bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphinalkylene, 50. Zur Struktur von 2,2,2‐Triphenyl‐1,2λ5‐oxaphospholanen
Authors: Bestmann Hans Jürgen , Riemer Claus , Dötzer Reinhard 
Published: July 2007

Phosphine Alkylenes, 50. — On the Structure of 2,2,2‐Triphenyl‐1,2λ5‐oxaphospholanes2,2,2‐Triphenyl‐1,2Δ5‐oxaphospholanes (5a—h) were synthesized from methylene‐triphenylphosphorane (1, R=H) and suitable epoxides (2a—g). Oxaphospholane 5e was subjected to an X‐ray structural analysis, which showed a five‐membered ring‐structure with a trigonal‐bipyramidal coordinate phosphorus atom. One phenyl group and the ring oxygen atom are apical ligands at phosphorus. According to the NMR spectra, oxaphospholanes have a ring structure in nonpolar solvents, whereas in polar solvents there exists an equilibrium with an open‐chain form.
[3.3]Metacyclophane mit anti‐Konformation
Authors: Breitenbach Jörg , Hoss Ralf , Nieger Martin , Rissanen Kari , Vögtle Fritz 
Published: July 2007

[3.3]Metacyclophanes with anti ConformationThe [3.3]metacyclophanes 5 and 9 with prevailing anti conformation were prepared by using different cyclisation techniques. 1H‐NMR studies and X‐ray structure analyses of both phanes 5 and 9 prove their unprecedented conformations.
Cyclische C6S6‐Isomere — Matrixspektroskopische und theoretische Untersuchungen
Authors: Maier Günther , Schrot Jürgen , Reisenauer Hans Peter , Frenking Gernot , Jonas Volker 
Published: July 2007

Cyclic C6S6 Isomers — Matrix‐Spectroscopic and Theoretical InvestigationsA yellow C6S6 isomer, which can be interconverted photo‐chemically into a colorless second C6S6 isomer, may be obtained upon matrix photolysis and flash pyrolysis of the precursor molecule 7. The structures of these isomers are most likely 3 and 5, as shown by comparison of their experimental with the calculated infrared spectra of the five possible cyclic C6S6 isomers 1—5.
Bis(di‐tert‐butylphosphanyl)methan‐Komplexe des Rhodiums: Geometrie, Elektronenstruktur und Derivate des 14‐Elektronenteilchens [Rh(dtbpm)Cl]. Molekülstruktur von Rh(dtbpm)Cl(PMe3)
Authors: Hofmann Peter , Meier Claudia , Englert Ulli , Schmidt Martin U. 
Published: July 2007

Bis(di‐tert‐butylphosphanyl)methane Complexes of Rhodium: Geometry, Electronic Structure, and Derivatives of the 14‐Electron Fragment [Rh(dtbpm)Cl]. Molecular Structure of Rh(dtbpm)Cl(PMe3)14‐Electron fragments [M(PR3)2X] (M = Rh, Ir, X = halogen etc.) are considered to be an important class of highly reactive, coordinatively unsaturated intermediates in many metal‐induced stoichiometric or catalytic transformations of organic substrates. As available theoretical data suggest a slightly preferred T‐shaped groundstate geometry with a less symmetric cis rather than the usually implied trans phosphane arrangement for such tricoordinate d8‐ML3‐type systems with monodentate phosphanes PR3, the chemistry of η2‐diphosphanylmethane complexes of rhodium with four‐membered RhPCP‐chelate rings and thus with enforced cis phosphane coordination and anomalously small cis P—Rh—P angles has been studied by theory and by experiment. MO calculations (EH) have been performed both for the model 14‐electron system [Rh(dhpm)Cl] (dhpm = diphosphanylmethane, H2P—CH2—PH2) and for the experimentally accessible fragment [Rh(dhbpm)Cl], where dtbpm is bis(di‐tert‐butylphosphanyl)‐methane, (tBu)2P—CH2—P(tBu)2. The electronic and geometric structure of these species is described. Employing the unusual ligand dtbpm, tailor‐made for stabilizing mononuclear η2‐ and destabilizing dinuclear μ‐diphosphanylmethane coordination, the chloro‐bridged dimer [Rh(dtbpm)Cl]2, has been synthesized. In agreement with steric and electronic considerations, its chemistry is dominated by a facile dissociation to monomeric (presumably solvent coordinated) fragments [Rh(dtbpm)Cl], even in benzene, as suggested by molecular mass determinations. Accordingly, by using [Rh(dtbpm)Cl]2 as a starting material, a series of sterically very congested but nevertheless mononuclear, square‐planar complexes Rh(dtbpm)Cl(L) (L = CO, PMe3, PPh3, PCy3, pyridine, acrylonitrile) with chelating dtbpm could be readily prepared and fully characterized. The relative stability of these potential alternative precursors of a [Rh(dtbpm)Cl] intermediate towards dissociation of ligands L is reported. The molecular structure of Rh(dtbpm)Cl(PMe3) as the first representative of this class of compounds has been determined by X‐ray crystallography.
Photoreaktion von (μ‐η]2:2‐Acetylen)tetracarbonylbis(η5‐cyclopentadienyl)‐dimolybdän und ‐wolfram mit Acetylen und 1,3‐Butadien
Authors: Kreiter Cornelius G. , Würtz Alban , Bell Peter 
Published: July 2007

Photoreaktion von (μ‐η]2:2‐Acetylen)tetracarbonylbis(η5‐cyclopentadienyl)‐dimolybdenum and ‐tungsten with Acetylene and 1,3‐Butadiene[Mo2(η5‐C5H5)2(CO)4(μ‐η2:2‐C2H2)] (1) and [W2(η5‐C5H5)2(CO)4‐(μ‐η2:2‐C2H2)] (2) react upon UV irradiation with acetylene, 1,3‐butadiene, and isoprene. Main products of the reactions with acetylene are the fly‐over complexes [M2(η5‐C5H5)2(CO)2(η1:3:3:1‐1,3,5‐hexatriene‐1,6‐diyl)] (8: M = Mo; 9: M = W). There is some IR evidence for the formation of [Mo2(η5‐C5H5)2(CO)(η5η1:4:1‐1,3‐butadiene‐1,4‐diyl)] (10). In addition [Mo3(η5‐C5H5)6(μ‐η1:2‐ethynyl)] (12) is obtained. 1 reacts with 1,3‐butadiene with C—C bond formation to give [Mo2(η5‐C5H5)2>(CO)(μ‐η1:2‐CO)(μ‐η1:2:3‐1,5‐hexadiene‐1,4‐diyl)] (15) and [Mo2(η5‐C5H5)2 (CO)4[μ‐η1:3‐E,Z‐2,4‐hexadiene‐1‐ylidene)] (18). With isoprene [Mo2(η5‐C5H5)2(CO)4[μ‐η1:3‐E,Z‐5‐methyl‐2,4‐hexadiene‐1‐ylidene)] (18a) is obtained. The reaction of 2 with 1,3‐butadiene yields six complexes. Beside thermolabile [W2 [W2(η5‐C5H5)2(CO) (μ‐η1:2:1‐3‐oxo‐1‐propene‐1, 3‐diyl)(η4‐1,3‐butadiene)] (21), (η5‐C5H5)2(CO) (μ‐η1:4‐3‐methylene‐1,4‐pentadiene‐1‐yl)] (20), the tungsten homologue of 15, [W2(η5‐C5H5)2(CO) (μ‐η1:2:3‐1,5‐hexadiene‐1,4‐diyl)] (16), its isomer [W2(η5‐C5H5)2(CO)2(μ‐η1:2:3‐1,5‐hexadiene‐1,4‐diyl)] (23) with a W—W double bond, and [W2(η5‐C5H5)2(CO)2(μ‐η1:2:1‐1,4‐hexadiene‐1,6‐diyl)] (17) are isolated. Furthermore, [W2(η5‐C5H5)2(CO)2 (μ‐η1:2‐vinylidene)] (11) is obtained. In solution 21 rearranges to 23. The crystal and molecular structures were determined for 15 and 18. The constitutions of the other products were deduced from the IR and 1H‐NMR spectra.
A Contribution to the Direct Observation of a Didehydroheteroaromatic with a Five‐Membered Ring: 2,3‐Didehydrothiophene
Authors: Teles Joaquim Henrique , Hess B. Andes , Schaad Lawrence J. 
Published: July 2007

AbstractThe flash vacuum pyrolysis and the photolysis of 2,3‐thiophenedicarboxylic acid anhydride (6) were investigated by using the technique of matrix isolation combined with FT‐IR spectroscopy. No conclusive proof for the existence of 2,3‐didehydrothiophene (1) could be found, but two hitherto unknown isomers were isolated and characterized: vinylidenethioketene (10) and thioformylvinylidenecarbene (15).
Ein Dipyrrino‐Cryptand — Synthese, Kristallstruktur, Metallkomplexierung
Authors: Seel Christian , Vögtle Fritz , Nieger Martin 
Published: July 2007

A Dipyrrino Cryptand — Synthesis, Crystal Structure, Metal ComplexationThe orange red cryptand 1, containing a dipyrrin chromophore, has been synthesized in seven steps. Its C2‐symmetrical X‐ray structure exhibits a planar dipyrrin unit and a twisted but not collapsed crown ring, two of the ether oxygen atoms projecting outwards. The complexation of alkali and transition metal cations by this concave dyestuff leads to changes of the color and to strong shifts in the UV/Vis spectra.
Synthese und Deoxygenierung substituierter 1‐Azaadamantan‐4,6‐dione
Authors: Risch Nikolaus , Billerbeck Ulrich , Krieger Evelyn 
Published: July 2007

Synthesis and Deoxygenation of Substituted 1‐Azaadamantane‐4,6‐diones1‐Azaadamantanes 5 and a variety of derivatives are accessible by a triple Mannich reaction of 1,3‐cyclohexanediones 1 with hexamethylenetetramine to yield the 1‐azaadamantane‐4,6‐diones 2. Deoxygenation of the sterically hindered and non‐enolizable β‐dioxo group in 2 succeeds by radical processes. Treatment with NaBH4/MeOH and subsequent chlorination give the dichlorides 4, which are dehalogenated with nBu3SnH. Quaternary ammonium salts 6 are available in high yields.
A General Synthesis of (Z)‐1,2‐Ethenediol Derivatives
Authors: Wulff Günter , Birnbrich Paul 
Published: July 2007

AbstractBy retro‐Diels‐Alder reaction of suitably substituted 9,10‐dihydro‐9,10‐ethanoanthracene‐cis‐11,12‐diol derivatives (4, 6, 8, 10, 12, 14) a number of known and unknown (Z)‐1,2‐disubstituted ethenes (5, 7, 9, 11, 13, 14) have been prepared in high yield, including derivatives with two different substituents. In contrast to this, attempts to prepare 1,3,2‐dioxasiloles bearing only substituents on the silicon atom gave dimers containing the ten‐membered ring system (Z,Z)2,2,7,7‐tetraalkyl‐1,3,6,8‐tetraoxa‐2,7‐disilacyclodeca‐4,9‐diene (19b, 21b, 23b, 25b). Again these compounds are formed diastereoselectively with respect to the double bonds.
Darstellung phenylsubstituierter Derivate des Tricyclo[4.1.0.02,7]heptans und des 1,2,3,4‐Tetrahydro‐1,2,3‐methenonapthalins
Authors: Stangl Roland , Jelinek‐Fink Hans , Christl Manfred 
Published: July 2007

Preparation of Phenyl‐Substituted Derivatives of Tricyclo[4.1.0.02,7]heptane and 1,2,3,4‐Tetrahydro‐1,2,3‐methenonaphthaleneThe phenyl derivatives 3, 4, and 13 of tricyclo[4.1.0.02,7]heptane (1) and 17, 20, and 22 of 1,2,3,4‐tetrahydro‐1,2,3‐methenonaphthalene (2) have been prepared from the dibromocarbene adducts of 1‐phenyl‐1‐cyclohexene, 3‐phenyl‐1‐cyclohexene, 1,3‐diphenyl‐1‐cyclohexene, 1,2‐dihydro‐2‐phenylnaphthalene, 1,2‐dihydro‐4‐phenylnaphthalene, and 1,2‐dihydro‐2,3‐diphenylnaphthalene, respectively, by treatment with methyllithium. The dibromocarbene adduct 10 of 1,6‐diphenyl‐1‐cyclohexene reacts with methyllithium to give the bicyclo[3.2.0.02,7]heptane 11.
Regioselective Acylations of Ketones to 1,3‐Diketones via Metalated Dimethylhydrazones[1]
Authors: Enders Dieter , Pathak Vijai N. , Weuster Peter 
Published: July 2007

AbstractAcyclic and cyclic unsymmetrical ketones 1 are regioselectively acylated via their corresponding metalated dimethyl‐hydrazones 3 by using acid chlorides or anhydrides, arylnitriles, ethyl formate, carbon disulfide/methyl iodide, alkyl chloroformates, dialkyl carbonates, phenyl isocyanate, or phenyl isothiocyanate as acylating agents. Subsequent acidic hydrolysis leads to the 1,3‐diketones 6 in acceptable to excellent overall yields. The tautomeric structure of the product hydrazones 4, 5, 7, and 8 is determined. Cyanation of 3 with cyanogen bromide affords the α‐cyano dimethylhydrazones 9.
Reaktive EC(p–p)π‐Systeme, XXXII[1a] Phosphorylide Me3P = C(X)P(F)CF3 mit π‐Donor‐Substituenten X = F, OMe, OEt
Authors: Grobe Joseph , Van Due Le , Althoff Ulrike , Lange Gudrun 
Published: July 2007

Reactive E = C(p–p)π Systems, XXXII[1]. – Phosphorus Ylides Me3P = C(X)P(F)CF3 with π‐Donor Substituents X = F, OMe, OEtFluorophosphaalkenes of the type F3CP = C(X)F react with tri‐methylphosphane in a 1:1 molar ratio at temperatures below – 20°C to give the novel phosphorus ylides Me3P = C(X)P(F)CF3 in good yields [X = F (4), 70%; OMe (7), 62%; OEt (8), 74%]. Compounds 4, 7 and 8 are stable up to about 10°C, but decompose at higher temperatures yielding in case of 4 Me3PF2 as main product. The 31P‐NMR spectra indicate a high barrier of rotation for the F3C(F)P group around the PIII–sp2C bond. The new ylides owe their existence to the electron withdrawing effect of the F3C(F)P unit which over‐compensates the destabilizing influence of the fluorine or alkoxy substituents on the sp2C atom.
Organophosphorverbindungen, 53[1] Cyclopropenyliden‐methylen‐diphosphane – neue gekreuzt konjugierte Phosphapolyene[2]
Authors: Breit Bernhard , Memmesheimer Holger , Boese Roland , Regitz Manfred 
Published: July 2007

Organophosphorus Compounds, 53[1]. – Cyclopropenylidene‐methylene‐diphosphanes – New Cross‐Conjugated Phosphapolyenes[2]The reaction of chloromethylenephosphanes 7 with the inverse cyclopropenylidenephosphanes 6, 10 leads to the formation of the title compounds 8 and 11 as a new class of cross‐conjugated phosphapolyenes. The structure of compound 8a has been confirmed by an X‐ray structural analysis.
Nichtkonzertierte Cope‐Umlagerung? 1,2,6,7‐Cyclodecatetraen‐Thermolyse
Authors: Roth Wolfgang R. , Schaffers Thomas , Heiber Margarita 
Published: July 2007

Nonconcerted Cope‐Rearrangement? 1,2,6,7‐Cyclodecatetraene ThermolysisFrom the pressure and oxygen dependence of the trapping rate a two‐step mechanism for the Cope rearrangement of the title compound is deduced, its energy profile established, and the heat of formation of the intermediate diradical 3 determined. In contrast to the meso compound the rearrangement of the rac isomer proceeds by two competing processes, a concerted and a nonconcerted pathway. The different behavior of the meso and rac compound can be correlated to the boat and chair geometry of the respective transition states.
Synthese, Strukturen und Eigenschaften von Cl2TeSeN2S und [Se2N2S]22+ [XSO3−]2 (X = F, CF3)
Authors: Haas Alois , Kasprowski Jörg , Pryka Michael 
Published: July 2007

Synthesis, Structures, and Properties of Cl2TeSeN2S and [Se2N2S]22+ [XSO3−]2 (X = F, CF3)Treatment of Se(NSO)2 with TeCl4 provides the colvalent five‐membered ring species (1). Reaction of Se(NSO)2 with XSO3H (X = F or CF3) leads to bis(1,3,4,2,5‐thiadiselenadiazolium) cations with the anions FSO3− (2a) and CF3SO3− (2b). X‐ray structure analyses for 1 and 2b are presented.
Reaktionen von Fluorphosphoranen mit (Trimethylsilyloxy)essigsäure(trimethylsilyl)ester: Synthese, NMR‐spektroskopische Studien und Röntgenstrukturuntersuchungen an mono‐ und spirocyclischen (Acyloxy)phosphoranen[1]
Authors: Well Michael , Albers Wilfried , Fischer Axel , Jones Peter G. , Schmutzler Reinhard 
Published: July 2007

Reactions of Fluorophosphoranes with Trimethylsilyl (Trimethylsilyloxy)acetate: Structures, NMR‐Spectroscopic Studies and X‐ray Investigations of Mono‐ and Spirocyclic (Acyloxy)phosphoranes[1]The reaction of the tetrafluorophosphoranes RPF4 (R = Me, Ph) with trimethylsilyl (trimethylsilyloxy)acetate (1) yields the corresponding monocyclic fluoro(acyloxy)phosphoranes 2 and 3 by cleavage of the Si—O bond and elimination of (CH3)3SiF. 2 and 3 were investigated by NMR spectrometry. The spirocyclic (acyloxy)phosphoranes 4–13 are formed analogously by the reaction of 1 with the fluorophosphoranes RPF4 [R = F, Me, Et, iPr, Me3SiCH2, CH2Cl, CHCl2, H2C = CH, C6H5, 2,5‐(CH3)2C6H3] in a molar ratio of 2:1. Spirophosphorane 14 is synthesized by the reaction of with PhN3 in the presence of a base. The trifluorophosphoranes R2PF3 (R = Me, Ph) react with 1 to form the monocyclic fluoro(acyloxy)phosphoranes 15 and 16, where the fluorine atom occupies an axial position at trigonal‐bipyramidal (TBP) phosphorus. X‐ray structure analyses of 4 and 7 reveal TBP geometry at phosphorus. The acyloxy ligand is found to form a chelate ring, whereby one axial and one equatorial site at TBP phosphorus are bridged.
Bis(triisopropylphosphan)rhodiumdichlorid: Bildung und Struktur
Authors: Rappert Thomas , Wolf Justin , Schulz Michael , Werner Helmut 
Published: July 2007

Bis(triisopropylphosphane)rhodium Dichloride: Formation and StructureThe mononuclear rhodium(II) complex trans‐[RhCl2(PiPr3)2] (4) has been obtained from [RhCl(PiPr3)2]n (3) and CCl4. The X‐ray structural analysis of 4 reveals a square‐planar coordination at the metal center. Reaction of 4 with H2 leads to the formation of the monohydrido compound [RhHCl2(PiPr3)2] (7) which on further treatment with H2 in the presence of Na[N(SiMe3)2] gives the dihydride [RhH2Cl(PiPr3)2] (8). Complex 7 has also been prepared from 3 and HCl.
Alkyleisen‐ und Alkylcobalt‐Reagenzien, V[1] Anticheleselektive Cyanoalkylierungen mit Cyanoalkyl‐Derivaten von Eisen(II), Titan(IV) und weiteren Übergangsmetallen
Authors: Kauffmann Thomas , Kieper Hansjörg 
Published: July 2007

Alkyliron‐ and Alkylcobalt Reagents, V[1]. – Anticheleselective Cyanoalkylation with Cyanoalkyl Derivatives of Iron(II), Titanium(IV) and Further Transition MetalsIn intermolecular competition experiments with substrate pairs which consist of a β‐functionalized ketone and a normal ketone, cyanoalkyl derivatives of Fe, Ti, Cr, and Mn prefer in every case the normal ketone (‚anticheleselectivity”). NC—CH2Ti(OiPr)3 (4a) and NC–CH2FeCl (3a) are the best reagents for the anticheleselective transfer of the cyanomethyl group. For the anticheleselective transfer of the cyaniosopropyl group, NC–CMe2FeCl (3b) is superior to the corresponding Ti reagents. The ability of 4a as a highly anticheleselective cyanomethylating reagent has also been demonstrated with an intramolecular competition system (diketone 13). The reasons for the observed anticheleselectivity are discussed.
Alkyleisen‐ und Alkylcobalt‐Reagenzien, VI[1] Hohe Überlegenheit der Reagenzien Me4CoLi2 und Me4FeLi2 im Vergleich zu Me2CuLi und Me4MnLi2 bei Kreuzkupplungen mit Vinylbromiden
Authors: Kauffmann Thomas , Stach Dirk 
Published: July 2007

Alkyliron and Alkylcobalt Reagents, VI[1]. – High Superiority of Me4CoLi2 and Me4FeLi2 in Comparison to Me2CuLi and Me4MnLi2 in Cross Coupling Reactions with Vinyl BromidesThe complexes Me4MLi2 (M = Co, Fe, Mn) and Me2CuLi (prepared in situ, but well‐known in isolated form) were treated with a series of vinyl bromides. In nearly all cases Me4CoLi2 and Me4FeLi2 proved to be by far the best methylating reagents (high yields, reaction at – 78°C, short reaction time, no excess of the reagent necessary). These reagents will tolerate a hydroxy or cyano group in the substrate, whereas the classical reagent for methylation of vinylbromides, Me2CuLi, is strongly inhibited by these groups. With the methylation of hydroxyvinyl bromides a new method was found for the synthesis of allyl alcohols.
Nickelkomplexe eines 1,4‐Dihydro‐1,4‐Diboranaphthalin‐Derivates
Authors: Schulz Hartmut , Pritzkow Hans , Siebert Walter 
Published: July 2007

Nickel Complexes of a 1,4‐Dihydro‐1,4‐diboranaphthalene Derivative*2,3‐Diethyl‐1,4‐dihydro‐1,4‐dimethyl‐1,4‐diboranaphthalene (1) reacts with bis(1,5‐cyclooctadiene)nickel to form the complexes 2 and 3. The latter is also obtained from 1 and bis(allyl)nickel. However, the reaction of 1 with Ni(C3H5)2 in a 1:1 ratio leads to 4 containing the 1,5‐hexadiene ligand. The bis(allylnickel) triple‐decker 5 is obtained from the dianion 12‐ and [(C3H5)NiBr]2. In addition, the diamagnetic 44‐VE tetradecker 6 is formed in low yield. The constitutions of the complexes 2, 3, 4, and 6 are derived from spectroscopic data and are proven by X‐ray structure analyses.
Neutrale 30‐Valenzelektronen‐Tripeldeckerkomplexe mit cyclo‐E5‐Mitteldeck (E = P, As)
Authors: Rink Barbara , Scherer Otto J. , Heckmann Gert , Wolmershauser Gotthelf 
Published: July 2007

Neutral 30 Valence‐Electron Tripledecker Complexes with cyclo‐E5 Middle Deck (E = P, As)[1]In a stacking reaction of [(η5‐E5)M(η5‐C5Me5)] (3: E = P, As; M = Fe, Ru) with [M′(CO)3(NCMe)3] (4: M′ = Cr, Mo, W) at room temperature the neutral 30 valence‐electron tripledecker complexes [(η5‐C5Me5)M(μ‐η5:5‐E5) M′(CO)3] (5) are formed. Complexes 5b (M = Fe, E = P, M′ = Mo) and 5c, d (M = Fe, E = As, M′ = Cr, Mo) have been characterized by X‐ray structure analyses.
Phenylsilyl Chalcogenides, (Phenylsilyl)amines and Related Phosphonium (Phenylsilyl)methylides
Authors: Mitzel Norbert W. , Schier Annette , Beruda Holger , Schmidbaur Hubert 
Published: July 2007

AbstractThe synthesis of 1,3‐diphenyldisiloxane (1) by hydrolysis of chloro(phenyl)silane is optimized, 1,3‐diphenyldisilthiane (2) is made available by the reaction of H2S with PhH2SiCl and triethylamine. 1,3‐Diphenyldisilselenane (3) is prepared from K2Se and PhH2SiBr. Selective ammonolysis of PhH2SiBr leads either to bis(phenylsilyl)amine (4) or to tris(phenylsilyl)amine (5). (Phenylsilyl)bis(trimethylsilyl)amine (6) is prepared by the reaction of 1,1,1,3,3,3‐hexamethyldisilazane with chloro(phenyl)silane and triethylamine. According to a crystal structure determination the molecule of6features a planar Si3N skeleton. Phenylsilylated phosphonium methylides are available by two synthetic pathways: Transsilylation of phosphonium (trimethylsilyl)methylides and direct silylation of unsubstituted phosphonium methylides R3P = CH2. The structure of the molecule Me3P = C(SiH2Ph)2(11) in the crystal also exhibits a virtually planar PCSi2skeleton, isoelectronic with Si3N.
Enantioselektive Katalyse, VIII. Neue 1,2‐Bisphosphanliganden mit vier stereogenen Zentren und zusätzlichen Methoxygruppen für die asymmetrische katalytische Hydrierung
Authors: Nagel Ulrich , Bublewitz Alexander 
Published: July 2007

Enantioselective Catalysis, VIII[1]. – New 1,2‐Bisphosphane Ligands with Four Stereogenic Centers and Additional Methoxy Groups for Asymmetric Catalytic Hydrogenation*The synthesis of N‐acyl derivatives of all possible diastereomers of [P(R,S), 3R, 4R,P′(R,S)]‐3,4‐bis[(benzyl)phenylphosphanyl]‐pyrrolidine and [P(R,S), 3R, 4R,P′(R,S)]‐3,4‐bis[(2‐methoxybenzyl)phenylphosphanyl]pyrrolidine in optical pure form is described. Palladium and rhodium complexes with these ligands were prepared. The enantioselective hydrogenation of acetamidocinnamic acid with these rhodium complexes was studied at H2 pressures between 1 and 75 bar. There is only a small influence of the 2‐methoxy group in the ligand on the catalytic hydrogenation when compared with the respective unsubstituted diastereomer. The structure of {[PR,3R, 4R,P′R)‐1‐(tert‐butoxycarbonyl)‐3,4‐bis[(2‐methoxybenzyl)phenylphosphanyl]pyrrolidine‐P,P′}diiodopalladium was determined by X‐ray diffraction.
Isocyanid‐ und Heteroallen‐verbrückte Metallkomplexe, X. Protonierung und Alkylierung von (μ‐Acylisocyanid)‐ und (μ‐Iminoacylisocyanid)dieisen‐Komplexen
Authors: Schröder Andreas , Sperber Wilfried , Fuchs Joachim , Fehlhammer Wolf Peter 
Published: July 2007

Isocyanide‐ and Heteroallene‐Bridged Metal Complexes, X[1,2]. – Protonation and Alkylation of (μ‐Acylisocyanide)‐ and (μ‐Iminoacylisocyanide)diiron ComplexesProtonation of the acyl isocyanide‐bridged diiron complexes cis‐[Fe2Cp2(CO)3(μ‐CNCOR)] [R = Ph (1a); C6H4NO2‐(4) (1b)] with HBF4 or HPF6 occurs at the isocyano nitrogen to give the cationic μ‐aminocarbyne complexes 2a and 2b, respectively. In contrast, the μ‐iminoacyl isocyanide complex 3 is both protonated and alkylated at the imino nitrogen. According to an X‐ray structure analysis of 4a, the resulting ligand systems in cis‐[Fe2Cp2(CO)3{μ‐Cmagnified imageNmagnified imageC(Ph)magnified imageN(Ph)R}]+BF4+ [R = H (4a); Et (4b)] are best described as hybrids of μ‐2‐azaallylidene‐and μ‐2‐azaallenylidene‐type resonance structures.
Synthese und Struktur von CpAlCl2‐Verbindungen mit sterisch anspruchsvollen Substituenten (Cp = Me5C5, EtMe4C5)
Authors: Koch Hans‐Joachim , Schulz Stefan , Roesky Herbert W. , Noltemeyer Mathias , Schmidt Hans‐Georg , Heine Andreas , Herbst‐Irmer Regine , Stalke Dietmar , Sheldrick George M. 
Published: July 2007

Synthesis and Structure of CpAlCl2 Compounds with Sterically Demanding Substituents (Cp = Me5C5, EtMe4C5)[1]The compounds Cp*AlCl2 (3) (Cp* = Me5C5) and Cp′AlCl2 (4) (Cp′ = EtMe4C5) have been prepared by the reaction of Cp*SiMe3 (1) and Cp′SiMe3 (2) with AlCl3. The single‐crystal X‐ray structures of 3 and 4 are reported.
Synthesis of the Novel μ‐(Phosphanoalkylidene) Complexes [Fe2Cp2(CO)2(μ‐CO){μ‐C(CN)PR2}] (PR2 = PEt2, PHCy, PHPh) and Molecular Structure of the PEt2 Derivative
Authors: Busetto Luigi , Carlucci Lucia , Zanotti Valerio , Albano Vincenzo G. , Monari Magda 
Published: July 2007

AbstractReplacement of SMe2 at the pseudo‐alkylidyne μ‐carbon atom of [Fe2Cp2(CO)2(μ‐CO){μ‐C(CN)SMe2}]SO3CF3 by PR2H (PR2 = PEt2, PCyH, PPhH) results in the formation of the phosphonium salts [Fe2Cp2(CO)2(μ‐CO){μ‐C(CN)PHR2}]SO3CF3 which upon deprotonation with NEt3 yield the corresponding neutral complexes [Fe2Cp2(CO)2(μ‐CO){μ‐C(CN)PR2}]. These μ‐(phosphanoalkylidene) complexes have been characterized on the basis of IR, 31P{1H}‐, 1H‐, and 13C{1H}‐NMR spectra and by the X‐ray molecular structure of [Fe2Cp2(CO)2(μ‐CO){μ‐C(CN)PEt2}].