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  • 1
    Digitale Medien
    Digitale Medien
    s.l. : American Chemical Society
    Organometallics 11 (1992), S. 3111-3116 
    ISSN: 1520-6041
    Quelle: ACS Legacy Archives
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 68 (1985), S. 1658-1669 
    ISSN: 0018-019X
    Schlagwort(e): Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The synthesis and characterization of the novel 4,7-bis(dialkylamino)tricyclo[5.2.1.04,10]deca-1(10), 2,5,8-tetraenes 12 from 1,4,7-trihalotriquinacenes 8 and secondary amines is reported. The structural and electronic characteristics of these as well as the acepentalene dianion (32-) and some related systems as determined by semiempirical (MNDO) calculations are discussed. Thereby, 32- should be a triply etheno-bridged trimethylenemethane dianion exhibiting Y-delocalization favored over the formation of a peripheral 10π-electronic system. Attempts directed towards the generation of 32- by reacting tetraenes 12 with Na led to the formation of tris(dialkylamino)triquinacenes 9, presumably by a kind of reduction/disproportionation mechanism.
    Zusätzliches Material: 8 Tab.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 713-724 
    ISSN: 0009-2940
    Schlagwort(e): Bicyclo[3.2.0]hepta-1,3-dienyl complexes ; Calculations, semiempirical ; Alkyne trimerization ; Cobalt complexes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Three 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.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 118 (1985), S. 2757-2776 
    ISSN: 0009-2940
    Schlagwort(e): Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Beschreibung / Inhaltsverzeichnis: Bridgehead Olefinic Isomers of Triquinacene: Derivatives of Tricyclo[5.2.1.04,10]deca-1,5,8- and -1,6,8-trieneBridgehead halides 12 and 13 of triquinacene (2) with soft nucleophiles undergo a syn-stereoselective SN2′ reaction forming derivatives of tricyclo[5.2.1.04,10]deca-1,5,8-triene 15 and 17, respectively, and of tricyclo[5.2.1.04,10]deca-1,6,8-triene 18. The relative stability of these bridgehead olefins is discussed with regard to force field calculations as well as semiempirical MNDO calculations.
    Notizen: Brückenkopf-Mono- 12 und -Dihalogenide 13 des Triquinacens (2) reagieren mit weichen Nucleophilen im Sinne einer syn-stereoselektiven SN2′-Reaktion zu Derivaten des Tricyclo[5.2.1.04,10]-deca-1,5,8-triens 15 bzw. 17 und des Tricyclo[5.2.1.04,10]deca-1,6,8-triens 18. Die relative Stabilität dieser Brückenkopf-Olefine wird anhand von Kraftfeld-Rechnungen sowie semiempirischen MNDO-Rechnungen diskutiert.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 5
    ISSN: 0009-2940
    Schlagwort(e): {[ω-(Phosphanyl)alkyl]cyclopentadienyl}cobalt(I) ; Cobalt complexes ; Bidentate ligand ; Alkynes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: An improved synthesis of [(2-phosphanylethyl)cyclopenta-dienyl]cobalt(I) chelate complexes is presented, in which the paramagnetic chloride 3 is a precursor of the ethene complex 4. The latter readily undergoes ligand exchange reactions which in the case of bidendate reagents (1,5-cyclooctadiene, 1,2-bis(diisopropylphosphanyl)ethane, 2,2′-bipyridine, nor-bornadiene) cause a decomplexation of the phosphane arm at room temperature with formation of 7, 5, 6, 8. The ethene ligand in 4 can be replaced by alkynes under equally mild reaction conditions (formation of 9, 11 - 16). The reaction with ethyne results in the formation of vinylidene complex 10. The yields of the reactions with nonaromatic alkynes could be improved by treating 3 with the alkyne in the presence of sodium amalgam. The unsubstituted vinylidene complex 10 and its tert-butyl derivative 17 were obtained by this route in 38 and 40% yield, respectively.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1651-1656 
    ISSN: 0009-2940
    Schlagwort(e): Bicyclo[3.2.0]hepta-1,3-dienyl complexes ; Ring slippage ; Cycloadditions ; Cobalt complexes ; DSC ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The title reaction, which was detected by a comparison of the DSC analysis of title compound 2 with that of the corresponding bicyclo[3.3.0]octa-1,3-dienyl complex 3, takes place at 200°C with various dienophiles (dimethyl fumarate, dimethyl maleate, diphenylethyne, N-methylmaleinimide). 3,4-Dimethylenecyclopentenyl complex 12 most likely is the key intermediate of the reaction.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 127 (1994), S. 137-144 
    ISSN: 0009-2940
    Schlagwort(e): Bicyclo[3.2.0]hept-2-en-6-one, cine substitution ; DSC ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: exo-7-Chloro-endo-7-phenylbicyclo[3.2.0]hept-2-en-6-one (5) undergoes cine substitution reactions with methoxide anions and with dialkylamines to give 5-methoxy or 5-dialkylamino derivatives 13, 14, 16-19 in high yield. While attempts directed to an acetalization have failed, the addition of Grignard reagents to the methoxy derivatives proceeds stereoselectively in high yield. Hydrochlorides 20/21 lose amine at 110°C to form 2-phenyltropone (22). Thermolysis of diethylamino derivative 24 at 170°C (temperature determined by DSC) results in the formation of the dienaminone 25.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 123 (1990), S. 93-99 
    ISSN: 0009-2940
    Schlagwort(e): (Bibenzyl)tricarbonylchromium(O)/Reductive coupling by Cr(0)/(Stilben)tricarbonylchromium(O) ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Reaction of Cr(CO)3(NH3)3 with benzylic mono-, di-, and trihalides leads to the formation of 1,2-diarylethanes, -ethenes, and diphenylethyne in satisfactory yields. Di(halomethyl)benzene derivatives yield product mixtures containing both reduction products and coupling products. With a higher excess in chromium(O), under otherwise unchanged reaction conditions, the corresponding (arene)tricarbonylchromium(O) complexes of the coupling products are formed in a one-pot reaction from the benzylic halides.
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
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  • 9
    ISSN: 0009-2940
    Schlagwort(e): Acepentalene ; 4,7-dihydro ; complexes ; Degenerate haptotropic rearrangement ; Cobalt complexes ; Iron complexes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The (cyclopentadienyl)cobalt(I) complex 4 of the 4,7-dihydroacepentaleneThe numbering of the ring system corresponds to the tricyclo-decatetraene nomenclature used in the Exp. Part. Thus, 4,7-substitution would be 2a,4a-substitution in acepentalene numbering. derivative 2b has been prepared by the reaction of the ligand with (cyclopentadienyl)bis(ethene)cobalt(I). NOE experiments indicate a complexation at the convex face of the polyolefinic ligand. 1H-NMR spectra establish a degenerate haptotropic rearrangement with CpCo migration from one diene unit to the adjacent one. The activation energy of this process is estimated to be 15 kcal/mol. An X-ray crystal structure determination of (η4-4,7-dihydroacepentalene)tricarbonyliron derivative 3a shows a distorted coordination of Fe(CO)3 at the convex face of the ligand, too.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 126 (1993), S. 1657-1669 
    ISSN: 0009-2940
    Schlagwort(e): Anions, [ω-(phosphanyl)alkyl]cyclopentadienyl ; Cobalt, [ω-(phosphanyl)alkyl]cyclopentadienyl complexes ; Cobalt(I) chelate complexes ; Iron, [ω-(phosphanyl)alkyl]cyclopentadienyl complexes ; Zirconium, [ω-(phosphanyl)alkyl]cyclopentadienyl complexes ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The syntheses and characterisation of the [ω-(phosphanyl)alkyl]cyclopentadienyl anions 2, 3, 6-8, 10, and 11 are described. These anions form metallocenes 12-15 and 17-19 with FeCl2 · 2 THF and with ZrCl4 · 2 THF, respectively. With ICo(CO)4 chelated carbonbyl complexes 23-25, 28, and 29 are formed. The unchelated intermediate 20 has been detected by IR spectroscopy. The carbonyl chelate complexes are thermally stable. Under photochemical conditions, ligand exchange reactions are possible which in the case of 1,5-cyclooctadiene proceed with decomplexation of the phosphane arm. This does not prevent a reaction at the cobalt(I) atom; treatment of 35 with diphenylethyne gives the corresponding tetraphenylcyclobutadiene complex 36 in good yield, the phosphane arm remaining uncoordinated.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
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