Bis -phenylphosphine

R = MeO, n — 2) were prepared from binaphthalenes 144 and o-phenylene-bis[phenylphosphine] under high-dilution conditions in 55, 49, and 87% yields, respectively (Scheme 12.54). 145 demonstrated a remarkable stability against oxidation due to their rigid conformation, directing the lone pairs of the P atoms toward the center of the ring. Contrary to the expectation, the crystal structure of the NiCla complex 146 shows the NiP2Cl2 plane completely twisted out of the macrocycle, which demonstrates the flexibility of this compound and makes it less suitable candidate for efficient chiral catalysis [136, 137]. 

Pentafluorophenylmagnesium bromide or lithium can be converted to other pentafluorophenyl organometabics by reaction with the corresponding metal chloride (237). Bis(pentafluorophenyl)phenylphosphine [5074-71-5] (Ultramark 443), (CgF )2CgH P, is offered commercially as a marker for mass spectral standardi2ation (238). 

This group has also developed two ring-contraction systems of potential use in crown synthesis. In the first of these, extrusion of a phenylphosphine oxide unit results from treatment with alkoxide ion. In the second, similar conditions initiated decarbonyla-tion of a bis-pyridyl ketone Despite the apparent potential of these methods for crown synthesis, direct formation of crowns by processes which involve them do not appear to have enjoyed great success thus far. 

This procedure also incorporates the use of bis(3-dimethylamino-propyl)phenylphosphine as a combined amine-phosphine reagent. The merits of using this basic phosphine as opposed to a tertiary amine and a phosphine lies in the ease of workup. Excess phosphine and phosphine sulfide can be removed by extraction with aqueous dilute acid. 

Although of limited success, this Ni-catalysed coupling strategy builds on a previous report of the successful, direct synthesis of poly(4,4 -diphenylphenyl-phosphine oxide) (70c) from bis(p-chlorophenyl)-phenylphosphine oxide (71) (Scheme 21) [66]. The white soluble material (70c) (Aj ax 280 nm) was found to have a single phosphorus environment by NMR spectroscopy, a comparatively high molecular weight (Mn= 15,300) together with a low molecular... 

B. Reactions.—(/) Nucleophilic Attack at Phosphorus. A reinvestigation of the reaction between phosphorus trichloride and t-butylbenzene in the presence of aluminium chloride has shown that the product after hydrolysis is the substituted phosphinic acid (11), and not the expected phosphonic acid (12). Bis(A-alkylamino)phosphines have been reported to attack chlorodiphenyl phosphine with nitrogen, in the presence of a base, to give bis-(A-alkyl-A-diphenylphosphinoamino)phenylphosphines (13). In (13), the terminal phosphorus atoms are more reactive than the central one towards sulphur and towards alkyl halides. 

Finally, prochiral bis(hydroxymethyl)phenylphosphine oxide 82 was desym-metrisized using either a lipase-catalysed acetylation (Method A) or hydrolysis of the corresponding diacetyl derivative 83 (Method B), to give the chiral monoacetate 84. Application of the two reverse procedures made it possible to obtain both enantiomerically enriched forms of 84 (Equation 40). ... 

Also, desymmetrization of prochiral hydroxyalkylphosphine P-boranes was successfully performed using similar reagents and conditions. In the case of bis(hydroxymethyl)phenylphosphine P-borane 87, both its acetylation and hydrolysis of the diacetyl derivative 89 gave good results, although in addition to the expected monoacetate 88, the diol 87 and diacetate 89 were always present in the reaction mixture (Equation 42). °°... 

In turn, bis(2-hydroxyethyl)phenylphosphine P-borane 90 underwent acetylation only in the presence of the lipase from Pseudomonas fluorescens, but its stereochemical outcome depended on the solvent used (Equation 43). The absolute configuration of 91 was not determined. 

Bardaji, M., Laguna, A. and Vdlacampa, M.D. (2000) Bis[bis(diphenylphos-phrnomethyl)phenylphosphine] dichlorotetragold(I) bis[chlorotris (pentafluorophenyl)aurate(lll)]. Acta CrystaUographica, Section C Crystal Structure Communications, C56(ll), E487-E488... 

The trinuclear gold(I) complexes [(AuX)3( j,-triphos)] (triphos = bis(2-diphenylphos-phinoethyl)phenylphosphine X = Cl, Br, I, CgFs ), where X = Br and I , were reported to emit at room temperature with emission energies significantly red-shifted from that ofthe free phosphine ligand (2477 cm for Br with Agx 350 nm 4482 cm for I with Aex 385 nm) [41]. The chloro, pentafluorophenyl, and l,3,5-tris(trifluor-omethyl)phenyl derivatives do not emit, even at Aex <300 nm. The emission properties... 

The bi- and tridentate phosphines dppp (l,3-bis(diphenylphosphino)propane) and dppep (bis (2-diphenylphosphinoethyl)phenylphosphine) have been complexed with Co and their divalent four- and five-coordinated thiophenolate complexes Co(dppp)(SPh)2 and Co(dppep)(SPh)2 have been isolated and structurally characterized.379 Somewhat related to dppp is the bidentate silane Ph2PCH2SiMe2CH2PPh2, which forms high-spin, pseudo-tetrahedral dihalocobalt(II) complexes.380... 

Bis[2-(diphenylphosphino)phenyl]phenylphosphine (TP) is a very inflexible ligand with a rigid backbone and gives the trinuclear complex [Au3Cl3(TP)] (452), that has a compact unsymmetrical structure in the solid state which is retained in solution owing to the fixation of the gold atoms through intermetallic contacts.2651... 

The 31P NMR spectra of 28-30 showed signals characteristic of their structural features. Dimeric species 28 with l,l,l-tri(diphenylphosphinomethyl)ethane affords two singlets at 23.0 and —28.6 ppm due to the coordinated and nonco-ordinated P donors, respectively. For trimeric species 29, two singlets occur at 24.3 and 14.4 ppm, ascribed to two classes of P donors in bis[2-(diphenylphos-phino)ethyl]phenylphosphine. Because of two types of P donors in tri[2-(diphenylphosphino)ethyl]phosphine, tetrameric species 30 exhibits two singlets at 16.4 and 24.0 ppm. 

Heterocycles (74) and (75), obtained by the interaction of bis(oxy-methyl)phenylphosphine and o-phenylenediamine [Eq. (37)], have been described (82IZV440). 

On studying a series of ammonium 1,3,2,5-dioxaborataphosphorinane oxides (111), the dependence of the tautomeric equilibrium position on amine basicity was analyzed. The equilibrium position was estimated from chemical shift values of bis(oxymethyl)phenylphosphine oxide with 8 3IP of 35 ppm being used as a model of an acyclic form and 5-Ph-5-oxo-1,3,5-dioxaphosphorinane (107, R = H) with 8 3IP of 6 ppm used as a model of a cyclic compound. The chemical shift values (111, X = 0, R = H) and dissociation constants (pKa) of conjugate acids for amines are presented in Table V. 

The reaction with m- and p-aminobenzoic acids results in the formation of 1,5,3,7-diazadiphosphacyclooctane (155), possessing the structure of a double betaine [Eq. (119)]. These compounds were obtained from bis(hydroxymethyl)phenylphosphine (89IZV1340). 

It should be noted that oamino benzoic acid is inert to bis(oxymethyl)-phenylphosphine and 2,5-diphenyl-1,3,2,5-dioxaboraphosphorinane (90) (89IZV1340). 

Bis(a-aminomethyl)phosphines having a mobile hydrogen atom could be expected to undergo a borylation reaction with borane, hydrogen being evolved. In fact, bis(Af-phenylaminomethyl)-phenylphosphine (199) and its sulfide (200) appeared to interact with borane under mild conditions, yielding a new type of phosphorus-boron-containing heterocycle—2-... 

Complexes with silver nitrate are also obtained, the number of ligands depending on the ratio of reagents [Eq. (156)]. Notably, the 3IP chemical shift changes from -20 to 0 ppm on addition of silver nitrate to bis(oxy-methyl)phenylphosphine. This change probably results from the coordina-... 

The Monsanto group have used the cationic catalysts Rh(diene)(diphosphine)+ (see Section II,B,1) with diphosphine (22), R,R-bis[(anisole)(phenylphosphine)] ethane (BAPPE), to reduce a-acylami-noacrylic acids in basic alcohol solution to products with 95- 96% ee (244, 245). 

---