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  • P ligands  (2)
  • palladium  (2)
  • Allylic bromination  (1)
  • 1
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1999 (1999), S. 1091-1097 
    ISSN: 1434-193X
    Schlagwort(e): Phosphanorbornadiene ; Allylic metalation ; Allylic bromination ; BIPNOR dioxide ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: -3-Methyl-substituted 1-phosphanorbornadiene oxides or sulfides such as 1a,b are either metalated by a strong base (n-BuLi or LDA) or brominated by NBS at the methyl substituent. The reaction of the resulting delocalised carbanions 2a,b takes place either at C-2 (H+, MeI) or at the methylene group (Me3SiCl, ClPPh2, I2). In the last case, γ-functional (5a,b or 6a,b) or bridged (7) phosphanorbornadienes are obtained. Similarly, the reaction of 3-bromomethyl-1-phosphanorbornadiene oxides such as 8 with nucleophiles [NaCH(CO2Me)2, PhO-, Me2NH, PhCH2NH2] yields the corresponding γ-functional phosphanorbornadienes 9-12. This chemistry has also been applied to the BIPNOR dioxide 13.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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  • 2
    ISSN: 0947-6539
    Schlagwort(e): asymmetric catalysis ; hydrogenations ; palladium ; phosphorus ligands ; rhodium ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: Optically active phosphorus ligands are widely used in homogeneous asymmetric catalysis. However, among the numerous available structures of this type, the subclass of optically active bisphosphines with at least one chiral phosphorus atom is rather underdeveloped. A bisphosphine with two chiral, nonracemizable bridgehead phosphorus centers, (meso,d/l)-2,2′,3,3′-tetraphenyl-4,4′,5,5′-tetramethyl-6,6′-bis-1-phosphanorborna-2,5-dienyl (BIPNOR), can be obtained by thermolysis of 1,1′-bisphospholyl with diphenylacetylene. Here, we report the resolution of the d/l isomer by means of a chiral palladium complex to give the two optically active forms of BIPNOR. We then investigate the catalytic properties of BIPNOR, incorporated in RhI and RuII catalysts for the hydrogenation of olefins and ketones and in a PdII catalyst for asymmetric alkylation reactions. BIPNOR is shown to give good results in these catalytic reactions.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 130 (1997), S. 843-849 
    ISSN: 0009-2940
    Schlagwort(e): P ligands ; Phosphorus heterocycles ; 2-Phosphanylphosphinines ; Dinuclear complexes ; Metal carbonyls ; Chemistry ; Inorganic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Notizen: The 2-phosphanyl-4,5-dimethylphosphinines 1-5 are powerful bridging ligands able to stabilize metal-metal single and triple bonds between low-valent transition metal centres. Their reaction with Mn2(CO)10 in refluxing xylene yields the corresponding Mn2(CO)8 complexes 6 and 7. Reaction with [Fe2Cp2(CO)4] under UV irradiation similarly yields the Fe-Fe-bridged Fe2Cp2(CO)2 complexes 8 and 9. An additional observation is that the 2-phosphininyl-3,4-dimethylphosphaferrocene 10 is formed upon reaction of the 2-phospholylphosphinine 5 with [Fe2Cp2(CO)4] at high temperature under CO pressure. A clean addition occurs at the Mo≡Mo triple bond of [Mo2Cp2(CO)4] to give the Mo-Mo single-bonded complexes 11-15. The thermolysis of these complexes succeeds when the phosphanyl group is a phosphonite P(OEt)2 (13) or P(OAr)2 (14), affording cleanly the Mo2Cp2(CO)4 triple-bonded complexes 16 and 17, respectively. The metal-metal triple bonds of these complexes readily add two molecules of CO to reform 13 and 14, or one molecule of tBu-N≡C to give 18 and 19. The X-ray crystal structure analysis of the MO2C2(CO)4 complex 13a, with the 2-P(OEt)2- phosphinine, shows a gauche orientation of the two Cp rings and very short P-Mo bonds of 2.3565(4) and 2.406(2) Å to the phosphinine and P(OEt)2 groups, respectively.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 36 (1997), S. 2364-2366 
    ISSN: 0570-0833
    Schlagwort(e): homogeneous catalysis ; P ligands ; palladium ; platinum ; Chemistry ; General Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
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