bluuebunny/crossref_metadata_2025_split huggingface dataset:
Silaheterocyclen, XXII. Diels‐Alder‐Reaktionen von Dichlor(neopentyl)silaethen mit Furanen und Umlagerung der erhaltenen Bicyclen zu monocyclischen Si – O‐Siebenring‐Verbindungen
Authors: Auner Norbert , Wolff Astrid 
Published: July 2007

Sila Heterocycles, XXII[1]. – Diels‐Alder Reactions of Dichloro(neopentyl)silaethene with Furans and Rearrangement of the Resulting Bicycles into Monocyclic Si – O Seven‐Membered Ring compoundsThe reaction of trichloro(vinyl)silane (1) and LitBu (2) initially leads to the α1‐lithio adduct Cl3SiCH(Li)CH2tBu (3) which can be trapped by trimethylsilyl triflate yielding the C1‐silylated product [Cl3SiCH(SiMe3)CH2tBu (5)]. 1,2‐LiCl elimination from 3 gives dichloro(neopentyl)silaethene [Cl2SiCHCH2tBu (4)] as intermediate. This can be established by insertion of 4 into the Si – O bond of Me3SiOMe to Cl2Si(OMe)CH(SiMe3)CH2tBu (6). 4 is a dienophile of high activity and reacts with the furans 7 – 9 to give the [4 + 2] cycloaddition compounds 10 – 12. These Diels‐Alder products are thermally unstable and decompose slowly at room temperature into the starting furans and tetrachlorodisilacyclobutane (15). Under thermolysis conditions (3 d/17°C) they rearrange into the monocyclic Si – O seven‐membered ring compounds 16 – 18. A mechanism for the 7‐Oxa‐2‐silabicyclo[2.2.1]hex‐5‐en → 1‐Oxa‐2‐silacyclohepta‐4,6‐diene rearrangement is proposed.
Synthesis and Molecular Structure of Heterocycles Containing two Phosphorus(V) Centers Bridged by Two‐Coordinate Phosphorus and Arsenic
Authors: Gamper Siegfried F. , Schmidbaur Hubert 
Published: July 2007

Abstract1,1‐Bis[(diphenylphosphanyl)methyl]ethene (3) reacts with PCl3 or AsCl3 in the presence of SnCl2 as a reducing agent to form cationic heterocycles in which the two newly generated phosphonium centers are bridged by two‐coordinate, negatively charged phosphorus (4a) or arsenic (4b) centers. Hexachlorostannate(IV) dianions function as counterions to these heterocycles, in which the exocyclic methylene group is retained. By treatment of 4a with a base a rearrangement is induced which includes a proton migration from an endo‐to the exocyclic CH2 group to give 5‐methyl‐1,1,3,3‐tetraphenyl‐1λ5,2λ3,3λ51‐triphosphinine (5), a novel 1,2,3‐triphosphabenzene species. The reaction of the arsenic compound 4b with base did not yield the corresponding arsa‐diphosphabenzene, but gave only decomposition products. Compound 4b · 0.5 CH3CN has been studied by X‐ray crystallography. The six‐membered heterocycle shows a chair conformation with an arsenic atom solely coordinated by two phosphorus atoms at roughly equal distances with a sharp angle P – As – P of only 93.0(1)°.
Übergangsmetall‐Stannyl‐Komplexe, 7. Darstellung von Carben‐Komplexen (π1‐Aromat)(CO)2CrCR2 durch Umsetzung der anionischen Stannyl‐Komplexe [(π1‐Aromat)(CO)2CrSnPh3]– mit R2CX2 oder [R2CX]Y
Authors: Schubert Jürgen , Mock Stefan , Schubert Ulrich 
Published: July 2007

Transition Metal Stannyl Complexes, 7[1]. – Preparation of Carbene Complexes (π1‐Arene)(CO)2CrCR2 by the Reaction of the Anionic Stannyl Complexes [(π1‐Arene)(CO)2CrSnPh3]– with R2CX2 or [R2CX]YCarbene complexes (π1‐arene)(CO)2CrCR2 are formed in substitution/elimination reactions from the anionic stannyl complexes K[(π1‐arene)(CO)2CrSnPh3] [π1‐areneC6H6 (1a), 1,3,5‐Me3C6H3 (1b), 1,2,4,5‐Me4C6H2 (1c)] C6Me6 (1d) and organic dihalides R2CX2 containing activated C – X bonds or ionic halides [R2CX]Y. Bis(stannyl) complexes (π1‐arene)(CO)2Cr(SnPh3)2 (3) and hydrido(stannyl)complexes (π1‐arene)(CO)2Cr(H)SnPh3 are formed as byproducts due to the reaction of the eliminated Ph3SnCl with the anionic starting complexes or electron transfer reactions, respectively. The portion and ratio of the byproducts is largely influenced by the steric properties of both the (π1‐arene)(CO)2Cr fragment and the organic halide. Pyridinylidene complexes 2) are only obtained from 2‐chloro‐N1‐methylpyridinium tetrafluoroborat with 1a – c, but not with 1d. With the sterically less demanding halides [R2NC(H)Cl]Cl [NR2NMe2, (n3, 4)] or 3,3‐dichloro‐1,2‐diphenylcyclopropene the carbene complexes (π1‐arene)(CO)2CrC(H)NR2 or are obtained with all employed π1‐arene ligands.
Über die‐Synthese und Molekülstruktur von CH3M(SiH3)3 (MSi, Ge)
Authors: Lobreyer Thomas , Oeler Johannes , Sundermeyer Wolfgang , Oberhammer Heinz 
Published: July 2007

Synthesis and Molecular Structure of CH3M(SiH3)3 (MSi, Ge)A solution of 2‐isotetrasilanylsodium (1a) was obtained in good yield from silane and sodium under special conditions. Methylation of 1a with methyl p1‐toluenesulfonate yields 2‐methylisotetrasilane (1b). The corresponding methyltrisilylgermane (2b) was synthesized via (K, Cs)Ge(SiH3)3 (2a) resulting from the reaction of cesium trichlorogermanide with KSiH3 followed by methylation. The molecular structures of 1a and 1b were determined by electron diffraction analyses.
Vinylidene Transition Metal Complexes, XXII[1]. – Alkyne, Alkynyl(hydrido)1‐, Vinylidene‐, and Vinylvinylidene Complexes of Rhodium from OH‐, NH2‐, and Cl‐Functionalized Alkynes
Authors: Werner Helmut , Rappert Thomas 
Published: July 2007

AbstractThe reaction of [RhCl(PiPr3)2]n with γ1‐functionalized 1‐alkynes HCC‐CRR′X (XOH, OMe, Cl, NH2) at room temperature leads to the formation of either alkyne‐, alkynyl(hydrido)1‐, or vinylidenerhodium complexes. The alkyne and alkynyl‐(hydrido) derivatives rearrange thermally or in the presence of deactivated Al2O3 to the isomeric vinylidenerhodium compounds in almost quantitative yield. On treatment of the γ1‐functionalized vinylidenerhodium complexes trans‐[RhCl(CCH‐CRR′X)(PiPr3)2] with Al2O3 or traces of acids, elimination of HX occurs and (for RH, CH3; R′CH3; XOH, Cl, NH2) the (vinylvinylidene)rhodium compounds trans‐[RhCl(CCH‐CRCH2)(PiPr3)2] are formed. In contrast, the reaction of trans‐[RhCl(CCHCPh2OH)(PiPr3)2] with either Al2O3 or acid gives the allenylidene complex trans‐[RhCl(CCCPh2)(PiPr3)2]. The 1‐hexyne derivatives HCC[CH2]3CH2X (XOH, Cl) react with [RhCl(PiPr3)2]n to give alkyne‐, alkynyl(hydrido)1‐, and vinylidenerhodium compounds; attempts to form the cyclic vinylidene complex trans‐ by HX elimination from trans‐[RhCl(CCCH[CH2]3CH2X)(PiPr3)2] (XOH, Cl) failed. The half‐sandwich‐type (vinylvinylidene)rhodium compounds [C5H5Rh(CCH‐CRCH2)(PiPr3)] (RH, Me) are obtained from [RhH(CC‐CRCH2)Cl(py)(PiPr3)2] and NaC5H5.
Synthesewege zu (μ1‐HO)Zn21‐Komplexen
Authors: Alsfasser Ralf , Vahrenkamp Heinrich 
Published: July 2007

Synthetic Pathways for (μ1‐HO)Zn2 ComplexesThe reactions of the 3‐substituted kalium hydrotris(pyrazolyl)1‐borates 1c, d (Rtert1‐butyl, anisyl) with Zn(ClO4)2 · 6 H2O produce the dinuclear μ1‐hydroxo complexes [L3Zn – O(H) – ZnL3](ClO4)3 (2a, b; L5‐tert1‐butylpyrazole, 5‐anisylpyrazole), due to hydrolytic cleavage of the B – N bonds. These and similar complexes (2c, d;5‐tert1‐butyl‐3‐methylpyrazole, 5‐phenylpyrazole) are also accessible directly from Zn(ClO4)2 · 6 H2O, the substituted pyrazole, and KOH, and in one case (2b; L5‐anisylpyrazole) by hydrolytic cleavage of [HB(3‐anisylpyrazolyl)3ZnEt] with perchloric acid. With other pyrazole and imidazole ligands, the Zn(ClO4)2/L/KOH reaction produces the simple complexes [ZnL6](ClO4)2 (3a, b; Lpyrazole, 3‐methyl‐5‐phenylpyrazole) and [ZnL4](ClO4)2 (4; L2‐methylimidazole). The crystal structures of 2a and 4, each containing tetrahedrally coordinated zinc atoms, have been determined.
(Bicyclo[3.2.0]hepta‐1,3‐dienyl)cobalt(I) Complexes
Authors: Angermund Klaus P. , Betz Peter , Butenschön Holger 
Published: July 2007

AbstractThree isomeric bicyclo[3.2.0]heptadienes 1 – 3 are compared by semiempirical calculations. Experimental attempts directed to the synthesis of derivatives of 1 are described. The synthesis, properties and some reactions of (η51‐bicyclo[3.2.0]hepta‐1,3‐dienyl)(η41‐cycloocta‐1,5‐diene)cobalt(I) (22), including an X‐ray crystal structure determination of the reaction product with diphenylethyne, the tetraphenylcyclobutadiene complex 30, are presented.
Enzym‐katalysierte Reaktionen, 15. Darstellung von (R)1‐2‐(Sulfonyloxy)nitrilen und ihre Reaktionen mit Acetaten — Konfigurationsumkehr optisch aktiver Cyanhydrine[2]
Authors: Effenberger Franz , Stelzer Uwe 
Published: July 2007

Enzyme‐Catalyzed Reactions, 15[1]. – Preparation of (R)1‐2‐(Sulfonyloxy)nitriles and Their Reactions with Acetates – Inversion of the Configuration of Optically Active Cyanohydrins2‐(Sulfonyloxy)nitriles (R)‐6, 7, 8 are obtained in high optical purity from the respective cyanohydrins (R)‐2 by sulfonylation with methanesulfonyl chloride (3), toluenesulfonyl chloride (4), and trifluoromethanesulfonic anhydride (5), respectively. In contrast to the aliphatic (sulfonyloxy)nitriles (R)‐6, 7, 8a – e, the benzylic‐type mandelic acid derivatives (R)‐7,8í are unstable at higher temperature. The 2‐(sulfonyloxy)nitriles (R)1‐ 6, 7, 8a – e react at room temperature with alkali acetates in a typical SN2 manner to give the cyanohydrin acetates (S)‐9 in high optical purity. Under these reaction conditions, however, the mandelic‐type compounds (R)‐7, 8í partly racemize and decompose. By hydrolysis of the acetates (S)‐9, (S)1‐cyanohydrins (S)‐2 of aliphatic aldehydes are easily available.
Photoinduced Electron Transfer in Porphyrin‐Quinone Cyclophanes, 8 Conformational Mobility and Crystal Structures of Porphyrin‐Quinone Cyclophanes
Authors: Krieger Claus , Dernbach Matthias , Voit Guido , Carell Thomas , Staab Heinz A. 
Published: July 2007

AbstractIn order to correlate photoinduced electron‐transfer in porphyrin‐quinone cyclophanes to specific molecular conformations, the internal mobility of single‐and double‐bridged porphyrin‐quinone cyclophanes was studied by low‐temperature 1H‐NMR measurements. The dynamic processes observed are discussed in terms of N‐H/N tautomerisation, of the rotation of the rings in the bridges, and of a specific “swinging bridge” process back and forth between two equivalent unsymmetrical conformations with a tilted orientation of the porphyrin and quinone ring planes. For comparison with the conformational situation in solution the results of X‐ray structure analyses of 3(XOMe) and 6, as representative examples of single‐bridged quinone‐porphyrin cyclophanes, and of the corresponding tetramethoxybenzene‐bridged octamethylporphyrin cyclophane 4(XOMe) are reported and discussed. In contrast to the previously solved crystal structure of the quinone‐porphyrin‐quinone cyclophane 1(XH), all three X‐ray structure analyses of the single‐bridged porphyrin cyclophanes proved the existence of unsymmetrical, tilted‐plane structures similar to those discussed as the stable conformations in the “swinging bridge” process.
Pyrano[4,3‐b]pyran‐2,5‐dione, 1. Einfache Synthese von Pyranopyrano‐chinolintrionen
Authors: Saalfrank Rolf W. , Hörner Bernd 
Published: July 2007

Pyrano[4,3‐b]pyran‐2,5‐diones, 1. – Convenient Synthesis of Pyranopyrano‐quinolinetrionesReaction of malondiamides 1 with malonyl chloride (5) leads to 2,5‐dioxo‐2H,5H1‐pyrano[4,3‐b]pyrans 7, which readily react with diazomethane to give the corresponding methyl ethers 8. Thermically induced cyclisation of 8 affords 7,12‐dihydro‐2H,5H1‐pyrano[2′,3′ :4,5]pyrano [2,3‐b]quinoline‐2,5,12‐triones 9. Acidic hydrolysis of 9 yields 4H1‐pyrano[2,3‐b]quinoline‐4,5(10H)1‐diones 10, while basic hydrolysis of 9 gives 4‐hydroxy‐2(1H)1‐quinolinones 11.
Metallkomplexe in Biologie und Medizin, VI. Darstellung und Kristallstruktur von (Penicillaminato‐O,S,N)bismut(III)1‐chlorid
Authors: Herrmann Wolfgang A. , Herdtweck Eberhardt , Pajdla Liba 
Published: July 2007

Metal Complexes in Biology and Medicine, VI[1]. – Synthesis and Structure of (Penicillaminato‐O,S,N)bismuth(III) ChlorideBismuth(III) oxychloride reacts with D‐(–)1‐penicillamine to form [D‐(–)1‐penicillaminato‐O,S,N]bismuth(III) chloride (1), the solid state structure of which has been determined by single‐crystal X‐ray diffraction. The tridentate chelation of the metal center by sulfur, nitrogen, and oxygen atoms leads to the formation of five‐membered rings. Due to interaction of bismuth with oxygen atoms of the carboxy groups, a polymeric two‐dimensional structure results in the crystal lattice. Bismuth has a seven‐fold inner coordination sphere.
1,2‐Azaborolyl‐Komplexe, XXVIII. (η5‐1‐tert1‐Butyl‐2‐methyl‐1,2‐azaborolyl)carbonyl‐Phosphan‐und ‐Olefin‐Cobalt‐Komplexe
Authors: Schmid Günter , Kilanowski Bert , Boese Roland , Bläser Dieter 
Published: July 2007

1,2‐Azaborolyl Complexes, XXVIII[1]. – (η5‐1‐tert1‐Butyl‐2‐methyl‐1,2‐azaborolyl)carbonyl Phosphane and ‐Olefin Cobalt ComplexesBy using (η5‐1‐tert1‐butyl‐2‐methyl‐1,2‐azaborolyl)dicarbonyl‐cobalt [η51‐AbCo(CO)2] (1) as starting material, various phos‐phane and olefin derivatives of the type AbCo(CO)L are synthesized. The phosphanes LPMe3, PEt3, P(nPr)3, P(nBu)3, and P(OPh)3 give, due to the chirality of 1, the enantiomeric compounds 2–6, whereas the phosphanes P(tBu)MePh, P(OsBu)Ph2, and PPh2 [OCH(CH3)CO2CH3] form the diaster‐eoisomers 7–9. The orange‐red, oily and volatile compounds are isolated with yields between 30 and 60%. The mechanism of formation of [η51‐AbCo(CO)PMe3] (2) has been studied by means of intermediates at low temperatures. To avoid a 20e configuration when PMe3 is added to 1, the allyl complex [η31‐AbCo(CO)2PMe3] (2a) is formed. With an excess of PMe3 it can even be transferred into the mono‐hapto complex [η11‐Ab‐Co(CO)2(PMe3)2] (2b) with a Co – C‐3 s̀ bond. 2a as well as 2b change to [η51‐AbCo(CO)PMe3] (2) when warmed up to room temperature. In contrast to substitution reactions of [Cp‐Co(CO)2] where intermediates have never been observed, here an addition‐elimination process is proved. With dimethyl ma‐leate, maleic anhydride, and methylmaleic anhydride three olefin complexes 10, 11, and 12 are obtained. However, 10 contains the fumaric ester, due to a cis‐trans isomerisation during the complexation. X‐ray structure analyses prove the molecular structures of 11 and 12. The original goal of this project, namely to prepare pure enantiomeric [η51‐AbCo‐(CO)olefin] half‐sandwich complexes in order to study the ster‐eoselective influence of the Ab ring on addition reactions to the olefin ligands could not yet be reached.
AM1 and X‐ray Studies of the Structures and Isomerization Reactions of Indigo Dyes
Authors: Grimme Gabriele , Boldt Peter , Grimme Stefan , Jones Peter G. 
Published: July 2007

AbstractAM1‐SCF and AM1‐SDCI calculations have been carried out for indigo and three conformers of N,N′1‐diacetylindigo in their cis and trans configurations. The molecular structure of trans‐ N,N′1‐diacetylindigo was determined by X‐ray diffraction. The calculated ground‐state data obtained within the SCF approximation (relative energies, structural parameters) are in excellent agreement with the corresponding experimental values. Potential energy curves (PEC) for the isomerization reaction cis/trans in several electronic states were obtained from AM1‐SDCI calculations. For N,N′1‐diacetylindigo the ground state PEC has a maximum at a torsion angle about the central CC bond of 90°, whereas the S1‐ and T11‐state PEC's show minima at the corresponding geometry. For indigo itself significant barriers to the photoisomerization in the S1‐ and T11‐excited states are predicted because of increased NH…OC hydrogen bonding. The results provide an explanation for the phototropic behaviour of N,N′1‐diacetylindigo and the photostability of indigo. The calculated enthalpies of activation for the isomerization process cis → trans in the ground state compare well with available experimental data, thus rendering feasible the prediction of the thermal stability of cis isomers not yet synthesized.
Substituenteneffekte auf die C – C‐Bindungsstärke, 11. Thermolyse von Tetraalkylpinacoldimethylethern
Authors: Birkhofer Hermann , Beckhaus Hans‐Dieter , Rüchardt Christoph 
Published: July 2007

Effects of Substituents on the Strength of CC Bonds, 11[1]. – Thermolysis of Tetraalkylpinacol Dimethyl EthersThe products and the kinetics of the thermolysis reaction of the pinacol dimethyl ethers 1a‐1f have been studied. A linear correlation between Δ≢ (300°C) of thermolysis and the strain enthalpies Hs of 1, or its release Ds during the dissoziation into radicals 2, is observed. From this correlation a stabilization enthalpy HR2.1 ± 0.5 kcal/mol is deduced for α1‐methoxy‐alkyl radicals 2 as compared to tert1‐alkyl radicals.
Kohlenwasserstoffverbrückte Komplexe, XXVII. C—C‐Kupplung von ungesättigten Kohlenwasserstoffen in anionischen und kationischen Komplexen. Addition der Anionen von μ1‐(Diphenylmethan)1‐, μ1‐Fluoren‐und μ1‐(9,10‐Dihydroanthracen)1‐bis(tricarbonylchrom) an koordinierte Olefin‐, Benzol‐, Cyclohexadienyl‐, Cycloheptadienyl‐und Cycloheptatrienyl‐Liganden
Authors: Wieser Michael , Karaghiosoff Konstantin , Beck Wolfgang 
Published: July 2007

Hydrocarbon‐Bridged Complexes, XXVII[1]. – CC Coupling of Unsaturated Hydrocarbons of Anionic and Cationic Complexes. Addition of Anions from μ1‐(Diphenylmethane)1‐, μ1‐Fluorene‐, and μ1‐(9,10‐Dihydroanthracene)1‐bis(tricarbonylchromium) to Coordinated Olefin, Benzene, Cyclohexadienyl, Cycloheptadienyl, and Cycloheptatrienyl LigandsHerrn Professor Herbert D. Kaesz zum 60. Geburtstag gewidmet.
The addition of the anions 1 – 3 of μ1‐(diphenylmethane)1‐, μ1‐fluorene‐, and μ1‐(9,10‐dihydroanthracene)1‐bis(tricarbonylchromium) to π1‐bonded hydrocarbons (olefin, benzene, cyclohexadienyl, cycloheptadienyl, and cycloheptatrienyl) in cationic complexes of manganese, rhenium, iron, chromium, molybdenum, tungsten, and cobalt provides a synthesis of new hydrocarbon‐bridged heterometallic complexes 4 – 10.
Organo‐substituierte Silole durch zweifache Organoborierung von Di‐1‐alkinylsilanen
Authors: Köster Roland , Seidel Günter , Süß Jürgen , Wrackmeyer Bernd 
Published: July 2007

Organo‐Substituted Siloles by Twofold Organoboration of Di‐1‐alkynylsilanesMe2Si(CCR)2 [RMe (A), Bu (B), tBu (C), iPent (D), Ph (E), Me3Si (F)], prepared from Me2SiCl2 and MCCR (MLi, Na, K), react with Et3B by 1,1‐ethyloboration to form the organo‐substituted siloles Me2 (1a – f) in high yields with different reaction rates: F > B ≈︁ D > A > C > E. Me2Si(C CiPent)(C  CPh) (H) and Et3B give a 5 : 1 mixture of the two regioisomeric substituted siloles 2 and 2′. – 1a and e are deborylated with H2NCH2CH2OH or MeCO2H to 3a and e, respectively. 1a reacts with maleic anhydride to yield the [4 + 2] addition compound 4a. With (OC)5Fe, Cp‐Co(C2H4)2, and (CDT)Ni the cycloracemic (ligand)transition metal η41‐complexes [(OC)3Fe‐1a (5a), (OC)3Fe‐3a (6a), CpCo‐3a (7a)] and the cyclodiastereomeric η4,η41‐complexes Ni‐(3a)2 (8a/8a′) are formed. All products were characterized by multinuclear NMR, including measurements of J(29Si13C) and J(13C13C).
Synthesis and Chemical Transformations of 1,3‐Diaryltetrazolium Salts. Preparation of Mercury(II) and Palladium(II) Complexes of 1,3‐Diaryltetrazolylene and Reactions of 5‐Substituted 1,3‐Diphenyltetrazolium Salts with Nucleophiles
Authors: Araki Shuki , Wanibe Yasumi , Uno Fujio , Morikawa Akinao , Yamamoto Kaori , Chiba Kyoko , Butsugan Yasuo 
Published: July 2007

Abstract1,3‐Diaryltetrazolium salts 5 and 6 have been prepared by nitric acid oxidation of the corresponding 5‐thiolates 4. The reaction of 5 with mercury(II) acetate gives (1,3‐diaryltetrazolylene)mercury(II) complexes 7, which provide 5‐halotetrazolium salts 8 – 10 by treatment with halogen. 1,3‐Diphenyltetrazolylene (16), generated in situ by proton abstraction of 1,3‐diphenyltetrazolium salts 5a or 6a, has been trapped with p‐(dimethylamino)benzenediazonium tetrafluoroborate to form 18/18′. The palladium(II) complex 19 of 1,3‐diphenyltetrazolylene has been prepared by oxidative addition of tetrakis(triphenylphosphane)palladium(0) to 5‐chlorotetrazolium salt 8. The reactivity of various 5‐substituted tetrazolium salts toward carbon nucleophiles depends on the nature of the substituents at C‐5. With electronegative substituents, nucleophilic substitution proceeds at C‐5, whereas electron‐donating substituents direct the nucleophiles towards N‐2 yielding ring‐cleaved products.
Syntheses and Structures of Transition‐Metal Complexes of Mesoionic Olate, Thiolate, Selenolate, and Cyclopentadienide
Authors: Araki Shuki , Butsugan Yasuo 
Published: July 2007

AbstractThe dicarbonyl(η1‐cyclopentadienyl)iron(II) complex 5 of 1,3‐diphenyltetrazolium‐5‐olate (4) and the pentacarbonylmolybdenum(0) complexes 7, 11, and 9 of 1,3‐diphenyltetrazolium‐5‐thiolate (6), −5‐selenolate (10), and 5‐methyl‐1,4‐diphenyl‐1,2,4‐triazolium‐3‐thiolate (8) as well as tricarbonylchromium(0) complex 13 and ‐molybdenum(0) complex 14 of 1,3‐diphenyltetrazolium‐5‐cyclopentadienide (12) have been prepared. Their physicochemical properties are discussed on the basis of spectroscopic properties.
Synthese und Charakterisierung von substituierten Nickelhemiporphyrazinen
Authors: Hanack Michael , Haberroth Klaus , Rack Michael 
Published: July 2007

Synthesis and Characterization of Substituted Nickel HemiporphyrazinesThe butoxy‐substituted (hemiporphyrazinato)nickel compounds (C4H9O)2HpNi (7), (C4H9O)4HpNi (11), and (C4H9O)6HpNi (12) are prepared from isoindolenine 4 or 4,7‐dibutoxy‐1,3‐dihydro‐1,3‐diiminoisoindole (8), 2,6‐diaminopyridines and nickel acetate. The complexes 7, 11, and 12 are soluble in common organic solvents and were characterized by 1H‐and 13C‐NMR spectroscopy.
Reactions of Electrochemically Generated Organometallics, 2. The Use of Zinc, Tin, Aluminium, Indium, and Iron as Sacrificial Anodes in the Electrochemically Assisted Reformatsky Reaction of Ethyl 2‐Bromoalkanoates with Succinic Anhydride
Authors: Schwarz Karl‐Heinz , Kleiner Katharina , Ludwig Rolf , Schick Hans 
Published: July 2007

AbstractZinc, tin, aluminium, indium, and iron were applied as sacrificial anodes in the electrochemically assisted Reformatsky reaction of succinic anhydride (1) with ethyl 2‐bromoalkanoates 2. In all cases the expected 1‐ethyl 3‐oxohexanedioates 3 were abtained in good to moderate yields. However, the amount of current consumed for the dissolution of one equivalent of anode metal strongly depends on the kind of metal. Whereas aluminium and iron require 1 Faraday per equivalent (Faraday val–1), tin demands only 0.9 Faraday val–1, and zinc and indium require an even smaller amount of current. It is assumed that in the case of the last three metals the electro‐chemical Reformatsky reaction is overlapped by a current‐independent normal Reformatsky reaction, in which the anode acts as activated metal.
Rate‐Determining Effects in the Formation of Hantzsch 1,4‐Dihydropyridines from N‐(1‐Haloalkyl)azinium Halides and Methyl 3‐Amino‐2‐butenoate
Authors: Eynde Jean‐Jacques Vanden , Mayence Annie , Maquestiau André , Anders Ernst 
Published: July 2007

AbstractN‐(1‐Haloalkyl)azinium halides react with methyl 3‐amino‐2‐butenoate to yield 4‐substituted dimethyl 1,4‐dihydro‐2,6‐dimethyl‐3,5‐pyridinedicarboxylates. The rates of formation of the latter compounds are monitored by 1H‐NMR spectroscopy. Mechanistic and practical considerations are discussed.
Flüssigkristalline Verbindungen, 77. Neue makroheterocyclische Palladium‐Komplexe
Authors: Gündogan Bilgi , Praefcke Klaus 
Published: July 2007

Liquid Crystals, 77[1]. – Novel Macroheterocyclic Palladium ComplexesThe double cyclopalladation of the bisimine 1 affords spacious tetrapalladium complexes 2a – c which represent new thermotropic metallomesogens, the heaviest low‐molecular liquid crystals (mol. mass ≈︁ 3500 – 4000) studied so far.