authors: Lavayssière Hélène , Dousse Gabriel , Satgé Jacques , Barrau Jacques , Traoré Moussa
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1082. DOI:10.1002/anie.198210820
Complexes of Crown Ethers with Uronium Salts: Preparation and Crystal Structure of [18]Crown‐6 Uronium Nitrate (1/1) and Benzo[27]crown‐9 Uronium Perchlorate (1/1)
Authors: Uiterwijk Jos W. H. M. , Harkema Sybolt , Reinhoudt David N. , Daasvatn Kari , den Hertog Herman J. , Geevers Jan
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1100. DOI:10.1002/anie.198211000
Conformation and Biological Activity of Cyclic Peptides
Authors: Kessler Horst
Published: December 2003

Cyclic peptides containing biologically active hormone sequences are suitable models for studying conformation‐activity relationships. In such models the usual flexibility of peptide chains is reduced by their cyclic arrangement. However, conformational analysis of such systems by experimental means is possible only if a single conformer predominates at equilibrium, and criteria for this are put forward. NMR spectroscopic methods, including many recent advances, are discussed in relation to their ability to contribute to peptide conformational analysis.
Electron Spin Resonance Studies of the Sulfur Catalysis of the Industrial Dichlorination of Benzene
Authors: Bock Hans , Stein Udo , Rittmeyer Peter
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1145. DOI:10.1002/anie.198211450
Formation of Metal‐Metal Bonds and Conversion of the Metal Aggregate {Mo4(S2)4(S′2)2} by Atom‐Transfer and Redox Reactions at Nonequivalent Ligands; [Mo4S4(NO)4(CN)8]8− an Anion with a Central Cubane‐Like Unit
Authors: Müller Achim , Eltzner Werner , Clegg William , Sheldrick George M.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1177. DOI:10.1002/anie.198211770
Diastereogenic Addition of Crotylmetal Compounds to Aldehydes
Authors: Hoffmann Reinhard W.
Published: December 2003

In an ideal synthesis, the formation of the CC bonds as well as the creation of the chiral centers and of the final functionality would be carried out simultaneously in each step. Accordingly, stereoselective CC bond forming reactions are required. Instead of a pair of diastereomers, a synthesis should yield only one of the two possible diastereomers. Such selectivity is often achieved in the addition of crotylboron, ‐aluminum, ‐tin, ‐titanium, and ‐chromium compounds to aldehydes. Depending on whether one starts from E‐ or Z‐crotyl compounds, one diastereomeric adduct is formed preferentially. In this case the newly formed CC bond carries a methyl substituent. However, the synthetic goal is often a compound carrying an oxygen function at the site of the new CC bond. Compounds of this type can be obtained through addition of heteroatom‐substituted allylboronic acid esters or analogous reagents to aldehydes.
Palladium(0)‐Catalyzed [3 + 2]‐Cycloadditions of Diphenylmethylenecyclopropanes to Alkenes
Authors: Binger Paul , Bentz Peter
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1385. DOI:10.1002/anie.198213850
Double Layer Formation with a Surfactant‐Type Crown Ether Complex: Crystal Structure of 15,15‐Bis(dodecyloxymethyl)[16]crown‐5·NaSCN
Authors: Czugler Mátyás , Weber Edwin , Kálmán Alajos , Stensland Birgitta , Párkányi László
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1373. DOI:10.1002/anie.198213730
Controlled Modification of Crystal Habit by “Tailor‐Made” Impurities: Application to Benzamide
Authors: Berkovitch‐Yellin Ziva , Addadi Lia , Idelson Marian , Lahav Mein , Leiserowitz Leslie
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1336. DOI:10.1002/anie.198213360
A 2,6‐Diazasemibullvalene
Authors: Schnieders Christoph , Altenbach Hans‐Josef , Müllen Klaus
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1353. DOI:10.1002/anie.198213530
Signal Substances and their Reception in the Sexual Cycle of Marine Brown Algae
Authors: Jaenicke Lothar , Boland Wilhelm
Published: December 2003

Attraction and repulsion are responses to chemical stimuli which can be received and processed even by unicellular organisms without a morphologically defined nervous system. Chemical substances trigger off a chain of events which starts with a membrane‐bound signal receptor and, after a sequence of regulatory and modulatory steps, ends in the modulation of a motor effector organ. Binding of the signal substances to the receptor produces conformational changes in which the receptor subunits are mutually dependent on one another, and also leads to chemical modification of the subunits and affects their molecular activity. These interactions, together with the characteristic type of movement, result in a physiological pattern of behavior which enables the flagellated sex cells (gametes) of marine brown algae to finally locate their partners. The simple but highly specific brown algae gamete systems have been investigated structurally and their biological activity analyzed. The signal substances are mainly highly unsaturated aliphatic or cyclic hydrocarbons with unsaturated side chains (general formula e. g. C11H14, C11H16, C11H18). These systems also serve as a simplifying model which helps in the understanding of complex ganglionic pathways in higher living organisms where the sense organs convey information from the surroundings to the central nervous system through nerve pathways. The information is then processed and answered, via efferent pathways, as movement.
[Ag5I6]−, A One‐Dimensional Infinite Anion with 105 mc Symmetry
Authors: Peters Karl , Ott Walter , von Schnering Hans Georg
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1479. DOI:10.1002/anie.198214790
Cleavage of the Metal‐Metal Triple Bond by Chelate‐Forming Diazoalkane Bridges
Authors: Herrmann Wolfgang A. , Kriechbaum Gangolf W. , Ziegler Manfred , Pfisterer Heike
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1575. DOI:10.1002/anie.198215750
Cycloadditions of Azulene at High Pressure
Authors: Klärner Frank‐Gerrit , Dogan Barbara , Roth Wolfgang R. , Hafner Klaus
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1499. DOI:10.1002/anie.198214990
[MoS4(CN)12]8−, a Cluster with High Negative Charge and Cubane‐Like Mo4S4‐Moiety—On the Significance of Cyanothiomolybdates for the Prebiotic Evolution
Authors: Müller Achim , Eltzner Werner , Bögge Hartmut , Jostes Rainer
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1643. DOI:10.1002/anie.198216430
From Isocyanides via Four‐Component Condensations to Antibiotic Syntheses
Authors: Ugi Ivar
Published: December 2003

The four‐component condensation of amines and carbonyl compounds with isocyanides

Previously, isocyanides were almost always referred to as isonitriles. However, according to IUPAC Rule C‐833.1 only the name “isocyanides” is permissible.

and suitable acid components (water, thiosulfuric acid, hydrogen selenide, hydrogen azide, cyanic acid, thiocyanic acid, carboxylic acids, methyl hydrogen carbonate) to form α‐amino acid derivatives was discovered in 1959. This reaction principle shares some features with the Strecker synthesis and the Passerini reaction. The four‐component condensation affords easy and effective one‐pot synthesis of complex molecules from simple building blocks. Only in recent years, however, have the preparative advantages of the four‐component condensation been exploited by numerous authors in the synthesis of diverse natural products and related compounds, although many of the possibilities opened by this principle were recognized more than two decades ago. In this progress report some instructive syntheses of various antibiotics are reviewed. The design of each of these syntheses involves a four‐component condensation as key step, by means of which lengthy sequences of reactions are avoided, which otherwise would be required to achieve the synthetic goal.
Novel Tungsten‐Alkyl and Tungsten‐Acyl Complexes with Acetylene as Four‐Electron Ligand
Authors: Alt Helmut G. , Eichner Manfred E. , Jansen Brigitte M.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1826. DOI:10.1002/anie.198218260
Tris(trimethylplumbyl)heptaphosphanortricyclene P7(PbMe3)3
Authors: Weber Dieter , Mujica Carlos , von Schnering Hans Georg
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1801. DOI:10.1002/anie.198218010
Erythro‐Selective Aldol‐Type Addition of Titanated Aldehyde‐Hydrazones
Authors: Reetz Manfred T. , Steinbach Rainer , Kesseler Kurt
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1899. DOI:10.1002/anie.198218990
Stabilization of Unusual Oxidation and Coordination States by the Ligands OSF5, OSeF5, and OTeF5
Authors: Seppelt Konrad
Published: December 2003

Compounds with the ligands OSF5, OSeF5, and OTeF5 are now known for most of the chemical elements. The ability of these ligands to stabilize the highest valency levels of the central atoms to which they are bound is unsurpassed by any other polyatomic ligand. Examples are Xe(OTeF5)6, Te(OTeF5)6, W(OTeF5)6, and U(OTeF5)6 or I(OTeF5)5 and Br(OSeF5)3. Because of the ligands' size and internal bonding they hardly ever form bridges, and in this respect they differ from fluorine, although they do share the latter's high electronegativity.
Steric and Electronic Control of Ligand Field Strength in Octahedral Co3+ Spin‐Crossover Complexes
Authors: Eberspach Werner , Murr Nabil El , Kläui Wolfgang
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1943. DOI:10.1002/anie.198219430
The HCo3(CO)9‐Catalyzed Olefin Isomerization
Authors: Fachinetti Giuseppe , Stefani Annibale
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1967. DOI:10.1002/anie.198219670
Stabilization of the Unstable Tautomers of Phosphino‐ and Arsino‐Substituted Ylides by Coordination to Transition Metals
Authors: Weber Lothar , Boese Roland , Meyer Wolfgang
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1934. DOI:10.1002/anie.198219340
Olefin Selectivities in the Addition of Carbenes
Authors: Schoeller Wolfgang W. , Aktekin Nevzat , Friege Henniger
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1992. DOI:10.1002/anie.198219920
Kinetic and Thermodynamic Control in the Reaction of (Ph3P)2PtO2 with (E)‐2‐Butenal
Authors: Broadhurst Michael J. , Brown John M. , John Robert A.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1. DOI:10.1002/anie.198300010
Intermetallic Compounds and the Use of Atomic Radii in Their Description
Authors: Simon Arndt
Published: December 2003

Metallic radii, which are obtained from atomic distances in the pure elements, are generally used for the calculation of distances in intermetallic compounds. However, the procedure for using such radii depends on the individual structural type: (a) For high coordination numbers and only slightly differing distances between atoms of the same kind and different atoms, all distances in a structure are proportional to the sum of radii, weighted according to the compositon. Such a “Vegard” relationship for ordered compounds is obeyed by intermetallic compounds with topological close packings, but strictly only if the various kinds of distances are correlated via symmetry relationships. For compounds with low coordination numbers the simple sum of radii holds for atoms participating in the shortest bond (e.g. in ionic crystals).‐(b) The number of neighbors determines the size of each atom. It can be shown that the bond strength‐bond length concept, developed for valence compounds, and often dealt with in the literature over the last ten years, is also applicable for alloys. On this basis a formalism is developed which uniformly describes the size of the atoms as a function of the coordination number for both the limiting cases of multiple bonds in molecules and for close packed atomic arrangements in alloys.
Catalysis by Molecular Metal Clusters
Authors: Muetterties Earl L. , Krause Michael J.
Published: December 2003

Molecular metal clusters form a very large and diverse family. They present the opportunity of modeling the intermediates involved in surface mediated catalytic reactions, of providing a source of very reactive mononuclear metal fragments, and of effecting catalytic cycles in which the cluster remains intact. The last mentioned aspect is the subject of this review article. The state‐of‐the‐art of cluster catalysis is critically analyzed. The possibilities offered by molecular metal catalysts of performing catalytic reactions at multimetal atom sites are also discussed.
Chromatographic Resolution of Cyclic Organic Compounds on a Λ‐Tris(1,10‐phenanthroline)ruthenium(II) Montmorillonite Column
Authors: Yamagishi Akihiko , Ohnishi Ryuichiro
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 140. DOI:10.1002/anie.198301400
Optically Active Iron Complexes with Tetrahedral Structure
Authors: Brunner Henri , Miehling Wolfgang
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 84. DOI:10.1002/anie.198300840
FT‐FIR Spectroscopy of Ligand‐Free Metal Clusters; Matrix Effects on the Molecular Geometry of Trichromium, Cr3
Authors: Ozin Geoffrey A. , Baker Mark D. , Mitchell Steven A. , McIntosh Douglas F.
Published: December 2003

The complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 92. DOI:10.1002/anie.198300920