Olefin hydrogenation catalyst

Polymer—Cp—MCl complexes have been formed with the Cp-group covalendy bound to a polystyrene bead. The metal complex is uniformly distributed throughout the bead, as shown by electron microprobe x-ray fluorescence. Olefin hydrogenation catalysts were then prepared by reduction with butyl hthium (262). 

Layered inorganic solids have been used for site isolation, for example, nickel phosphine complexes confined within the interlayer spaces of sepiolite have been used as olefin hydrogenation catalysts [63], and similarly there has been the encapsulation of metal complexes into zirconium phosphates [64], The principal idea is illustrated in Figure 5.8. The metal complex can be encapsulated by covalent means (a) or by non-covalent interactions (b). 

P-31 NMR was a powerful tool in studies correlating the structure of tertiary-phosphine-rhodium chloride complexes with their behavior as olefin hydrogenation catalysts. Triphenylphosphine-rhodium complex hydrogenation catalyst species (1) were studied by Tolman et al. at du Pont and Company (2). They found that tris(triphenylphosphine)rhodium(I) chloride (A) dissociates to tri-phenylphosphine and a highly reactive intermediate (B). The latter is dimerized to tetrakis(triphenylphosphine)dirhodium(I) dichloride (C). 

The bis(rj-cyclopentadienyl)titanium(III) aryl complexes form interesting dinitrogen derivatives (Section III,B) the 1-methyl, 17-allyl complex (Tj-C5H5)2Ti(i73-C4H7) is the precursor to a particularly effective homogeneous olefin hydrogenation catalyst (Section VI). Attempts to prepare bis(i7-cyclopentadienyl)titanium(III) monoalkyl complexes were unsuccessful (40). 

Typical catalysts that employ this mechanism are nickel hydrides and Ru hydrides such as HRhCl[P(C6H5)3]3 (which is also a classic olefin hydrogenation catalyst) and [HNi P(C6H5)3 3], which is present in the system Ni[P(QH5)3]4/ CF3COOH according to eq. (9) [19, 20]. 

Ethers are also attacked by metal atoms e.g., tetrahydrofuran (THF) oxidatively adds to Mo atoms to yield a reactive intermediate that may serve as an olefin hydrogenation catalyst... 

The liquid clathrate phase will dissolve substances that act as olefin hydrogenation catalysts, creating homogeneous hydrogenation catalysts.Polymerization catalysts comprised of stable liquid clathrate aluminoxane, aromatic solvents, and organic, inorganic, or organometallic compounds were described.Liquid clathrate compositions comprised of a metal halide, a quaternary ammonium salt, a quaternary phosphonium salt, or a ternary sulfonium salt an aluminum trihalide and an aromatic hydrocarbon have proven useful as reusable aluminum catalysts in Friedel-Crafts reactions. 

Dietiker, R., Chen, P. (2004) Gas-phase Reactions of the [(PHOX)lrL2]" Ion Olefin-hydrogenation Catalyst Support an tf/lr Cycle. Angew. Chem. Int. Ed. 43 5513-5516. 

Gas-phase reactions oftiie [(PHOX)IrL2] ion olefin-hydrogenation catalyst support an Ir-I/Ir-III. AngEiu Chem. Int. Ed., 43, 5513-5516. 

In 1965, Wilkinson (together with his former Ph.D. student John Osborn), and Coffey independently discovered the first homogeneous olefin hydrogenation catalyst, Wilkinson s catalyst, [RhCl(PPh3)3]. In 1970, Henri Kagan reported in a patent... 

The development of homogeneous olefin hydrogenation catalysts based on soluble rhodium and iridium complexes, in particular Wilkinson s catalyst (33) [27], Crabtree s catalyst (34) [41], and the Schrock-Osborn catalyst (35)... 

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