bluuebunny/crossref_metadata_2025_split huggingface dataset:
2‐Azaallenyl‐Chromkomplexe; Insertion von 1‐Aminopropin in M = C‐ und C = 0‐Bindungen. Intramolekulare Cyclopropanierung sowie [3 + 2]‐Cycloaddition unter Bildung eines 1,3‐Diaminoindens
Authors: Aumann Rudolf , Heinen Heinrich , Krüger Carl , Betz Peter 
Published: July 2007

Organic Syntheses via Transition Metal Complexes, 43. ‐ 2‐Azaallenyl Chromium Complexes; Insertion of 1‐Amino‐propyne into M  C and C  0 Bonds: Intramolecular Cyclopropanation and [3 + 21 Cycloaddition with Formation of a 1,3‐DiaminoindeneOrganic Synthese via Transition Metal Complexes, 431). ‐ 2‐Azaallenyl Chromium Complexes; Insertion of 1‐Aminopropyne into M = C and C = O Bonds; Intramolecular Cyclopropanation and [3+2]Cycloaddition with Formation of a 1,3‐Diaminoindene The 2‐azaallenyl complex LnM⊖ ‐C(Ph)=N⊕ = C(Ph)OCO‐Ph 3 [LnM = Cr(CO)5] adds to the 1‐aminopropyne Et2N‐C = C‐CH3 (4) to give the aminocarbene complexes LnM=C(NEt2)‐C(CH3)=C(Ph)‐N(COPh)2 [(E)‐5] and LnM=C(NEt2)‐C(CH3)=C(Ph)‐NH(COPh) [(E)‐9] (by insertion of 4 into the M = C bond of 3) as well as a 1,3‐diaminoindene 6 (by [3+2] cycloaddition). An iminocarbene complex LnM = C(Ph) ‐ N=C(Ph) ‐O‐C(Ph) = C(CH3)‐CONEt2 (7) is formed as a further product (by insertion of4 into the C=O bond of 3). The latter type of reaction can also be applied to metal‐free carbonyl compounds: thus phthalic anhydride reacts smoothly with 4 to give a γ‐lactone 12 and a 1,3‐indanedione 13 by insertion of 4 into a C=O and C‐O bond, respectively. The thermolysis of the iminocarbene complex 7 yields a cyclopropane derivative 14 by an intramolecular attack of the carbene carbon at the (O)C=C bond. The structure of 14 has been determined by a crystal structure analysis. On thermolysis of 3 a triphenyloxazole 15 is obtained. The mechanisms of these reactions are discussed.
Ein neuer Zugang zu enantiomerenreinen β‐Lactamen aus α‐Aminosäuren durch präparative Anwendung der Isonitril‐Nitril‐Umlagerung
Authors: Haaf Klaus , Rüchardt Christoph 
Published: July 2007

A New Approach to Enantiomerically Pure β‐Lactams from a‐Amino Acids by Applying the Isonitrile‐Nitrile Rearrangement(S)‐Phenylalanine (1) was converted into (S)‐3‐benzyl‐2‐azetidinone (8b) by a multistep reaction sequence. The key step of this approach is a stereospecific isonitrile‐nitrile rearrangement (3 → 4) by flash pyrolysis, which may be performed in 20‐g batches of 3. An improved procedure for the preparation of (S)‐Phenylalaninol (2a) is described.
Neue Synthesen Trifluormethyl‐substituierter Heterocyclen
Authors: Rabe Gerd , Sundermeyer Jörg , Roesky Herbert W. , Schmidt Hans‐Georg , Noltemeyer Mathias 
Published: July 2007

New Syntheses of Trifluoromethyl‐Substituted HeterocyclesDimeric hexafluorothioacetone (HFTA) (1) reacts with thiourea or phenylthiourea to give 1,2,4‐dithiazolines 2a and 2b. Similarly, 1,2,4‐thiaselenazoline 3 is obtained from the reaction of 1 with selenourea. Reaction of 1 with oxamic hydrazide or thiosemicarbazide leads to acyclic molecules 4 and 5. Besides 5, the cyclic isomer 6 is also observed in solution. The N‐trifluoroacetyl derivative 6a is obtained from the reaction of 5 with trifluoracetic anhydride. The structures of 2b, 3, 5, and 6a have been determined by single‐crystal X‐ray crystallography.
Darstellung und Eigenschaften von und Reaktionen mit metallhaltigen Heterocyclen, LXIX1) Unabhängige Mechanismen der Cyclocotrimerisierung von Thiophosphinitomangan‐Komplexen mit Alkinen. – Ein einfacher Zugang zu fünfgliedrigen Heterocyclen
Authors: Lindner Ekkehard , Käss Volker , Mayer Hermann A. 
Published: July 2007

Metal‐Containing Heterocycles: Preparation, Properties, Reactions. LXIX It. – Independent Mechanisms of the Cyclocotrimerization of Thiophosphinito Manganese Complexes with Alkynes. – An Easy Access to Five‐Membered HeterocyclesIn solution the dimeric thiophosphinitomanganese complexes (1), Et (2), nPr(3)] are in equilibrium with the monomeric species . For R1= iPr (7) and CY (8) the complexes are kinetically stabilized. In THF 4 – 8 react with different activated alkynes R2C≡CR2 to from the S‐isomeric five‐membered heterocycles (11a, b, e–i). With additional alkynes R2C≡CR2, 11a, b, e–i are trans membered heterocycles (10g to i are also obtained. In n‐hexane, the P‐isomeric seven membered thiaphosphamanganacycloheptadiens (14g‐K) are formed in a [2 + 2 + 2) cycloaddition of 7, 8 to two molecules of R2C≡CR2. at elevated temperatures 14g‐K eliminate CO with formation of the bicyclic compounds 12g‐k. the action of MeC≡CCO2Me on 8 affords the seven‐membered ring 15 in a regiospecific [2 + 2 +2] cycloaddition. 12a‐d, h, i and 15 are starting compounds for easy access to the different substituted thiophenes 17, 18a‐d, furans 19 h, i, and hte phosphole complexes 20a, b, h, i.
Azo‐Borane – eine neue Verbindungsklasse
Authors: Hünig Siegfried , Kraft Petra 
Published: July 2007

Azo Bridges from Azines, XI. – Azo‐Boranes – A New Class of CompoundsRigid systems with azo bridges of 2,3‐diazabicyclo[2.2.1]hept‐2‐ene (DBH)‐ and 2,3‐diazabicyclo[2.2.2]oct‐2‐ene (DBO)‐type form azo‐boranes as stable, colourless solids on addition of BH3‐SMe2 or BH3‐THF (1–3, 5, 6, 8). On reaction of stoichiometric amounts of the two components CC double bonds are not attacked (2, 8, exception 4). So far unexplained violet and blue colorations of the reaction mixtures are described.
Künstliche molekulare Anion‐Wirte. Die Synthese eines chiralen bicyclischen Guanidinium‐Salzes als funktionalisierte Ankergruppe für Oxo‐Anionen
Authors: Gleich Alexander , Schmidtcher Franz P. , Scheuplein Stefan W. , Kusche Andreas , Brückner Reinhard , Harms Klaus 
Published: July 2007

Artificial Molecular Anion Hosts. Synthesis of a Chiral Bicyclic Guanidinium Salt Serving as a Functionalized Anchor Group for 0x0 AnionsStarting from 1‐asparagine, the synthesis of the S,S‐bis(hydroxymethyl)‐substituted bicyclic guanidinium salt 3 is described, which is obtained in 20% overall yield with a diastereomeric excess de > 98%. The guanidinium compound 3 may serve as a binding module in the enantioselective recognition of oxo anions in polytopic abiotic receptors.
Organosubstituierte 1,6‐Dioxa‐2‐sila‐5‐bora‐3‐cycloalkene – Herstellung und Charakterisierung
Authors: Köster Roland , Seidel Günter , Boese Roland , Wrackmeyer Bernd 
Published: July 2007

Organosubstituted 1,6‐Dioxa‐2‐sila‐5‐bora‐3‐cycloalkenes – Preparation and Characterisation1)The cis‐alkenes ROSi(CH3)2C(R)  C(C2H5)B(C2H5)OR (R  CH3: 11; C2H5: 12; C6H5: 13) are prepared from CH3NSI[CH3)2C(R)C(C2H5)BC2H5 [R  CH3: A; R  C(CH3)  CH2: B] with the monohydroxy compounds ROH (R  CH3, C2H5, C6H5). A or B react with aliphatic dihydroxy compounds HOR′OH [R′  CH2CH2: 1; CH(CH3)CH2: 2; CH(CH3)CH(CH3): 3; C(CH3)2C(CH3)2: 4; (CH2)3: 5; (CH2)4: 6] to give 8‐, 9‐, and 10‐membered ring compounds OSi(CH3)2C(R)  C(C2H5)OR′ [15a,b, 16/16′, meso/rac‐17a, D‐17a,b, 18, 19, (20)n]. A is initially cleaved at the SiN bond with formation of 14 Compound 15a crystallises as the 16‐membered (15a)2 [X‐ray structure analysis). The aromatic dihydroxy compounds catechol (7), resorcinol (8), 2,3‐dihydroxynaphthalene (9), 1, 8‐dihydroxynaphthalene (10) react with A to form 21 to 24, but mainly by protolytic BCvinyl fission to give the 2,5‐dihydro‐1,2,3‐dioxaboroles (e.g. 7f1, 9f1, 10f1) and the acyclic boron‐free compounds 7f′3, 9f3, 10f3. The MS and NMR (1H, 11B, 13C, 29Si) data of the new compounds are discussed.
Hydrocarbonylierende Cyclisierung von Dienen, 8. Cyclisierung von 1,4‐Dienen mit funktionellen Gruppen in 3‐Stellung
Authors: Eilbracht Peter , Hüttmann Gerd‐Erich , Deußen Rainer 
Published: July 2007

Hydrocarbonylating Cyclization of Dienes, 81. – Cyclization of 1,4‐Dienes with Functional Groups in 3‐Position1,4‐Dienes 1a–i with functional groups at C‐3 were synthesized and treated under the conditions of metal‐catalyzed hydrocarbonylating cyclization. Under the usual conditions no cyclization products could be isolated. Modifications of the reaction conditions did not lead to the expected cyclopentanones of type 2 or 3 either. Instead, the original functional groups are split off. Depending on the reaction conditions, either the non‐functionalized 2‐cyclopentenones 5, the cyclopentanones 6, or the 2‐cyclopentenones 7 with a functional group introduced from the solvent into the 2‐methyl group are obtained. These unexpected products of type 7 at least formally correspond to allylic rearrangement products of the expected but not observed type‐3 exo‐methylenecyclopentanones. The mechanism of the formation of these products is discussed.
Carbonylierende Ringerweiterung, 3. Stereochemie der Komplexierung und carbonylierenden Ringerweiterung von 1,3,5‐Trimethyl‐1,3‐cyclohexadien
Authors: Eilbracht Peter , Hittinger Christel , Kufferath Klaus 
Published: July 2007

Carbonylating Ring Enlargement, 31). – Stereochemistry of Complexation and Carbonylating Ring Enlargement of 1,3,5‐Trimethyl‐1,3‐cyclohexadieneThe stereochemical course of the complexation and the metal‐ and Lewis acid induced carbonylating ring enlargement of cyclohexadienes 1 to bicyclo[3.2.1]oct‐3‐ene‐2,8‐diones 4 via diene iron tricarbonyl complexes 2 and complexed sevenmembered ring ketones 3 is investigated by synthesis and conversion of the diastereomeric complexes exo‐ and endo‐12 of 1,3,5‐trimethyl‐1,3‐cyclohexadiene (7). It can be concluded, that the stereochemical information of the starting materials can be transferred to the product. In the first step exo and endo substituents retain their relative position towards the metal. The introduction of the second carbon monoxide unit and ketone bridge formation also occurs stereospecifically from the side of the complexing metal without loosing the preestablished position of the substituents. Mechanistic aspects of these results are discussed.
Präorganisierte Bis‐ethine: Molekulare π‐Pinzetten?
Authors: Vögtle Fritz , Papkalla Thomas , Koch Herbert , Nieger Martin 
Published: July 2007

Preorganized Bis‐ethynes: Molecular π‐Tweezers?1,8‐Bis[(arylethynylphenyl)]naphthalenes of type V (e.g. 10, 11) and 1,8‐bis[(arylethenylphenyl)]naphthalenes (6, 6a, 7, 7a) were synthesized for the first time. In contrast to the known 1,8‐bis(arylethynyl)naphthalenes VI their “stereologs” 10 and 11 are thermally stabile. Yet they react with pentacarbonyliron to yield dinuclear transition metal complexes of the type 12, 13, i.e. a strained cyclophane macrocycle is formed by C‐C bond formation. The X‐ray analysis of the di‐tert‐butyl compound 11 shows that the peri substituents diverge, but with increasing distance from the naphthalene skeleton one of the arylethynyl units is bent to the opposite direction (Figure 2). The question whether the new molecular skeleton V can be viewed as molecular tweezers is discussed: as the hydrocarbons react irreversibly with transition metal carbonyls, they may rather be taken as “tweezers for single use”.
Alkine und Cumulene, XXI. über einige neue Oligomere des Allens
Authors: Hopf Henning , Kretschmer Olaf , Ernstb Ludger 
Published: July 2007

Alkynes and Cumulenes XXI1). – On Some New Oligomers of AlleneThe thermaloligomerization of allene (1) in the gas phase has been reinvestigated. AT 260°C and low conversions, 1,6,7‐trimethylenespiro[3.5]nonan (14) and 1,2,5,6‐tetramethylene cyclooctane (15) have been detected besides the already known thermal oligomers 2‐8, increase of substrate concentration and reaction time lead to significant amounts of a hexamer fraction which contains the new allene oligomers 16‐23 according to sepctroscopic analysis, Possible routes of formation of the unusual hexamers 16and 20 are discussed.
Enolate, II. Einfache Synthese von 3,4‐Dihydro‐2,4‐dioxo‐2H‐pyranen und 2‐Pyronen Enolate als 1,3‐Dianion‐Äquivalente Kristall‐ und Molekülstruktur von 6‐Ethoxy‐3,4‐dihydro‐3,3‐dimethyl‐2,4‐ dioxo‐2H‐pyran‐5‐carbonsaure‐ethylester
Authors: Saalfrank Rolf W. , Gundel Jiirgen , Roomanna Gunther , Hanek Martin , Rost Walter , Petersb Karl , Schneringb Hans Georg Von 
Published: July 2007

Enolate Ions, I11). – Convenient Synthesis of 3.4‐Dihydro‐2.4‐dioxo‐2H‐pyrans and 2‐Pyrones. – Enolate Ions as Synthetic Equivalents of 1.3‐Dianions. – Crystal and Molecular Structure of Ethyl 6‐Ethoxy‐3,4‐dihydro‐3,3‐dimethyl‐2,4‐dioxo‐2H‐pyran‐5‐carboxylateReaction of dimethylmalonyl chloride (Sa) or cyclic 1,l‐dicar‐ bony1 dichlorides 6b – d with two equivalents of lithium enol‐ ates 7, 22, and silyl enol ethers 8, respectively, yields 3,4‐ dihydro‐2,4‐dioxo‐2H‐pyrans 10, 24, or spiro compounds 11 – 13,25‐ 27. The spiro[2S]octenes 11 and 25 isomerize spontaneously to give 2‐pyrones 14, 28, whereas spiro[3S]nonenes 12, 26 rearrange only on heating in the presence of aluminium trichloride to form the corresponding 2‐pyrones 15 and 29.However, 10, 13 as well as 24, 27 do not isomerize under these conditions. Reaction of dicarbonyl dichlorides 6a, c with one equivalent of ketene acetal 16 leads to hydroxy‐dioxo‐2H‐pyr‐ ans 17a, c. On the contrary, treatment of tetraethoxyallene (18) with dicarbonyl dichlorides 6a, b leads to dihydro‐2,4‐dioxo‐2H‐pyran 19a (X‐ray structure analysis) and spiro[2.5]octene 19b, respectively. Isomerization of 19 b yields a mixture of 2‐pyrone 20 and 4‐pyrone 21.
Transformation of a Platinum Carbonyl into a Platinum Carbene Moiety by Reaction with (η4‐Butadiene)zirconocene
Authors: Erker Gerhard , Menjón Babil 
Published: July 2007

AbstractWhile (η4‐butadiene)zirconocene and ‐hafnocene do not react with Pt(PPh3)2(CO)2 (2) in toluene solution at room temperature, cp2Zr(η4‐C4H6) (1a: cp = η5‐C5H5; 1b: cp = η5‐C5H4CH3) reacts with cis‐Pt(C6F5)2L(CO) (3: L = CO; 5: L = PiPr3) under similar conditions to give the metallacyclic Fischer‐type carbene complexes (4: L = CO; 6: L = PiPr3). When L = CO, isomerization takes place by UV irradiation (cis‐4⇌trans‐4) presumably as the result of a dissociative CO scrambling process. This is not observed when L = PiPr3.
β‐hydroxydithipozimtsäure als Ligand. Palladium(II)‐ und Platin(II)‐Komplexe von 2‐benzoyl‐1‐,1‐ethendithiolat. Kristallstrukturanalyse von cis‐{(Ph3P)2Pt[S2CCHC(O)C6H5]}
Authors: Weigand Wolfgang , Bosl Gabriele , Polborn Kurt 
Published: July 2007

β‐Hydroxydithiocinnamic Acid as Ligand. Palladium(I1) and Platinum(I1) Complexes of 2‐Benzoyl‐1,l‐ethenedithiolate. Crystal Structure Analysis of cis‐{(Ph3P)2Pt[S2CCHC(O)C6H5]}β‐Hydroxydithiocinnamic acid reacts with L2Mcl2 (L = Et3P, Ph3P, 1/2 dppe; M = Pd, Pt) to yield 2‐benzoyl‐1,1‐ethenedithiolate complexes L2M[S2CCHC(O)C6H5] (2a: L = Ph3P, M = Pd; 2b: L = Et3P, M = Pt; 2c: L = Ph3P, m = Pt; 2d: L = 1/2 dppe, M = Pt). The compounds 2a–2d were characterized by their spectroscopic data (IR; 1H, 13C, 31P NMR); the structure of 2c was determined by X‐ray diffraction. A fluid solution of 2c shows fluorescence.
Synthese und Charakterisierung von (Iodcyan)iodonium‐hexafluoroarsenat, [ICNI]⊕[AsF6]⊖
Authors: Tornieporth‐Oetting Inis , Klapötke Thomas 
Published: July 2007

Synthesis and Characterization of (lodocyano)iodonium Hexafluoroarsenate. [ICNI]⊕[AsF6]⊖(Iodocyano)iodonium hexafluoroarsenate, [ICNI]⊕[AsF6]⊖ (1), was synthesized quantitatively by the reaction of iodine cyanide with [I3]⊕[AsF6]⊖ and was characterized by chemical analysis, IR, Raman and 19F‐NMR data. The [ICNI]⊕ cation in 1 represents the first example of its kind which is stable at room temperature, formally containing an N⊕‐I bond.
Neuartige basische Liganden für die homogenkatalytische Methanolcarbonylierung, XXVI. Dynamisches und reaktives Verhalten von (Ether‐Phosphan)ruthenium(II)‐Komplexen in Abhängigkeit von der O‐Basizität
Authors: Lindner Ekkehard , Karle Berthold 
Published: July 2007

Novel Basic Ligands for the Homogeneous Catalytic Carbonylation of Methanol, XXVIl). ‐ Dynamic and Reactive Behaviour of (Ether‐Phosphane)Ruthenium(II) Complexes in Dependence on the o‐BasicityReaction of the ether‐phosphane ligand Ph2PCH2C4H7O2 (3a) with Cl2Ru(PPh3)3 (2) results in the formation of the bis(chelate) complex trans‐Cl2Ru(PˆO)2 (4a). (P∼O = η1P‐coordinated; PˆO = η2O,P‐coordinated). With CO both Ru–O bonds are cleaved to give all‐trans‐Cl2Ru(CO)2(P∼O)2 (7a). At 35°C 7a is transformed into the monocarbonyl ruthenium complex trans‐Cl2(PˆO)(P∼O)RuCO (5a) with elimination of one CO molecule. On heating all‐trans‐7a to 110°C in toluene the thermodynamically more stable complex cis‐Cl2(OC)2Ru(trans‐P∼O)2 (6a) is obtained. All reaction steps are reversible. Upon irradiation cis,cis,trans‐6a is retransformed at 40°C into 4a via all‐trans‐7a and 5a. The latter and the corresponding complexes 5b, c, containing THF and CH2OCH3 as ether substituents, show fluxional behaviour. The coalescence temperatures (10, 80, and 55°C, resp.) and the estimated ΔG≢ values (52, 65, and 59 kJ/mol, resp.) of the exchange process indicate the weakest Ru‐O contact in 5a compared to 5b, c. The lower basicity of the dioxanyl function is also responsible for the different reaction behaviour of 4a, 5a, and 7a compared to the corresponding complexes with the ligands 3b, c.
Arenhydride, 8. Konkurrenz zwischen SET und nucleophilem Angriff bei Reaktionen von α‐Bromisobutyrophenon mit Carbanionen. Fragmentierung des Anions von Tetrahydrobianthracen
Authors: Werry Jürgen , Stamm Helmut , Sommer Andreas 
Published: July 2007

Arene Hydrides, 8. ‐ SET vs. Nucleophilic Attack in Reactions of α‐Bromoisobutyrophenone with Carbanions. Fragmentation of the Anion of TetrahydrobianthraceneSET is the main reaction pathway between α‐bromoisobutyrophenone (1) and the carbanions 7a–j− of diarylmethanes or disubstituted acetonitriles: 7− → 7. + e and e + 1 →→ Br− PhCOCMe.2 (3). Main secondary reactions are dimerization of the radical 7. (to form 6) and further reduction of 3: 7− + 3 → 7. + 4 [enolate of isobutyrophenone (5)]. Occasionally substitution products (9) of 1 are obtained. They are probably formed by combination of 7. with 3 (0% 9e at room temperature, 38% 9e at −65°C). This combination seems to be favored by cation coordination. In the reaction with 7f− (“anthracene hydride”) the dimer 6f (and probably 9f, too) undergoes fragmentation to form anthracene. The epoxide 16, arising from 1 by carbonyl attack, has been found only once with 7a–j−; (1% 16b). In contrast, 16 was the (elusive) main product in the reaction of 1 with the carbanions 7k–n− of monosubstituted acetonitriles. Here, 6 and 9 have been found only once (61, 9n). The elusive 16k–n underwent eliminative ring fission.
Struktur von N,N′‐(Phenoxathiin‐4,6‐dicarbonyl)bis(prolin‐methylester) ‐ Konformation im Kristall und in Lösung sowie nach semiempirischen Methoden
Authors: Manero Javier , Feigel Martin , Knoch Falk 
Published: July 2007

Structure of N,N′‐(Phenoxathiine‐4,6‐dicarbonyl)bis(proline methyl ester) ‐ Conformation in the Crystal, in Solution, and According to Semiempirical MethodsThe title compound 1 is synthesized by coupling phenoxathiine‐4,6 ‐dicarboxylic acid (2) with proline methyl ester. An improved synthesis of 2 is presented. The conformation of 1 in the crystal structure and in solution is discussed. The geometry of the product is investigated by semiempirical methods.The conformative hypersurfaces (Ramachandran diagrams) of N‐acetylproline methyl ester and N‐acetylproline methylamide are calculated with PM3.
Darstellung und Konformationsanalyse von 9,11‐Diphenyl[5](2,6)‐pyranophan‐10‐on
Authors: Massa Werner , Schween Michael , Steuber Friedrich W. , Wocadlo Sigrid 
Published: July 2007

Preparation and Conformational Analysis of 9,ll‐Diphenyl[5](2,6)‐pyranophan‐lO‐onePhanone 5 has been generated by pyrolysis of bis(sulfone) 4. This reaction is the first example of a combined allylic‐aliphatic pyrolysis of bis(sulfones); it follows a two‐step mechanism, as is concluded from the absence of cross products and the formation of mono(sulfone) 5a as a by‐product. The flipping of the pentamethylene chain of 5 is unhindered at room temperature as shown by 1H NMR. At 213 K this flipping process is slowed on the NMR time scale, and rotation about the C‐2C‐3 axis is no longer possible. The crystal structure of 5 shows the expected tub‐like conformation of the heterocycle.
Kurzmitteilung/Short Communication Mikrowellen‐induzierte Reaktionen organischer Substrate im Hohlraum von Zeolithen
Authors: Ipaktschi Junes , Brück Matthias 
Published: July 2007

Microwave‐Induced Reactions of Organic Substrates in the Cage of ZeolitesMicrowave irradiation of compounds 1, 7, 15, 19, 23, and 24adsorbed on Y zeolites has been studied. The reaction rate of the corresponding rearrangement, dehydrogenation and dehydration is dramatically enhanced as compared with reactions under thermal conditions.
η2‐tert‐Butylphosphaacetylen‐Komplexe des Titanocens und Zirkonocens
Authors: Binger Paul , Biedenbach Bruno , Herrmann Albert T. , Langhauser Franz , Betz Peter , Goddard Richard , Krüger Carl 
Published: July 2007

η2‐tert‐Butylphosphaacetylene Complexes of Titanocene and Zirconocene(η2‐2‐tert‐Butyl‐1‐phosphaacetylene)(trimethylphosphane) complexes of titanocene (5a) and zirconocene (5b) are obtained in 85 and 73% yield, resp., by the reaction of 2‐tert‐butyl‐1‐phosphaacetylene (1) with the corresponding bis(trimethylphosphane)metallocenes 2a (MTi) and 2b (MZr). For the preparation of 5b it is more convenient to start with the (1‐butene)zirconocene complex 3 or with the tolanezirconocene complex 4. With the help of a suitable Lewis‐acid, e.g. triethylborane, trimethylphosphane can be eliminated from 5a or 5b to yield the new coordinatively unsaturated phosphaalkyne metallocenes 6a (MTi) and 6b (MZr), which are unstable and oligomerize easily to the dimer 7 (MTi) and trimer 8 (MZr); only the monomer 6a can be observed in solution. The crystal structures of 5a, 7, and 8 are determined by X‐ray analyses.
Functionalized cyclopentadienyl ligands, IV. Synthesis and complexation of linked cyclopentadienyl‐amido ligands
Authors: Okuda Jun 
Published: July 2007

Abstract[(tert‐Butylamino)dimethylsilyl]cyclopentadienes C5H5‐n‐(CMe3)n(SiMe2NHCMe3) (n1, 2) and C5H4(SiMe3)(SiMe2‐NHCMe3) have been prepared and the complexation of their lithium derivatives with FeCl2(THF)1.5 and TiCl4(THF)2 investigated.
s̀‐Push‐pull substitution in iminophosphanes, a theoretical study
Authors: Schoeller Wolfgang W. , Busch Thilo , Niecke E. 
Published: July 2007

AbstractA combination of α‐electron‐withdrawing/‐releasing substituents (push‐pull substitution) at iminophosphanes considerably lengthen (shorten) the central PN bond as revealed by ab initio calculations on model geometries; they also stress the importance of the energy barrier to inversion at nitrogen.
Mitteilungen über Metalltrifluorphosphan‐Komplexe, 51. Hexakis(trifluorphosphan)vanadium(0)‐Synthese, Eigenschaften und Reaktionen
Authors: Collong Wilfried , Kruck Thomas 
Published: July 2007

Communications on Metal Trifluorophosphine Complexes, 51. – Hexakis(trifluorophosphine)vanadium(0) – Synthesis, Chemical Properties, and Reactions[Na(diglyme)2][V(PF3)6] reacts with [PhN2][BF4] to afford the highly volatile, paramagnetic compound V(PF3)6 (1), while the reaction with [C7H7][BF4] yields [C7H7][V(PF3)6]. The metallocenium complexes [MCp2][V(PF3)6] (MFe, Co, Ni) are prepared by one‐electron oxidation of MCp2 by 1.
Aza‐crown ethers with quinone side chains: Synthesis, complexation, and protonation
Authors: Ossowski Tadeusz , Schneider Hermann 
Published: July 2007

AbstractThe synthesis and spectroscopic investigation of aza‐crown ethers with anthraquinone‐ and 1‐aminoanthraquinone‐functionalized side chains are described. Cation‐induced shifts in the UV/VIS absorption spectra of the ligands dissolved in propylene carbonate are observed only for Li+ among the alkali metal ions and for Mg2+ among the alkaline earth metal ions as well as for Ag+ and Tl+. Only hypsochromic shifts of the absorption spectra of anthraquinone‐bearing aza‐crown ethers are observed on protonation. The variations of the extinction coefficients are discussed with respect to the sequence of protonation of the different amino groups.