954149-64-5Relevant academic research and scientific papers
Coordination and catalytic properties of a semihomologous Dppf congener, 1-(diphenylphosphino)-1′-[(diphenylphosphino)methyl]ferrocene
Stepnicka, Petr,Cisarova, Ivana,Schulz, Jiri
, p. 4393 - 4403 (2011/10/18)
Alcohol Ph2PfcCH2OH (2, fc = ferrocene-1,1′- diyl) reacts smoothly with Ph2PH and Me3SiCl/NaI in acetonitrile to give 1-(diphenylphosphino)-1′-[(diphenylphosphino)methyl] ferrocene (1), a new ferrocene diphosphine that fills the obvious gap left between the well-studied 1,1′-bis(diphenylphosphino)ferrocene (dppf) and its bis-spaced analogue, 1,1′-bis[(diphenylphosphino)methyl]ferrocene. The P-oxidized alcohols Ph2P(E)fcCH2OH (E = O, 3; S, 4) behave similarly, yielding the corresponding semichalcogenides Ph 2P(E)fcCH2PPh2 (E = O, 5; S, 6). Exhaustive oxidations of 1 with hydrogen peroxide or elemental sulfur produce Ph 2P(E)fcCH2P(E)Ph2 (E = O, 7; S, 8), while similar oxidations of 5 and 6 afford the unsymmetric bis-chalcogenides Ph 2P(O)fcCH2P(S)Ph2 (9) and Ph 2P(S)fcCH2P(O)Ph2 (10), respectively. Compounds 1 and 3-10 were characterized by spectral methods, and the crystal structures of 3 and 8-10 were determined by single-crystal X-ray diffraction analysis. Compound 1 reacts with group 10 metal dichloride precursors to give the respective chelate complexes [MCl2(1-κ2P,P′)] (11, M = Ni; 12, M = Pd; and 13, M = Pt). The Ni complex is paramagnetic and tetrahedral; the Pd and Pt complexes are expectedly square-planar and diamagnetic. Crystal structures of 11-13 reveal less acute ligand bite angles (P-M-P′) than those observed in the analogous dppf complexes, the difference being considerably larger for the Ni complex than in the less flexible square-planar complexes. Similarly to dppf and fc(CH 2PPh2)2, ligand 1 reacts with [(L NC)PdCl]2 (LNC = [2-(dimethylamino)methyl] phenyl) to give a diphosphine-bridged complex, [(μ-1){(LNC)PdCl} 2] (14), whereas the reaction with the mononuclear precursor [(L NC)Pd(MeCN)2]ClO4 yields a mixture of isomeric bis-chelates [(LNC)Pd(1-κ2P,P′)]ClO 4 (15a,b). Catalytic tests in Pd-catalyzed Suzuki-Miyaura cross-coupling and in Pd-catalyzed cyanation of aryl halides with K 4[Fe(CN)6]?3H2O suggest that introduction of one methylene spacer group into the structure of dppf influences catalytic performance only marginally.
New (1-phosphanylferrocen-1′- and -2-yl)methyl-linked diaminocarbene ligands: Synthesis and rhodium(I) complexes
Labande, Agnes,Daran, Jean-Claude,Manoury, Eric,Poli, Rinaldo
, p. 1205 - 1209 (2008/02/06)
Two ferrocenylmethanols, [1′-(diphenylthiophosphanyl)-ferrocen-1-yl] methanol (3) and [2-(diphenylthiophosphanyl)-ferrocen-1-yl]methanol (6), have been converted in one step into the 1,1′- and 1,2-ferrocenediyl-linked thiophosphane/N-R-imidazolium salts 4a,b and 7a,b (a: R = Me; b: R = 2,4,6-Me3C6H2 or Mes). This straightforward method allows the linkage of an imidazolium group to a ferrocene unit with a nonsubstituted methylene bridge. After desulfurisation of the phosphane group, the ligands reacted with an RhI precursor, in the presence of tBuOK, to give cationic complexes 9a,b and 10a,b. All compounds were characterised by elemental analysis, NMR spectroscopy and mass spectrometry. The molecular structures of compounds 4a, 7a and 9a were determined by X-ray crystallography. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
