ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Organische Synthesen mit übergangsmetall-Komplexen, 51. 1-Metalla-1,3,5-triene und 1-Metalla-1,3-dien-5-ine von Chrom und Wolfram durch Insertion von Alkinen in M=C- bzw. C=C-Bindungen von 1-Metalla-1,3-dienen bzw. 1-Metalla-1-en-2-inen (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 1229-1236 
    Details
    ISSN: 0009-2940
    Keywords: Carbene complexes of chromium and tungsten ; 1-Metalla-1,3,5-trienes ; 1-Metalla-1,3-dien-5-ynes ; Insertion of alkynes into M=C and C=C bonds ; [2 + 2] Cycloaddition reactions of carbene complexes and alkynes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic Syntheses via Transition Metal Complexes, 51. - 1-Metalla-1,3,5-trienes and 1-Metalla-1,3-dien-5-ynes of Chromium and Tungsten by Insertion of Alkynes into M=C and C=C Bonds of 1-Metalla-1,3-dienes and 1-Metalla-1-en-3-ynes, respectively1-Metalla-1,3,5-trienes LnM=C(NEt2)-C(Me)—C(OEt)-CH=CHPh (3,4) and LnM=C(OEt)- CH=C(NEt2) - C(Me)=CHPh [5, LnM=Cr(CO)5 (a), W(CO)5 (b)] are obtained for the first time from the corresponding 1-metalla-1,3-dienes LnM=C(OEt) - CH=CHPh (1a, b) under very mild conditions by the insertion of the electron-rich alkyne Et2N-C ≡ C - Me (2) into the M=C and the C=C bonds, respectively, of 1. The chelate complex (6b) and the cyclobutenyl carbene complex 7b are isolated as minor side products. 1-Metalla-1,3-dien-5-ynes LnM=C(NEt2) - C(Me)=C(OEt) - C ≡ CPh [9, 10, LnM=Cr(CO)5 (a), W(CO)5 (b)] are formed with high regio- and stereoselectivity on insertion of 2 into the M=C bonds of 1-metalla-1-en-3-ynes 8. X-ray data are given for the tungsten complex 3b.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19911240541
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Organische Synthesen mit Übergangsmetallkomplexen, 53 4-Methylencyclopentene und 5-Methylencyclohexenone aus „Fischer-Carben“- Chromkomplexen, Allenen und Alkine (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 2335-2342 
    Details
    ISSN: 0009-2940
    Keywords: Cyclopentenes, 4-methylene-, synthesis of ; Cyclohexenones, 5-methylene-, synthesis of ; Tri(methylene)-methane chromium complexes ; [3 + 2]Cycloadditions with tri(methylene)methane complexes ; Carbene chromium complexes for organic synthesis ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic Syntheses via Transition Metal Complexes, 53.  -  4-Methylenecyclopentenes and 5-Methylenecyclohexenones from “Fischer Carbene” Chromium Complexes, Allenes, and AlkynesA method is described for the two-step construction of 4-methylenecyclopentenes 6 and 5-methylenecyclohexenones 7 from Fischer carbene chromium complexes, allenes, and alkynes. In the first step a tri(methylene)methane complex 3 is generated by the addition of the carbene chromium complex (CO)5Cr = C(0Et)Ph (1) to the allene 2. The second step involves an addition of 3 to alkynes HC≡CR [5: R = Ph (a), SiMe3 (b)] at 75°C to give 6 and/or 7 in high chemical yields. The product ratios strongly depend on the substituents R.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19911241029
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Organische Synthesen mit Übergangsmetall-Komplexen, 50 2H-Pyrrol-Komplexe durch stufenweise Insertion von Alkinen und Isocyaniden in M=C-Bindungen von Chrom- und Wolfram-Carbenkomplexen (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 213-218 
    Details
    ISSN: 0009-2940
    Keywords: Carbene complexes of chromium and tungsten ; 1-Metalla-1,3-dienes ; Insertion of alkynes and isocyanides into M = C bonds ; 2H-Pyrrole complexes of chromium and tungsten ; [1+2+2] Cycloaddition reactions of carbene complexes, alkynes and isocyanides ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic Syntheses via Transition Metal Complexes, 501). - 2H-Pyrrole Complexes by a Stepwise Insertion of Alkynes and Isocyanides into M=C Bonds of Carbene Chromium or Tungsten Complexes2H-Pyrrole complexes 6a, b are obtained in two step by [1+2+2] cycloaddition reactions of the carbene complex (CO)5W=C(OEt)C6H5 (1d), the alkyne EtO-C≡CH (2) and isocyanides R1-NC 4a, b [R1 = CH3, c-C6H11). Ln=C(OEt)R 1 [LnM = Cr(CO)5, W(CO)5; R = C6H5, CH3] reacts with 2 to give 1-metalla-1,3-dienes 3a-d. (E)/(Z)-3d and 4 yield 6a, b via 1-aza-1,2,4-pentatriene complexes 5, which are open-chain precursors of 6. 2H-Pyrrole complexes 11 and 14 are synthesized in overall [2+1+2] cycloadditions withe reversed connectivity, or formation of 1-chroma-1,3-dienes 10 and 13 by condensation of the methylcarbene complex 1a with acid amides, and cyclisation again with isocyanides 4.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19911240132
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Organische Synthesen mit übergangsmetall-Komplexen, 52 N-Vinylaminocarben- und N-(2-Propenyl)aminocarben-Komplexe durch Addition von Keteniminen an Carben-Eisenkomplexe (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 1795-1803 
    Details
    ISSN: 0009-2940
    Keywords: Aminocarbene complexes of iron ; N-Vinylaminocarbene complexes ; π-Allyl,σ-complexes of iron ; N-(2-Propenyl)aminocarbene complexes ; Methylenation of ketene imines by carbene complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic Syntheses with Transition Metal Complexes, 52 1). - N-Vinylaminocarbene and N-(2-Propenyl)aminocarbene Complexes by Addition of Ketene Imines to Carbene Iron ComplexesKetene imines R(Me)C = C = NPh (2, R = Me, Et, i-Pr) form 1 : 1 adducts with the carbene iron complex (CO)4,Fe=C(OEt)Ph (1). The initial step of the reaction involves an attack of the nitrogen atom of 2 at the carbene carbon atom of 1 and a subsequent rearrangement to give N-vinylaminocarbene complexes (E/Z)-4. In a parallel process with different regiochemistry the central carbon of the CCN unit is attached to the carbene carbon to yield π-allyl,σ-complexes (E/Z)-3. Alkylation of 3a with [Et3O]BF4 leads to the formation of a cationic N-(2-propenyl)-aminocarbene complex 6a. Protonation of 4 with trifluoroacetic acid results in a ring contraction to give the four-membered metallacycles 7. X-ray data are reported for prototypes (Z)-4c and 6a.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19911240816
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Organische Synthesen mit Übergangsmetall-Komplexen, 56 Homopyrrole und Dihydropyridine aus N-Vinylaminocarben-Eisenkomplexen und Alkinen durch Cyclisierung intermediärer 5-Aza-1-metalla-1,3,6-triene (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 2595-2602 
    Details
    ISSN: 0009-2940
    Keywords: Homopyrroles, mono- and bicyclic ; [3 + 2] Cycloadditions of N-vinylaminocarbene iron complexes to alkynes ; 5-Aza-1-ferra-1,3,6-trienes ; Intramolecular cyclopropanation, metal-induced ; 2H-Pyrrolium tricarbonyl iron complexes ; Pyridine, 1,2-dihydro-, tricarbonyl iron complexes ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic Syntheses via Transition Metal Complexes, 561). - Homopyrroles and Dihydropyridines from N-Vinylamino-carbene Iron Complexes and Alkynes by Cyclisation of Intermediate 5-Aza-1-metalla-1,3,6-trienes2,3-Homopyrroles 5 and dihydropyridines 7, 8 are obtained by the light-induced addition of alkynes 4a - d (RC = CR1; R, R1 = H, CH3, C6H5, CO2CH3) to the N-vinylaminocarbene iron complex (= 3-aza-1-ferra-1,4-diene) 3. The formation of the N-heterocycles 5 and 7 as well as that of the pyrrolium carbonylferrates 6 can be explained by assuming the chelated 5-aza-1-ferra-1,3,6-trienes A to be key intermediates in this reaction. Stereochemical considerations lead to the conclusion that the ring expansion of the 4 1/2-membered ring of 3 to the 6 1/2-membered ring of A occurs without prior ≡ decomplexation by the insertion of a C = C unit into the M = C bond. NMR measurements and MNDO calculations suggest that the bicyclic homopyrroles 5 are in equilibrium with the novel monocyclic homopyrrole species 9. The structure of 6c has been established by X-ray diffraction analysis.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19911241132
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Organische Synthesen mit Übergangsmetall-Komplexen, 55 5-Aza-1-metalla-1,3,5-triene von Chrom und Wolfram sowie deren Cyclisierung zu 2H-Pyrrol-Komplexen (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 2587-2593 
    Details
    ISSN: 0009-2940
    Keywords: Aminocarbene complexes, of chromium and tungsten ; 3-Aza-1-metalla-1,3-dienes, of chromium and tungsten ; 5-Aza-1-metalla-1,3,5-trienes, cyclization to 2H-pyrroles ; 2H-Pyrrole complexes, of chromium and tungsten ; Pyrroles, syntheses by metal-induced [3 + 2] cycloaddition reactions ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic Syntheses via Transition Metal Complexes, 551). - 5-Aza-1-metalla-1,3,5-trienes of Chromium and Tungsten, and Their Cyclization to 2H-Pyrrole Complexes5-Aza-1-metalla-1,3,5-trienes 5 and 6 [LnM = C - C = C - N = C, a: LnM = Cr(CO)5, b: W(CO)5] are obtained in two steps from aminocarbene complexes 1 [LnM = C(NH2)Ph, a: LnM = Cr(CO)5, b: W(CO)5]. The first step involves the condensation of 1 with benzaldehyde (2) in the prescence of TiCl4/Et3N to give 3-aza-1-metalla-1,3-dienes 3 (LnM = C - N = C). 3 adds to the 1-aminoalkyne 4 to give 5 and 6 by a chain extension of two carbon atoms. The trans isomers 5 are formed as the major products and are stable both in the solid state and in solution. The cis isomers 6 undergo a novel-type cyclization to give 2H-pyrrole complexes 8. Triene 5b was characterized by an X-ray analysis.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19911241131
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Organische Synthesen mit Übergangsmetall-Komplexen, 54 Cyclopentadiene aus 1-Metalla-1,3-dienen und Alkinen durch Cyclisierung intermediärer 1-Metalla-1,3,5-triene (Metall = Wolfram) (1991)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 124 (1991), S. 2343-2347 
    Details
    ISSN: 0009-2940
    Keywords: Cyclopentadienes, synthesis of ; [3 + 2] Cycloadditions of 1-metalla-1,3-dienes and alkynes ; 1-Metalla-1,3,5-trienes of tungsten, cyclization to cyclopentadiene complexes ; η1-Cyclopentadiene tungsten complexes ; Aminocarbene complexes of chromium and tungsten ; Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Organic Syntheses via Transition Metal Complexes, 54.  -  Cyclopentadienes from 1-Metalla-1,3-dienes and Alkynes by Cyclization of Intermediate 1-Metalla-1,3,5-trienes (Metal = Tungsten)We report on first examples of the formation of cyclopentadienes from a 1-metalla-1,3-diene LnM=C-C=C [LnM = W(CO)5] and an alkyne in [3 + 2] cycloaddition multistep reactions. In a first step the alkyne Et2N-C=C-Me (2) adds to the 1-metalla-1,3-diene (CO)5W = C(OEt)-CH=CHPh (1b) to give 1-metalla-1,3,5-trienes (CO)5W=C(NEt2)-CMe=C(OEt)-CH=CHPh (3b) and (CO)5W=C(OEt)-CH=C(NEt2)-CMe=CHPh (4b). In a second step 3b cyclizes to thecyclopentadiene complex 5, which has an η1 ylide-type structure as established by an X-ray analysis. Hydrolysis of 5 leads to the formation of a 3-aminocyclopentenone 7. The 1-metalla-1,3,5-triene 4b yields a cyclopentadiene complex 8. In contrast to 5 the carbon skeleton of 8 has a connectivity different from that of the C3 unit of the 1-metalla-1,3-diene 1.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19911241030
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...