bluuebunny/crossref_metadata_2025_split huggingface dataset:
Naphthalenophane durch doppelte Photocyclodimerisierung von Distyrylnaphthalinen
Authors: Meier Herbert , Praß Ellen , Zertani Rudolf , Eckes Heinz‐Ludwig 
Published: July 2007

AbstractBei der Belichtung von Distyrylnaphthalinen entstehen in regiospezifischen Kopf‐Kopf‐Cycloadditionen Naphthalenophane. Je nach Stellung der Styryl‐Gruppen beobachtet man vollkommen stereospezifische Prozesse (1d → 2, 1g → 3, 1h → 4) und Dimerisierungen mit partiellen Stereoselektivitäten (1b → 5–8, 1i → 9, 10). Maßgeblich sind die Rotamerenpopulation im Ausgangsprodukt 1 und die elektronischen und sterischen Effekte in den Excimeren. Prinzipiell sind Excimere mit paralleler Anordnung möglichst vieler π‐Zentren bevorzugt — ein experimenteller Befund, der durch HMO‐Rechnungen untermauert wird.
Umsetzungen am Tricyclo[5.3.0.02,8]deca‐3,5‐dien‐System: Pyrolysen, photochemische Reaktionen und Synthese neuer (CH)10‐Isomerer
Authors: Gleiter Rolf , Steuerle Ulrich 
Published: July 2007

AbstractDie Pyrolyse von Tricyclo[5.3.0.02,8]deca‐3,5‐dien (4) und von in der Ethano‐Brücke substituierten Derivaten führt zu Tricyclo‐[5.3.0.02,10]deca‐3,5‐dien (6) bzw. Derivaten von 6. π‐Substituenten erleichtern die [1,5]‐C‐Verschiebung und bedingen den selektiven Bruch der doppelt konjugierten Cyclobutan‐Bindung. Bei den Photolysen von 4 und seinen Derivaten findet man eine Konkurrenz zwischen dem elektrocyclischen Ringschluß der Butadien‐Einheit und einer [1,5]‐C‐Verschiebung; letztere erfolgt vermutlich aus dem Triplett‐Zustand. Bei Derivaten mit π‐Substituenten dominiert die [1,5]‐C‐Verschiebung. Die Synthese von Tetracyclo[5.3.0.02,8.03,6]deca‐4,9‐dien (5), einem neuen (CH)10‐Isomeren, wird beschrieben. Die Thermolyse und Photolyse von 5 führt zu einem Isomeren, 3,6‐exo‐Tetracyclo[5.3.0.02,10.03,6]deca‐4,8‐dien (54b).
The synthesis and molecular structure of tetra(isopropyl)silane
Authors: Anderson David C. , Rankin David W. H. , Robertson Heather E. , Frazão Carlos M. F. , Schmidbaur Hubert 
Published: July 2007

AbstractTetra(isopropyl)silane has been prepared using literature methods, with the individual steps improved by changes in some of the experimental conditions. The key reagent 2‐lithiopropene, which can now be obtained in good yields from 1‐methacrylic acid via 1,2‐dibromo‐1‐methylpropionic acid and 2‐bromopropene by treatment of the latter with ultrasound‐activated lithium metal, was shown to contain mono‐ and dilithiopropyne. The reaction with chlorotrimethylsilane led to the corresponding silylated derivatives, while with silicon tetrachloride tetra(isopropenyl)silane was obtained, which after purification is easily converted into the title compound by catalytic hydrogenation. — The gas phase molecular structure of [(CH3)2CH]4Si has been determined by electron diffraction. The parameters could be successfully refined for a model of S4 symmetry. Bond distances SiC, CC, and CH as well as bond angles SiCC and CCH show the steric compression of the four isopropyl substituents. Steric strain is minimized by twists of the methyl groups and the isopropyl groups away from the fully staggered conformations, but also by an increase of two of the CSiC angles as compared to the remaining four, which are decreased relative to the tetrahedral standard. The structure differs strongly (mainly in the twist angles) from that of the isoelectronic tetra(isopropyl)phosphonium cation in [(CH3)2CH]4P+[B(C6H5)4]−, but is very similar to those of tetra(cyclohexyl)silane and of tri(isopropyl)phosphonium isopropylide, where the pyramidal configuration of the ylidic carbon atoms leads to a pseudo homoleptic array of the substituents at phosphorus.
Niedermolekulare Phosphorsulfide in der Gasphase
Authors: Keck Helmut , Kuchen Wilhelm , Renneberg Heike , Terlouw Johan K. , Visser Herman C. 
Published: July 2007

Low‐Molecular Phosphorus Sulfides in the Gas PhaseIonized low‐molecular phosphorus sulfides, viz. PS+, PS, and P2S are generated by electron‐impact (EI) fragmentation of P4S10. The results of collisional‐activation (CA) mass spectra and semiempirical MO calculations suggest a linear structure for SPS+ (D∞;h) and a ring structure for P2S (D2h). As shown by neutralization‐reionization mass spectrometry (NRMS) all the ions mentioned above can be reduced to the corresponding neutral molecules. Thus, low‐coordinated phosphorus sulfides containing multiple‐bond systems prove to be stable molecules in the dilute gas phase.
Phenylvinylog erweiterte Triphenylmethylium‐Systeme
Authors: Hellwinkel Dieter , Fritsch Helmut 
Published: July 2007

AbstractAls isokonjugierte Modelle für (Phenylazo)tritylium‐Ionen des Typs A wurden die einfach bis dreifach Styryl‐ und Phenylethinyl‐substituierten Trityliumsysteme 1–6 untersucht. Im Einklang mit einfachen theoretischen Modellbetrachtungen weisen diese Ionen wesentlich längerwellige VIS‐Absorptionen als das Tritylium‐Ion selbst auf und zeigen auch die erwarteten bathochromen Bandenverschiebungen von den einzweigigen (1, 4) zu den zwei‐ und dreizweigigen Systemen (2, 3 bzw. 5, 6) hin. Ebenso klar kommen auch die für die 4‐Methoxystyryl‐ (1b–3b) und 4‐(Dimethylammoniostyryl)tritylium‐Ionen 1c–3c sowie das 4‐(Nitrostyryl)tritylium‐Ion 1d vorhergesagten bathochromen und hypsochromen VIS‐Bandenverschiebungen zum Ausdruck. Von den meisten der neu hergestellten Trityliumsysteme konnten voll aufgelöste NMR‐Spektren erhalten werden, deren Signallagen sehr gut mit den aus dem elementaren Konjugationsmodell folgenden Ladungsdichteverteilungen vereinbar sind. Beim farblich dem 4‐Styryltritylium‐Ion 1a entsprechenden 4,4′‐(1,2‐Ethendiyl)bistritylium‐System 12 zeigen nur die Resonanzlinien der inneren Protonen 3,β‐H und Kohlenstoffe C‐4,β signifikante Abweichungen von den entsprechenden Signallagen der Referenzsysteme 1a und Tritylium (13).
Beiträge zur Chemie des Bors, 198 Über die Reaktion von Amino‐imino‐boranen mit Dioxaphospholanen, Dioxarsolanen und Dioxastibolanen
Authors: Brandl Andreas , Nöth Heinrich 
Published: July 2007

Contributions to the Chemistry of Boron, 198. ‐ Reactions of Amino‐imino‐boranes with Dioxaphospholanes, Dioxarsolanes, and Dioxastibolanes(tert‐Butylimino)(2,2,6,6‐tetramethylpiperidino)borane (1) inserts into the exocyclic PX bond of 2‐methoxy‐ and 2‐(dimethylamino)‐1,3,2‐dioxaphospholanes, while ring expansions to the seven‐membered dioxazaphosphaborepanes 4 and 5 are observed with fluoro‐, chloro‐, bromo‐, and methyl‐dioxaphospholanes and their benzo derivatives. These decompose at elevated temperatures producing the (tetramethylpiperidino)dioxaborolane 12 and benzodioxaborole 20, respectively, and diazadiphosphetidine derivatives. Insertion into the exocyclic bond occurs also between 1 and methoxy‐benzodioxarsole (16) and ‐benzodioxastibole (17). The chloro derivatives, however, react with 1 to give 20 and (tBuN = ECl)2 (E = As, Sb) products. (2,6‐Diisopropylphenylimino)(2,2,6,6‐tetramethylpiperidino)borane (6) behaves similarly with the exception that 2‐chloro‐1,3,2‐benzodioxaphosphole yields the exocyclic insertion product. It appears from these experiments that the insertion into the exocyclic bond of the heterocyclic compounds yields kinetically controlled products, while ring expansion followed by expulsion of a dioxaborolane is thermodynamically controlled.
Diphosphabicyclobutane
Authors: Niecke Edgar , Metternich Hans Jürgen , Streubel Rainer 
Published: July 2007

DiphosphabicyclobutanesTwo isomeric diphosphabicyclobutanes (5,11) are obtained by treatment of the phosphaalkenes X‐P = C(Ph)Tms (1a) and X ‐ P = CTms2 (1b) (X = halogen Tms = trimethylsilyl) with 2, Mg, or Na. Both syntheses proceed by coupling of two phosphaalkene units affording, however, two different diphospha‐butadiene intermediates. 4 and 10 readily undergo isomerization reactions to form the diphosphabicyclobutanes. Irradiation of the phosphaalkenes Cp* ‐ P = C(Ph)Tms (12a) and Cp* ‐ P = CTms2 (12b) (Cp* = C5Me5) gives rise to a different reaction pathway. Dimerization of 12a, followed by homolytic cleavage of the Cp* ‐ phosphorus bond and intramolecular recombination produces the butterfly compound 5, whereas homolytic cleavage of the Cp* ‐ element bond in 12 b, followed by rearrangement and intermolecular recombination, affords the diphosphabicyclobutane 11.
Über Metallalkyl‐ und ‐aryl‐Verbindungen, 40 Strukturverfeinerung von Methyllithium durch Neutronenbeugung von (LiCD3)4 bei 1.5 und 290 K
Authors: Weiss Erwin , Lambertsen Thomas , Schubert Bernd , Cockeroft Jeremy Karl , Wiedenmann Albrecht 
Published: July 2007

Metal Alkyl und Aryl Compounds, 40% ‐ Structure Refinement of Methyl Lithium by Neutron Diffraction of (LiCD3)4 at 1.5 and 290 KThe structure of deuterated methyl lithium has been refined by neutron powder diffraction at 1.5 and 290 K. At both temperatures a cubic body‐centered arrangement of (LiCD3)4 units (Td, symmetry) is found. In agreement with previous X‐ray powder investigations (290 K) each tetramer contains a distorted cubic Li4C4 core with pyramidal methyl groups in staggered positions with respect to the adjacent Li3 unit. Refined values, in particular precise D positions, have now been obtained.
Geminale Vinyldiazide, IX Oxazole aus 3,3‐Diazido‐2‐cyanacrylsäure‐methylester und Aminen
Authors: Saalfrank Rolf W. , Ackermann Erich , Fischer Michael , Wirth Uwe , Zimmermann Helmuth 
Published: July 2007

Geminal Vinyl Diazides, IX. ‐ Oxazoles from Methyl 3,3‐Diazido‐2‐cyanoacrylate and AminesReaction of methyl 3,3‐diazido‐2‐cyanoacrylate (1) with amines 2 at ‐ 25°C yields methyl 3‐azido‐2‐cyanoacrylates 3, which on thermal or photochemical treatment give azirines 7 and/or oxazoles 10 (X‐ray structure analysis of 101), respectively. On the contrary, 1 reacts at 20°C with amines 13 to form methyl 2‐(cyanimino)glycinates 14. Reaction of methyl 3‐azido‐2‐cyanoacrylates 30,1 with triphenylphosphane leads to Staudinger adducts 15, which are transformed by elimination of nitrogen into phosphane imides 16.
Versuche zur Erzeugung von 1,5‐ und 2,3‐Didehydroquadricyclanen
Authors: Heywang Ulrich , Szeimies Günter 
Published: July 2007

Experiments towards the Generation of 1.5‐ and 2.3‐DidehydroquadricyclanesMetalation of the (hydroxymethyl)quadricyclanes 7a‐c with n‐butyllithium in ether is determined mostly by the chelating effect of the CH2O–Li group and only to a lesser extent by the magnitude of the 13C‐1H coupling constant of the position to be lithiated in the corresponding quadricyclane derivative. Similar results were obtained for 3‐quadricyclanol (20a). Treatment of the bromide 26a, prepared by lithiation of 7b, with strong bases apparently generates the 1,2‐didehydroquadricyclane 34 and not the 1,5‐didehydroquadricyclane 35. Attempts to convert the dihalide 9 into the 2,3‐didehydroquadricyclane 4 were unsuccessful.
Untersuchungen zur Chemie von Isoindolen und Isoindoleninen, XXXVI1. Reaktionen von 2‐Alkyl‐2H‐isoindolen mit Maleinimiden
Authors: Kreher Richard P. , Seubert Jürgen , Schmitt Dieter , Use Götz , Kohl Norbert , Muleta Tilahun 
Published: July 2007

Studies on the Chemistry of Isoindoles and Isoindolenines, XXXVI ‐ Reactions of 2‐Alkyl‐2H‐isoindoles with Maleic Imides2‐Alkyl‐2H‐isoindoles2react with maleic imides4exclusively in position 1 and 3 by cycloaddition to form Diels‐Alder adducts. The transformation of theendoisomers6into the thermodynamically more stableexoisomers7depends on the dienophile. The cycloaddition is useful for analytical detection of o‐quinoid hetarenes 2 and for the synthesis of 7‐azabicyclo[2.2.1]heptenes.
Synthese und Koordinationsverhalten von Selenoalkinylen R‐Se‐C≡C‐R′
Authors: Lang Heinrich , Keller Holger , Imhof Wolfgang , Martin Sabine 
Published: July 2007

AbstractSynthesis and Coordination Ability of Selenoalkynes R ‐ Se ‐ C ≡ C ‐ R′Several synthetic methods for the preparation of selenoalkynes R–Se–C≡C–R′ (1) are discussed. 1 reacts with octacarbonyl dicobalt to yield the η2‐π‐side‐on coordinated alkyne complexes R‐Se[(η2‐C≡C–R′)Co2(CO)6 (8) which contain a sterically hindered carbon–cobalt tetrahedrane cluster unit. The identity of compounds 1 and 8 is documented by analytical and spectroscopic [IR, MS, 1H‐, 77Se‐, and 13C‐NMR) data as well as by X‐ray analysis of C6H5)Co2‐(CO)6] (8a).
Synthese und chemische Eigenschaften von Pentafluorbenzolselenonsäure und Derivatisierung der Trifluormethanselenonsäure
Authors: Haas Alois , Schinkel Karen 
Published: July 2007

Synthesis and Chemical Properties of Pentafluorobenzeneselenonic Acid and Derivatives of Trifluoromethaneselenonic AcidOxidation of C6F5SeO2H with KMnO4 in aqueous solution gives C6F5SeO3K(1a), which is converted into C6F5SeO3H·2H2O by 70% HClO4. Dehydration at 80°C in vacuo leads to C6F5SeO3H (1), which is converted into its anhydride 1h by further dehydration at 200°C in vacuo. The acid is neutralized with MOH (M = Li, Na, NH4, 1/2 Ba) to form the corresponding salts C6F5SeO3M (1b–e). By metatheses with MNO3 1a is converted to C6F5SeO3M′ [M′ = Cs, Ag (1f, g)]. With RI or (CH3)3SiCl, respectively, C6F5SeO3Ag (1f) forms C6F5SeO3R [R = CH3, C2H5, n‐C3H7, (CH3)3Si (2a–d)]. At – 40°C, reaction between C6F5SeO3C2H5 (2b) and (CH3)2NH leads to C6F5SeO2‐N(CH3)2 (2e), which decomposes above – 20°C. If (CH3)2NH is used in excess, 4‐(CH3)2NC6F4SeO2N(CH3)2 (2f) is formed. It hydrolyses to 4‐[(CH3)2NH2][4‐(CH3)2NC6F4SeO3] (2g). Chlorination of C6F5SeO2H with SO2Cl2 yields C6F5Se(O)Cl. Esterification of CF3SeO3H is accomplished by treating CF3SeO3Ag with C2H5I. The ester 3a reacts with (CH3)2NH at – 40°C to form CF3SeO2N(CH3)2 (3b), which like the pentafluorobenzene compound is also unstable above – 20°C.
B2N4Se‐Bicyclo[2.2.1]heptanes and B2N4Se2‐Bicyclo[2.2.2]octanes
Authors: Yalpani Mohamed , Köster Roland , Boese Roland 
Published: July 2007

B2N4Se2‐Bicyclo[2.2.2]octanesAus 3,5‐Dialkyl‐1,2,4,3,5‐triselenadiborolanen [Alkyl = C2H5 (1a) und Alkyl = n‐C3H7 (1b)] werden mit Pyrazol (Pz), 3‐Methylpyrazol (mPz) und 3‐Phenylpyrazol (pPz) die Diselenabicyclo[2.2.2]octane 2–4 hergestellt. Demgegenüber reagieren 3,5‐Dimethyl‐ und 3,5‐Diphenylpyrazol (m2Pz, P2Pz) mit 1a zu den Monoselenabicyclo[2.2.1]heptanen 5 und 6. Von 2a und 5 liegen Kristallstrukturanalysen vor.
Zur Reaktion des Diphosphenyl‐Komplexes (η5‐C5Me5)(CO)2Fe – P=P – Aryl (Aryl = 2,4,6‐tBu3C6H2) mit elektronenarmen Alkenen. Röntgenstrukturanalyse des Diphosphetans
Authors: Weber Lothar , Frebel Matthias , Boese Roland 
Published: July 2007

Transition‐Metal‐Substituted Diphosphenes, XVIII1). – On the Reactivity of the Diphosphenyl Complex (η5‐C5Me5)(CO)2Fe – P=P – Aryl (Aryl = 2,4,6‐tBu3C6H2) with Electron‐Deficient Alkenes. X‐ray Analysis of the Diphosphetane The transition‐metal‐substituted diphosphene (η5‐C5Me5)(CO)2Fe – P=P – Aryl (1) reacts with fumarodinitrile (2a) to give the 1,2 diphosphetane all‐trans‐ as the result of a [2 + 2] cycloaddition. Similarly, compound 1 is converted by either dimethyl fumarate (2b) or dimethyl maleate (2c) into the same cycloadduct all‐trans‐ (3b). Diphosphetane 3a was completely characterized by a single‐crystal X‐ray analysis.
Übergangsmetall‐Silyl‐Komplexe, 34 Ein zweikerniger Gold‐Silyl‐Komplex mit Gold‐Gold‐Wechselwirkung zwischen einer (R3P)2Au‐ und einer (R′3Si)ClAu‐Einheit
Authors: Meyer Jürgen , Piana Hermann , Wagner Herbert , Schubert Ulrich 
Published: July 2007

Transition‐Metal Silyl Complexes, 34. – A Dinuclear Gold Silyl Complex with Gold‐ Gold Interaction Between an (R3P)2Au and an (R′3,Si)ClAu UnitPh2MeP‐Au‐Cl reacts with Ph2MeP‐Au‐SiPh3 to form the dinuclear complex (Ph2MeP)2Au2(Cl)SiPh3, which is in equilibrium with its starting compounds. An X‐ray structure analysis reveals that it consists of a (Ph2MeP)2Au and a (Ph3Si)ClAu unit, which are held together by Au‐Au interaction [298.07(4) Pm]. The approximately linear AuL2 units are orthogonal to each other.
Clathratbildner mit Allenstruktur – Wirtverbindungen, Kristalleinschluß und Struktur eines Dioxan‐Clathrats
Authors: Weber Edwin , Seichter Wilhelm , Goldberg Israel 
Published: July 2007

Clathrate Formers with Allene Structure – Host Compounds, Crystal Inclusion, and Structure of a Dioxane ClathrateThe tetraaryl‐substituted allenes 1–8 are synthesized, and their properties in crystal inclusion are determined. Dependent on the type and number of the substituents, host compounds result, which have different inclusion properties and clathrate selectivities. Host 1h forms inclusion compounds with a wide range of apolar and relatively polar cyclic guest solvents (26 inclusions altogether), while 2, 4, 5, and 7b form only one or two inclusions. In two‐component solvent systems, high inclusion selectivities are found for the host compounds. The crystal structure of the 4.dioxane (1:1) clathrate is reported. Relations between structure and inclusion selectivity are discussed.
Ein Cyclobutadiencarboxylat als Hetero‐1,3‐dien bei Diels‐Alder‐Reaktionen mit 2H‐Azirinen
Authors: Regitz Manfred , Michels Gisbert 
Published: July 2007

Antiaromatic Compounds, 26 – A Cyclobutadienecarboxylate as a Hetero‐1,3‐diene in Diels‐Alder Reactions with 2H‐AzirinesThe cyclobutadienecarboxylic ester 1 adds 2H‐azirines (2a‐1) to yield the oxaazatricyclic compounds 4a‐f. Under thermolysis conditions cleavage of isobutylene and formation of tricyclic ketones occurs (4a, c–e → 7a–d). The Dear pyridone 11 arises from the photolysis of 7a. The structures of compounds 4b and 11 are confirmed by X‐ray crystal structure analyses.
Beiträge zur Chemie des Bors, 202. Borylierung von Aminosäuren mit einem Amino‐imino‐boran
Authors: Geisberger Gilbert , Nöth Heinrich 
Published: July 2007

Contributions to the Chemistry of Boron, 2021). – Borylation of Amino Acids by an Amino‐imino‐boraneReactions of (tert‐butylimino)(2,2,6,6‐tetramethylpiperidino)‐borane (3) with amino acid esters or N,N‐dimethyl amino acids lead to the N‐borylated products 5 and boryl esters 11, respectively. Amino acids and 3 yield the O,N‐bis‐boryl compounds 13 and/or 1,3,2‐oxazaborolidin‐5‐ones 14, depending on the size of the organyl substituent R at the α‐carbon atom of the amino acid. Increasing the bulk of this group favours the formation of 14 with elimination of tert‐butylamine. The five‐membered OBNCC ring of 14 is planar according to an X‐ray structure analysis of 14e. (2,6‐Diisopropylphenylimino)(2,2,6,6‐tetramethylpiperidino)borane reacts with amino acids similar to 3, but tetramethylpiperidine is eliminated on ring formation to produce 20. N‐Monoalkyl amino acids and 3 predominantly give oxazaborolidin‐5‐ones.
Additions‐ und Einschiebungsreaktionen von subvalenten Bor‐Verbindungen mit Aromaten
Authors: Meller Anton , Seebold Uwe , Maringgele Walter , Noltemeyer Mathias 
Published: July 2007

Addition and Insertion Reactions of Subvalent Boron Species with Aromatic CompoundsDichloro(diisopropylamino)borane reacts with pentamethyl‐cyclopentadienide providing the substitution product 1. A suspension of a sodium‐potassium alloy in 1,2‐dimethoxyethane and 1,2,4,5‐tetramethylbenzene reacts with difluoro(diisopropylamino)borane to give 1,4‐bis[fluoro(diisopropylamino)‐boryl]‐2,3,5,6‐tetramethyl‐2,5‐cyclohexadiene(3). If o‐xylene is used instead of 1,2,4,5‐tetramethylbenzene in this reaction, 1,4‐bis[fluoro(diisopropylamino)boryl]‐2,3‐dimethyl‐2,5‐cyclohexadiene (4) is the main product; however, the bicyclic compound 5 is also formed by formal insertion of two aminoborene units “BNR2” into the carbon skeleton and by addition of two (FBNR2) units. The compounds are characterized by elemental analyses and spectroscopically [MS, NMR (1H, 11B, 13C, 19F)]. An X‐ray structure analysis of 5 is presented.
Synthese und Reaktionen von 2‐Pyridylphosphan, 2‐C5NH4‐PH2
Authors: Spiegel Gerd U. , Stelzer Othrnar 
Published: July 2007

Synthesis and Reactions of 2‐Pyridylphosphane, 2C5NH4‐PH2By reduction of diethyl 2‐pyridylphosphonate (1) with LiAlH4 2‐pyridylphosphane (2) is accessible in ≈︁80% yield. H/D exchange experiments and acid/base exchange reactions between 2 and PhPHLi or Ph2PLi show (2) to be a stronger pH acid than PhPH2 and Ph2PH. Silylation of the lithium phosphides 2‐C5NH4‐PRLi (R  H, SiMe3) with Me3SiCl affords the corresponding silyl derivatives 2‐C5NH4‐PR2 with CH3I or CH2Cl2 yields the mono‐ or bidentate secondary phosphanes 2‐C5NH4‐PHMe (6) and 2‐C5NH4PHCH2PH‐2‐C5H4N (5), respectively. On treatment of 2 with CH3I or HCl the pyridinium salts [(2‐C5NH4R)PH2]+X− (R  H, Me; X= Cl, I) are formed. However, coordination of 2 to transition metals in low oxidation states occurs by the phosphorus atom. Addition of the PH bonds in 2 to the activated CC double bonds in acrylic acid esters, mesityl oxide, cinnamnic acid esters, and dimethyl vinylphosphonate leads to chiral P,N hybrid ligands with functional groups in the alkyl side chain.
Notizen/Notes. Natrium‐ und Kaliumfluorsilylamide – Synthese und Kristallstruktur
Authors: Pieper Ursula , Stalke Dietmar , Vollbrecht Susanne , Klingebiel Uwe 
Published: July 2007

Sodium and Potassium Fluorosilylamides – Synthesis and Crystal Structurestert‐Butyl(di‐tert‐butylfluorosilyl)amine (1) reacts with sodium or potassium to give the alkali salts 2 or 3, respectively. 2 and 3 crystallize as THF adducts and form head‐to‐tail dimers. Sodium is tetracoordinated in 2 and potassium hexacoordinated in 3. The crystal structures of the alkali salts are discussed.
Carbonylierende Ringerweiterung, 4. Diastereoselektive Synthesen von Bicyclo[3.2.1]oct‐3‐en‐2,8‐dionen durch doppelte Carbonylierung von (R)‐(‐)‐α‐Phellandren
Authors: Eilbracht Peter , Hittinger Christel , Kufferath Klaus , Henkel Gerald 
Published: July 2007

Carbonylating Ring Enlargement, 41). – Diastereoselective Syntheses of Bicyclo[3.2.l]oct‐3‐ene‐2,8‐diones by Double Carbonylation of (It)‐(‐)‐α‐PhellandreneIn order to clarify the stereochemistry of the carbonylating ring enlargement of cyclohexadiene complexes 1 to complexed seven‐membered ring ketones 2 and the further carbonylation to bicyclo[3.2.1]oct‐3‐ene‐2,8‐diones 3 the exo and endo isomers of (R)‐(‐)‐α‐phellandrene complex 7 were synthesized in pure form and in various isomeric ratios and converted. The optically active ring‐enlargement products 11 and 12 obtained therefrom, as well as the enantiomerically pure bicyclooctenes 20–22, implicate a stereospecific reaction course under retention of the configuration predetermined by the starting material 6 and its complexes 7. This was confirmed by an X‐ray determination of the absolute configuration of exo‐12. Thus, the method is suitable for the diastereoselective synthesis of bicyclo[3.2.1]oct‐3‐ene‐2,8‐diones 3 from 1,3‐cyclohexadiene complexes 1.
4H‐3,1‐Benzoxathiine aus Benzothiet und Carbonylverbindungen
Authors: Schmidt Michael , Meier Herbert , Niedermann Hans‐Peter , Mengel Rudolf 
Published: July 2007

4H‐3,1‐Benzoxathiines from Benzothiete and Carbonyl CompoundsThe o‐quinoid 8‐π electron system 2, generated by thermal ring opening of benzothiete (1) undergoes [8π + 2π] cycloaddition reactions with electron‐deficient carbonyl compounds 3. In accordance with the frontier orbital theory, 4H‐3,1‐benzoxathiines (4) are obtained in a regioselective manner.
Sandwich‐ und Tripeldecker‐Komplexe des 1,4‐Diboracyclohexadiens ausgehend von 1,4‐Dibora‐2‐cyclohexen‐Derivaten1)
Authors: Wörner Karl‐Fred , Uhm Jae‐Kook , Pritzkow Hans , Siebert Walter 
Published: July 2007

Sandwich und Triple‐Decker Complexes of 1,4‐Diboracyclohexadienes Starting with 1,4‐Dibora‐2‐cyclohexene DerivativesReactions of 1,4‐dibora‐2‐cyclohexene derivatives 1 with transition‐metal complex fragments yield the complexes of 1,4‐dibora‐2,5‐cyclohexadienes 2 by dehydrogenation. The tetra‐ and tricarbonyl complexes 4a, 5a, b are formed in the reaction of la, b with (CH3CN)3Cr(CO)3 and Fe2(CO)9, respectively: with bis(toluene)iron the sandwich 6b is obtained. The triple‐ decker complexes 7a and 8a, b are formed from 1 a, b and the dimeric carbonyl (cyclopentadienyl) complexes of nickel and iron, respectively. The bis(methallylnickel) triple‐decker 9a is obtained as a mixture of cis/trans isomers, la and [(C2H4)2‐RhCl]2 yield the tris(1,4‐diboracyclohexadiene)dirhodium triple‐decker sandwich 10a by elimination of the ethene ligands and the chlorine bridge.