bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of tetrakis[(tri‐tert‐butylphosphane)gold(I)]phosphonium salts and crystal structure of the tetraphenylboroxinate salt {[(tBu)3PAu]4P}+ [O(PhBO)2BPh2]—
Authors: Zeller Edgar , Beruda Holger , Schmidbaur Hubert 
Published: July 2007

AbstractThe reaction of (Me2Si)3P with {[(tBu)3PAu]3O}+ BF4– in tetrahydrofuran at —78C affords the compound {[(tBu)3‐PAu]4P}+ BF4— (1a) in high yield. This product is converted into the tetraphenylborate salt (1b) by treatment with Na[BPh4]. The two compounds have been identified on the basis of their analytical and spectroscopic data, but could not be crystallized. In attempts to prepare single crystals of 1b, a crystalline salt {[(tBu)3PAu]4P}+ [O(PhBO)2BPh2]— (1c) has been obtained in very small quantities, probably by partial anion hydrolysis. A single crystal X‐ray diffraction study of 1c CH2Cl2 shows the compound to be built up of cations with a strongly distorted tetrahedral (PAu)4P skeleton and anions with a planar six‐membered boroxine ring. Two of the phenyl groups are attached to two trigonal‐planar boron atoms and the other two phenyl groups to the third (tetrahedral) boron atom of the heterocycle. The origin of the peculiar cation structure is discussed in the light of findings with related ammonium‐ and arsonium‐centered gold clusters.
Reaktionen cyclischer Oxalylverbindungen, 35. Untersuchung von Reaktionsmechanismen durch Isotopenmarkierung, 11. Zur Umsetzung von 4‐Benzoyl‐5‐phenylfuran‐2,3‐dion mit S‐Heterocumulenen — Präparative und mechanistische Aspekte
Authors: Heilmayer Werner , OliverKappe C. , Sterk Heinz , Kollenz Gert , Peters Karl , Peters Eva‐Maria , Schnering Hans Georg Von , Walz Leonhard 
Published: July 2007

Reactions of Cyclic Oxalyl Compounds, 35[1]. — Mechanistic Investigation Aided by Isotopic Labeling, 11[2]. — On the Reaction of 4‐Benzoyl‐5‐phenylfuran‐2,3‐dione with S‐Heterocumulenes — Preparative and Mechanistic Aspects[3]The furan‐2,3‐dione 1 combines with N‐sulfinylamines or sulfur diimides to afford the pyrrole‐2,3‐diones 2, while with N‐tosylsulfinylamine the (α‐iminobenzyl)furandione 3 is obtained. (α‐Iminobenzyl)pyrrolediones 4 are formed in the reaction of 2c with N‐tosylsulfinylamine or from 3 with N‐tosylsulfur diimides. Diisopropylcarbodiimide and the pyrroledione 2c or the (iminobenzyl)furandione 3a undergo [4 + 2] cycloaddition reactions accompanied by novel and surprising rearrangements to furnish the bicyclic compounds 5 and 6, respectively. The molecular skeleton of 6 was confirmed by an X‐ray diffraction analysis. With the aid of 17O‐labeling experiments and 17O‐NMR spectroscopy mechanistic pathways including novel rearrangements were made evident.
Phosphanalkylene, 54[1a]. Kumulierte ylide, 21[1b]. Ein neuer weg zu N‐substituierten (triphenylphosphoranyliden)keteniminen
Authors: Bestmann Hans Jürgen , Hotz Michael , Witschel Matthias , Roth Dieter 
Published: July 2007

AbstractPhosphane Alkylenes, 54[1a]. – Cumulated Ylides, 21[1b]. – A New Way to N‐Substituted (Triphenylphosphoranylidene)‐keteniminesReaction of methylenetriphenylphosphorane (1) with isothiocyanates 5 leads to ylides 6B, which can be methylated at the S atom to give the phosphonium salts 8. Treatment of 8 with sodium methanolate gives rise to formation of the phosphoranes 10, which on treatment with sodium bis(trimethylsilyl)‐amide undergo β‐elimination to form the N‐substituted (tri‐phenylphosphoranylidene)ketenimines 3.
CFNO‐Isomere — Theoretische und experimentelle Studien
Authors: Jacobs Jürgen , Jülicher Bernd , Schatte Gabriele , Willner Helge , Mack Hans‐Georg 
Published: July 2007

CFNO Isomers — Theoretical and Experimental StudiesGeometrical parameters, relative thermodynamic stabilities, and vibrational wavenumbers have been calculated for six CFNO isomers by using various ab initio methods. The results are compared with those of the respective CHNO species. In noble gas matrices the most stable CFNO isomer fluoroisocyanate, FNCO, was prepared by photolysis of FC(O)N3 as well by the reaction FN + CO and FCN + O. The short‐lived intermediate (fluorocarbonyl)nitrene, FC(O)N, formed during photolysis of FC(O)N3, was trapped as FC(O)NCO in a CO matrix. In each case the courses of the investigated matrix reactions were rationalized by identification of nearly all products and the time dependence of their formation. For the FNCO molecule a complete vibrational spectrum including 15N‐, 13C‐, and 18O‐isotopic data was measured which enabled calculation of its general valence force field.
Chemoselectivity in Catalytic Transfer Hydrogenation — Reduction of Alkenes and Alkynes with the H2PO2—NH4+ · H2O/Pd‐C System
Authors: Khai Bui The , Arcelli Antionio 
Published: July 2007

AbstractThe H2PO2—NH4+ · H2O/Pd‐C system acts as an unusually powerful reducing agent, which is able to reduce cyclooctene to cyclooctane, Δ9,10‐octalin to decalins, α‐ and β‐pinenes to pinanes at room temperature in high yield without the formation of byproducts. This system selectively reduces each of these compounds or partly (alkynes to alkenes), depending on the competition between the transfer hydrogenation to give alkanes and the protonolysis to give hydrogen gas on the palladium catalyst.
Functionalized Enantiomerically Pure [1.1.1]‐, [2.1.1]‐, [2.2.1]‐, and [2.2.2]Triblattanes
Authors: Müller‐Bötticher Hermann , Fessner Wolf‐Dieter , Melder Johann‐Peter , Prinzbach Horst , Gries Stefan , Irngartinger Hermann 
Published: July 2007

AbstractThe methylene (2, 7, 10) and spirocyclopropane derivatives (8, 11, 12) are made accessible from rac‐trishomocubane(mono‐, di‐, tri‐)ones and optically pure unsaturated and benzoannulated [2.1.1]‐ (19, 48), [2.2.1]‐ (30, 53), and D3‐symmetrical [2.2.2]triblattanes (3, 4) from the enantiomers of these ketones by expeditious (one pot) ring enlargement and olefination procedures. In the case of the central [2.2.2]trienes (+)‐3/(—)‐3, novel members of the (CH)14 family, optical resolution is advantageously postponed to the stage of the intermediate [2.2.2]triones (35, 41) and effected via their (R,R)‐2,3‐butanediol acetals. In the α‐diketone series only the [2.1.1]dione (70) is sufficiently stable to allow isolation; tetrone 73 and hexone 5 are indirectly identified as quinoxalines 74 and 76, respectively. Tribenzo[2.2.2]triblattane (—)‐4 is established as the M‐helical enantiomer by X‐ray crystallography. Generally the thermal stabilization pathway of unsaturated and benzoannulated triblattanes is a [4 + 2] cycloreversion with the primary cycloreversion products [e.g. (1α,2α,7α,10α)‐tricyclo[8.4.0.02,7]tetradeca‐3,5,9,11,13‐pentaene (78) from rac‐3] being unstable under the drastic reaction conditions required. The stereochemical course of the perepoxidation of rac‐3 is investigated.
Organofluorverbindungen und Fluorierungsagenzien, 9. Von Glycosylfluoriden zu chiralen Kronenethern
Authors: Miethchen Ralf , Gabriel Torsten 
Published: July 2007

Organofluorine Compounds and Fluorinating Agents, 9[1a]. — From Glycosyl Fluorides to Chiral Crown EthersMethyl D‐galactofuranoside (1), methyl D‐glucofuranoside (3), 3‐O‐substituted 1,2:5,6‐di‐O‐isopropylidene‐α‐D‐glucofuranoses (5a—g), 1,2‐O‐isopropylidene‐3,5,6‐tri‐O‐methyl‐α‐D‐glucofuranose (7) as well as the trans‐decalin analog 1,2‐O‐ethanediyl‐3,4,6‐tri‐O‐methyl‐β‐D‐glucopyranose (13) are selectively transformed with deacetalisation into the corresponding acylated glycosyl fluorides 2, 4, 6a—g, 8, and 14 by HF/nitro‐methane/carboxylic acid anhydride. The reaction is realized without change of the ring size if the three‐component agent system is mixed some time before the carbohydrate is added. 3,5,6‐Tri‐O‐methyl‐2‐O‐pivaloyl‐D‐glucofuranosyl fluoride (8) and 2‐O‐(2‐acetoxyethyl)‐3,4,6‐tri‐O‐methyl‐α‐D‐glucosyl fluoride (14) are used as starting materials to synthesize three isomeric, chiral crown ethers, the bis‐β‐D‐glucofuranosido‐12‐crown‐4 derivative 12 and both stereoisomeric bis‐D‐glucopyranosido‐12‐crown‐4 derivatives 20 and 21.
Gas‐Phase Generation and Characterization of Hydrogen Cyanide N‐Methylide
Authors: Goldberg Norman , Iraqi Muhammad , Schwarz Helmut 
Published: July 2007

AbstractThe recently described (Maier et al.[2]) title compound is not only viable in an argon matrix (10 K) but is also accessible in the gas phase. Electron impact ionization of (CH3)3CCX2NC (X = H, D) gives rise to HCNCX2+, which can be successfully neutralized in a beam experiment.
Octa‐, Hexa‐, and Tetracoordination in Tin(IV) Derivatives of cis‐β‐(Methylthio)stilbene‐α‐thiol
Authors: Schrauzer Gerhard N. , Chadha Raj K. , Zhang Cheng , Reddy Hussain K. 
Published: July 2007

AbstractThe S‐methyl‐cis‐stilbene‐α,β‐dithiolate of Sn(IV), Sn[Ph(S)C=C(SCH3)Ph]4, has an octacoordinate structure with two sets of four covalent and coordinate Sn–S and Sn–S(CH3) bonds of 2.425(3) and 3.599(3) Å, respectively. Both types of Sn–S bonds are close to being tetrahedral, the coordination geometry is a distorted cube. This unprecedented structure appears to involve conventional covalent and outer‐sphere coordinative Sn–S bonds. In the diphenyl derivative Ph2Sn[Ph(S)C=C(SCH3)Ph]2 the SnC2S2 core formed by the covalent Sn–C and Sn–S(thiolato) bonds is tetrahedral, but two coordinate outer‐sphere Sn‐S(CH3) bonds of 3.500(3) Å are also present. In the related SnCl2[Ph(S)C=C(SCH3)Ph]2 the presence of the polar Sn–Cl bonds prevents outer‐sphere bonding; the coordination geometry is distorted octahedral. In the triphenyltin derivative Ph3Sn[Ph(S)C=C(SCH3)Ph] the coordination geometry is tetrahedral, the thiol‐thioether ligand being monodentate with the SCH3 group in a non‐interactive position.
Zur Synthese und Charakterisierung von Platincyclobutadien‐Komplexen durch Reduktion von Hexachloroplatinsäure
Authors: Steinborn Dirk , Nünthel Ralph , Sieler Joachim , Kempe Rhett 
Published: July 2007

Synthesis and Characterization of Platinumcyclobutadiene Complexes by the Reduction of Hexachloroplatinic AcidHexachloroplatinic acid is reduced in 1‐butanol in the presence of an alkyne R–C≡C–R′ (R, R′ = Me, Et, nPr) to give platinumcyclobutadiene complexes [PtCl2(C4R2R2′)] (1). H[PtCl3(CH3CH2CH=CH2)] (2) is an intermediate which is isolated as bis(triphenylphosphoranylidene)ammonium salt (PPN‐salt) [PPN][PtCl3(CH3CH2CH=CH2)] (3). The molecular structure of [PtCl2(C4Et4)] (1b) shows in the solid state a planar cyclobutadiene ring with internal bond angles of 93(3) and 87(2)°. The Pt–C bond lengths are 208(2) and 210(2) pm. The ethyl groups are pushed out of the ring plane, away from the Pt atom, with an angle of 7(2)°.
Darstellung und Eigenschaften von und Reaktionen mit metallhaltigen Heterocyclen, LXXXV. Konsekutive Insertions‐ und [2 + 2]‐Cycloadditions‐Reaktion von Hexafluor‐2‐butin mit einem (η2‐Thiophosphinito)cobalt‐Komplex
Authors: Lindner Ekkehard , Schlenker Tilman , Fawzi Riad , Steimann Manfred 
Published: July 2007

Metal‐Containing Heterocycles: Preparation, Properties and Reactions, LXXXV[1]. – Consecutive Insertion and [2 + 2] Cycloaddition Reaction of Hexafluoro‐2‐butyne with an (η2‐Thiophosphinito)cobalt complexInsertion of hexafluoro‐2‐butyne (2) into the Co—P bond of the (η2‐thiosphosphinito)cobalt complex (OC)2Ph3PCo(η2‐SPt2) (1) and subsequent [2 + 2] cycloaddition to a second alkyne 2 results in the formation of the stable (η3‐cyclobutenyl)cobalt complex 3. According to an X‐ray structural analysis 3 crystallizes in the triclinic space group P1 with Z = 2.
Unsaturated Hetero Chains, II. 1‐Oxa‐3,5,7‐triaza‐1,3,5,7‐octatetraenes – Syntheses and Structures
Authors: Buhmann Martin , Würthwein Ernst‐Ulrich , Möller Manfred H. , Rodewald U. 
Published: July 2007

AbstractThree independent routes for the synthesis of the hitherto unknown substituted 1‐oxa‐3,5,7‐triazaoctatetraenes 4 have been developed. Method 1 utilizes N‐lithiated imines 1 and 1,3,5‐oxadiazinium salts 2 for the synthesis of 4b–e. Method 2 takes advantage of the new 6‐alkoxy‐1‐oxa‐3,5‐diazahexatrienes 5, which are allowed to react with imino lithium compounds to produce 4f. Method 3 is based on the combination of the lithiated 1,3‐diazabutadiene 7 with the N‐acylimidate 8 and gives access to 4g–j. Depending on the substitution pattern, the title compounds show ring‐chain tautomerism; in the case of the pentaphenyl system, only the triazine derivative 3a is observed. An X‐ray analysis of 4f reveals a non‐planar structure with (+)‐gauche‐Z‐(–)‐gauche‐Z‐(+)‐gauche conformation, resulting from amide‐like n/π interactions between C=N–π systems and the lone pair of the adjacent nitrogen atoms. Detailed spectroscopic data for all open‐chain and cyclic compounds are given. Quantum mechanical calculations (MP2/6‐31G*//6‐31G*) of model compounds 13 predict that non‐planar isomers with gauche‐configurated subunits are favored by more than 8 kcal/mol over a planar all‐trans structure as in polyenes. Most planar isomers correspond to low‐lying transition states for the rotation around the C–N bonds, but not to local minima, indicating high molecular flexibility of these oligonitrile chains.
all‐Homocalixarene: Carbocyclische Wirtverbindungen mit intra‐ und extraannularen Ligandarmen
Authors: Schmitz Jürgen , Vögtle Fritz , Nieger Martin , Gloe Karsten , Stephan Holger , Heitzsch Olaf , Buschmann Hans‐Jürgen , Hasse Wolfgang , Cammann Karl 
Published: July 2007

all‐Homocalixarenes: Carbocyclic Host Compounds with Intra‐ and Extraannular Ligand ArmsMethoxy‐substituted [2n]metacyclophanes 1–10, obtained by Müller‐Röscheisen cyclization, are converted into all‐homocalixarenes 11–20 with free phenolic hydroxy functions. The well‐soluble cyclic pentamer 11 and octamer 14 with endo‐acidic host properties are investigated with regard to guest binding. They exhibit selectivity towards alkaline earth metal ions (Ba2+) in liquid/liquid extraction studies. Some of the macrocyclic oligophenols are transformed into homocalixarenes 21–25 with intra‐ or extraannular oxapropionate groups. The diester 22 and the tetraester 23 are converted into carbocycles 26 and 27 with two and four free oxapropionic acid groups. Complexation properties of the oligoesters in extraction studies and log K values in water are reported. X‐ray structural analyses were performed of the [6]‐, [8]‐ and [4]‐ homocalixarenes 9 and 21, 14 and 23; the inclusion of solvent molecules is proven.
4,5,12,13‐Tetrabromo[2.2]paracyclophane – A New Bis(aryne) Equivalent
Authors: König Burkhard , Knieriem Burkhard , Rauch Karsten , Meijere Armin De 
Published: July 2007

AbstractThe reaction of 2 with nBuLi at –78°C generates aryne intermediates within the aromatic rings of [2.2]paracyclophane which are trapped in Diels‐Alder reactions with dienes like furan, 1,9‐diphenylisobenzofuran, or cyclopentadiene. Reductive deoxygenation with low‐valent titanium reagents or TMSI converts the adducts of furan and isobenzofuran into anti‐[2.2]paracyclophanes 4 and 5, respectively. The reaction of two aryne intermediates with [2.2](2,5)furanophane (7) yields 8 with three [2.2]paracyclophane units arranged in a stair‐like fashion; yet, in this compound the highly shielded oxygen atoms cannot be removed anymore by reduction.
A Soluble Benzodifluoranthene Derivative by Dehydration of an Oxygen‐Bridged Precursor
Authors: Schirmer Heike , Schlüter Arnulf‐Dieter , Enkelmann Volker 
Published: July 2007

AbstractSynthesis and characterization of the alkyl chain‐substituted benzodifluoranthene 6 are described. The final synthetic step involves an acid‐promoted dehydration whose conversion is determined to be quantitative. The solubilities of compounds 4e, 5, and 6 are qualitatively correlated with structural features. The molecular structure of 6 in the crystal is elucidated by an X‐ray structure analysis.
Synthese mittlerer und großer Ringe, XXXIV. Stereoselektive Synthese überbrückter und verzweigter Methyl‐desoxyfuranoside aus 3,6‐Hexanooxepin‐4,5‐dicarbonsäure‐dimethylester
Authors: Tochtermann Werner , Popp Brigitta , Mattauch Anne‐Katrin , Peters Eva‐Maria , Peters Karl , Schnering Hans Georg Von 
Published: July 2007

Syntheses of Medium and Large Rings, XXXIV[1,2]. – Stereoselective Synthesis of Bridged and Branched Methyl Deoxyfuranosides from Dimethyl 3,6‐Hexanooxepine‐4,5‐dicarboxylateThe stereoselective synthesis of the bridged methyl furanosides 4–8 with four, five, and six stereogenic centers is described. The reaction sequence starts with the addition of methanol to the oxepine 1. The photochemical electrocyclic ring closure of 2 gives the cyclobutene 3. Ruthenium tetraoxide oxidation of 3 leads to the title compound 4 that is further converted to 5–8 by stereoselective reductions.
Soluble (Phthalocyaninato)ruthenium(II) Phosphane Complexes
Authors: Bulatov Alexander , Knecht Siegfried , Subramanian L. R. , Hanack Michael 
Published: July 2007

AbstractHitherto unknown ruthenium phthalocyanine complexes with phosphane ligands – PcRu(PEt2Ph)2 (1) and PcRu(PPh3)2 (2) – soluble in common organic solvents were prepared. Two methods were used for their synthesis: 1) Reaction of phthalonitrile with [Ru2Cl3(PEt2Ph)6]Cl in n‐pentanol in the presence of 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) and 2) reaction of PcRu with the corresponding phosphanes. The products 1 and 2 were characterized by their IR, UV/Vis, FD‐MS, and 1H‐NMR data.
Synthese und Struktur des ersten oligomeren cyclischen Dimethylsilyl‐substituierten Carbodiimids
Authors: Kienzle Andreas , Aldinger F. , Obermeyer Axel , Simon Arndt , Riedel Ralf 
Published: July 2007

Synthesis and Structure of the First Oligomeric Cyclic Dimethylsilyl‐Substituted CarbodiimideNew oligomeric cyclic silylcarbodiimides 1–3 are synthesised by the reaction of the respective dichlorosilanes with cyanamide. From the resulting reaction mixture with dichloro‐dimethylsilane the tetrameric compound of the hypothetical [(CH3)2Si=N–CN] is isolated. In this molecule sixteen atoms build a nearly planar ring structure with a special steric arrangement of the groups. This oligomeric silylcarbodiimides present a new kind of precursors for the pyrolytic synthesis of ceramics in the ternary system SiCN.
Synthese eines 2H‐Inden‐2‐on‐Dianion‐Komplexes durch Reduktion eines metallgebundenen Dicarbens
Authors: Öfele Karl , Dyckhoff Florian , Krist Herbert G. 
Published: July 2007

Synthesis of a 2H‐Inden‐2‐one Complex by Reduction of a Metal‐Bound DicarbeneHerrn Professor Dr. Dr. h. c. mult. E. O. Fischer zum 75. Geburtstag gewidmet.
Tetracarbonylchromium complexes with chelating o‐phenylene‐biscarbene ligands are reduced in two steps as shown by cyclic voltammetry. The first step corresponds to a reversible one‐electron transfer, the second to an irreversible one‐electron reduction followed by a rapid rearrangement of the biscarbene ligand into an η5‐bound 2H‐inden‐2‐one system by a twofold C–C coupling with one CO ligand. By reaction of tetracarbonyl[o‐phenylenebis(methoxymethylene)]chromium (4) with sodium amalgam in acetonitrile the diamagnetic tricarbonyl(η5‐1,3‐dimethoxy‐2‐indenone)chromium dianion [6]2– is formed as the final reduction product. Its structure was determined by NMR and IR spectroscopy.
C*Ru‐Thiolkomplexe, II[1]. Adduktbildung in [Cp*RuII(π‐SR)]2 und [Cp*Ru(C6F5)(μ‐SC6F5)(μ‐S)RuCp*]. Molekülstruktur von cis‐[Cp*Ru(μ2‐StBu)(CO)]2 und [Cp*Ru(C6F5)(μ‐SC6F5)(μ‐S)RuCp*]
Authors: Hörnig Andreas , Rietmann Christian , Englert Ulli , Wagner Trixie , Kölle Ulrich 
Published: July 2007

Cp*Ru Thiol Complexes, II[1]. – Adduct Formation in [Cp*RuII(μ‐SR)]2 and Cp*Ru(C6F5)(μ‐SC6F5)(μ‐S)RuCp*]. Molecular Structure of cis‐[Cp*Ru(μ2‐StBu)(CO)]2 and [Cp*Ru(C6F5)(μ‐SC6F5)(μ‐S)RuCp*]Reaction of [Cp*Ru(μ‐OMe)]2 (1) with thiols RSH gave the sulfur analogues to 1, [Cp*Ru(μ‐SR)]2 (2), and with PhSH after carbonylation cis‐[Cp*Ru(μ‐SPh)(CO)]2 (11). C6F5SH as thiol reacts with 1 to form [Cp*Ru(C6F5)(μ‐SC6F5)(μ‐S)RuCp*] (3a) with oxidative migration of a C6F5 group from S to Ru. For elucidation of the constitutions molecular structures of 3a and cis‐[Cp*Ru(μ‐StBu)(CO)] (10) were determined by single crystal X‐ray diffraction. Adduct formation and bridge cleavage of the doubly coordinatively unsaturated dinuclear complexes 2 and singly unsaturated complex 3 with donor and acceptor ligands is investigated and the donor/acceptor character of the Ru centers in thiol complexes 2 compared to those in 1. Substitution reactions of [{Cp*Ru(μ‐OMe)}2(dppm)] (4) with PhSH and C6F5SH yield complexes [{Cp*Ru(μ‐SR)}2(dppm)] (R = Ph 5, C6F5 6).
Synthese und Röntgenstrukturanalyse einer neuartigen gemischtvalenten zwitterionischen Diphosphor‐Fluor‐Verbindung
Authors: Dunmur Richard E. , Thönnessen Holger , Müller Christian , Farkens Michael , Fischer Axel , Jones Peter G. , Schmutzler Reinhard 
Published: July 2007

Synthesis and X‐Ray Crystal Structure Analysis of a Novel Mixed‐Valent Zwitterionic Diphosphorus Fluoro CompoundThe cyclic zwitterionic λ6P,λ4P‐diphosphorus compound F5P–N(Me)P+ [N(Me)C(=O)]2NMe (3), which contains a biuret system, was synthesized by the reaction of (MeNPF3)2 (1) with MeNCO (2). Compound 3 was characterized by means of 1H‐, 13C‐, 19F‐ and 31P‐NMR spectroscopy, IR spectroscopy, and mass spectrometry. A single‐crystal X‐ray structure determination revealed the presence of two independent formula units, in which the –N(Me)PF5 side chains display widely differing conformations.
Gasphasenthermolyse von Pyrazolinen, 3[1]. Elektronische Struktur und Gasphasenpyrolyse von 4‐substituierten 3,5,5‐Trialkyl‐3,5‐dihydro‐4H‐1,2,3‐triazolen untersucht durch Photoelektronenspektroskopie und semiempirische Rechnungen
Authors: Kindermann Markus Karl , Kowski Klaus , Rademacher Paul , Quast Helmut 
Published: July 2007

Gas‐Phase Thermolysis of Pyrazolines, 3[1]. – Electronic Structure and Gas‐Phase Pyrolysis of 4‐Substituted 3,5,5‐Trialkyl‐3,5‐dihydro‐4H‐1,2,3‐triazoles Studied by Photoelectron Spectroscopy and Semiempirical CalculationsThe PE spectra of the 3,5‐dihydro‐4H‐1,2,3‐triazoles 1–3 have been recorded. The ionization potentials have been assigned to molecular orbitals on the basis of MNDO, AM1, and PM3 calculations. The most important occupied MOs are characterized as πNNN, πC=X (X = O, NCH3, CH2), nN‐3, nNN+, nNN– and nX. The gas‐phase thermolyses of 1–3 have been studied by PE‐controlled real‐time gas analysis. After extrusion of molecular nitrogen, the remaining reactive species cyclize to three‐membered rings. At higher temperatures and in flash vacuum pyrolysis, subsequent reactions lead to smaller acyclic compounds.
Synthese mittlerer und großer Ringe, XXXV[1]. Funktionalisierte Hydroazulenone durch transannulare Cyclisierungen von 10‐Oxo‐3,6‐hexanooxepin‐4,5‐dicarbonsäure‐dimethylester
Authors: Tochtermann Werner , Habeck Thorsten , Wolff Christian , Peters Eva‐Maria , Peters Karl , Schnering Hans Georg Von 
Published: July 2007

Synthesis of Medium and Large Rings, XXXV[1]. – Functionalized Hydroazulenones by Transannular Cyclizations of Dimethyl 10‐Oxo‐3,6‐hexanooxepine‐4,5‐dicarboxylateTwo differently bridged hydroazulenones 2 and 3 are obtained in 69 and 61% yield, respectively, by treatment of the title compound 1 with sodium methoxide. The course of these intramolecular transannular cyclizations strongly depends on the amount of added base. 2 is hydrogenated to the ketones 9 and 10. Oxidative cleavage of the enol ether double bond of 3 and 10 leads to the octahydroazulene‐1,6‐dione 11 and to the decahydroazulene‐3,8‐dione 12, respectively.