Rhodium phosphine ligand anchored

An example of such an analysis of rhodium phosphine ligand anchored catalysts is presented (58). A survey scan of a copolymer containing a diphosphine ligand prior to introduction of the metal is shown in Figure 1, spectrum h. The presence of phosphorus in the polymer is evident from this spectrum. 

Hydroformylation of vinyl acetate to give mainly the branched product in >90% ee has been achieved using a rhodium catalyst containing binaphthol and phosphine ligands anchored to polystyrene. 

Rhodium(I) complexes anchored by phosphine ligands usually have high selectivity but low stability.270-273 One of the possible way to tackle this problem is to bond the metal complexes by oxygen-containing anchoring ligands (14 in Fig. 7.12).274 275... 

The highly toxic osmium complex Os3(CO)8(M-Cl)2PPh3 was immobilized via an anchored phosphine ligand as Os3(CO)8(/x-Cl)2Ph2P-[Res]. The bonding may be more complex, for example, Kalck and coworkers have proposed that each rhodium atom of the dinuclear carbonyl is anchored to the resin (equation 9) ... 

Schweb and Mecking have reported one of the first examples of noncovalent anchoring of catalysts to soluble polymeric supports in 2001. This noncovalently anchored catalyst featured phosphine ligands that were bound by multiple sulfonate groups to soluble polyelectrolytes using electrostatic interactions. The catalyst system was employed in the hydroformylation of 1-hexene and exhibited typical selectivity for a bis-triphenylphosphine-bound rhodium catalyst. The complex was readily recovered and recycled by ultrafiltration. Independently, Reek et al. described similar systems, but these systems made use of a soluble... 

Here triphenylphosphine, the most important ligand in organometallic catalysis, is coupled to the benzene rings of cross-linked polystyrene. An anchored catalyst is then formed by coordination of the phosphine group to the metal center of a rhodium complex (Eq. 6-2). 

Benes prepared some new chiral phosphines suitable as ligands for this reaction.Capka anchored (C2H50)3Si(CH2)3P(Ph)Men to silica (6). Complexed with rhodium, a catalyst for the enantioselective hydrosilylation of ketones like acetophenone and propiophenone was obtained. 

Hughes, O.R. and Unruh, J.D. (1981) Hydroformylation catalyzed by rhodium complexes with diphosphine ligands. Journal of Molecular Catalysis, 12,71 Sanger, A.R. (1977) Hydroformylation of 1-hexene catalysed by complexes of rhodium(I) with di- or tritertiary phosphines. Journal of Molecular Catalysis, 3,221 Sanger, A.R. and Schallig, L.R. (1977) The structures and hydroformylation catalytic activities of polyphosphine complexes of rhodium(l), and related complexes immobilised on polymer supports. Journal of Molecular Catalysis, 3, 101 Pittman, C.U. and Hirao, A. (1978) Hydroformylation catalyzed by cis-chelated rhodium complexes - extension to polymer-anchored cis-chelated rhodium catalysts. The Journal of Organic Chemistry, 43, 640. 

A phosphine-phosphonium ylide ligand bearing a chiral sulfinyl moiety was prepared by the reaction of (o-diphenylphosphinophenyl)diphenylphosphonium methylide with (A)-menthyl / -tolylsulfinate. Reaction of this ylide with [Rh(cod)2]PF6 gave stable cationic disymmetrically P,C-chelated rhodium complexes 401 and 402 with an asymmetric ylidic carbon atom anchored to the metal center. 

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