bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bifunktionelle Katalyse der Reaktion von Kohlendioxid mit Oxiranen
Authors: Dümler Walter , Kisch Horst 
Published: July 2007

Bifunctional Catalysis of the Reaction of Carbon Dioxide with OxiranesKinetic investigation of the Lewis acid/Lewis base‐catalyzed reaction of carbon dioxide with monosubstituted oxiranes 1 to cyclic carbonates 2 at atmospheric pressure reveals that the rate depends first order on substrates and the catalyst components ZnCl2 and (n‐Bu)4NI. Electron‐releasing substituents accelerate the reaction, except they are sterically demanding like the tert‐butyl group in which case complete inhibition occus; 2,2‐disubstituted oxiranes are inert. The activation parameters are ΔH≠ = (71.4 ± 3.7) kJ ± mol‐1 und ΔS≠ = (–49.2 ± 9.3) J ± K‐1. A rate law is established for the multi‐step reaction mechanism and simplified for the extremes of high and low pressure of carbon dioxide. The reactivity pattern of several catalyst combinations suggests that solvated zinc chloride and trihalogenozincates are the Lewis acids which catalyze the nucleophilic ring opening of the oxirane by iodide to the corresponding iodo alcoholate. This is stabilized by the Lewis acid as indicated by the investigation of the stereochemistry at the unsubstituted ring carbon atom by the use of [2‐D]‐2‐phenyloxirane. Nucleophilic attack of te alcoholate at carbon dioxide leads t the linear carbonate which is transformed into the product by intramolecular substitution of iodide.
Ungewöhnliche Reaktion eines Diazaphosphetidinthions mit Trimethylsilylazid
Authors: Gruber Matthias , Schmutzler Reinhard 
Published: July 2007

Unusual Reaction of a Diazaphosphetidinethione with Trimethylsilyl Azide2‐Dimethylamino‐1,3‐dimethyl‐1,3‐diaza‐2‐phosphetidine‐4‐thione (1) and trimethylsilyl azide do not react with formation of the expected phosphane imine 2. Instead, (a) addition of trimethylsilyl azide to the °C=S group of 1, (b) sulfurization of the phosphorus atom of 1 and formation of the racemic thiophosphoryl compound 3 (as a result of intramolecular methyl/trimethylsilyl migration) take place. For 3 two pairs of diastereomers are discussed, which have been studied by 1H‐, 13C‐ and 31P‐NMR spectroscopy, and through a 1H‐13C NMR correlation.
Ozonolysen von Olefinen mit vinylständigen Chlorsubstituenten auf Polyethylen
Authors: Griesbaum Karl , Greinert Reinhard 
Published: July 2007

Ozonolyses of Olefins with Chloro Substituents in Vinylic Positions on PolyethyleneOzonolyses of the chloro‐substituted 5‐ and 6‐membered cycloolefins 20a, 20b and 30a–c on polyethylene afforded the corresponding chloro‐substituted ozonides. The thermal decomposition of these ozonides is described. Ozonolyses of the same olefins in solution and of the acyclic chloro olefins 5 and 8 both on polyethylene and in solution gave no ozonides.
Nickelapnicogencubane
Authors: Scherer Otto J. , Braun Jürgen , Wolmershäuser Gotthelf 
Published: July 2007

NickelapnicogencubanesThe thermolysis of [C*pNi(CO))]2 (1) (C*p=η5‐C5Me5) and [Cp′Ni(CO)]2 (6) (Cp′ = η5‐C5H4Me) with the pnicogens E4 (E = P, As) affords the distorted cubanes [(C*pNi)3(μ3‐E)(E4)] (2a: E = P; 2b: E = As), the sandwich complex [C*pNi(η3‐P3)] (3), as well as the cubanes [Cp′Ni(μ3‐E)]4 (7a,b) and the trinuclear cluster [(Cp′Ni)3(μ3‐CO)2] (8). With [M(CO)5(thf)], 2a and 3 give the multinuclear clusters [(C*pNi)3(μ3‐P)(P4)M(CO)5] (4a: M = CR; 4b: M = Mo; 4c: M = W) as well as [C*pNi(P3)‐{Cr(CO)5}3] (5). In addition to the NMR studies, 2a,b and 3 have been characterized by X‐ray structure analyses.
Alkin⇄Vinyliden‐Umwandlungen auf Vierkernclustern
Authors: Albiez Thomas , Powell Anne K. , Vahrenkamp Heinrich 
Published: July 2007

Alkyne ⇄ Vinylidene Rearrangements on Tetranuclear ClustersThe expansion of vinylidene‐bridged FeCo2 and RuCo2 clusters 1a–d, 2d with (cyclopentadienyl)rhodium building blocks 3a, b mainly yields alkyne‐bridged FeCo2Rh and RuCo2Rh clusters (4b–d, 5a, b, 6d), which exist as two isomers A and B. Additionally, in a few cases tetranuclear clusters 7, 8 containing one more CO group and bearing a μ4‐vinylidene ligand are formed. The two cluster types can be interconverted by CO transfer. Starting from both types of FeCo2Rh clusters (4b, d, 8b), metal exchange with NaMoCp(CO)3 produces a product mixture in which the majour tetranuclear complex is the novel tetrahedral FeCoRhMo compound (11b, d, 12b) with a μ3‐vinylidene ligand. Thus it is shown that the shape as well as the mode of attachment of the CCHR ligand are controlled by the number and electronic structure of the organometallic building blocks. The structural assignments have been confirmed by four X‐ray structure determinations [4b(A), 4b(B), 8a, 11b].
Partial Hydrogenation: From Anthracene to Coronene
Authors: Yalpani Mohamed , Köster Roland 
Published: July 2007

Reduktion kondensierter Arene mit ‐Boranen. – Partielle Hydrierung: Anthracen bis CoronenTetrapropyldiboran(6) (TPDB) katalysiert die Hydrierung polycyclisher Arene [z. B. Anthracen (A), Tetracen (TET), Pyren (PY), Perylen (PER) oder Coronen (C)] unter Wasserstoff‐Druck bei 200°C. In einigen Fällen können sehr hohe Ausbeuten an Hydroarenen erzielt werden [z. B. Tetrahydroanthracen (4H‐A), Octahydroanthracen (8H‐A), Dodecahydrotetracen (12H‐TET), Tetrahydropyren (4H‐PY), Hexahydroperylen (6H‐PER) oder Hexahydrocornen (6H‐C)]. Neben unterschiedlichen kleinen Mengen an Perhydroarenen bilden sich nach langer Reaktionszeit aus sämtlichen Arenen auch C – C‐Spaltungsprodukte.
[4 + 2]‐Cycloadditionen mit Übergangsmetall‐koordinierten Heteroalkenen: Einfluß der Koordination auf die Stereoselektivität der Cycloaddition
Authors: Fischer Helmut , Hofmann Josef , Treier Kornelia , Gerbing Ulrike 
Published: July 2007

[4 + 21 Cycloadditions with Transition‐Metal‐Coordinated Heteroalkenes: The Influence of the Coordination on the Stereoselectivity of the CycloadditonPentacarbonyl(thiobenzaldehyde), ‐(selenobenzaldehyde), and ‐(diphenyl selenoketone) complexes (CO)5M[X = C(Ph)R] [R = H: M = W, X = S (1a), Se (1b); M = Cr, X = S (1c), Se (1d); R = Ph: M = W, X = Se (1e)] react with cyclopentadiene (2) and 1,3‐cyclohexadiene (4), respectively, by [4 + 2] cycloaddition to give metal‐coordinated this‐ and selenacycles 3 and 5. The additions of 2 and 4 to 1a‐d are stereoselective. In contrast to the endo selectivity observed in the reactions of 2 and 4 with uncomplexed thio‐ and selenoaldehydes, the additions of 2 and 4 to 1a‐d are exo selective. However, the reactions of pentamethylcyclopentadiene (6) with 1a,b to form 7 are endo selective. The structures of the main isomer of the addition of 4 to 1c (5c‐exo) and of 6 to 1 b (7b‐endo) were confirmed by X‐ray analyses.
Zur Reaktivität von Phosphaalkenyl‐ und Phosphavinyliden‐Komplexen des Molybdäns und Wolframs gegenüber dem Schwefelylid Me2S(O)=CH2 Röntgenstrukturanalyse von
Authors: Weber Lothar , Matzke Thomas , Boese Roland 
Published: July 2007

Transition‐Metal‐Substituted Acylphosphanes and Phosphaalkenes. XIV. – Transition‐Metal Sulfur Ylide Complexes, XXVIII. – Reactivity of Phosphaalkenyl and Phosphavinylidene Complexes of Molybdenum and Tungsten towards the Sulfur Ylide Me,S(O) = CH2. X‐ray Structure Analysis of The phosphavinyliden complexes (η5‐C5H5)(CO)2M=P=C(SiMe3) 2 [3, M = Mo (a); W (b)] react with equimolar amounts of sulfur ylide Me2S(O)=CH2 (2) to afford the red metallophosphane‐substituted sulfur ylides (η5‐C5H5)(CO)2M=P[CH‐(SiMe3 2][CH=S(O)Me2] (5a, b). Compounds 3a, b as well as 5a, b are trans‐formed to the metallaheterocycles (η5‐C5H5)‐ (6a, b) by excess of ylide. Constitution and configuration of 5 and 6 were established by spectroscopic means (IR, 1H, 13C, 31P NMR and MS). In addition, the molecular structure of 6a was elucidated by single crystal X‐ray diffraction analysis.
Eine 1,3‐Methyl‐Verschiebung an der ungesättigten BCSi‐Kette
Authors: Paetzold Peter , Schmitz Thomas , Tapper Alexander , Ziembinski Ralf 
Published: July 2007

A 1.3‐Methyl Shift along the Unsaturated BCSi SkeletonThe synthesis of the methoxy[tris(trimethylsilyl)methyl]boranes X‐(MeO)B–C(SiMe3)3 (1a‐d; X = Cl, Br, Ph, PhCH2) is described. The methylenoboranes Me‐B=C(SiMe2Hal) (3a, b), the 2,3‐dihydro‐1H‐1‐sila‐3‐boraindene species 6, and the 1,2,3,4‐tetrahydro‐1‐sila‐3‐boranaphthalene species 7 are formed by the thermal elimination of MeOSiMe3 from 1a/b or 1c or 1d, respectively. The boranes 3a, b undergo cyclodimerization at the B=C bond at 25 and 69°C, respectively, the diboretanes 4a, b being formed. The oxaboretanes 5a, b are isolated from the reaction of 3a, b with Ph2CO. The thermal elimination of MeOSiMe3 from Me′‐(MeO)B–C(SiMe3)3 (1g;; Me′ = CD3) and subsequent addition of Ph2CO gives the oxboretanes 5g′/5g″ in the ratio of 1:6, showing that an equilibrium Me′‐B=C(SiMe32 ⇄ Me—B=C(SiMe3(SiMe2Me′) with a statistical distribution of Me′ among seven methyl places is established in the hot tube before Ph2CO finally attacks the double bond. All these results are in accord with the primary formation of the methyleneboranes X‐B=C(SiMe3)2 from 1a‐d, followed by a 1,3‐shift of Me along the unsaturated BCSi skeleton and the subsequent transformation into the isolated products.
Reaktionen von Pentacarbonyl(trifluormethylisocyanid)chrom mit Nucleophilen
Authors: Lentz Dieter , Marschall Robert 
Published: July 2007

Reactions of Pentacarbonyl(trifluoromethyl isocyanide)chromium with NucleophilesPentacarbonyl(trifluoromethyl isocyanide)chromium (1) reacts with nucleophilic reagents like secondary amines (2a‐d), 1,2‐dimethylhydrazine (2e), or methanol (2f). The first nucleophilic attack occurs at the isocyanide carbon atom. The formed Fischer‐type carbene complexes readily eliminate HF under the reaction conditions forming a difluoromethanimine moiety, which is further attacked by the nucleophile. The isolated products are carbene complexes of the type (CO)5Cr[C(NR2]N=C(NR2)F] (3a‐c), (CO)5Cr[C(NR2)N=C(NR2)2](3d), (CO)5Cr[CN(CH3)N(CH)3C{N(CH3)H}=N] (3e), and (CO)5Cr(C(OCH3)N=C(OCH3)2] (3f). The structure of 3c has been determined by an X‐ray crystal structure analysis.
Neue optisch aktive Chelat‐Phosphane – Synthese und Verwendung in der enantioselektive Katalyse
Authors: Brunner Heari , Lautenschlager Hans‐Jürgen , König Wilfried A. , Krebher Ralph 
Published: July 2007

Asymmetric Catalysis, LI. – New Optically Active Chelating Phosphines – Synthesis and Application in Enantioselective CatalysisThe known triphosphines 1 and 4 were transformed into their monophosphine oxide and monophosphine sulfide derivatives 2, 3, 5, and 6 via NiCl2 complexes. 21 optically active phosphines were used as ligands in the Rh‐catalysed hydrogenation of (Z)‐α‐acetamidocinnamic acid and itaconic acid as well as in the Ni‐catalysed cross‐coupling reaction of phenylethylmagnesium chloride with vinyl bromide. The optical inductions of the Grignard cross coupling reaction were determined the first time by enantioselective gas chromatography.
Die β‐Spaltung von α‐(Methoxycarbonyl)alkyl‐Radikalen
Authors: Metrger Jürgen O. , Klenke Kurt 
Published: July 2007

Investigations on the Selectivity of the β‐Scission of Alkyl Radicals, 11′1. – Selectivity of the β‐Fragmentation of α‐(Methoxycarbony1)alkyl RadicalsThe rate of β‐scission of α‐(Methoxycarbonyl)alkyl radicals 3 und 9, generated by addition of cycloalkyl radicals to appropriate methyl 2‐methylenealkanoates 1 and methyl (E)‐2‐alkenoates 8, resp., has been measured relative to the hydrogen transfer from cycloalkanes. The rate of β‐scission increases with increasing stability of the leaving radical R*, Polar effects reversing the stability sequence have also been observed, e. g. the stability sequence have also been observed, e. g. the more stable (methoxycarbonyl) methyl radical leaves more slowly than a less stable secondary alkyl radical.
Radikalische Cyclisierung von Dienen, III Radikalische Cyclisierung von (R)‐(‐)‐Carvon – Über den Einfluß von Charge‐Transfer‐Wechselwirkung auf den spezifischen Drehwert
Authors: Weinges Klaus , Maurer Wplfgang , Reichert Hans , Schilling Gerhard , Oeser Thomas , Iragartinger Hermann 
Published: July 2007

Radical‐Type Cyclisation of Dienes, 111. – Radical‐Type Cyclisation of (R)‐( – )‐Carvone – On the Influence of Charge‐ Transfer Interactions on the Optical RotationUnder the conditions of radical cyclisation, a 1:1 diastereomeric mixture of (1R,2S,5R,R)‐(+)‐ (2a) and (1R.2S,5R,6S)‐(+)‐6‐methoxy‐2,6‐dimethylbicyclo[3.2.1]octan‐3‐ones (2b) is obtained from (R)‐(‐)‐carvone in 70% yield. the configuration fo 2a and 2b were confirmed by X‐ray structure analyses of their hydrazones 2d and 2e. The regio‐ and stereoselectivity of the radical cyclisation of 1 to 2a and 2b are discussed. The high value of the specific rotation [‐555] of 2d is traced back to charge‐transfer interactions between the endo‐standing methoxy group at C‐6 as electron donor and the dinitrophenyl‐hydrazone group as electron acceptor.
Notizen / Notes Phosphorverbindungen ungewöhnlicher Koordination, 43 Hochfunktionalisierte λ3‐Phosphinine aus 5,5‐Dimethoxycyclopentadienen und einem kinetisch stabilisierten Phosphaalkin
Authors: Amena Ulrich , Regitz Manfred , Klugeb Heinz 
Published: July 2007

Phosphorus Compounds with Unusual Coordination, 43. – Highly Functionalized λ3‐Phosphinines from 5,5‐Dimethoxycyclopentadienes and Kinetically Stabilized Phosphaalkyne1,2,3,4‐Tetrachloro‐5,5‐dimethoxycyclopentadiene (5) is transformed into the λ3‐phosphinine 10 by reaction with the phosphaalkyne 6; the bicyclic compound 7 is assumed to be the intermediate of the process. In an analogous way the reaction 14 + 6 yields the isomeric λ3‐phosphinines 15 and 17.
Disproportionierung von Schwefeldioxid am Molybdän(0)‐Komplex trans‐[(dppe)2Mo(N2)2] Molekülstruktur von trans‐[(dppe)2Mo(S)O]·SO2·H2SO4
Authors: Lorenz Ingo‐Peter , Walter Gudrun , Hiller Wolfgang 
Published: July 2007

Disproportionation of Sulfur Dioxide by the Molybdenum(0) Complex trans‐[(dppe)2Mo(N2)2]. Molecular Structure of trans‐[(dppe)2Mo(S)O]·SO2·H2S04Sulfur dioxide disproportionates into sulfur monoxide and sulfuric acid, when it is passed through a solution of the molybdenum(0) complex trans‐[(dppe)2Mo(N2)2] (1) in toluene. Whereas SO undergoes an oxidative addition reaction onto the intermediate 14 VE‐complex fragment (dppe)2Mo to give the mixed dichalkogenidomolybdenum(IV) complex trans‐[(dppe)2Mo(S)O] (3), both molecules H2SO4 and intact SO2 remain in the solvating sphere. According to an X‐ray structural analysis 3 crystallizes in the monoclinic space group P21/n and shows an octahedral configuration at the central molybdenum atom with the oxo and sulfido ligands in trans positions; the two solvent molecules ethanol and toluene are also incorporated into the crystal lattice.
Metallabis(dialkylphosphito)‐Einheiten als Komplexbildner, VI. Darstellung und Komplexbildungsvermögen des metallorganischen Chelatliganden {C5Me5RhI[P(O)(OMe)2]2}−
Authors: Valderrama Mauricio , Scotti Mario , Campos Pedro , Werner Helmut , Müller Gerhard 
Published: July 2007

Complexes Containing Metallabis(dialky1phosphito) Units, VI1. – Synthesis and Complex‐Forming Properties of the Organometallic Chelating Ligand {C5Me5RhI[P(0)(OMe)2]2}‐The dinuclear complexes [C5Me5NiBr]2 and [C5Me5RhI2]2 react stepwise with P(OMe)3 by cleavage of the halide bridges and a subsequent Michaelis‐Arbuzov‐type reaction to give the neutral compounds C5Me5Ni[P(O)(OMe)2][P(OMe)3] (3) and C5Me5RhI[P(O)(OMe)2][P(OMe)3 (6). Treatment of 6 with an equimolar amount of NaI gives the sodium salt of the {C5Me5RhI[P(O)(OMe)2]2}− anion Na[L] (7) isolated as an adduct with 0.6 NaI. Reaction 7 with H2SO4 in water leads to the formation of the protonated complex C5Me5RhI[P(O)(OMe)2][P(OH)(OMe)2] (8), from which on treatment with thallium acetylacetonate C5Me5RhI[P(O)(OMe)2]2TI (9) is obtained. The X‐ray structural analysis of 9 reveals that the organometallic anion L− is coordinated as a bidentate ligand by the P = O oxygen atoms to thallium, L− also behaves as a bidentate chelating ligand in the complexes [L]2Mg(OH2)2 (12), [L]2Zn (13) and [L]2UO2 (14), whereas it is presumably coordinated as an O,O′,I‐tripod ligand in the compounds [L]PtMe3 (10) and [L]2Cu (11). In acid solution 8 reacts with NaBPh4 to give the diphenylborane derivative LBPh2 (15).
Hydrocarbonylierende Cyclisierung von Dienen, 7. Cyclisierung von 1,4‐Dienen mit funktionalisierten Seitenketten an C‐3
Authors: Eilbracht Peter , Hüttmann Gerd‐Erich 
Published: July 2007

Hydrocarbonylating Cyclization of Dienes, 71. – Cyclization of 1,4‐Dienes Containing Functionalyzed Side Chains at C‐3In order to test, whether functional groups are tolerable in rhodium‐ or cobalt‐catalyzed hydrocarbonylating cyclizations of 1,4‐dienes 1 to substituted cyclopentanones 2, various dienes of type 3 with functionalyzed side chains in C‐3 were synthesized and treated under cyclization conditions. Ester, hydroxy, alkoxy, and acetate groups proved to be sufficiently stable (the latter only in rhodium‐catalyzed conversions), so that the corresponding cyclopentanones 4 could be obtained in medium to good yields. Free carboxylic acid and aldehyde groups, however, prevented the formation of significant amounts of cyclization products. Pentenynes of type 6 under analogous conditions yielded at best only minor amounts of cyclopentanones.
Carbonylierende Ringerweiterung, 5. Enantioselektive Synthese des Bicyclo[3.2.1]oct‐3‐en‐2,8‐dion‐Systems durch doppelte Carbonylierung von α‐Terpinen und anderen prochiralen Cyclohexadienen
Authors: Eilbracht Peter , Hittinger Christel , Kufferath Klaus , Schmitz Anja , Gilsing Hans‐Detlev 
Published: July 2007

Carbonylating Ring Enlargement, 51). – Enantioselective Synthesis of the Bicyclo[3.2.l]oct‐3‐ene‐2,8‐dione Systems by Double Carbonylation of α‐Terpinene and Other Prochiral CyclohexadienesThe steric information in tricarbonyl iron complexes of type 2(R1 ≠ R2), established during the complexation of prochiral 1,3‐cyclohexadienes can be transferred to bicyclo[3.2.1]oct‐3‐ene‐2,8‐diones by metal‐induced ring enlargement and bridging carbonylation. This was verified by the synthesis and conversion of optically active tricarbonyl iron complexes 2 of α‐terpinene (1). These complexes can be either obtained by chirality transfer during complexation and rearrangement of (R)‐(+)‐ or (S)‐(‐)‐limonene (7) or by separation of racemic mixtures on triacetyl cellulose. The separation on chiral phases and subsequent stereoselective conversion to bicyclo[3.2.1]oct‐3‐ene‐2,8‐diones may also be carried out with other tricarbonyl iron complexes of prochiral cyclohexadienes (lacking additional functional groups).
Konformationsanalysen von pyrolytisch erzeugten [2.2]phanen des 4‐Pyranons
Authors: Massa Werner , Schween Michael , Steuber Friedrich W. , Wocadlo Sigrid 
Published: July 2007

Conformational Analyses of [2.2]Phanes of 4‐Pyranone Generated by PyrolysisThe synthesis of the first phanes of 4‐pyranone is accomplished by pyrolysis of bis(sulfone) 4. Analogously, 9, 10 and 11 are synthesized. While 5is conformationally mobile in solution, 9 and 10 are fixed (up to 100°C) and exhibit anti conformation as shown by X‐ray structural analysis (11). Like 9 and 11, 5, exists in a staircase‐like structure in the crystal. 1H‐NMR spectra of the metaparacyclophane 10 shows coalescence of the signals of the methylene protons at room temperature. The flexibility at 10 at 60°C is interpreted as a swinging process. The crystal structure of bis(sulfone) 8a shows that the two planar rings are tilted by 60°C with respect to each other.
Koordinationschemie π‐gebundener Cyclopentadienyl‐Chalkogeno‐Ether, I. Chelatkomplexe von Pentakis(methylthio)cymantren mit Metallcarbonylen
Authors: Sünkel Karlheinz , Blum Adrian , Polborn Kurt , Lippmann Elisabeth 
Published: July 2007

Coordination Chemistry of rr‐Bonded Cyclopentadienyl Chalcogeno Ethers, I. ‐ Chelate Complexes of Pentakis(methylthio)cymantrene with Metal Carbonyls[C5(SMe)5]Mn(CO)3 (1) reacts with W(CO)5(THF), Mo(CO)4(πC7H8), Cr(CO)3(NCMe)3, and Re(CO)4(π‐C3H5)/HBF4 to yield the monochelate complexes [[C5(SMe)5]Mn(C0)3][M(CO)4] (M = W: 2; M = Mo: 3) and the dichelate complexes [[C5(SMe)5]Mn(CO)3][M(C0)4]2 (M = W: 4; M = Cr: 5; M = Re⊕ BFF4⊖ : 6). The reaction with Mo(CO)3(p‐xylene) in THF leads via unstable intermediates, which contain coordinated THF, to a mixture of 3 and [[C5(SMe)5]Mn(CO)3][Mo(CO)4]2 (7). The structures of 3 and 4 in the crystal have been determined by X‐ray diffraction methods.
Beiträge zur Chemie des Phosphors, 206. Über die cyclische Silaphosphane (tBuSi)4P2l6, (t/BuSiP)4H2Cl2 und (tBuSiP)4HCl – Vorstufen des Silaphosphacubans (tBuSiP)4
Authors: Baudler Marianne , Scholz Guido 
Published: July 2007

Contributions to the Chemistry of Phosphorus, 206. ‐ The Cyclic Silaphosphanes (tBuSi)4P2Cl6, (tBuSiP)4H2Cl2, and (tBuSiP)4HC1 ‐ Precursors of the Silaphosphacubane (tBuSiP)4The reaction of tBuSiCl3 with LiAl(PH2)4 yields the silaphosphacubane 2. Besides the compounds 1,3, and 4, which were already identified, three additional silaphosphanes (tBuSi)4‐P2Cl6 (5), (tBuSiP)4H2Cl2 (6), and (tBuSiP)4HCl (7) have been found representing precursors of 2. According to NMR spectroscopic investigations, 5, is a derivative of 1,3‐diphospha‐2,4‐disiletane, whereas 6 and 7 exhibit a structure analogous to norcubane and secocubane, respectively. The compounds 3 – 7 reveal the reaction pathway from 1 to 2.
Pyrazole‐Organoboranes, VII. Addition Complexes of Pyrazolylboranes
Authors: Yalpani Mohamed , Boese Roland , Köster Roland 
Published: July 2007

AbstractThe monomeric 9‐pyrazolyl‐9‐borabicyclo[3.3.1]nonanes react in situ with either excess of 9H‐9‐BBN or of some pyrazoles to form the 2:1 or 1:2 adducts 1–5 or 7–11, respectively. Spectroscopic data (NMR, IR) suggest and the solid state structure of 4 confirms the presence of a central heterocycle in complexes of the type 1–5. In solutions of 7–11 NMR data at room temperature indicate a rapid exchange of the four nitrogen atoms of the two pyrazole rings at the boron atom of the 9‐BBN moiety. In the solid state (X‐ray structure of 8) intermolecular N–H ⃛N bonds lead to dimeric structures. In the almost insoluble adduct 7 a polymeric structure is suggested. Pyrazoles with large substituents, e. g. 3,5‐diphenylpyrazole (P2Pz) give addition complexes of the type 1–5 only in solution in equilibrium with the corresponding monomeric species (11B NMR) and none of the type 7–11.
Verbindungen mit dem 1,3‐dimethyl‐1,3,2‐diazaphosphetidin‐4‐on‐Grundgerüst: Synthese von 1,3‐Dimethyl‐1,3,2‐diazaphosphetidin‐4‐on‐2‐oxid‐Derivaten
Authors: Breker Johannes , Schmutzler Reinhard 
Published: July 2007

Compounds Involving the 1,3‐Dimethyl‐1.3,2‐diazaphosphetidin‐4‐one Framework Synthesis of 1,3‐Dimethyl‐1.3,2‐diazaphosphetidin‐4‐one 2‐Oxide DerivativesThe oxidation of 1,3,2‐diazaphosphetidinones 3, 4, 7–9 to the respective P‐oxides using NO2 (3→5 and 4→6) or (Me3SiO)2 (7→10, 8→11, and 9→12) is described. Other diazaphosphetidinone P‐oxides 13–15 are obtained by the reaction of N,N′‐dimethylurea with phosphonic dichlorides in the presence of triethylamine as an HCl acceptor. The compounds 5, 6, 10 – 15 contain the novel structural element, involving λ4P. The reaction of 10 and 15 with methanol leads to the formation of the acyclic methyl esters MeOP‐(O)(Y)N(Me)C(O)N(Me)H (20) [Y = N(CH2)4] and (21) [Y = Ph].
Funktionalisierte meso‐Arylporphyrine als Edukte für die Synthese von Oligoporphyrinylen
Authors: Hammel Dirk , Kautz Christian , Müllen Klaus 
Published: July 2007

Functionalized meso‐Arylporphyrins, Precursors for the Synthesis of OligoporphyrinylsLithiation and subsequent formylation of bromo‐substituted tetraarylporphyrins 3a–d, prepared under Adler‐Rothemund conditions, afford a mixture of the porphyrinylbenzaldehydes 4a–d and the corresponding dialdehydes (cis and trans isomer) 7a/7d and 8a/8d, which may beisolated by column chromatogrphy. The readily available porphyrins are suitable precursors for the synthesis of oligoporphyrinyl systems which is demonstrated for the case of the novel stilhene‐linked diporphyrinyl 12. Alkyl substitution of the nonfunctionalized aryl groups brings about sufficient solubility of the porphyrins in organic solvents.