bluuebunny/crossref_metadata_2025_split huggingface dataset:
Komplexchemie perhalogenierter Cyclopentadiene und Alkine, VII Darstellung einiger Tetrachlormetallole von Cobalt, Rhodium und Iridium; Struktur eines Iridacyclopentadien‐Derivats
Authors: Siinkel Karlheinz 
Published: July 2007

Coordination Chemistry of Perhalogenated Cyclopentadienes and Alkynes, VII1). – Synthesis of Several Tetrachlorometalloles of Cobalt, Rhodium, and Iridium; Structure of a Iridacyclopentadiene DerivativeThe reaction of dichloroethyne with CpCo(PPh3)2, RhCl(EPh3)3 (E = P, As, Sb), and IrCl(N2)(PPh3)2 leads to the formation of complexes containing a tetrachloro‐1‐metallacyclopentadiene unit. The crystal‐structure determination of (Ph3P)2(Cl)‐ is reported.
Photochemische Mitteilungen, 76 Studien im Umfeld der Oxanorbornadien → Oxepin‐Isomerisierung. Eine intramolekulare Dien/Enon‐[4 + 2]‐Photocycloaddition
Authors: Wollenweber Markus , Fritz Hans , Prinzbach Horst , Rihs Grety 
Published: July 2007

Photochemical Transformations, 761). – Studies in the Area of the Oxanorbornadiene → Oxepine Isomerization. An Intramolecular Diene/Enone [4 + 2] PhotocycloadditionAt room temperature, the “tropone‐annulated” oxanorborna diene 2b dimerizes regio‐ and stereospecifically to give a [6 + 4] adduct (5). Direct photoexcitation of this adduct induces intramolecular diene/enone [4 + 2] addition to 16 followed by a [2 + 2] cycloaddition to provide the dodecacycle 17. An X‐ ray crystal structure analysis of 17 documents the influence of the heteroatom and of the quasi‐bisected ester functions on the length of the three types of oxaquadricyclane – three‐membered ring bonds. Direct and sensitized excitation of 2b, c produces polymers; yet, after changing the troponoid chromophor (9, 10) oxaquadricyclane formation takes place (13, 14). In the thermolysis of the annulated oxaquadricyclanes (13, 14) the different cyclopropane C – C bonds are cleaved at a comparable rate.
Studien zur enantio‐ und diastereoselektiven α‐Metallierung prochiraler Sulfoxide mit (+)‐Menthyllithium
Authors: Maercker Adalbert , Schuhmacher Rudolf , Buchmeier Willi , Lutz Heinz Dieter 
Published: July 2007

Enantio‐ and Diastereoselective α‐Metallation of Prochiral Sulfoxides by (+)‐MenthyllithiumSix out of ten prochiral dialkyl sulfoxides 3 with diastereotopic α methylene protons were stereoselectively metallated by (+)‐menthyllithium (11) to yield two diastereomeric pairs of enriched enantiomers 29 after the reaction with benzophenone. The maximum e.e. was 40%. Dicyclohexyl sulfoxide (3c) was deprotonated enantioselectively with an e.e. of 30%. 2‐Bornyllithium (21) was unsuccessful as a chiral base and was shown for the first time to contain 4% of isobornyllithium (22). The reactions were performed in pentane at – 80°C; in diethyl ether and THF the e.e.'s were only slightly higher, and at higher temperatures the selectivity was rapidly decreasing. It was shown that racemization takes place by an intermolecular transmetallation reaction. The structure of 29f [n = 3] was elucidated by an X‐ray analysis.
Organic Electron Transfer Systems, II Substituted Triarylamine Cation‐Radical Redox Systems – Synthesis, Electrochemical and Spectroscopic Properties, Hammet Behavior, and Suitability as Redox Catalysts
Authors: Dapperheld Steffen , Steckhan Eberhard , Brinkhaus Karl‐Heinz Grosse , Esch Thomas 
Published: July 2007

Abstract21 triarylamines (1n – 1z, 1za, 1zb) and triarylamine analogs (2a, 2b, 3a, 3b, 4a, 4b) with substituents in at least all three p positions and some of their cation‐radical hexachloroantimonates have been synthesized. The electrochemical behavior has been studied by cyclic voltammetry. Most of the compounds show chemically and electrochemically reversible first oxidation waves in the formation of the cation radicals. With the exception of 4a and 4b, the second wave for the formation of the dication is chemically irreversible. The UV spectra of the triarylamine cation radicals have been obtained in the presence of a slight excess of SbCl5. A good Hammett correlation between the first anodic potential of only p‐substituted triarylamines and the σ/σ values has been established. Some redox‐catalytic properties of triarylamine cation radicals are described.
7,15‐Dihydroxy[2.2](2,6)pyridinophan: Darstellung über selenoorganische Stufen und Aggregation durch Wasserstoff‐Brückenbindungen
Authors: Breitenbach Jörg , Nieger Martin , Vögtle Fritz 
Published: July 2007

7,15‐Dihydroxy[2.2](2,6)pyridinophane: Synthesis via Organoselenium Compounds and Aggregation by Hydrogen Bonds*7,15‐Dihydroxy[2.2](2,6)pyridinophane (5) was prepared by using dimethoxy‐diselena[3.3]pyridinophane 3 as a precursor. The X‐ray structural analyses of both phanes (5 x 2 HI x 2 DMSO and 3), show the extremely syn‐shaped [3.3]phane 3 and the [2.2]phane 5 with antagonistically hydrogen‐bonded solvent molecules.
Organische Synthesen mit Übergangsmetall‐Komplexen, 55 5‐Aza‐1‐metalla‐1,3,5‐triene von Chrom und Wolfram sowie deren Cyclisierung zu 2H‐Pyrrol‐Komplexen
Authors: Aumann Rudolf , Heinen Heinrich , Goddard Richard , Krüger Carl 
Published: July 2007

Organic Syntheses via Transition Metal Complexes, 551). – 5‐Aza‐1‐metalla‐1,3,5‐trienes of Chromium and Tungsten, and Their Cyclization to 2H‐Pyrrole Complexes5‐Aza‐1‐metalla‐1,3,5‐trienes 5 and 6 [LnM = C – C = C – N = C, a: LnM = Cr(CO)5, b: W(CO)5] are obtained in two steps from aminocarbene complexes 1 [LnM = C(NH2)Ph, a: LnM = Cr(CO)5, b: W(CO)5]. The first step involves the condensation of 1 with benzaldehyde (2) in the prescence of TiCl4/Et3N to give 3‐aza‐1‐metalla‐1,3‐dienes 3 (LnM = C – N = C). 3 adds to the 1‐aminoalkyne 4 to give 5 and 6 by a chain extension of two carbon atoms. The trans isomers 5 are formed as the major products and are stable both in the solid state and in solution. The cis isomers 6 undergo a novel‐type cyclization to give 2H‐pyrrole complexes 8. Triene 5b was characterized by an X‐ray analysis.
HCl‐Abspaltung aus Ethansulfenylchlorid und Chlordimethylsulfid
Authors: Maier Günther , Flögel Ulrich , Reisenauer Hans Peter , Andes Jr. B. Hess, , Schaad Lawrence J. 
Published: July 2007

HCl Elimination from Ethanesulfenyl Chloride and Chlorodimethyl SulfideThioacetaldehyde (5) is prepared by matrix photolysis of ethanesulfenyl chloride (3) or thiirane (4) and by flash pyrolysis of allyl ethyl sulfide (6). Matrix irradiation of 3 or 5 with 222‐nm light results in a dehydrogenation, and a mixture of thiirene (7), ethynethiol (8), and thioketene (9) is formed. Flash pyrolysis of chlorodimethyl sulfide (1) yields ethenethiol (11) together with thiirane (4), whereas ethanesulfenyl chloride (2) gives ethene under the same conditions. The identification of thioacetaldehyde (5) is based on the comparison between the experimental and calculated IR spectra.
Wasserstoffübertragungen, 17 Elektronentransfer‐induzierte Aromatisierung von 1,4‐Dihydronaphthalin durch Tris(4‐bromphenyl)aminiumyl‐Ionen
Authors: Giese Georg , Heesing Albert 
Published: July 2007

Hydrogen Transfer Reactions, 171). — Electron‐Transfer‐Induced Aromatization of 1,4‐Dihydronaphthalene by Tris(4‐bromophenyl)aminiumyl IonsThe first step in the aromatization of 1,4‐dihydronaphthalene (1) by the radical cation 2 of tris(4‐bromophenyl)amine (3) is a rapid electron transfer in an equilibrium completely shifted to the side of the substrates. The deprotonation of the radical cation 7 of 1,4‐dihydronaphthalene is rate‐determining as shown by both cyclovoltagrams and isotope effects of deuterated hydrogen donors.
Anticancer Agents, 17 1,4‐Disila[6]radialene: Aktivierungsparameter der Sessel‐Twist‐Inversion und analytische Enantiomerentrennung der Twist‐Konformeren
Authors: Tietze L. F. , Krach T. , Beller M. , Arlt M. 
Published: July 2007

AbstractA New Highly Efficient Method for the Synthesis of 1'‐Alkyl‐ and 1'‐Phenyl‐Substituted Pyrimidine Acyclonucleosides
1,2,3‐Triborolane aus Norbornenderivaten, Allylbenzol und Dehalogenierungsprodukten von Dichlor(diisopropylamino)boran; 2,4,5‐Tris(diisopropylamino)‐2,4,5‐triborabicyclo[1.1.1]pentan‐Bicyclus oder Carboran?
Authors: Bromm Dietmar , Seebold Uwe , Noltemeyer Mathias , Meller Anton 
Published: July 2007

1,2,3‐Triborolanes from Norbornene Derivatives, Allylbenzene and Dehalogenation Products of Dichloro(diisopropyl‐amino)borane; 2,4,5‐Tris(diisopropylamino)‐2,4,5‐triborabicyclo[1.1.1]pentane‐Bicyclus or Carborane?The new 1,2,3‐tris(diisopropylamino)triborolanes 1, 2, 3 and 4 have been prepared by treatment of mixtures of 2‐norbornene (A), 5‐methylene‐2‐norbornene (B), 5‐ethylidene‐2‐norbornene (C) and allylbenzene (D) with dichloro(diisopropylamino)borane with Na/K alloy in hexane. The corresponding species 5, derived from 2,5‐norbornadiene (E), is relatively unstable and by a retro Diels‐Alder reaction gives 2,3,4‐tris(diisopropylamino)‐1,5‐dicarba‐closo‐pentaborane(5) (6). The compounds are characterized by chemical analyses, MS and NMR (1H, 11B, 13C, 15N) and 1, 4 and 6 also by X‐ray structure analyses.
1,3‐Bis[tert‐butyl(di‐tert‐butylfluorsilyl)amino]trisulfan – eine Verbindung mit FSiNSSSNSiF‐Helix
Authors: Klingebiel Uwe , Pauer Frank , Sheldrick George M. , Stalke Dietmar 
Published: July 2007

1,3‐Bis[tert‐butyl(di‐tert‐butylfluorosilyl)amino]trisulfane – a Compound with FSiNSSSNSiF HelixThe lithium derivative of tert‐butyl(di‐tert‐butylfluorosilyl)‐amine (1) reacts with sulfur or selenium to give the bis[(fluorosilyl)‐amino]di‐ and ‐trisulfanes 2, 3 and ‐selane 4, respectively. The trisulfane 3 crystallizes from n‐hexane and exhibits a helical structure (X‐ray analysis).
1,6‐Heptadien‐Nickel(0)‐Komplexe: rac/meso‐(μ‐η2,η2‐C7{Ni( η2,η2‐C7H12)}2 und L‐Ni(η2,η2‐C7H12)
Authors: Proft Bernd , Pörschke Klaus‐Richard , Lutz Frank , Krüger Carl 
Published: July 2007

1,6‐Heptadiene Nickel(0) Complexes:rac/meso‐(μ‐η2,η2‐C7{Ni(η 2,η2‐C7H12)}2 und L‐Ni(η2,η2‐C7H12)Ni(CDT) dissolves in 1,6‐heptadiene with displacement of the CDT to yield the dinuclear homoleptic product rac/meso‐(μ‐ η2,η2‐C7H12){Ni(η2, η2‐C7H12)}2 (1) as a mixture of stereoisomers, in which the nickel atoms are trigonal‐planar coordinated by a chelating 1,6‐diene ligand and one CC bond of a bridging diene ligand. The stereoisomers differ in the coordination mode of the bridging diene ligand.‐The bridging diene ligand in 1 can be displaced by various donor/acceptor molecules. In pentane, 1 reacts with ethene to yield a solution of mononuclear (C2H4)Ni(η2,η2‐C7H12) (2). With alkynes unstable complexes are formed of which the anticipated ethyne derivative (C2H2)Ni(η2,η2‐C7H12) (3) decomposes explosively at – 100°C. With isocyanides, methylenephosphoranes, methyllithium, amines, pyridines, phosphanes, and phosphites (i.e. C, N, P donors) crystalline complexes of type L‐Ni(η2.η2 C7H12) have been obtained, of which the derivatives with L=tBuN  C 4, Me3PCH2 5, LiCH3 6, C7H13N7, C5H5N 8, Me3P 9, iPr3P 10, Ph3P 11, (PhO)3P 12 are characterized here. For 11 the crystal structure has been determined.
Azoalkan‐ und Nitren‐verbrückte Carbonylmetall‐Cluster des Eisens und Rutheniums
Authors: Hansert Bernhard , Powell Anne K. , Vahrenkamp Heinrich 
Published: July 2007

Azoalkane‐ und Nitrene‐Bridged Carbonyl Metal Clusters of Iron and RutheniumBy using cluster buildup reactions, the new azoalkane‐bridged clusters Ru3(CO)9(RNNR) (3a, RMe, 3b, REt), Fe2Ru(CO)9(EtNNEt) (4), Ru4(CO)12(RNNR) (5a, RMe, 5b, REt), and FeRu3(CO)12(EtNNEt) (6) were obtained. Upon attempts to prepare further such compounds, the N‐N bond was cleaved resulting in nitrene‐bridged clusters including the new compound Fe4(CO)11(μ4‐NEt)2 (9). Cluster buildup starting from Ru3(CO)9(μ3‐NPh)2 resulted in Ru4(CO)11(μ4‐NPh)2 (10) and FeRu3(CO)11(μ4‐NPh)2 (11). The crystal structures of 5b and 9 as well as some reactions of the nitrene‐bridged clusters are described.
Verbindungen mit dem 2,4‐Dimethyl‐2,4‐diaza‐1,5‐diphosphapentan‐3‐on‐Grundgerüst; Synthese, Struktur und Eigenschaften von 1,5‐Di‐tert‐butyl‐2,4‐dimethyl‐1,5‐diphenyl‐2,4‐diaza‐l,5‐diphosphapentan‐3‐on und Derivaten
Authors: Vogt Roland , Jones Peter G. , Schmutzler Reinhard , Kolbe Alfred 
Published: July 2007

Compounds with the 2,4‐Dimethyl‐2,4‐diaza‐1,5‐diphosphapentan‐3‐one Skeleton; Synthesis, Structure, and Properties of 1,5‐Di‐tert‐butyl‐2,4‐dimethyl‐1,5‐diphenyl‐2,4‐diaza‐1,5‐diphosphapentan‐3‐one and Its DerivativesN,N′‐Dimethyl‐N‐N′‐bis(trimethylsilyl)urea (1) reacts with tert‐butylchlorophenylphosphane (2) to form the monophosphino/ trimethylsilyl‐substituted urea 3. Under more vigorous conditions the bisphosphino‐substituted derivative 4 was also obtained. The reaction of 4 with the tetracarbonyl norbornadiene derivatives of Cr, Mo, and W furnished the unusual chelate complexes 5–7, in which the ligand 4 is coordinated to the metal through one of the two phosphorus atoms and the oxygen atom of the carbonyl group. The free ligand 4 and the isostructural complexes 5 and 6 were subjected to X‐ray structure analyses. The approximate twofold symmetry of 4 is lost as a result of a major conformational change on complex formation. In contrast, 4 reacts with Fe2(CO)9 and with (COD)‐PtCl2 (COD=1,5‐cyclooctadiene) to give the complexes 8 and 9. In both 8 and 9 the ligand 4 is coordinated by both phosphorus atoms. Reaction of 4 with sulfur and selenium led to the disulfide 10 and diselenide 11, whereas with tellurium no reaction was observed.
Decaethyl‐2,6,8,10‐tetracarba‐nido‐decaboran(10) – Herstellung, Struktur im festen Zustand und Stabilität(1)
Authors: Köster Roland , Seidel Günter , Wrackmeyer Bernd , Bläser Dieter , Boese Roland , Bühl Michael , Schleyer Paul Von Ragué 
Published: July 2007

Decaethyl‐2,6,8,10‐tetracarba‐nido‐decaborane(10) – Preparation, Structure in the Solid State, and Stability[1]The title compound 6, prepared in two steps from the pentaethyl‐1,5‐dicarba‐closo‐pentaborane(5) (1), is characterized at 103 K as the low‐temperature solid phase LT‐6 by a single‐crystal X‐ray structure analysis; 6 reacts with alkali metals (K, Cs) to form the C4B6Et10 dianion (62–) which is easily oxidized to 6 (e.g. with I2, FeCl2, HgCl2). Ab initio MO and IGLO calculations of compound 6 have been carried out.
Carbonyl(η5‐cyclopentadienyl)(trimethylphosphan)[η2‐(methylthio)‐phenylcarben]molybdän‐tetrafluoroborat – ein amphiphiler Carbenkomplex
Authors: Kreißl Fritz R. , Stegmair Claudia M. 
Published: July 2007

Carbonyl(η5‐cyclopentadienyl)(trimethylphosphane)[η2‐(methylthio)phenylcarbene]molybdenum Tetrafluoroborate – an Amphiphilic Carbene ComplexThe title complex 1 adds the electrophile SMe+ as well as the nucleophilic PMe3 at the carbene carbon to form the complexes 2 and 3, respectively.
Reduktive Umwandlungen, 18(2) Cycloanellierung und Überbrückung von Cyclooctatetraen(1)
Authors: Auchter‐Krummel Petra , Krummel Günter , Müllen Klaus , Lex Johann 
Published: July 2007

Reductive Transformations, 18[2]. – Cycloannulation and Bridging of Cyclooctatetraene[1]Reductive alkylations of cyclooctatetraene (1) with biselectrophiles have hitherto been described as proceeding solely under 1,2‐cycloannulation. Using different alkylating agents with varying chain lengths, conformational mobility, and leaving groups we succeeded in achieving regio‐ and stereoselective reactions of the intermediate monoalkyl monoanion 3. By systematic variation of the biselectrophiles the subtle competition of 1,2‐ versus 1,4‐ and of 1,n‐cis‐ versus 1,n‐trans‐cyclization is elucidated. It is shown that the regio‐ and stereoselectivity are controlled mainly by the structure of the alkylating reagents while other parameters such as solvent or leaving group do not play an important role. Reductive alkylation of 1 provides an easy access to a large number of compounds which may be oxidized to new cyclooctatetraene systems or serve as substrates for further skeletal rearrangements. – X‐ ray structure analyses are performed for compounds 15, 27 a, 28, and 29.
Small and Medium Rings, 781) Cage Dimers of Norbornadiene with Perpendicular Arrangement of Subchromophores: Orbital Interaction in the Heptacyclo[6.6.0.02,6.03,13.04,11.05,9.010,14]tetradecane System
Authors: Albert Bernhard , Elsässer Dominik , Martin Hans‐Dieter , Mayer Bernhard , Chow Tahsin J. , Marchand Alan P. , Ren Chien‐Tai , Paddon‐Row Michael N. 
Published: July 2007

AbstractThe syntheses of functionalized norbornadiene dimers 1 are described. These cage compounds feature remarkably high D2d symmetry as regards the dimethylene and dioxo derivatives 1d and 1e. On the other hand, the mixed enone compound 11 behaves differently: πcc and lone‐pair nco orbitals mix strongly with each other, albeit only by means of the intervening five‐bond σ system. All theoretical conclusions have been verified by using PE spectroscopy. A comparison is made between systems 1 and the geometrically similar adamantanes 2, on the one hand, and the attractive but still unknown derivatives of garudane 3 on the other hand. The latter exhibit the interesting parallel topology of suitable chromophores, thus making these polycycles 3 desirable candidates for transmission studies.
Oxidative Trimerisierung von Alkinylgruppen an Trimethylphosphan‐Palladium‐Komplexen
Authors: Klein Hans‐Friedrich , Zettel Bernd , Flörke Ulrich , Haupt Hans‐Jürgen 
Published: July 2007

Oxidative Trimerization of Alkynyl Groups at Trimethylphosphane Palladium ComplexesAlkynylpalladium halides trans‐PdX (C ≡ CR)(PMe3)2 [1, 2, 4, X = Cl, R = SiMe3, (CH2)2CH3, (CH2)5CH3; 3, X = Br, R = (CH2)2CH3] were synthesized by routine methods, while further examples of the series trans‐PdX (C ≡ CR)(PMe3)2 [5, 7, 8, 10, X = Br, R = SiMe3, CMe3, (CH2)2CH3, Ph; 7, 9, 11, X = I, R = SiMe3, SiPh3, OEt] and trans‐PdX (C ≡ CR)(PPh3)2 (12‐14, X=I, R=SiMe3, CMe3, CH2OH) were obtained by oxidative addition of 1‐halogeno‐1‐alkynes to PdL4 (L=PMe3, PPh3). Just above the melting point or decomposition point 5‐7 are transformed by oxidative trimerization of the alkynyl groups to give enediynyl complexes trans‐PdX[C(C ≡ CR)=C(C ≡ CR)R](PMe3)2 (15, 16, R=SiMe3, X=Br, I; 17, X=Br, R=CMe3). According to an X‐ray structure analysis 17 has E configuration.
Synthese, Struktur und Reaktivität eines Stanna(II)‐nickela(II)‐cyclobuten‐Komplexes
Authors: Pluta Christian , Pörschke Klaus R. , Ortmann Ingo , Krüger Carl 
Published: July 2007

Synthesis, Structure, and Reactivity of a Stanna(II)‐nickela(III)‐cyclobutene KomplexesThe (ethyne)nickel(0) complex (iPr2PC2H4PiPr2)Ni(C2H2) (1) reacts with the stannene Sn[CH(SiMe3)2]2 below −30°C to yield the stanna(II)‐nickela(II)‐cyclobutene complex (iPr2PC2H4PiPr2)YYNiCH=YYCHSn[CH(SiMe3)2]2 (2; 83%) as the kinetically controlled product; 2 has been characterized by IR and NMR spectroscopy and an X‐ray crystal‐structure determination. The latter shows the central four‐membered ring to be planar with a long Ni—Sn bond [2.626(1) Å]. According to the temperature‐dependent NMR spectra, 2 dissociates reversibly in solution to the starting components. The synthesis reaction thus represents an equilibrium as long as the temperature is below 20°C. These observations indicate that the structural lability of the stanna(II)‐nickela(II)‐cyclobutene moiety is associated with the weakness of the Ni—Sn bond. The bonding situation in 2 is best described as an “inner complex” in which a stannyl anion is coordinated to a nickel(II) cation. An ethereal solution of 2 undergoes an oxidative addition of one ethyne C—H bond to the stannene at 20°C to give the Ni(0)/Sn(IV) complex iPr2PC2H4PiPr2)Ni({η2‐HC≡CSn(H)[CH(SiMe3)2]2} (3) as the thermodynamically controlled product. Reaction of 3 with CO liberates the new alkyne ligand.
Elektroreduktion organischer Verbindungen, 19 Bildung benzoanellierter Schwefelheterocyclen durch intramolekulare kathodische Cyclisierung von Dithiocarbonsäureestern
Authors: Gade Thomas , Streek Michael , Voß JüRgen 
Published: July 2007

Electroreduction of Organic Compounds, 19. — Formation of Benzoanellated Sulfur Heterocycles by Intramolecular Cathodic Cyclization of Dithiocarboxylic EstersCathodic reduction of aryl (3) and benzyl (5) dithiopivaloates and related dithioesters with leaving groups at the benzene ring or a side chain yield the sulfur heterocycles 23, 30—32, and 34 depending on the nature of the starting material and the reaction conditions. In case of the α‐oxo‐dithioester 22, thioindigo (44) is formed. — The corresponding thioamides 14, 16, and 18 show a strong tendency to reductive dehalogenation but the S,N‐heterocycles 38 and 39 are also formed in minor amounts. — The formation of the rearranged products 29—32, and 34 is discussed in terms of C,S‐splitting in the primarily formed radical anion and subsequent C,C‐coupling of the fragments and follow‐up reactions.
Übergangsmetallaktivierte organische Verbindungen, XXXV. Ortho‐Alkylierungen von aromatischen Azoverbindungen mit Alkyllithium‐Reagenzien und Lithiumtrimethylferrat(1‐)
Authors: Kauffmann Thomas , Jordan Jan , Sander Jörg 
Published: July 2007

Transitional‐Metal‐Activated Organic Compounds, XXXV. — ortho‐Alkylation of Aromatic Azo Compounds with Alkyllithium Reagents and Lithium Trimethylferrate(1‐)Whereas methyllithium reacts with 4‐(dimethylamino)‐, 4‐amino‐, and 4‐methoxyazobenzene, respectively, by ortho‐methylation of the electron‐rich phenyl residue of the azo compound, (CH3)3FeLi ortho‐methylates the less electron‐rich phenyl group of 4‐(dimethylamino)azobenzene. A mechanistic rationalisation is given for both reaction modes.
Untersuchungen zur Chemie von Isoindolen und Isoindoleninen, XXXIX. Reaktionen von 2‐Alkyl‐4,5,6,7‐Rn‐2H‐isoindolen (Rn=tetramethyl, tetrachlor) mit aktivierten C=C‐Dienophilen
Authors: Kreher Richard P. , Sewarte‐Roß G. , Vogt G. 
Published: July 2007

Studies on the Chemistry of Isoindoles and Isoindolenines, XXXIX. — Reactions of 2‐Alkyl‐4,5,6,7‐Rn‐2H‐isoindoles (Rn=tetramethyl, tetrachloro) with Activated C=C DienophilesSubstituted 2H‐Isoindoles 2 react with maleic imides in absolute ether. Cycloaddition in 1,3‐position leads to the formation of 1:1 adducts. The ratio between endo isomers 4 and exo isomers 5 depends on the substituents and the solvents. In the case of steric hindrance the Diels‐Alder addition can be induced by Lewis acids. In the presence of oxygen‐substituted 4,5,6,7‐tetrachloro‐2‐methylisoindolin‐1‐ones 7 are formed as minor products.
Synthese von 1,2‐Dioxolanen durch Ozonolyse 1,1‐disubstituierter nichtaktivierter Olefine
Authors: Reiser Ralf , Seeboth Rolf‐Günter , Sütting Carsten , Wagner Gabriele , Wang Jinkai , Schröder Gerhard 
Published: July 2007

Synthesis of 1,2‐Dioxolanes by Ozonolysis of 1,1‐Disubstituted Nonactivated OlefinsOzonolyses of the cyclopropyl‐substituted olefins 2a, 2b, and 2c do not produce the carbonyl oxides 1a, 1b, and 1c but formaldehyde oxide (1d); 1d can be trapped by the starting olefin and provides the 1,2‐dioxolanes 6a, 6b, and 6c, respectively, in ca. 10% yield. Other dioxolanes and normal ozonides may be obtained by the addition of olefins or aldehydes to solutions of the primary ozonides of 2a and 2b.
Wasserstoffübertragungen, 19. Zur Katalyse von Wasserstoff‐Transfer und 1,5‐H‐Shift durch Rhodium(III)‐chlorid in homogener organischer Phase
Authors: Wehage Hubert , Heesing Albert 
Published: July 2007

Hydrogen Transfer Reactions, 19. — The Catalysis of Hydrogen Transfer and 1,5‐H Shift by Rhodium(III) Chloride in Homogeneous Organic SystemsIn homogeneous solution, partly in the presence of a phase‐transfer catalyst, rhodium(III) chloride catalyzes the disproportionation of 1,3‐cyclohexadiene and to a lesser extent 1,5‐H shifts. In the start phase the catalyst is reduced to the active monovalent state. In these catalytic systems the dehydrogenation proceeds stereoselectively. – This was shown by tracer experiments and isotopes effects using deuterated 1,3‐cyclohexadienes 1a—d, which were synthesized with high isotopomeric purity.