83288-25-9Relevant academic research and scientific papers
THE MECHANISM OF ASYMMETRIC HOMOGENEOUS HYDROGENATION. SOLVENT COMPLEXES AND DIHYDRIDES FROM RHODIUM DIPHOSPHINE PRECURSORS
Brown, John M.,Chaloner, Penny A.,Kent, Alexander G.,Murrer, Barry A.,Nicholson, Philip N.,et al.
, p. 263 - 276 (2007/10/02)
Bicyclohepta-2,5-diene and cycloocta-1,5 diene(biphosphine)rhodium tetrafluoroborates react with hydrogen at 1 atmosphere in methanol or other polar solvents.The initial product may be either a solvated dihydride or a solvate; depending on phosphine structure the equilibrium between these two species varies widely.Dihydrides are normally the stable product when the ligand is a monophosphine although (o-methoxyphenyl)methylphenylphosphine is an exception. cis-Chelating biphosphines normally form solvate complexes with no affinity for hydrogen.R-Phenyl bis-diphenylphosphinoethane falls into this category, but the 31P NMR spectra of its complexes demonstrate an equilibrium between monomeric and dimeric species, and addition of triethylamine gives rise to a trimer. trans-Chelating biphosphines show more variable behaviour, and in the case of bis-1,5-diphenylphosphinopentane, a number of complexes, including one requiring C-H activation, are observed.
31P NMR studies of catalytic systems containing rhodium complexes of chelating chiral and achiral diphosphines
Slack, David A.,Greveling, Ian,Baird, Michael C.
, p. 3125 - 3132 (2008/10/08)
31P NMR spectroscopy was utilized to determine the nature of the olefin hydrogenation catalyst species present in solution (a) on treating [RhCl(C2H4)2]2 with chelating diphosphines and (b) on treating the complexes [(NBD)Rh(diphosphine)]+ with hydrogen. In all cases, reaction of the generated species with (Z)-α-acetamidocinnamic acid was also studied. A brief investigation of the oxidative addition of hydrogen, hydrogen chloride, and oxygen to bis[1,3-bis(diphenylphosphino)propane]chlororhodium(I) was carried out.
