Patent Publication Number: US-2004059159-A2

Title: A Method of Generating A Functionalised Arylphosphine

Description:
Detailed Description of the Invention 
     Detailed Description 
     [0001] The present invention relates to a method of generating a functionalised arylphosphine, novel intermediates and novel functionalised arylphosphines. These functionalised arylphosphines may find applications in catalysis, in such reaction media as, but not limited to, water, supercritical carbon dioxide (scCO 2 ) and perfluorinated solvents.  
     [0002] Arylphosphines are the most widely used ligands in homogenous catalysis. One of the most significant problems associated with homogeneous catalysis is the separation of catalyst from product. The problem can be overcome by immobilising the catalyst in a medium that is immiscible with the product phase. Water, perfluorinated solvents and scCO 2   have extensively been studied as immobilising phases, due either to the immiscibility of the first two with common organic liquids or to the controllable solvent strength in the case of scCO 2 . The key to effective immobilisation of the catalysts is to design and synthesise aqueous, fluorous and scCO 2   soluble ligands. A ligand can be made water soluble by bonding it to a hydrophilic group such as, for example, a sulfonate, hydroxy, ammonium or carboxylate, whereas by attaching it to a perfluorinated moiety or a long alkyl chain the ligand becomes either fluorous soluble or scCO 2   soluble .  
     [0003] The present invention provides a novel method of generating a functionalised arylphosphine bearing, for example, a fluoroalkyl, alkyl, alkenyl, carboxy, siloxy, or silyl group. Some of these groups can also be used to anchor the arylphosphine ligand onto polymers and inorganic oxides.  
     [0004] Fluorinated arylplosphines are disclosed in U.S. Pat Nos. 4,681,693, 4,454,349 and 4,011,267. Synthesis of the arylphosphines involves the preparation of fluoroalkylether substituted aryl halides followed by metathesis with PCl 3 , except in the case of fluoroamide substituted arylphosphines where fluoro esters are reacted with expensive arminoarylphosphines. A disadvantage of such methods is that each arylphosphine has to be prepared from a fluorinated aryl halide, meaning that the preparation is less flexible and less efficient in terms of the use of the expensive fluorinated reagents in comparison to a method in which fluorinated substituents would be incorporated into the arylphosphines in the last few steps of the preparation. Also, for every arylphosphine each step of the preparation has to be optimised. Another disadvantage of these methods is that they use organolithium reagents, which are moisture and oxygen sensitive and relatively unstable and thus require special handling. Yet a further disadvantage is that the reaction with PCl 3   is conducted at -78º C., making commercial operations both difficult and costly. Analogous arylphosphines are also disclosed in the U.S. Pat. Nos. 4,454,349; 4,011,267 Kainz, D. Koch, W. Baumann, and W. Leitner, Angew. Chem. Int. Ed. Engl, 1997, 36, 1628; B. Betzemeier, and P. Knochel, Angew. Chem. Int. Ed. Engl., 1997,36,2623; and P. Bhattacharyya, D. Gudmunsen, E. G. Hope, R. D. W. Kemmitt, D. R. Paige, and A. M. Stuart, J. Chem. Soc., Perkin Trans. 1, 1997,3609.  
     [0005] All the processes described have either the aforementioned or more limitations.  
     [0006] U.S. Pat. Nos. 5,929,273, 5,684,181, 5,247,183 and 505,618 disclose the preparation of water-soluble arylphosphines by sulfonation. The problems with sulfonation are well known in the art and include harsh reaction conditions, the formation of mixtures of products and labourious separation procedures.  
     [0007] U.S. Pat. No. 5,925,785 discloses the preparation of sulfonated aryl phosphines using pyrophoric phosphorus hydrides.  
     [0008] Carboxylated arylphosphines are much less well documented. Their preparation can be found in O. Herd, A. Hebler, M. Hingst, P. Machnitzki, M. Tepper and, O. Stelzer, Catal. Today, 1998, 42, 413; V. Ravidar, H. Hemling, H. Schumann and, J. Blum, Syn. Commun, 1992, 22, 841 and W. A. Herrmann and, C. W. Kohpaintner, Angew. Chem. Int. Ed. Engl., 1993, 32, 1524 and references therein. The starting materials, such as, phenylphosphine, iodobenzoic acid and bromobenzenitrile are expensive and/or difficult-to-handle.  
     [0009] Thus, a new method that is versatile, simple and economical and that uses readily accessible starting materials would be highly desirable.  
     [0010] According to a first aspect of the present invention there is provided a method of generating a functionalised arlyphosphine comprising the steps of reacting 
     [0011] i) a haloarylphosphine oxide with 
     [0012] ii) one of: 
     [0013] a) an organohalide, 
     [0014] b) an alkene; 
     [0015] c) carbon monoxide and a compound bearing a hydroxy group; 
     [0016] d) an amine; and 
     [0017] e) an alcohol or thiol 
     [0018] in the presence of 
     [0019] iii) a metal or a metal containing compound 
     [0020] to generate iv) a substituted arylphosphine oxide, and 
     [0021] v) reducing the substituted arylphosphine oxide to generate 
     [0022] vi) the functionalised arylphosphine. 
     [0023] In one embodiment the haloarylphosphine oxide is reacted with an organo halide in the presence of a metal such as, for example, copper or a copper containing compound and the substituted arylphosphine oxide is reduced to form the functionalised arylphosphine. A general reaction scheme for such a reaction is illustrated in FIG. 1.  
     [0024] In another embodiment the haloarylphosphine oxide is reacted with an alkene in the presence of a metal such as, for example, palladium and/or nickel or a palladium and/or nickel containing compound and the substituted arylphosphine oxide is reduced to form the functionalised arylphosphine A general reaction scheme for such a reaction is illustrated in FIG. 2.  
     [0025] In yet another embodiment the haloarylphosphine oxide is reacted with carbon monoxide and a compound bearing a hydroxy group, in the presence of a metal such as, for example, palladium and/or nickel or a palladium and/or nickel containing compound and the substituted arylphosphine oxide is reduced to form the functionalised arylphosphine. A general reaction scheme for such a reaction is illustrated in FIG. 3.  
     [0026] In yet another embodiment the haloarylphosphine oxide is reacted with an amine in the presence of a metal, such as, for example, palladium and/or nickel or a palladium and/or nickel containing compound and the substituted arylphosphine oxide is reduced to form the finctionalised arylphosphine. A general reaction scheme for such a reaction is illustrated in FIG. 4.  
     [0027] In yet another embodiment the haloarylphosphine oxide is reacted with an alcohol or thiol in the presence of a metal, such as, for example, palladium and/or nickel or a palladium and/or nickel containing compound and the substituted arylphosphine oxide is reduced to form the functionalised arylphosphine. A general reaction scheme for such a reaction with an alcohol is illustrated in FIG. 5.  
     [0028] The methods of the invention utilize haloarylphosphine oxides of the general formula I, II or III to generate a functionalised arylphosphine.  
     [0029] Such compounds can be produced by standard methodology.  
     [0030] Formula I 
                 
             
     [0031] where 
     [0032] R is selected from the group consisting of: 
     [0033]  alkyl; alkenyl; cycloalkyl; aryl; alkoxy and aralkyl and any such group additionally substituted by one or more of the following groups: 
     [0034]  alkyl; cycloalkyl, aryl, alkoxy and halo; 
     [0035]  Preferred R groups include: C 1 --C 10   alkyl groups, phenyl and naphythl. 
     [0036]  Ar is an aryl group  
     [0037] and any such group additionally substituted by one or more of the following groups: 
     [0038]  alkyl; alkenyl; aryl; alkoxy; aralkyl and alkoxycarbonyl; 
     [0039]  any of which may be substituted by one or more of the following groups: 
     [0040] alkyl; alkenyl; alkoxy; alkoxycarbonyl; siloxy; silyl and halo; 
     [0041]  Preferred aryl groups include: phenyl and naphthyl.  
     [0042] X is selected from the group consisting of Cl, Br and I; 
     [0043]  and n is 0, 1 or 2; 
     [0044]  with the proviso that each R n   can be the same or different, and each (Ar-X) can be the same or different.  
     [0045] Formula II is 
                 
  
             
     [0046] where: 
     [0047] R, Ar and X are as defined in formula I above, 
     [0048] Y is a linking group, and 
     [0049] m is 0 or 1.  
     [0050] Preferably Y is a linking group selected from: acyclic bridges including alkano groups, such as, for example, methano; alkeno groups, such as, for example, etheno; cyclic hydrocarbon bridges (which may be saturated or unsaturated) such as, for example, epicyclopenta or benzeno; and groups such as binaphthyl and biphenyl and substituted variants thereof.  
     [0051] Formula III is 
                 
             
     [0052] where [w] q  is P q  O q  V q  Y (q-1) 
  
             
     [0053] where q is a whole number; and V is (Ar-X) or R and R, Ar and X are as defined in formula I above and Y and m are as defined in formula II above.  
     [0054] Thus, for example where q=1 
     [0055] [W] q  is as shown in formula IV 
     [0056] Formula IV is 
                 
             
     [0057] and when q=2 
     [0058] [W] q   is as shown in formula V.  
     [0059] Formula V is 
                 
             
     [0060] By reacting the haloarylphosphine oxides of general Formula I, II or III such that X, the halo group, is substituted by R 6 , intermediates of the general formula VI, VII &amp; VIII are obtained. 
     [0061] Formula VI is 
                 
             
     [0062] Where R, n and Ar are as defined in formula I above, and R 6   is a) --CQ 2 R 1  b)
                 
c)
                 
d)
                 
  
             
     [0063] e)  --O--R 5 
  
             
     [0064] or  
     [0065] --S--R 5 
  
             
     [0066] Formula VII is 
                 
             
     [0067] where R and Ar, are as defined in formula I above, Y and m are as defined in formula II above; and 
     [0068] R 6   is as defined in Formula VI above; and 
     [0069] Formula VIII is 
                 
             
     [0070]  where R and Ar are as defined in formula I above, Y and m are as defined in formula II above, V is as defined in formula III above or is (Ar-R 6 ) and R 6   is as defined in formula VI above.  
     [0071] The substitution reaction generating these intermediates can be initiated by one of five routes: 
     [0072] a) using Z CQ 2   R 1 
  
             
     [0073] where Q is selected from F and Cl and Q can be the same or different.  
     [0074] where Z=Cl, Br, or I; 
     [0075] and R 1   is selected from the group consisting of: alkyl, alkenyl, aryl, cycloalkyl and alkoxy and any of the above substituted by an alkyl, cycloalkyl, aryl, alkoxy, carboxy, halo, siloxy or silyl group.  
     [0076] In this case the substitution is as illustrated in FIG. 1.  
     [0077] Referring to FIG. 1, Z CQ 2   R 1   is reacted in a first step with a haloarylphosphine oxide of eg. formula I in the presence of copper or a copper containing compound. CQ 2   R 1   is substituted for X in the presence of a catalytical amount of a stabilising ligand such as bipyridine. The intermediate is then subjected to a second step in which it is reduced by, for example, a chlorosilane; 
     [0078] b) using an alkene of the general formula 
                 
  
             
     [0079] where each R 2   is independently selected from the group consisting of: hydrogen alkyl, cycloalkyl, alkenyl, aryl, alkoxy, hydroxy, carboxy, and halo. The alkyl, cycloalkyl, alkenyl, aryl, alkoxy and carboxy groups may be substituted by an alkyl, cycloalkyl, aryl, alkoxy, carboxy, halo, hydroxy, amino, siloxy or silyl group.  
     [0080] In this case the substitution is as illustrated in FIG. 2.  
     [0081] Referring to FIG. 2
                 
  
             
     [0082] is reacted in a first step with a haloarylphosphone oxide of, eg. formula I in the presence of nickel and/or palladium or a nickel and/or palladium containing compound. 
                 
  
             
     [0083] is substituted for X and the by-product of the reaction is adsorbed by, for example, a base, such as, for example, sodium acetate. The intermediate is then subjected to hydrogenation to saturate it, and the phosphine oxide is then reduced: c) using-carbon monoxide (CO) and a compound bearing a hydroxy group (HOR 3 ) one generates a group 
                 
  
             
     [0084] where R 3   is selected from the group consisting of: alkyl, alkenyl, cycloalkyl and aryl and any of the above may be substituted by an alkyl, cycloalkyl, aryl, alkoxy, carboxy, halo, siloxy or silyl group.  
     [0085] Referring to FIG. 3. 
                 
  
             
     [0086]   is reacted in a first step with a haloaryilphosphine oxide of, eg. formula I in the presence of nickel and/or palladium or a nickel and/or palladium containing compound,
                 
  
             
     [0087] is substituted for X and the by-product is absorbed by, for example, a base. The intermediate is then subjected to a reduction with, for example, chlorosilane; 
     [0088] d) using an amine of the formula 
                 
  
             
     [0089] where R 4   is an alkyl, aryl or aralkyl any of which may be substituted with an alkyl, alkenyl, alkoxy, cycloalkyl or aryl group and R 4´   is R 4   or hydrogen and additionally R 4   and R 4´   may form a cyclic amine which may include one or more heteroatoms, such as, for example, N, S and O and may additionally comprise an alkyl, aryl or aralkyl substituent.  
     [0090] Referring to FIG. 4, H N R 4   R 4´   is reacted in a first step with a haloarylphosphine oxide of eg. formula I in the presence of nickel or palladium and/or a nickel and/or palladium containing compound.
                 
  
             
     [0091] is substituted for X and the by-product of the reaction is adsorbed by, for example, a base such as, for example, Cs 2 CO 3   and NaO t Bu. The intermediate is then subjected to a second step in which it is reduced; and 
     [0092] e) using an alcohol of the formula HOR 5   or a thiol of the formula HSR 5   where R 5   is selected from the group consisting of: alkyl, aryl, and aralkyl and any of the above may be substituted by an alkyl, alkenyl, cycloalkyl or aryl group.  
     [0093] In the case of alcohol the substitution is as illustrated in FIG. 5.  
     [0094] Referring to FIG. 5, HOR 5   is reacted in a first step with a haloarylphosphine oxide of eg. formula 1 in the presence of palladium and/or nickel or a palladium and/or nickel containing compound.  
     [0095] OR 5   is substituted for X in the presence of a base, such as, for example, an alkali carbonate or alkoxide; for example Cs 2 CO 3   or NaO t Bu.  
     [0096] The intermediate is then subjected to a reduction.  
     [0097] The reaction with the thiol is basically identical with `O` being replaced by `S`.  
     [0098] Of course, in the general reaction mechanisms exemplified with reference to FIGS. 1 to 5, starter compounds of the general formula I can be replaced with compounds of the general formula II or III.  
     [0099] In each of the above the term alkyl refers to a straight-chain or branched alkyl group having from 1 to 30 carbon atoms, alkenyl refers to a C 2 --C 30   group with at least one carbon-carbon double bond, aryl refers to a C 5 --C 30  cyclic aromatic group, alkoxy refers to an alkyl group bound to an oxygen atom, aralkyl refers to an alkyl group substituted by an aryl substituent, cycloalkyl refers to a C 3 --C 30   cyclic alkyl group, alkoxycarbonyl refers to --C(O)OR 7   group wherein R 7   is an alkyl group, siloxy refers to [--Si(R 8 )(R 8 )--O--]pR 8   with each R 8   being independently selected from alkyl or aryl and where p=1-100, silyl refers to SiR 9 
   
                3   wherein each R 9   is an alkyl or alkoxy; and halo refers to fluorine, chlorine and bromine.  
     [0100] By subjecting the substituted arylphosphine oxide intermediates generated in step 1 to a reduction step (step 2 of the reaction mechanisms illustrated in FIGS. 1 to 5) the desired aryl phosphines are obtained.  
     [0101] It may however be necessary to conduct an additional hydrolysis step to make carboxylated arylphosphine. When R 1 , R 2 , R 3 , R 4   or R 5   contain carbon carbon double bonds, hydrogenation may be carried out before the reduction of the phosphine oxide using methods established in the art.  
     [0102] The resulting functionalised arylphosphines have the general formula IX, X, or XI.  
     [0103] Formula IX is 
                 
             
     [0104]  where R, n and Ar are as identified in formula I and R 6   is as identified with reference to formula VI.  
     [0105] Formula X is 
                 
             
     [0106] where R, and Ar are as defined in Formula I above, Y and m are as defined in Formula II above and R 6   is as defined in formula VI above.  
     [0107] Formula XI is 
                 
             
     [0108] where R and Ar are as defined in formula I above, Y and m are as defined in formula II above, R 6   is as defined in formula VI above and [U] q  is Pq Vq Y (q-1) where q is a whole number; and V is (Ar-X) or R and is defined in formula III above or is (Ar--R 6 ).  
     [0109] Thus for example when q=1 formula XI is 
                 
  
             
     [0110]  and when q=2 formula XI is 
                 
  
             
     [0111] The invention is further described by way of example only with reference to the specific examples.  
     EXAMPLE 1 
     [0112] Tris(4-perflurohexylphenyl)phosphine oxide 
     [0113]  A mixture of tris(4-bromophenyl)phosphine oxide (515 mg, 1 mmol), 1-iodoperfluorohexane (1.405 g, 3.15 mmol), copper powder (450 mg,. 7 mmol), 2,2&#39;-bipyridine (34 mg, 0.2 mmol) and DMSO (20 ml) was stirred for 36 h at 120 °C. After cooling to room temperature, the reaction mixture was diluted with CHCl 3   (50 ml) and water (50 ml), filtered through a pad of Celite and washed with CHCl 3   (2x20 ml). The organic layer was separated, washed with 1N HCl (2x50 ml), water (2x50 ml) and brine (50 ml), dried (MgSO 4 ) and evaporated under reduced pressure to give the crude product, which upon recrystallisation from EtOH yielded the title compound (1.123 g, 91%) as colourless needles.  
     EXAMPLE 2 
     [0114] (4-perfluorohexylphenyl)diphenylphosphine oxide 
     [0115] A mixture of 4-bromophenyldiphenylphosphine oxide (2.143 g, 6.0 mmol), 1-iodoperfluorohexane (2.809 g, 6.3 mmol), copper powder (900 mg, 14.1 inmol), 2,2&#39;-bipyridine (67 mg, 0.4 mmol) and DMSO (20 ml) was stirred for 15 h at 120 °C. After cooling to room temperature, the reaction mixture was diluted with CHCl 3   (50 ml) and water (50 ml), filtered through a pad of Celite and washed with CHCl 3   (2.x20 ml). The organic layer was separated, washed with 1N HCl (2x50 ml), water (2x50 ml) and brine (50 ml), dried (MgSO 4 ) and evaporated under reduced pressure to give the crude product. Recrystallisation from hexane afforded the pure title compound as colourless needles (3.413 g, 95.4%).  
     EXAMPLE 3 
     [0116] Bis(4-perfluorohexylphenyl)phenylphosphine oxide 
     [0117] A mixture of bis(4-bromophenyl)phenylphosphine oxide -(1.308 g, 3.0 mmol), 1-iodoperfluorohexane (2.809 g, 6.3 mmol), copper powder (900 mg, 14 mmol), 2,2&#39;-bipyridine (67 mg, 0.4 mmol) and DMSO (20 ml) was stirred for 24 h at 120°C. After cooling to room temperature, the reaction mixture was diluted with CHCl 3   (50 ml) and water (50 ml), filtered through a pad of Celite and washed with CHCl 3   (2x20 ml). The organic layer was separated, washed with 1N HCl (2x50 ml), water (2x50 ml) and brine (50 ml), dried (MgSO 4 ) and evaporated under reduced pressure to give the crude product. Recrystallisation from hexane afforded the pure title compound as colourless needles (2.606 g, 95%).  
     EXAMPLE 4 
     [0118] Tris(4-perfluorooctylphenyl)phosphine oxide 
     [0119] A mixture of tris(4-bromophenyl)phosphine oxide (1.030 g, 2 mmol), 1-iodoperfluorooctane (3.440 g, 6.30 mmol), copper powder (900 mg, 14 mmol), 2,2&#39;-bipyridine (67 mg, 0.4 mmol), DMSO (2.188 g, 28 mmol) and perfluoro-1,3-dimethylcyclohexane (20 ml) was refluxed for 72 h. After cooling to room temperature, the reaction mixture was diluted with CHCl 3   (200 ml), filtered through a pad of Celite and washed with CHCl 3   (2x20 ml). The filtrate was washed with 1N HCl (2x100 ml), water (2x100 mnl) and brine (100 ml), dried (MgSO 4 ) and evaporated under reduced pressure. The residue was recrystallised from CHCl 3 -hexane affording the title compound as colourless needles (2.863 g, 93%).  
     EXAMPLE 5 
     [0120] Tris[4(1H,2H-perfluoro-1-octenyl)phenyl]phosphine oxide 
     [0121]  A mixture of tris(4-bromophenyl)phosphine oxide (1.030 g, 2 mmol), 1H, 1H, 2H-perfluoro-1-octene (2.284 g, 6.6 mmol), palladacycle (56 mg, 0.06 mmol), NaOAc (656 mg, 8 mmol) and DMF (20 ml) was stirred for 24 h at 125 °C. DMF was removed under reduced pressure. The residue was dissolved in CHCl 3   (100 ml), washed with water (2x100 ml) and brine (100 ml), dried (MgSO 4 ) and evaporated under reduced pressure. The residue was purified by flash chromatography (SiO 2 , EtOAc:CHCl. 3 =1:8) to give the title compound as a pale-yellow oil (2.384 g, 91%).  
     EXAMPLE 6 
     [0122] [4-(1H,2H-perfluoro-1-octenyl)phenyl]diphenylphosphine oxide 
     [0123] A mixture of 4-bromophenyldiphenylphosphine oxide (2.143 g, 6.0 mmol), 1H, 1H,2H-perfluoro- 1-octene (2.284 g, 6.6 mmol), palladacycle (56 mg, 0.06 mmol), NaOAc (656 mg, 8 mmol) and DMF (20 ml) was stirred for 20 h at 125 °C. The solvent was removed under reduced pressure. The residue was dissolved in CHCl 3   (100 ml), washed with water (2x100 ml) and brine (100 ml), dried (MgSO 4 ) and evaporated under reduced pressure. The residue was purified by flash chromatography (SiO 2 , EtOAc:CHCl3=1:8) to give the title compound as pale-yellow oil (3.461 g, 92.7%).  
     EXAMPLE 7 
     [0124] Bis[4-(1H,2H-perfluoro-1-octenyl)phenyl]phenylphosphine oxide 
     [0125] A mixture of bis(4bromophenyl)phenylphosphine oxide (1.308 g, 3.0 mmol), 1H,1H,2H-perfluoro-1-octene (2.284 g, 6.6. mmol), palladacycle (56 mg, 0.06 mmol), NaOAc (656 mg, 8 mmol) and DMF (20 ml) was stirred for 24 h at 125.°C. The solvent was removed under reduced pressure. The residue was dissolved in CHCl 3   (100 ml), washed with water (2x100 ml) and brine (100 ml), dried (MgSO 4 ) and evaporated under reduced pressure. The residue was purified by flash chromatography (SiO 2 , EtOAc:CHC 3 =1:8) to give the title compound as pale-yellow oil (2.714 g, 93.6%).  
     EXAMPLE 8 
     [0126] Tris[4-(2-butoxycarbonylvinyl)phenyl]phosphine oxide 
     [0127] A mixture of tris(4-bromophenyl)phosphine oxide (2.060 g, 4 mmol), n-butyl acrylate (2.307 g, 18 mmol), palladacycle (56 mg, 0.06 mmol), NaOAc (1.312 mg, 16 mmol) and DMF (50 ml) was stirred for 15 h at 125°C. DMF was removed under reduced pressure. The residue was dissolved in CHCl 3   (50 ml), washed with water (2x50 ml) and brine (50 ml), dried (MgSO 4 ) and evaporated under reduced pressure. The residue was purified by flash chromatography (SiO 2 , EtOAc:CHCl 3 =1:8) to give the title compound as colourless crystals (2.312 g, 98%).  
     EXAMPLE 9 
     [0128] Tris[4-(1-hexenyl)phenyl]phsphine oxide 
     [0129] A mixture of tris(4-bromophenyl)phosphine oxide (2.060 g, 4.0 mmol), 1-hexene (3.030 g, 36 mmol), palladacycle (56 mg, 0.06 mmol), NaOAc (1.312 mg, 16:0 mmol) and DMW (50 ml) was stirred for 24 h at 125 °C. in an autoclave under 10 atm of nitrogen. The solvent was removed under reduced pressure. The residue was dissolved in CHCl 3   (50 ml), washed with water (2x50 ml) and brine (50 ml), dried (MgSO 4 ) and evaporated under reduced pressure. The residue was purified by flash chromatography (SiO 2 , CHCl 3 ) to give the title compound as colourless oil (1.920 g, 91.4%), containing about 10% of tris(4-(2-hexenyl)phenyl]phosphine oxide.  
     EXAMPLE 10 
     [0130] Tris[4-(1-decenyl)phenyl]phsphine oxide 
     [0131] A mixture of tris(4-bromophenyl)phosphine oxide (2.060 g, 4 mmol), 1-decene (2.525 g, 18 mmol), palladacycle (56 mg, 0.06 mmol), NaOAc (1.312 mg, 16 mmol) and DMF (50 ml) was stirred for 24 h at 125°C. DMF was removed under reduced pressure. The residue was dissolved in CHCl, (50 ml), washed with water (2x50 ml) and brine (50 ml), dried (MgSO 4 ) and evaporated under reduced pressure. The residue was purified by flash chromatography (SiO 2 , CHCl 3 ) to give the title compound as a colourless oil (2.556 g, 93%) containing about 10% of tris [4-(2-decenyl)phenyl]phosphine oxide.  
     EXAMPLE 11 
     [0132] Tris[4-(1-hexadecenyl)phenyl]phosphine oxide 
     [0133] A mixture of tris(4bromophenyl)phosphine oxide (2.060 g, 4.0 mmol), 1-hexadecene (3.366 g, 15 mmol), palladacycle (56 mg, 0.06 nimol), NaOAc (1.312 mg, 16.0 mmol) and DMF (50 ml) was stirred for 30 h at 125°C. The solvent was removed under reduced pressure. The residue was dissolved in CHCl 3   (50 ml), washed with water (2x50 ml) and brine (50 ml), dried (MgSO 4 ) and evaporated under reduced pressure. The residue was purified by flash chromatography (SiO 2 , CHCl 3 ) to give the title compound as colourless oil (3.256 g, 86%), containing about 10% of tris[4-(2-hexadecenyl)phenyl]phosphine oxide.  
     EXAMPLE 12 
     [0134] Tris[4-(1H, 1H,2H,2H-perfluorooctyl)phenyl]phosphine oxide 
     [0135] A mixture of tris[4-(1H,2H-perfluoro-1-octenyl)phenyl)phosphine oxide (2.611 g, 2.0 mmol), 10% Pd/C (50 mg) and EtOAc (40 ml) was stirred for 5 h at room temperature under 10 bar of hydrogen, and filtered through a pad of Celite. The filtrate was evaporated under reduced pressure to give the title compound as a pale-yellow oil, which solidified on standing (2.660 g, 100%).  
     EXAMPLE 13 
     [0136] Tris[4-(1H, 1H,2H,2H-perfluoro-1-octenyl)phenyl]phosphine 
     [0137] A mixture of tris[4-(1H, 1H,2H,2H-perfluoro-1-octenyl)phenyl]phosph- ine oxide (666 mg, 0.5 mmol), trichiorosilane (339 mg, 2.5 mmol), triethylarnine (380 mg, 2.8 mmol) and toluene (10 ml) was stirred for 5 h at 120ºC. After cooling to room temperature, saturated NaHCO 3   aqueous solution (0.5 ml) was added. The mixture was stirred for 5 min at room temperature, and filtered through a pad of alumina, washed with toluene (3.times.15 ml). The filtrate was evaporated under reduced pressure to give the title compound as white solid (630 mg, 96%).  
     [0138] Reduction of the other phosphine oxides were similarly performed in one step using a chlorosilane as reductant according to previously established procedures known in the art, with yields &gt;95% in all cases. Saturation of the carbon-carbon double bonds in the substituents on the phenyl rings was accomplished by hydrogenation, and conversion of the alkoxycarbonyl groups to carboxylates was by hydrolysis, all with yields &gt;95%.