bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oxygen Transfer from Inorganic and Organic Peroxides to Organic Substrates: A Common Mechanism?
Authors: Mimoun Hubert 
Published: December 2003

AbstractIn this progress report an attempt is made to rationalize, from a mechanistic point of view, the different ways in which oxygen is transferred from inorganic and organic peroxides to nucleophilic substrates, particularly olefins. Oxygen transfer from transition‐metal peroxides, which is relevant to catalytic oxidations using O2, H2O2 or ROOH, occurs via a cyclic or “pseudocyclic” peroxymetalation in which a dioxametallacycle is formed. Owing to the wide discrepancy between peroxymetalation and the conventional oxidation mechanism, i.e. nucleophilic attack of the substrate at the electrophilic “active oxygen”, we propose an alternative mechanism involving dioxiranes as the reactive species. The generation of dioxiranes appears to be a common denominator in the reactions of most organic peroxides e.g. peroxy acids, the reaction of electrophilic ketones with H2O2, or ozonizations. Oxygen transfer from dioxirane reagents probably involves the formation of a charge‐transfer π‐complex between the substrate and the carbon atom of the dioxirane, and the subsequent formation of a cyclic peroxidic intermediate.
Determination of the Structure of Dimethyldioctadecylammonium Chloride in Solution by Small Angle X‐Ray Scattering; Reversible Phase Transition
Authors: Paradies Hasko H. 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1670. DOI:10.1002/anie.198216700
(2,9 : 6,12‐η‐2,3,5,6‐Tetrakis(methylene)‐bicyclo[2.2.2]octane)zirconocene, an Isolable Bis(olefin)zirconium(II) Compound
Authors: Erker Gerhard , Engel Klaus , Vogel Pierre 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1746. DOI:10.1002/anie.198217460
Indirect Electrochemical Regeneration of NADH by a Bipyridinerhodium(I) Complex as Electron‐Transfer Agent
Authors: Wienkamp Rainer , Steckhan Eberhard 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1739. DOI:10.1002/anie.198217390
Alkylation of α‐Diazoketones with Alkyldiazonium, Ions: Facile Synthesis of β‐Alkoxyethylenediazonium Salts
Authors: Bott Kaspar 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1702. DOI:10.1002/anie.198217020
Tricyclo[3.3.0.02,8]octan‐3‐ones: Photochemically Prepared Building Blocks for Enantiospecific Total Syntheses of Cyclopentanoid Natural Products
Authors: Demuth Martin , Schaffner Kurt 
Published: December 2003

AbstractBi‐ and tricyclopentanoid natural products have been in the focus of synthetic interest in recent years. With widely applicable building blocks lacking, most work has been restricted in the past to specific approaches to single racemic target structures. A novel concept is now presented which uses for the first time a simple building block, tricyclo[3.3.0.02,8]octan‐3‐one, providing enantiospecific access to diverse cyclopentanoid structures. Tricyclooctanone is obtained in a few steps and in high yield from benzene, via the triplet‐sensitized oxadi‐π‐methane rearrangement of bicyclo[2.2.2]octenone as a photochemical key reaction. Smooth preparations of both enantiomers are possible by resolving the racemic mixture and of the bicyclooctenone. Owing to its structural properties the tricyclooctanone undergoes a wide array of regio‐ and stereoselective transformations in high yields, in compliance with the expectations for a synthetic key compound of general applicability. The total syntheses of boschnialactone, allodolicholactone, irido‐ and isoiridomyrmecin, and loganin aglucone 6‐acetate provide the first examples of successful applications. Promising entries to coriolin, 6a‐carbaprostacyclin and homologs, and 6,11‐dehydroestrone complement this review of the potential of tricyclooctanone as a versatile building block for the enantiospecific total synthesis of polycyclopentanoids and related compounds.
Immobilized Biomaterials—Techniques and Applications
Authors: Sharma Bhavender P. , Bailey Lorraine F. , Messing Ralph A. 
Published: December 2003

AbstractThe immobilization of enzymes, cofactors and whole cells offers the potential of economical exploitation of biomaterial activity. Enzymes or cells can be immobilized by binding to carriers through adsorption or covalent linkages or by entrapment in a polymer matrix or microencapsulation. The development of immobilized biomaterial systems requires the involvement of biochemical, kinetics and reactor design principles. Examples of commercial scale applications of immobilized biomaterial systems are the production of a fructose‐rich syrup from starch and the synthesis of L‐amino acids by selective hydrolysis of N‐acyl‐D,L‐amino acids.
Reversible Photoisomerization between Silaethenes and Methylsilylenes (Methylsilanediyls)
Authors: Reisenauer Hans Peter , Mihm Gerhard , Maier Günther 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1785. DOI:10.1002/anie.198217850
“Isoretinol” and Retinal: An Unorthodox, but Simple Entry to the Vitamin A Series
Authors: Ruzziconi Renzo , Schlosser Manfred 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1853. DOI:10.1002/anie.198218530
Synthesis of an N‐Functionalized 1,3‐Diaza‐ and a P‐Functionalized 1,3‐Diphospha‐2,4‐disilacyclobutane
Authors: Klingebiel Uwe , Vater Norbert 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1865. DOI:10.1002/anie.198218650
First Metal Complexes of the Norcaradiene Form of 1,6‐Methano[10]annulene
Authors: Mues Peter , Benn Reinhard , Krüger Carl , Tsay Yi‐Hung , Vogel Emanuel , Wilke Günther 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1891. DOI:10.1002/anie.198218910
The Reaction of (Butadiene)zirconocene and ‐hafnocene with Ethylene
Authors: Erker Gerhard , Engel Klaus , Dorf Ulrich , Atwood Jerry L. , Hunter William E. 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1974. DOI:10.1002/anie.198219740
Catalyst Deactivation during Zirconocene‐ and Hafnocene‐Induced Ethylene Dimerization
Authors: Dorf Ulrich , Engel Klaus , Erker Gerhard 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1984. DOI:10.1002/anie.198219840
Coordinatively Unsaturated Trinuclear Molybdenum‐Sulfur Cluster Chelates with Dithiophosphinato Bridge
Authors: Keck Helmut , Kuchen Wilhelm , Mathow Jürgen , Wunderlich Hartmut 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1982, 1962. DOI:10.1002/anie.198219620
Thio‐ and Seleno‐Compounds of Main Group Elements—Novel Inorganic Oligomers and Polymers
Authors: Krebs Bernt 
Published: December 2003

AbstractDuring the last decade modern preparative and structural methods have led to novel and often unexpected oligomeric and polymeric main group element‐sulfur compounds having remarkable bonding and structural properties and reactivities. Examples of important new developments in this area are: the discovery of boron sulfides B8S16 and (BS2)n and of ion‐conducting air‐stable thioborates with tetrahedrally coordinated boron; the successful use of boron sulfides in organic and inorganic syntheses; the preparation of different homologous series of molecular polynuclear thio‐ and selenoanions of Ga, In, Si, Ge and Sn, and of new polynuclear sulfide‐ and selenide‐halides of Si and Ge as interesting reagents for inorganic and organic reactions; the synthesis of argyrodite(Ag8GeS6)‐like phases with remarkable solid‐state properties; and the characterization of the SH…S type hydrogen bridge in thiocarbonic acid and thiophosphinic acids, which is of importance for an understanding of certain interactions in sulfur‐containing biomolecules.
Generation and Stabilization of Phosphanyl‐ and Arsanylketenes within the Coordination Sphere of Tungsten
Authors: Kreissl Fritz Roland , Wolfgruber Mathias , Sieber Werner , Alt Helmut Guido 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 148. DOI:10.1002/anie.198301480
Reversible Opening of a Thioketene‐Iron Cluster Containing a μ2‐C2, μ2‐S‐Thiocarbonyl Group
Authors: Umland Henning , Edelmann Frank , Wormsbächer Detlev , Behrens Ulrich 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 156. DOI:10.1002/anie.198301560
Synthesis of [(η5‐C5H5)Rh(PMe3)(η2‐CH2E)] with ES, Se, Te: Thio‐, Seleno‐, and Telluroformaldehyde as Ligands in Mononuclear Rhodium Complexes
Authors: Paul Wilfried , Werner Helmut 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 396. DOI:10.1002/anie.198303960
Synthesis of C‐α‐ and C‐β‐D‐Glucopyranosyl Derivatives from O‐(α‐D‐Glucopyranosyl) Trichloroacetimidate
Authors: Schmidt Richard R. , Hoffmann Michael 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 543. DOI:10.1002/anie.198305430
Synthesis and Structure of (CO)4W[C(NEt2)PMePh], A Novel Cyclic Carbene Complex
Authors: Fischer Ernst Otto , Reitmeier Rudolf , Ackermann Klaus 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 488. DOI:10.1002/anie.198304880
Phosphorothioate Analogues of Nucleotides—Tools for the Investigation of Biochemical Processes
Authors: Eckstein Fritz 
Published: December 2003

AbstractNucleoside phosphorothioates are analogues of nucleotides with a wide range of applications. Thus, on the one hand, in many but not all cases they are more stable against hydrolysis than the unmodified nucleotides—a property which they share with other nucleotide analogues. On the other hand, however, they are good substrates for many, but not all reactions where the nucleotide or the phosphorothioate group is transferred to an acceptor other than H2O. As a consequence, once incorporated into a system such as DNA, phosphorothioates cannot be easily removed.What makes these compounds unique to a certain extent is the chirality at the phosphorus center if two nonequivalent residues are linked to the phosphorothioate group. This opens the way for the use of these compounds to investigate stereochemical aspects of enzymatic reactions. In addition to these properties, there are those expected from exchange of an oxygen for a sulfur atom in a phosphate group, e.g. the increased affinity towards mercury derivatives and the large chemical shift of the 31P‐NMR sinals.If one considers how many biologically interesting compounds contain phosphate groups, the considerable interest in these nucleotide analogues is not surprising.
Bond‐Forming Initiation in Spontaneous Addition and Polymerization Reactions of Alkenes
Authors: Hall H. K. 
Published: December 2003

AbstractSpontaneous addition and polymerization reactions of alkenes of different electron‐densities result in a wide variety of small organic molecules and high polymers. Tetramethylenes are proposed as key intermediates, i.e. resonance hybrids of 1,4‐diradical and zwitterionic limiting structures. Their character is determined by the substituents at the terminals: Zwitterionic character is favored by strong donors, such as alkoxy and dialkylamino groups, at the carbenium center and strong acceptor group such as diesters and cyano‐esters, at the acceptor end, and aryl and vinyl groups as donors. Zwitterionic tetramethylenes initiate ionic homopolymerization, while diradical tetramethylenes initiate alternating copolymerization, thus providing an extremely sensitive technique for the detection and characterization of these intermediates. The effects of the donor and acceptor substituents can be arranged as an “Organic Chemist's Periodic Table”, wherein the areas of mechanistic change clearly emerge and which provides predictive capability.—This unifying concept of bondforming initiation is extended to spontaneous addition and polymerization reactions of heteroatom acceptor molecules and 7,7,8,8‐tetrasubstituted quinodimethanes and of compounds possessing labile σ‐bonds, such as halogens and peroxides. Radical‐ion pairs, charge‐transfer complexes and adventitious impurities are excluded as significant initiators.
Diaminodiphosphenes—Synthesis, Crystal Structure and Bonding Properties
Authors: Niecke Edgar , Rüger Reinhold , Lysek Manfred , Pohl Siegfried , Schoeller Wolfgang 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 639. DOI:10.1002/anie.198306390
Through‐Bond Interaction via Strained σ‐Bonds—The Synthesis and PE Spectrum of 1,5‐Dimethyltetracyclo[3.3.0.0 2,8.04,6]octane‐3,7‐dione
Authors: Jähne Gerhard , Gleiter Rolf 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 661. DOI:10.1002/anie.198306610
The Cation Di‐μ‐oxo‐trans‐dioxobis[(1,4,7‐triazacyclononane)molybdenum(V)](Mo—Mo) and its Acid‐Catalyzed cis‐Isomerization
Authors: Wieghardt Karl , Hahn Manfred , Swiridoff Wolfgang , Weiss Johannes 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 583. DOI:10.1002/anie.198305830
Aerial Oxidation of Benzene in the Presence of Electrochemically Generated Cu+ Ions
Authors: Kinoshita Tatsuyuki , Harada Junji , Ito Sotaro , Sasaki Kazuo 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 599. DOI:10.1002/anie.198305990
Metal Complexes of Sulfur Ylides: Coordination Chemsistry, Preparative Organic Chemistry, and Biochemistry
Authors: Weber Lothar 
Published: December 2003

AbstractIn recent years both acyclic and cyclic sulfur ylides have proved to be interesting and versatile ligands in preparative organometallic chemistry. In addition to paralleling the coordination chemistry of their phosphorus analogues, sulfur ylide complexes show specific structural and chemical features; they are becoming more important in preparative inorganic and organic chemistry, and may also be biochemically relevant as methylene transfer agents. Recent studies of the complexes of the ylidic λ4‐thiabenzenes and λ6‐thiabenzene 1‐oxides have frequently demonstrated unexpected and novel reactions, and thereby enriched the chemistry both of ylides and of carbonylmetals.
Quenching of the Aromaticity of the 5‐Dibenzo[a,d]cycloheptenylium Ion by Complexing with (CO)3Cr
Authors: Ceccon Alberto , Gambaro Alessandro , Romanin Annamaria , Venzo Alfonso 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 734. DOI:10.1002/anie.198307340
[Cl2FeS2MoO(S2)]2−, a Novel Bimetallic Complex with Unusual Electronic Structure and a Substituted Tetrachalcogenometalate as “Ligand”
Authors: Müller Achim , Sarkar Sabyasachi , Bögge Hartmut , Jostes Rainer , Trautwein Alfred , Lauer Uschi 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 747. DOI:10.1002/anie.198307470
Highly Selective Extraction of Uranyl Ions by Acyclic Ligands Containing L‐Phenylalanine Moieties
Authors: Delcanale Maurizio , Marchelli Rosangela , Mangia Alessandro , Dossena Arnaldo , Casnati Giuseppe 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 794. DOI:10.1002/anie.198307940
Holographic Methods for the Investigation of Photochemical and Photophysical Properties of Molecules
Authors: Bräuchle Christoph , Burland Donald M. 
Published: December 2003

AbstractHolography is most frequently thought of as a method of photography that results in three‐dimensional images of the object being photographed. It is certainly true that this is the most visually spectacular aspect. But holography can also be used as a powerful tool for the investigation of a variety of photochemical and photophysical processes. These experimental techniques rely on the fact that small spatial modulations of a material's optical properties (index of refraction and absorption coefficient) can deflect an incident light beam into another direction. By following the growth or decay in intensity of this deflected beam, one can follow the underlying photochemical and photophysical processes producing the changes in optical properties. If a CW laser is used to produce the hologram one can use the technique to investigate solid state photochemistry. If a pulsed laser is used one can investigate a broad range of time dependent processes; energy transfer, diffusion, rotational relaxation, charge transport etc. Compared to conventional spectroscopic techniques the holographic method shows various advantages. So for example it is a highly sensitive zero‐background technique and permits free choice of detection wavelength and detection beam intensity.As a result of information obtained using the holographic technique as a scientific tool, one can also find new classes of materials for the recording of holograms. This is the way in which two‐photon four‐level systems for hologram recording process gated on and off with an auxiliary source, and can be read with the infrared recording laser with no erasing of the hologram.
The One‐Electron Oxidation of Diazasilacyclopentenes
Authors: Graalmann Onno , Hesse Michael , Klingebiel Uwe , Clegg William , Haase Martin , Sheldrick George M. 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 874. DOI:10.1002/anie.198308740
Photocycloaddition of 6‐Cyanouracil to Ketene Diethyl Acetal: Synthesis of a Uracil Derivative Possessing a Cyclobutenone Framework
Authors: Saito Isao , Kubota Fuyuhiko , Shimozono Koji , Matsuura Teruo 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 835. DOI:10.1002/anie.198308350
Synthesis and Structure Determination of [(PEt3)RhC2B9H10]2− A Binuclear Rhodacarborane Containing Four Bonds Betweeen Two Icosahedra
Authors: Behnken Paul E. , Knobler Carolyn B. , Hawthorne M. Frederick 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 929. DOI:10.1002/anie.198309290
Formation of CC Bonds by Addition of Free Radicals to Alkenes
Authors: Giese Bernd 
Published: December 2003

AbstractThere are many reactions in which CC bonds are formed by addition of free radicals to alkenes. Information about the mechanism is important for the synthesis of specific target molecules. The rate of addition of alkyl radicals to alkenes is controlled by steric and polar effects. The stabilities of the educts and products are of only limited importance, since the transition states for these exothermic reactions occur very early on the reaction coordinate. Variations in reactivity and selectivity can be described using frontier orbital theory: for nucleophilic radicals the dominant interactions are those between SOMO's and LUMO's, and for electrophilic radicals those between SOMO's and HOMO's. The large differences in the steric effects of α ‐ and β‐ substituents of alkenes can be explained by postulating an unsymmetrical transition state— the radical approaches one of the C atoms preferentially. Regioand stereoselectivities can be predicted and are determined, in general, by steric effects.
Raw Materials and Energy: A Challenge for Polymer Research
Authors: Weissermel Klaus , Cherdron Harald 
Published: December 2003

AbstractThe substantial rapid growth of synthetic polymers—plastics, man‐made fibers, films, rubbers, and coatings—which continued unabated over many years, suffered a severe setback for the first time in 1973–1974 followed by another in 1980. A major cause of these reverses was the changed situation with respect to raw materials and energy. For industrial polymer research, in particular, this presents a fresh challenge with considerably changed priorities. The individual ways of meeting this challenge are highlighted and illustrated by examples: the search for alternative raw material sources for monomers; the development of economic methods for production and processing of polymers; the recycling of polymers; and finally the development of new raw material‐saving and energy‐saving technologies based on the use of polymers. In the future, the applications of polymers to new technologies such as communication‐ and information‐systems or biotechnology will join the traditional uses. But the efforts required in research and development to achieve this demand wide‐ranging interdisciplinary cooperation on an even greater scale than hitherto.
Fourier Transform Far‐Infrared (FT‐Far‐IR) Spectroscopy of Silver Atoms and Silver Clusters Entrapped in Zeolite NaY
Authors: Ozin Geoffrey A. , Baker Mark D. , Parnis J. Mark 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1075. DOI:10.1002/anie.198310750
New Naturally Occurring Amino Acids
Authors: Wagner Ingrid , Musso Hans 
Published: December 2003

AbstractThe majority of the 500 or so naturally occurring amino acids known today were discovered during the last 30 years, for example during the search for new antibiotics in the culture media of microorganisms, or as components of the antibiotics in fungi, seeds, in numerous plants and fruits, and in the body fluids of animals. Some 240 of these amino acids occur free in nature, some only as intermediates in metabolism. This article provides an overview of the developments that have taken place in this area since 1956 when the last review appeared. Summary accounts are presented, dealing with new unsaturated amino acids, cyclopropane‐ and cyclobutane‐amino acids, heterocyclic amino acids, halogen‐containing amino acids sulfur‐, selenium‐ and phosphorus‐containing amino acids as well as aliphatic amino acids. In a few cases, e. g. betalamic acid and muscaflavin, the biosynthesis is described in detail.
Facile Synthesis of the (±)‐6‐Deoxycarminomycinone from Aloe‐Emodin
Authors: Krohn Karsten , Sarstedt Burkhard 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1267. DOI:10.1002/anie.198312670
(C6H5)2P2[Cr(CO)5]2, a Diphosphene Complex with Free Phosphorus–Phosphorus Double Bond
Authors: Borm Jutta , Zsolnai Laszlo , Huttner Gottfried 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1477. DOI:10.1002/anie.198314770
Chelation or Non‐Chelation Control in Stereoselective Reactions of Titanium Reagents with Chiral Alkoxycarbonyl Compounds
Authors: Reetz Manfred T. , Kesseler Kurt , Schmidtberger Susi , Wenderoth Bernd , Steinbach Rainer 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1511. DOI:10.1002/anie.198315110
Activity of Coordinated 1,4‐Diaza‐1,3‐dienes (dad) in CC Bond Forming Reactions: 1,5‐Dihydropyrrol‐2‐ones from (dad)Fe(CO)3 and Dimethyl Acetylenedicarboxylate
Authors: Frühauf Hans‐Werner , Seils Frank , Romao Maria J. , Goddard Richard J. 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1435. DOI:10.1002/anie.198314350
The Transformation of Acetylene from a Four‐ to a Two‐Electron Ligand: Acetylene(carbonyl)nitrosyl Complexes of Tungsten
Authors: Alt Helmut G. , Hayen Heidi I. 
Published: December 2003

AbstractThe complete manuscript of this communication appears in: Angew. Chem. Suppl. 1983, 1364. DOI:10.1002/anie.198313640