Bis diphenylphosphine

Snyder, R.M., Mirabelli, C.K. and Johnson, R.K. (1986) Modulation of the antitumor and biochemical properties of bis(diphenylphosphine)ethane with metals. Cancer Research, 46, 5054-5060. 

Another class of chiral sulfur-containing ligands, diphosphine ligands based on a thiophene backbone, has been successfully developed by Sannicolo et For the first time, bis(diphenylphosphines) bidentate ligands incor-... 

In 1999, Casado et al. developed heterotetranuclear complexes (TiRh3) depicted in Scheme 10.3 with bridging sullido ligands combined with P-donor ligands. These complexes were further tested as catalysts for the asymmetric hydroformylation reaction of styrene. In this process, [CpTi((/i3-S)3 Rh(tfbb 3] was efficiently active under mild conditions (10 bar, CO/H2 = 1 atm, 353 K). In order to explore the effect of the added phosphorus ligand and the possibilities of this system for the asymmetric hydroformylation of styrene, achiral diphosphines such as dppe (l,2-bis(diphenylphosphine)ethane) and... 

Gan, K.-S. Hor, T. S. A. l,l -Bis(diphenylphosphine) ferrocene. Coordination chemistry, organic synthesis, and catalysis. VCH Weinheim, Germany. In Ferrocenes-Homogeneous Catalysis, Organic Synthesis, Materials Science, Togni, A., Hayashi, T., Eds., 1995, p 3. 

The polydentate ligands 2-(diphenylphosphino)-6-[3-(2 -pyridyl)pyrazol-l-yl)pyridine and 2-(diphenylphosphino)-6-(pyrazol-l-yl)pyridine react with [Ag(NCMe)4]C104 to give the dinuclear complexes where the ligands are P,N,N bonded as in (249).1 82 The reaction of two equivalents of AgBF4 with 6,6-bis(diphenylphosphine)-2,2 -bipyridyl (P2-bipy) gives the complex [Ag4(P2-bipy)2](BF4)4. Addition of Br or I leads to complexes [Ag4X2(P2-... 

It is well recognized that protonated phosphine complexes such as [M(dppe)(H)2]+ (dppe = 2-bis(diphenylphosphine)ethane), M = Co, Ir),39 [Fe(dppe)(L)H]+,40 or [Pt(PEt3)3H]+41 catalyze proton reduction at very negative potentials, 2 V vs. SCE. In contrast, the protonated [(,/s-CsI Is)CoIII P(OMe)3 2I I]1 complex is a catalyst for hydrogen production at —1.15 V vs. SCE at a Hg-pool cathode in pH 5 aqueous buffer.42 Dihydrogen is evolved from the reduced [(r/5-Cd fdCo1"-(P(OMe)3)2H]° form of the complex, which decays to H2 or reacts in a proton-hydride reaction. 

A hydrosilylation/cyclization process forming a vinylsilane product need not begin with a diyne, and other unsaturation has been examined in a similar reaction. Alkynyl olefins and dienes have been employed,97 and since unlike diynes, enyne substrates generally produce a chiral center, these substrates have recently proved amenable to asymmetric synthesis (Scheme 27). The BINAP-based catalyst employed in the diyne work did not function in enyne systems, but the close relative 6,6 -dimethylbiphenyl-2,2 -diyl-bis(diphenylphosphine) (BIPHEMP) afforded modest yields of enantio-enriched methylene cyclopentane products.104 Other reported catalysts for silylative cyclization include cationic palladium complexes.105 10511 A report has also appeared employing cobalt-rhodium nanoparticles for a similar reaction to produce racemic product.46... 

R)- and (S)-(6,6 -Dimethylbiphenyl-2,2 -diyl)bis(diphenylphosphine), BIPHEMP (1). This is the first example of an optically active bis(triarylphosphine) containing the axially disymmetric biphenyl group. The 6,6 -dimethyl groups are used to... 

The dicarboxamide 443 could be sequentially lithiated and substituted twice under similar conditions and was reacted with several electrophiles . The sequence is shown in equation 120 for the synthesis of the bis(diphenylphosphine) 445. Only a little meso-445 is formed, removing most of the minor enantiomer of 445. The phosphines 444, 445 and meso-445 had been prepared earlier by Jendralla and Paulus applying the Snieckus method, and had been tested in enantioselective Pd-catalysed reactions . 

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