Synthesis and properties of a novel family of fluorous triphenylphosphine derivatives

Article abstract of DOI:10.1021/jo991548v

A novel approach to the preparation of perfluorotail-functionalized triarylphosphines using a p-silyl substituent as the branching point has been developed. This approach enabled the attachment of between three and nine perfluorotails per phosphorus atom, resulting in the production of highly fluorous tris[p-(1H,1H,2H,2H-perfluoroalkylsilyl)aryl]phosphines, P[C₆H₄-p-SiMe_3-n(CH₂ CH₂C_xF_2x+1)_n]₃ (n = 1, 2, 3; x = 6, 8), containing between 50 and 67 wt % fluorine. ³¹P NMR studies indicate that the phosphorus atoms, and consequently the σ-donor and π-acceptor properties of these phosphines, are not influenced by the electron-withdrawing perfluoroalkyltails. The fluorous triarylphosphines are readily soluble in fluorous solvents and display fluorous phase preference in several fluorous biphasic systems. The phase partitioning of these fluorous ligands, as well as their donor properties, is discussed in relation to their potential for fluorous biphasic catalyst separation.

Full text of DOI:10.1021/jo991548v

VOLUME 65, NUMBER 13
J UNE 30, 2000
© Copyright 2000 by the American Chemical Society
Articles
Syn th esis a n d P r op er ties of a Novel F a m ily of F lu or ou s
Tr ip h en ylp h osp h in e Der iva tives
Bodo Richter,† Elwin de Wolf,† Gerard van Koten,† and Berth-J an Deelman*,‡
Department of Metal-Mediated Synthesis, Debye Institute, Utrecht University, Padualaan 8,
3584 CH Utrecht, The Netherlands, and Elf Atochem Vlissingen B.V., P.O. Box 70,
4380 AB Vlissingen, The Netherlands
Received October 5, 1999
A novel approach to the preparation of perfluorotail-functionalized triarylphosphines using a p-silyl
substituent as the branching point has been developed. This approach enabled the attachment of
between three and nine perfluorotails per phosphorus atom, resulting in the production of highly
fluorous tris[p-(1H,1H,2H,2H-perfluoroalkylsilyl)aryl]phosphines, P[C6H4-p-SiMe3-n(CH2CH2CxF2x+1)n]3
(n ) 1, 2, 3; x ) 6, 8), containing between 50 and 67 wt % fluorine. 31P NMR studies indicate that
the phosphorus atoms, and consequently the σ-donor and π-acceptor properties of these phosphines,
are not influenced by the electron-withdrawing perfluoroalkyltails. The fluorous triarylphosphines
are readily soluble in fluorous solvents and display fluorous phase preference in several fluorous
biphasic systems. The phase partitioning of these fluorous ligands, as well as their donor properties,
is discussed in relation to their potential for fluorous biphasic catalyst separation.
In tr od u ction
industrial interest.6 Often, appropriate catalytic reactions
for this new immobilization technique involve transition
metal phosphine catalysts. Therefore, converting con-
ventional phosphine ligands into fluorous solvent soluble
derivatives, while keeping their essential stereoelectronic
properties intact, seems to be a key point. The metal
complexes derived from these modified ligands are ex-
Since Horva´th and Ra´bai’s1 initial report on using the
fluorous biphase concept in catalysis, as an alternative
to catalyst immobilization in water,2 in ionic liquids,3 on
surfaces of macromolecules,4 or on inorganic supports,5
this field has experienced a growing scientific and
* Author to whom correspondence should be addressed. Currently
based at the Department of Metal-Mediated Synthesis of Utrecht
University. Fax: +31 30 2523615. E-mail: b.j.deelman@chem.uu.nl.
† Utrecht University.
(3) (a) Chauvin, Y.; Olivier-Bourbigou, H. CHEMTECH 1995, 25,
26. (b) Chauvin, Y.; Mussmann, L.; Olivier, H. Angew. Chem., Int. Ed.
Engl. 1995, 34, 2698. (c) Herrmann, W. A.; Bo¨hm, V. P. W. J .
Organomet. Chem. 1999, 572, 141.
(4) Knapen, J . W. J .; van der Made, A. W.; de Wilde, J . C.; van
Leeuwen, P. W. N. M.; Wijkens, P.; Grove, D. M.; van Koten, G. Nature
1994, 372, 659.
(5) Petrucci, M. G. L.; Kakkar, A. K. Adv. Mater. 1996, 8, 251 and
refereces therein.
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Curran, D. P. Angew. Chem., Int. Ed. Engl. 1998, 37, 1174. (c) Horva´th,
I. T. Acc. Chem. Res. 1998, 31, 641. (d) de Wolf, E.; van Koten, G.
Deelman, B.-J . Chem. Soc. Rev. 1999, 28, 37.
‡ Elf Atochem Vlissingen B.V.
(1) (a) Horva´th, I. T.; Ra´bai, J . Science 1994, 266, 72. (b) Horva´th,
I.; Ra´bai, J . U.S. Patent 5463082, 1995. (c) Horva´th, I. T.; Kiss, G.;
Cook, R. A.; Bond, J . E.; Stevens, P. A.; Ra´bai, J .; Mozeleski, E. J . J .
Am. Chem. Soc. 1998, 120, 3133.
(2) (a) Kuntz, E. G. CHEMTECH 1987, 17, 570. (b) Herrmann, W.
A.; Kohlpaintner, C. W. Angew. Chem., Int. Ed. Engl. 1993, 32, 1524.
(c) Roundhill, D. M. Adv. Organomet. Chem. 1995, 38, 155. (d) Cornils,
B. Angew. Chem., Int. Ed. Engl. 1995, 35, 1575. (e) Cornils, B.,
Herrmann, W. A., Eds. Aqueous-Phase Organometallic Catalysis.
Concepts and Applications; VCH: Weinheim, Germany, 1996.
10.1021/jo991548v CCC: $19.00 © 2000 American Chemical Society
Published on Web 05/27/2000

3886 J . Org. Chem., Vol. 65, No. 13, 2000
Richter et al.
Sch em e 1a
Ta ble 1. F lu or ou s P h osp h in es Ba sed on Differ en t
Hyd r oca r bon Sp a cer s
a
b
d
See ref 8b. See ref 8c. c See ref 8e. See ref 8a. e See ref 8d.
f See ref 9. See ref 7a. See ref 8f. See ref 12.
g
h
i
pected to be preferentially soluble in apolar perfluori-
nated solvents, as well as in supercritical carbon dioxide.7
Only a limited number of fluorous versions of catalyti-
cally important phosphines, such as PPh3 and R2PCH2-
CH2PR2 (R ) alkyl, aryl), have been reported.8 The most
common synthetic approach is the attachment of ali-
phatic fluorocarbon chains either directly to the phos-
phorus atom or to the organic substituents of a particular
phosphine. However, in all known cases, a nonfluorous
spacer group has been necessary to insulate the phos-
phorus atom from the strongly electron-withdrawing
perfluoroalkyltail (Table 1).
In previous studies, either (a) one or more CH2 groups,
(b) an aryl ring, or (c) both have been used as spacer,7a,b,8,9
leading to fluorous alkyl and aryl phosphines that have
also been referred to as “pony” or “pigtail” phosphines.
In addition, reports of a number of aryl phosphines with
perfluoroalkyl and perfluoroalkyl ether chains containing
aromatic C-F bonds have been published.10 Because
these bonds are known to be easily activated by late
transition metal complexes,11 these ligands appear to be
less suitable for catalysis. More recently, fluorinated
alkoxy groups (d) have been used to increase the solubil-
a
Reagents and conditions: (i) 30-fold excess of Mg, diethyl
ether, 25 °C; (ii) HSi(Me)3-nCln, Et2O; (iii) Br2, n-hexane (n ) 1,
2), n-hexane/FC-72 (n ) 3), 25 °C; (iv) 1.5 HSiMe2Cl, H2PtCl6(aq),
reflux.
ity of triarylphosphines in fluorous solvents.12 The ob-
served catalytic activities of fluorous phase soluble
catalysts derived from the phosphines in Scheme 1 are
generally an order of magnitude lower than those of their
nonfluorous analogues.13
Inspired by our work on dendrimeric structures con-
taining silicon branching points4 and work by Curran et
al.14 on the use of fluorous silyl tags and fluorous tin
hydrides in organic synthesis, we became interested in
developing aryl phosphine ligands with p-SiMe2CH2CH2
spacer groups (Figure 1). We anticipated that the silicon
would provide a positive inductive effect to the aromatic
system, in that way neutralizing the electron-withdraw-
ing effect of the perfluoro chain. Furthermore the suc-
cessive substitution of methyl for (CH2)2CxF2x+1 (x ) 6,
8) groups allows the attachment of up to nine perfluoro-
alkyl chains per P atom for a homoleptic triarylphosphine
(Figure 1), which is expected to lead to a reduction in
(7) (a) Kainz, S.; Koch, D.; Baumann, W.; Leitner, W. Angew. Chem.,
Int. Ed. Engl. 1997, 36, 1628. (b) Caroll, M. A.; Holmes, A. B. Chem.
Commun. 1998, 1395. (c) Morita, D. K.; Pesiri, D. R.; David, S. A.;
Glaze, W. H.; Tumas, W. Chem. Commun. 1998, 1397. (d) Hadida, S.;
Super, M. S.; Beckman, E. J .; Curran, D. P. J . Am. Chem. Soc. 1997,
119, 7406.
(8) (a) Betzemeier, B.; Knochel, P. Angew. Chem., Int. Ed. Engl.
1997, 36, 2623. (b) Langer, F.; Pu¨ntener, K.; Stu¨rmer, K.; Knochel, P.
Tetrahedron: Asymmetry 1997, 8, 715. (c) Bhattacharya, P.; Gudmun-
sen, D.; Hope, E. G.; Kemmitt, R. D. W.; Paige, D. R.; Stuart, A. M. J .
Chem. Soc., Perkin Trans. 1 1997, 3609. (d) Hope, G. H.; Kemmitt, R.
D. W.; Stuart, A. M. J . Chem. Soc., Dalton Trans. 1998, 3765. (e) Alvey,
L. J .; Rutherford, D.; J uliette, J . J . J .; Gladysz, J . A. J . Org. Chem.
1998, 63, 6302. (f) Kling, R.; Sinou, D.; Pozzi, G.; Chopin, A.; Quignard,
F.; Busch, S.; Kainz, S.; Koch, D.; Leitner, W. Tetrahedron Lett. 1998,
39, 9439.
(9) (a) Kainz, S.; Luo, Z.; Curran, D. P.; Leitner, W. Synthesis 1998,
1425. (b) Fawcett, J .; Hope, E. G.; Kemmitt, R. D. W.; Paige, D. R.;
Russell, D. R.; Stuart, A. M. J . Chem. Soc., Dalton Trans. 1998, 3751.
(10) (a) Gopal, H.; Tamborski, C. J . Fluorine Chem. 1979, 13, 337.
(b) Gopal, H.; Snyder, C. E.; Tamborski, C. J . Fluorine Chem. 1979,
14, 511.
(11) (a) Kiplinger, L. J .; Richmond, T. G.; Osterberg, C. E. Chem.
Rev. 1994, 94, 373. (b) Atherton, M. J .; Coleman, K. S.; Fawcett, J .;
Holloway, J . H.; Hope, E. G.; Karac¸ar, A.; Russell, D. R.; Saunders, G.
C. J . Chem. Soc., Dalton Trans. 1996, 3215.
(12) Sinou, D.; Pozzi, G.; Hope, E. G.; Stuart, A. Tetrahedron Lett.
1999, 40, 849.
(13) (a) For example, in the case of olefin hydroformylation, the
activity of the Rh/P[CH2CH2(CF2)5CF3]3 system is ca. 10 times less than
that of Rh/PPh3.1c In hydrogenation reactions employing similar
catalysts, 16-1073 turnovers in 24 h13b and 88-108 turnovers in 8
h13c have been observed, which are modest compared to, e.g., Wilkin-
son’s catalyst RhCl(PPh3)3 (150-600 turnovers/h).13d The positive effect
of using triarylphosphines instead of trialkylphosphines is well-known
in catalytic hydrogenation13e,f and has been attributed to the lower
basicity of triarylphosphines. Hence, for optimum activity, fluorous
triarylphosphines with steric and electronic properties that are closely
comparable to those of PPh3 would be highly desirable. (b) Haar, C.
M.; Huang, J .; Nolan, S. P.; Petersen, J . L. Organometallics 1998, 17,
5018. (c) Rutherford, D.; J uliette, J . J . J .; Rocaboy, C.; Horva´th, I. T.;
Gladysz, J . A. Catal. Today 1998, 42, 381. (d) Derived from data in:
Osborn, J . A.; J ardine, F. H.; Young, J . F.; Wilkinson, G. J . Chem.
Soc. A 1966, 1711. (e) Chaloner, P. A.; Esteruelas, M. A.; J oo´, F.; Oro,
L. A. Homogeneous Hydrogenation; Kluwer Academic Publishers:
Boston, MA, 1994; pp 8-9. (f) Montelatici, S.; van der Ent, A.; Osborn,
J . A.; Wilkinson, G. J . Chem. Soc. A 1968, 1054.
(14) (a) Curran, D. P.; Ferritto, R.; Ye, H. Tetrahedron Lett. 1998,
39, 4937. (b) Curran, D. P.; Hadida, S.; Kim, S.-Y.; Luo, Z. J . Am. Chem.
Soc. 1999, 121, 6607 and references therein.

Fluorous Triphenylphosphine Derivatives
J . Org. Chem., Vol. 65, No. 13, 2000 3887
Ta ble 2. Yield s Obta in ed in th e Syn th esis of F lu or ou s
Sila n es Accor d in g to th e Meth od s Used in Sch em e 1
total yield
entry
{n,x}
method
B{n ,x}a
C{n ,x}b
(%)c
1
2
3
4
5
6
7
{1,6}
{1,6}
{2,6}
{3,6}
{1,8}
{2,8}
{3,8}
b
a
a
a
b
a
a
-
60 (63)d
nd
60
nd
78
62
79
56
69
68
79
99
78 (70)e
80 (99)f
79 (66)d
80
F igu r e 1. Fluorous triphenylphosphines with various degrees
of fluorous character through the use of silicon as a branching
point.
-
70
75
92
a
Based on CxF2x+1C2H4I, yield of Grignard reaction included.
ligand and/or catalyst leaching during fluorous biphasic
separation.
Based on CxF2x+1CHdCH2 (n ) 1) or B{n ,x} (n ) 2, 3). c Based
b
d
on CxF2x+1CHdCH2 (n ) 1) or CxF2x+1C2H4I (n ) 2, 3). See ref
16. e See ref 18a. f See ref 18b.
In our previous work on fluorous triphenylphosphines
D{1,x} (x ) 6, 8) and in their successful application to
the recycling of highly active rhodium-based hydrogena-
tion catalysts by fluorous biphase separation,15 we ob-
tained indications that fluorous phosphines with higher
fluorine content could be advantageous, because recycling
of the intact catalyst was limited by the loss of free
phosphine (8 and 2% per cycle, respectively). Here, we
present (i) a full report on the preparation of fluorous
triarylphosphines D{1,x}; (ii) a new, versatile synthetic
route for the synthesis of higher substituted fluorous
triarylphosphines D{n ,x} (n ) 2, 3) involving the use of
a p-Si(Me)3-n[(CH2)2]n spacer (n ) 1, 2, 3); and (iii) a study
on the solubility of the new phosphines in organic and
fluorous solvents and their partition coefficients in fluo-
rous biphasic solvent systems.
was reported previously for B{3,x} (x ) 6, 10),18 has been
used to synthesize a six-member library of fluorous
alkylsilanes B{n ,x} (n ) 1, 2, 3; x ) 6, 8), with compounds
B{2,x} and B{3,8} as the new derivatives. This route also
allows more efficient access to silanes B{1,x} than
provided by hydrosilylation followed by reduction with
LiAlH4 (68% compared to 55% yield, x ) 6; Table 2, entry
2).16,19
The reactions with dichloromethylsilane and trichlo-
rosilane were straightforward and yielded the fluoro-
alkylsilanes B{n ,x} as air-stable and easy-to-handle
materials. Bromination of B{n ,x}, following modified
literature procedures for C{3,x} (x ) 6, 10),18b,c afforded
bromosilanes C{n ,x}. An overview of the yields of each
step in Scheme 1 is given in Table 2.
Two general strategies for the synthesis of the fluorous
aryl phosphines have been followed, specifically, route
a, the reaction of lithiated p-(fluoroalkylsilyl)bromoben-
zene E{n ,x} with PCl3 or P(OMe)3, and route b, the
reaction of fluoroalkylhalosilanes C{n ,x} (n ) 1, 2, 3)
with lithiated tris(p-bromophenyl)phosphine (Scheme 2).
To be able to compare the effect of the fluoroalkylsilyl
substituents with that of a regular methyl group, the
known trimethylsilyl derivative D{0}20 was prepared as
well, following the same synthetic procedure.
Rou te a (Sch em e 2). Silyl chlorides C{1,x} were
reacted with p-bromophenyllithium, which was obtained
by lithiation of 1,4-bromoiodobenzene or (less expensive)
1,4-dibromobenzene using an improved literature proce-
dure.21 The yields of aryl derivatives E{n ,x} are listed
in Table 3. Colorless liquid E{1,6} and white, waxy solid
E{1,8} are soluble in benzene, chloroform, and hexane.
Minor amounts of 1,4-[SiMe2(CH2)2CxF2x+1]2C6H4 (x ) 6,
8) were formed as side products. A similar side product
has been reported in the copper(I)-mediated coupling
reaction of CF3(CF2)5I with p-bromoiodobenzene.8d The
route to E{1,x} has also been used in our laboratory for
the synthesis of fluorous [NiCl{2,6-(CH2NMe2)2C6H2-4-
Resu lts a n d Discu ssion
Syn th esis. Scheme 1 gives an overview of the two
routes used to obtain fluorous silanes C{n ,x}, which serve
as precursors for the preparation of phosphines D{n ,x}.
Here n signifies the number of fluorotails per silicon
atom, whereas x represents the number of carbons in the
CxF2x+1 fluorotail. The synthesis of the fluorous phos-
phines D{n ,x} starts from either (1H,1H,2H,2H-per-
fluoro-1-alkyl)dimethylchlorosilanes C{1,x}15 or bis- and
tris(1H,1H,2H,2H-perfluoro-1-alkyl)bromosilanes C{n ,x}
(n ) 2, 3; x ) 6, 8; Scheme 1). The silanes C{1,x} are
commercially available but can also be obtained through
hydrosilylation of 1H,1H,2H-perfluoro-1-octene or -decene
(step iv, Scheme 1;16 Table 2, entries 1 and 5). The
internal olefins trans-Me(H)CdCF(CyF2y+1) (y ) 5, 7) were
obtained as side products (21-40%) and are responsible
for the rather moderate yield of the hydrosilylation step.
Most likely they are formed by the decomposition of the
unstable Markovnikov addition product.17
The route via the Grignard reagents of the 1H,1H,-
2H,2H-perfluoro-1-alkyl iodides (A{x}) and reaction with
chlorosilanes HSi(Me)3-xClx (Scheme 1, route a), which
(18) (a) Boutevin, B.; Guida-Pietrasanta, F.; Ratsimihety, A.; Ca-
poriccio, G.; Gornowitz, G. J . Fluorine Chem. 1993, 60, 211. (b) Studer,
A.; Curran, D. P. Tetrahedron 1997, 53, 6681. (c) Studer, A.; J eger, P.;
Wipf, P.; Curran, D. P. J . Org. Chem. 1997, 62, 2917.
(19) The polyfluoroalkyl iodides exhibit a high tendency to form
Wurtz-coupling products in the Grignard reaction, especially at tem-
peratures above 25 °C and at concentrations g0.4 M. However, the
amount of radical dimer could be kept below 10% by performing the
Grignard reaction slowly (15 h) at room temperature and at e0.22 M
concentrations in Et2O.
(20) First reported by: Frisch, K. C.; Lyons, H. J . Am. Chem. Soc.
1953, 75, 4078.
(21) (a) Gilman, H.; J ones, R. G. J . Am. Chem. Soc. 1941, 63, 1443.
(b) J ones, R. G.; Gilman, H. In Organic Reactions; Adams, R., Ed.;
Wiley: New York, 1951; Vol. 6, p 339. (c) Neumann, H.; Seebach, D.
Tetrahedron Lett. 1976, 4839.
(15) (a) Richter, B.; Deelman, B.-J .; van Koten, G. Eur. Pat. Appl.
98203308.6, Sept 30, 1998. (b) Richter, B.; Deelman, B.-J .; van Koten,
G. J . Mol. Catal. A: Chem. 1999, 145, 317. (c) Deelman, B.-J .; Richter,
B.; Van Koten, G. Book of Abstracts, Cerc3 Young Chemists Work-
shop: Homogeneous Catalysis, University of Rostock, Rostock, Ger-
many, Apr 21-24, 1999. (d) Deelman, B.-J .; Richter, B.; Van Koten,
G. Book of Abstracts, 218th American Chemical Society National
Meeting, New Orleans, LA, Aug 22-26, 1999. (e) Richter, B.; Spek, A.
L.; van Koten, G.; Deelman, B.-J . J . Am. Chem. Soc. 2000, 122, 3945.
(16) Ame´duri, B.; Boutevin, B.; Nouiri, M.; Talbi, M. J . Fluorine
Chem. 1995, 74, 191.
(17) Kim, Y. K.; Pierce, O. R.; Bajzer, W. X.; Smith, A. G. J . Fluorine
Chem. 1971/72, 1, 203.

3888 J . Org. Chem., Vol. 65, No. 13, 2000
Richter et al.
Sch em e 2a
a
Reagents and conditions: (i) X ) I, nBuLi, n-hexane/n-pentane, 0 °C; (ii) C{n ,x}, THF/n-pentane, -78 °C then room temperature; (iii)
2 BuLi, n-hexane, -78 °C then room temperature, or nBuLi, n-hexane, 0 °C then room temperature; (iv) 1/3 PCl3 or 1/3 P(OMe)3, n-hexane/
t
THF, -78 °C then room temperature; (v) X ) Br, nBuLi, n-hexane/Et2O, room temperature; (vi)
/ PCl3, n-hexane/Et2O, -78 °C then
3
1
t
room temperature; (vii) 6 BuLi, Et2O/hexane, -78 °C; (viii) 3 C{n ,x}, Et2O/n-hexane, -78 °C then room temperature.
Ta ble 3. Yield s Obta in ed in th e Syn th esis of
Non flu or ou s a n d F lu or ou s Com p ou n d s E a n d D
Accor d in g to Meth od s a a n d b in Sch em e 2
Ta ble 4. Over a ll Yield s of Ar yl P h osp h in es D Ba sed on
th e Differ en t Sta r tin g Ma ter ia ls Used
C{n ,x} PCl3 P(OMe)3 p-BrC6H4X
E{n ,x}a
D{n ,x}b
entry method {n,x}
(%)
(%)
(%)
(%)
entry
method
{n,x}
(%)
(%)
1a
1b
2
3
4
5
6
7a
7b
8
aa
ab
b
{0}
{0}
{0}
75
40
98
51
77
98
88
42
35
90c
88c
-
58
70
68
55
64
61
-
90
-
-
-
-
-
-
65
-
-
-
68 (X ) I)
36 (X ) I)
70 (X ) Br)
46 (X ) I)
55 (X ) Br)
64 (X ) Br)
61 (X ) Br)
38 (X ) I)
35 (X ) I)
71 (X ) Br)
70 (X ) Br)
1a
1b
2
3
4
5
6
7a
7b
8
ac,e
ad,f
b
{0}
{0}
{0}
98
98
-
83
-
-
-
75
40
98
62
77
98
86
48
41
90
88
aa
b
{1,6}
{1,6}
{2,6}
{3,6}
{1,8}
{1,8}
{2,8}
{3,8}
ac,f
b
{1,6}
{1,6)
{2,6}
{3,6}
{1,8}
{1,8}
{2,8}
{3,8}
b
b
b
b
aa
ab
b
ac,e
ad,f
b
87
87
-
57
71
69
9
b
9
b
-
a
t
b
Using BuLi in step ii. Using nBuLi in step ii. c Using a 10%
a
b
Based on C{n ,x}. Yield based on E{0}, E{1,x} (route a),
excess of C{n ,x}.
C{0}, or C{n ,x} (route b). c Using BuLi in step ii. Using nBuLi
t
d
in step ii. e Using P(OMe)3 in step iii. f Using PCl3 in step iii.
3-fold lithiation of tris(p-bromophenyl)phosphine in di-
ethyl ether is fast and essentially quantitative. Treat-
ment with silanes C{n ,x} (n ) 2, 3) afforded the
phosphines D{n ,x} (n ) 2, 3) in high yields (86-98%,
Table 3). Phosphines D{1,x} can also be synthesized more
efficiently following this procedure.
The advantage of using route b rather than route a
with respect to the use of different starting materials,
especially C{n ,x} and p-BrC6H4X (X ) Br, I), becomes
clear in a comparison of the overall yields of the phos-
phines (Table 4). The synthesis of tris[p-(trimethylsilyl)-
phenyl]phosphine (D{0}) by method b is nearly quanti-
tative with respect to silane (entry 2), in contrast to the
initially reported value (35-45%).20
SiMe2(CH2)2(CF2)5CF3}], a model catalyst for the selective
1:1 Kharasch addition of CCl4 to methyl methacrylate
under fluorous conditions.22
Compounds E{1,x} were easily lithiated using either
tBuLi (1:2 molar ratio) or nBuLi (1:1 molar ratio). The
fact that the yields were lower than expected is the result
of incomplete lithiation rather than side reactions (1H
NMR). Lithiation using BuLi instead of BuLi afforded
similar yields, but proved to be more time-consuming.
Metathesis of lithiated E{1,x} with PCl3 or P(OMe)3 at
0 °C afforded the desired phosphine ligands D{1,x} in
moderate overall yields (Table 4).
n
t
All novel derivatives B-E were characterized by their
NMR spectroscopic data [1H, 13C, 19F, 29Si, and 31P (for
phosphines D)] and, in several cases, by their correct
elemental analyses (B{2,8}, B{3,8}, C{2,8}, D{n ,x}; n
) 1, 2, 3; x ) 6, 8).
Interestingly, the silanes B{n ,6} and halosilanes C-
{n ,6} (n ) 1, 2, 3) are colorless oils, whereas extending
the perfluoro chain by two CF2 units (x ) 8) results in
waxy solids for n ) 2 and 3. Boiling and melting points
of C{n ,x} increase in order of increasing n (0 < 1 < 2 <
3) (Table 5). Remarkably, the opposite trend is observed
for the fluorous aryl phosphines D{n ,x}, with the excep-
Rou te b (Sch em e 2). After several unsuccessful
attempts to lithiate aryl bromides E{n ,x} bearing more
than one fluorotail (n > 1), we decided to introduce the
fluoroalkylsilyl group by reaction with lithiated tris(p-
bromophenyl)phosphine. The latter was synthesized in
71% yield by optimization of a literature procedure.23 The
(22) Kleijn, H.; J astrzebski, J . T. B. H.; Gossage, R. A.; Kooijman,
H.; Spek, A. L.; van Koten, G. Tetrahedron 1997, 54, 1145.
(23) (a) See Experimental Section. (b) Benassi, R.; Schenetti, M. L.;
Taddei, F.; Vivarelli, P.; Dembech, P. J . Chem. Soc., Perkin Trans. 2
1974, 1338. (c) Ravindar, V.; Hemling, H.; Schumann, H.; Blum, J .
Synth. Commun. 1992, 22, 841.

Fluorous Triphenylphosphine Derivatives
J . Org. Chem., Vol. 65, No. 13, 2000 3889
Ta ble 5. Boilin g a n d Meltin g P oin ts of Com p ou n d s C
a n d D
C{n ,x}
bp (°C)
entry {n,x} mp (°C) (pressure (mbar))
D{n ,x}
mp (°C)
1
2
3
4
5
6
7
{0}
-
-
51.0 (103)
76-80 (33)a
105 (0.1)
180 (0.1)
106-108 (33)a
-
194 (lit. 187-189)b
{1,6}
{2,6}
{3,6}
{1,8}
{2,8}
{3,8}
89
F igu r e 3. Equilibrium of the three rotational isomers of B-
{n ,x}, C{n ,x}, D{n ,x}, and E{n ,x} (n ) 1, 3).
-
67
50-55
101
72
123-125
-
-
55
93
Ta ble 6. Assign m en t of th e 19F a a n d 13Cb NMR Sign a ls of
th e 1H,1H,2H,2H-P er flu or ooctyl Ch a in in D{1,6}
-
a
b
See ref 15b. See ref 21.
a
b
282.4 MHz, C6D6, T ) 25 °C. 75.5 MHz, C6D6, T ) 25 °C.
For compounds B{2,x}, C{2,x}, D{2,x}, and E{2,x},
the methylene protons are diastereotopic, which gives
rise to more complicated ABCDX2Y2Z2 spin systems in
which the chemical shifts and the J H,H and J H,F spin-
spin coupling constants are different for each methylene
proton.
F igu r e 2. Experimental (top) and simulated (bottom) part of
the 1H NMR spectrum of C8F17(CH2)2Si(Me)2Cl (C{1,8}).
Simulation parameters: δA, 1.07; δB, 2.18; coupling constants
As is demonstrated for D{1,6} in Table 6, the complete
assignment of the 19F resonances of D{n ,6} with respect
to the position of the fluorine atoms in the perfluoroalkyl-
tail was made on the basis of literature information26 and
data from severalNMR experiments (13C-19F HETCOR,13C-
{1H}, 13C{19F}, 19F COSY, 19F selective decoupling) and
differs from that presented in some recent publications.8c,9,16
C-F correlations were made on the basis of a 13C-19F
HETCOR experiment. The CF3, R-CF2, and ꢀ-CF2 group
resonances in the 13C{1H} spectrum were assigned by
their characteristic multiplicities. The signal of the ꢀ-CF2
group was observed as a triplet of multiplets due to 1J C,F
2
3
3
4
(Hz), J A,A′ ) 2J B,B′ ) -15.3, J A,B ) 4.28, J A,B′ ) 13.1, J A,X
)
3
5
4
6
5
0.36, J B,X ) 18.0, J A,Y ) 0.18, J B,Y ) 1.56, J A,Z ) 0.08, J B,Z
) 0.50.
tion of D{3,8}, which has a melting point higher than
those of all other phosphines D{n ,x} (Table 5). Clearly,
for D{n ,x}, the introduction of more or longer fluoroalkyl
chains results in a decrease in the melting point despite
the increase in molecular weight.
The methylene protons of the -CH2CH2Si- spacer
group in compounds B, C, D, and E (n > 0) reveal second-
order behavior in their 1H NMR spectra, which, in the
case of one or three fluorotails per silicon atom (n ) 1,
3),can be interpreted as the AA′BB′part ofan AA′BB′X2Y2Z2
spin system with characteristic 3J H,F values (18 Hz)24 and
2
and slightly different J C,F couplings to CF3 and δ-CF2
groups, respectively. This assignment was confirmed by
selective 19F decoupling of all CF2 groups, resulting in a
single 19F-coupled signal of the ꢀ-CF2 group in the 13C-
{19F} spectrum (quartet due to 2J C,F coupling with CF3).
5
19F-19F COSY experiment, combined with the infor-
long-range couplings up to J H,F (Figure 2). In the case
A
mation from a 13C-19F HETCOR spectrum, allowed the
of compounds B{n ,x} (n ) 1, 3), this pattern became
visible only on selective decoupling of the CH2Si-H signal.
assignment of the remaining 13C and 19F signals, taking
into account the well-known phenomenon that J F,F
3
4
The sizes of the observed vicinal J AB (13.1 Hz) and
.
3J AB (4.3 Hz) coupling constants are in good agreement
with the time-averaged contributions calculated for the
three possible rotamers (13.7 and 4.6 Hz, respectively),
taking into account the influence of the inductive effect
of the silicon and CF2 substituents on the J H,H coupling
constants.25 The absence of significant changes in the
spectra of C{1,8} upon cooling to 238 K and warming to
343 K, except for small changes in line width, also
corresponds to a fast exchange between the three rota-
mers (Figure 3).
3J F,F for freely rotating fluorous aliphatic chains (∼10 and
∼0 Hz, respectively).26 Also, these assignments were
confirmed by selective 19F decoupling experiments.
In the case of the longer C8F17 chain, the 19F resonances
of the two additional CF2 moieties are not resolved from
the γ-fluorine signals. However, the 13C{19F} NMR
spectra exhibit two new signals (at δ 111.8 and 111.7 for
D{1,8} in C6D6).
The 29Si NMR spectra of phosphines D{n ,x} clearly
show a deshielding of the silicon atom with an increasing
(24) Brace, N. O. J . Org. Chem. 1971, 36, 1904.
(26) (a) Mason, J . Multinuclear NMR; Plenum Publishing: New
York, 1987; Chapter 16, p 443 and references therein. (b) Suhr, H.
Anwendungen der Kernmagnetischen Resonanz in der Organischen
Chemie; Springer-Verlag: Berlin, 1965.
(25) (a) Karplus, M. J . Chem. Phys. 1959, 30, 11. (b) Abraham, R.
J .; Gatti, G. J . Chem. Soc. B 1969, 961. (c) Phillips, L.; Wray, V. J .
Chem. Soc., Perkin Trans. 2 1972, 536.

3890 J . Org. Chem., Vol. 65, No. 13, 2000
Richter et al.
F igu r e 4. 31P and 29Si chemical shifts for the new fluorous
phosphine ligands D{n ,x} and nonfluorous D{0} and PPh3.
Conditions: 31P{1H} NMR, 121.5 MHz; 29Si{1H} NMR, 59.6
MHz; solvent, C6D6/C6F6, 1:1 (v/v); T ) 25 °C.
F igu r e 5. Plot of partition coefficients P (P ) cfluorous
/
phase
corganic phase) for phosphines D{n ,x} in several fluorous biphasic
solvent systems with c-C6F11CF3 as the fluorous phase at 0
°C.
Ta ble 7. Solu bilitiesa a n d F lu or ou s P a r tition
(0.25-0.28 mol/L). For n ) 3, the solubility drops to
values below 0.17 mol/L. The progressive decrease in
fluorocarbon solubility with increasing x (6 > 8 > 10)
Coefficien ts P b of th e F lu or ou s Ar yl P h osp h in es
n-octane
c-C6F11CF3
F content
(wt %)
compd
mol/L
g/L mol/L g/L
Pc
Pd
Pe
reported for fluorous trialkyl derivatives P(CH2-
8e
D{1,6}
D{1,8}
D{2,6}
D{2,8}
D{3,6}
D{3,8}
50
55
60
63
64
67
0.037
0.008
0.005
55 0.050
14 0.055
12 0.249 615 7.8 17
74 0.26 1.1 1.5
98 2.2 4.6 2.2
CH2CxF2x+1
)
is in contrast to the order 6 < 8 observed
3
for D{n ,x} (n ) 1 or 2). However, the reverse order (6 >
8) was observed for n ) 3. It is noteworthy that the
solubility of fluorous aryl phosphines D{1,x} in diethyl
ether is significantly higher than the solubilities in
n-octane, n-pentane, and c-C6F11CF3. For example, a >1.0
M diethyl ether solution of D{1,6} can be prepared,
whereas a saturated n-pentane solution is ca. 0.16 M. In
comparison with D{0}, the fluorotail-containing phos-
phines D{1,x} (x ) 6, 8) display increased n-pentane
solubility: At a value of ca. 0.22 mol/L, the solubility of
D{1,8} in n-pentane is more than twice that of D{0}
(<0.10 mol/L). These observations clearly indicate that
the fluorous character of D{1,x} is not yet very pro-
nounced, in contrast to that of the higher derivatives D-
{2,x} and D{3,x}.
5.7
9.2
0.001
3
-
3
0.277 851 7.8 28
0.162 502 4.3
0.029 127 2.1 12
f
f
-
9.4 15
20
0.7 × 10-3
a
Expressed as the amount of phosphine that dissolves in 1 L
b
of pure solvent at 25 °C. In a 50:50 (v/v) mixture of c-C6F11CF3/
organic solvent (P ) cfluorous phase/corganic phase) at 0 °C. Derived from
an analysis of each of the two phases on phosphorus by ICP-AAS,
assuming that the densities of the two phases are those of the
pure solvents. The estimated experimental error is less than (1
in the last digit. c c-C6F11CF3/toluene, Tc ) 89 °C, where Tc is
defined as the critical temperature of the biphasic solvent system.
d
See, for example, ref 27. c-C6F11CF3/n-octane, Tc ) 42 °C. e c-
C6F11CF3/n-pentane, Tc ∼ 10 °C. f Formation of a gel.
number of fluorotails, whereas an increase in the length
of the fluorotails (x ) 6 and 8, respectively) has little
effect (Figure 4). The opposite trend was observed for the
chemical shift changes of the 13C signals of the CH2Si
and CH3Si moieties. However, a comparison of the 31P
NMR data of compounds D{n ,x}, D{0}, and PPh3 indi-
cates clearly that the -SiMe3-n(CH2CH2)n- linker is
effective in insulating the phosphorus atom from the
electron-withdrawing perfluoroalkyltails. In fact, by com-
parison with the NMR data for D{0}, it can be concluded
that the observed chemical shift differences between PPh3
and D{n ,x} are predominantly due to the p-silyl substi-
tution (Figure 4).
Solu bility a n d P h a se Distr ibu tion Stu d ies. As our
primary objective for the perfluorotail functionalization
of aryl phosphines is to use them as ligands for im-
mobilization of phosphine-based homogeneous catalysts
in fluorous solvents,15 we were interested in the solubility
of fluorous aryl phosphines D in different solvents and
in biphasic solvent combinations. The solubilities of the
phosphines D in organic and fluorous solvents are listed
in Table 7. It appears that the “like dissolves like”
principle is valid: The fluorous phosphines have consis-
For applications in fluorous biphasic catalysis and for
catalyst recycling by fluorous extraction techniques, the
most important feature of the fluorous aryl phosphines
and derived catalytic complexes is the partition coefficient
P (P ) cfluorous phase/corganic phase) in fluorous biphasic sys-
tems. Partition coefficients of the fluorous aryl phos-
phines were determined in several fluorous biphasic
solvent combinations (Table 7 and Figure 5) and reflect
the same trend as their solubility data, i.e., there is an
optimum for D{2,6} and D{2,8}, except for c-C6F11CF3/
n-pentane for which, presumably because of the lower
critical temperature (Tc) of ca. 10 °C, a steady increase
of P with the weight percent of fluorine was found, with
a peak at D{3,8}. The best fluorous phase affinity was
found for D{2,8} in c-C6F11CF3/n-octane (P ) 28).
In comparison with fluorous trialkylphosphines P(CH2-
CH2C8F17)3 (P ) 332 in c-C6F11CF3/toluene),1c,8e relatively
small partition coefficients were found for our fluorotail-
bearing aryl phosphine ligands (cf. P ) 2.2 for D{1,8}).
Consequently, there is not a simple relation between P
and the weight percent of F in the phosphine; undoubt-
edly, there is also an effect of the partial degree of
aromatic character, i.e., the number of aryl groups in the
phosphine (Figure 5).
tently higher solubilities in the fluorous solvent c-C6F11
CF3 than in nonfluorous n-octane. Remarkably, an opti-
mum in the fluorocarbon solubility is observed for n ) 2
-

Fluorous Triphenylphosphine Derivatives
J . Org. Chem., Vol. 65, No. 13, 2000 3891
Ca u tion : Although the toxicity of the fluorous phosphines
developed is unknown, they are lipophilic and, therefore,
expected to be able to accumulate in body tissues, analogous
to behavior observed for perfluorocarbons.28 Hence, proper
precautions should be taken to prevent, for example, contact
with the skin.
Despite the relatively small fluorous phase affinity of
the fluorous phosphine D{1,x}, we have been able to
demonstrate that rhodium leaching for RhCl[D{1,x}]3 in
hydrogenation catalysis can be as low as 0.1%.15e Because
of their higher partition coefficients, fluorous phosphines
D{n ,x} with n > 1, especially with n ) 2, are even more
interesting for further reduction of Rh and phosphine
leaching in fluorous biphasic catalyst separation.
Gen er a l P r oced u r e for Rea ction of th e Gr ign a r d
Rea gen ts of 2-(P er flu or oa lk yl)iod oeth a n es w ith Ch lo-
r osila n es. The freshly prepared and filtered CxF2x+1(CH2)2I
Grignard solution was treated with a stoichiometric amount
(based on 90% conversion of the Grignard reaction) of the
respective chlorosilane and stirred overnight. The reaction
mixture, which consisted of either a liquid biphasic system or
a white suspension, was quenched with water (100 mL). After
phase separation, the organic phase was combined with two
20-mL diethyl ether extracts of the water phase, and the
resulting mixture was dried over MgSO4. Volatiles were
removed using a rotary evaporator. The light-yellow oils (B-
{2,6}, B{3,6}, and B{1,8}) and white, waxy solids (B{2,8} and
B{3,8}) contained e10% of the Wurtz coupling product, which
was removed by Kugelrohr distillation or by fractional distil-
lation (B{1,6}).
Con clu sion s
We have demonstrated straightforward synthetic routes
for the synthesis of novel, highly fluorous triarylphos-
phines, which are of interest for fluorous phase catalysis
and catalyst recovery by fluorous biphasic extraction. By
using silicon as a branching point, it became possible to
attach between three and nine perfluorotails per phos-
phorus atom. Through this method, phosphines contain-
ing between 50 and 67 wt % fluorine were prepared,
which reveal distinct fluorous phase affinity in fluorous
biphasic solvent systems and good solubility in fluorous
solvents. 31P NMR studies confirm the effective insulation
of the phosphorus atom, and consequently its donor
properties, from the electron-withdrawing effect of the
perfluorotails. Surprisingly, the fluorous phase solubility,
as well as the partition coefficients, of these particular
triarylphosphines in fluorous biphasic solvent systems
displays an optimum at ca. 63 wt % fluorine. Only in the
case of c-C6F11CF3/n-pentane did we observe a steady
increase of the fluorous phase affinity with the amount
of fluorous character, resulting in an optimum for 67 wt
% fluorine. Interestingly, there is a strong correlation
between the single phase fluoro- and hydrocarbon solu-
bility of these fluorous phosphines and their fluorous
phase affinity in fluorous biphasic systems.
Meth yl[bis(3,3,4,4,5,5,6,6,7,7,8,8,8-tr id eca flu or ooctyl)]-
sila n e (B{2,6}). A Grignard solution prepared from 12.5 g (26
mmol) of C6F13(CH2)2I treated with 1.24 mL (1.38 g, 12.0 mmol)
of HSiMeCl2 yielded 7.68 g (10.4 mmol, 79% based on 1H,-
1H,2H,2H-perfluorooctyl iodide). Bp: 96 °C (0.1 Torr). 1H NMR
(δ, CDCl3): 3.91 (oct, 1J Si,H ) 187 Hz, 3J H,H ) 3.8 Hz, 1H), 2.10
3
(m, 4H), 0.90 (m, 4H), 0.19 (d, J H,H ) 3.8 Hz, 3H). 19F NMR
(δ, CDCl3): -82.0 (m, 3F), -117.1 (m, J F,F ) 15 Hz, 2F), -123.0
29
(m, 2F), -124.0 (m, 2F), -124.5 (m, 2F), -127.3 (m, 2F).
-
Si{1H} NMR (δ, CDCl3): -6.78. 13C{1H} NMR (δ, CDCl3): 26.4
2
(t, J C,F ) 23 Hz), 2.33, -6.74.
Bis(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-h ep ta d eca flu or o-
d ecyl)m eth ylsila n e (B{2,8}). A Grignard solution prepared
from 26.2 g (45.6 mmol) of C8F17(CH2)2I treated with 2.13 mL
(2.36 g, 20.5 mmol) of HSiMeCl2 yielded 14.9 g (15.9 mmol,
69.7% based on 1H,1H,2H,2H-perfluoroalkyl iodide). Mp: 38-
40 °C. Anal. Calcd for C21H12F34Si: C, 26.85; H, 1.28; F, 68.84;
1
Si, 2.98. Found: C, 26.95; H, 1.36; F, 68.66; Si, 2.91. H NMR
Especially the phase partitioning of uncoordinated
fluorous ligands is a particularly relevant issue for
fluorous biphasic catalyst separation, as ligand dissocia-
tion is often an essential step in the catalytic cycle.
Leaching of dissociated ligand into the nonfluorous phase
is, therefore, a possible catalyst deactivation pathway.
With this aspect in mind, we are currently further
investigating fluorous catalysts based on our 6- and
9-fluorotail-containing phosphines.
(δ, CDCl3): 3.91 (oct, 1J Si,H ) 191 Hz, 3J H,H ) 3.6 Hz, 1H), 2.11
3
(m, 4H), 0.91 (m, 4H), 0.20 (d, J H,H ) 3.6 Hz, 3H). 19F NMR
(δ, CDCl3): -81.7 (m, 3F), -116.9 (m, J F,F ) 12 Hz, 2F), -122.7
(m, 6F), -123.5 (m, 2F), -124.1 (m, 2F), -127.0 (m, 2F). 29Si
NMR (δ, CDCl3): -6.81 (d, 1J Si,H ) 192 Hz). 29Si{1H} NMR (δ,
2
CDCl3): -6.77. 13C{1H} NMR (δ, CDCl3): 26.4 (t, J C,F ) 24
Hz), 2.26, -6.86. 13C{19F} NMR (δ, CDCl3): 118.4 (m), 117.5
1
(q, J C,F ) 269 Hz), 111.7, 111.5, 111.2, 111.1, 110.6, 108.8 (q,
1
1
2J C,F ) 26.3 Hz), 26.6 (tm, J C,H ) 130 Hz), 2.42 (tm, J C,H
)
1
119 Hz), -7.01 (qm, J C,H ) 121 Hz).
Tr is(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-h ep ta d eca flu or o-
d ecyl)sila n e (B{3,8}). A Grignard solution prepared from
24.5 g (42.6 mmol) of C8F17(CH2)2I treated with 1.08 mL (1.44
g, 10.7 mmol) of HSiCl3 yielded 14.7 g (10.7 mmol, 75% based
on 1H,1H,2H,2H-perfluoroalkyl iodide). Mp: 91 °C. Anal.
Calcd for C30H13F51Si: C, 26.27; H, 0.95; F, 70.71; Si, 2.04.
Found: C, 26.16; H, 1.10; F, 70.62; Si, 2.18. 1H NMR (δ; CDCl3/
C6F6, 3:1 (v/v)): 3.9 (m, 1J Si,H ) 192 Hz, 1H), 2.13 (m, 6H), 1.05
(m, 6H). 19F NMR (δ; CDCl3/C6F6, 3:1 (v/v)): -81.7 (m, 3F),
-116.9 (m, 2F), -122.7 (m, 6F), -123.6 (m, 2F), -124.2 (m,
2F), -127.0 (m, 2F). 29Si{1H} NMR (δ; CDCl3/C6F6, 3:1 (v/v)):
-2.38. 13C{19F} NMR (δ; CDCl3/C6F6, 3:1 (v/v)): 118.5 (m),
Exp er im en ta l Section
Gen er a l Rem a r k s. Reactions were conducted in a dinitro-
gen atmosphere unless noted otherwise. Solvents were ob-
tained and prepared as follows: benzene, toluene, n-pentane,
n-hexane, and diethyl ether were distilled from Na/benzophe-
none; FC-72, c-C6F11CF3, CF3C6H5 (Acros, Alfa), C6F6 (Acros),
C6D6, CDCl3, and n-C6D14 (Cambridge Isotope Laboratories,
Aldrich) were degassed and stored over molecular sieves.
Reagents were obtained and prepared as follows: CxF2x+1CHd
CH2 (x ) 6, 8) (Acros), CxF2x+1CH2CH2I (x ) 6, 8) (Lancaster),
and Mg turnings (Norsk Hydro, >99.8%) were used as
received; HSiCl3, HSi(Me)Cl2, HSiMe2Cl, and H2PtCl6(aq)
(Acros) were stored under nitrogen and used as received.
Elemental and ICP-AAS analyses were carried out by H.
Kolbe, Mikroanalytisches Laboratorium, Mu¨hlheim an der
Ruhr, Germany. 31P NMR spectra were referenced relative to
85% H3PO4 and 19F NMR spectra relative to CFCl3 (both
external). The 19F decoupler frequency in 13C{19F} NMR
experiments was set to either δ ) -121 or δ ) -81 to decouple
from the 19F nuclei of the CF2 moieties or the CF3 group,
respectively. For the simulation of 1H NMR spectra, the
computer program gNMR, version 3.6, Cherwell Scientific
Publishing Limited, Oxford, was used.
1
117.8 (q, J C,F ) 262 Hz), 111.8, 111.8, 111.4, 111.4, 110.9,
2
1
109.0 (q, J C,F ) 24.4 Hz), 26.6 (tm, J C,H ) 130 Hz), 1.0 (tm,
1J C,H ) 124 Hz).
Gen er a l P r oced u r e for Br om in a tion of 2-(P er flu or o-
a lk yl)eth ylsila n es B{n ,x}. The silanes B{n ,x} were dissolved
in either n-hexane or n-hexane/FC-72 mixtures, and a 2-fold
excess of Br2 was added to the reaction mixture at 0 °C. After
(27) Lo Nostro, P. Adv. Colloid Interface Sci. 1995, 56, 245-287.
(28) Lowe, K. C. In Organofluorine Chemistry, Principles and
Commercial Applications; Banks, R. E., Smart, B. E., Tatlow, J . C.,
Eds.; Plenum Publishing: New York, 1994; Chapter 26 and references
therein.

3892 J . Org. Chem., Vol. 65, No. 13, 2000
Richter et al.
2
1
the reaction mixture was stirred for 15 h at room temperature,
all of the volatiles were removed in vacuo. The slightly yellow
or colorless oils or waxy solids were further purified by
Kugelrohr distillation, fractional distillation, or recrystalliza-
tion, when necessary.
1J C,F ) 274 Hz, J C,F ) 31.6 Hz), 109.5 (tqt, J C,F ) 270 Hz,
2J C,F ) 31.6 Hz), 26.5 (t, J C,F ) 23.7 Hz), 5.56 (s, J C,Si ) 50.5
2
1
1
Hz), -3.65 (s, J C,Si ) 52.8 Hz).
1
Sid e P r od u ct 1,4-[C6F 13(CH2)2SiMe2]2C6H4. H NMR (δ,
CDCl3): 7.34 (s, 4H), 2.02 (m, 4H), 0.74 (m, 4H), 0.11 (s, 12H,
2J Si,H ) 6.6 Hz). 13C{1H} NMR (δ, C6D6): 139.0, 133.6, 26.6 (t,
2J C,F ) 24.2 Hz), 5.66 (t, 3J C,F ) 2.1 Hz), -3.34 (s, 1J C,Si ) 60.5
Hz).
Br om o(m eth yl)[bis(3,3,4,4,5,5,6,6,7,7,8,8,8-tr id eca flu o-
r ooctyl)]sila n e (C{2,6}). A solution of 25.4 g (34.3 mmol) of
B{2,6} in 100 mL of n-hexane was treated with 3.51 mL (11.0
g, 68.7 mmol) of Br2, yielding 27.6 g (34.0 mmol, 99% based
on B{2,6}) of the title compund. Bp: 105 °C (0.1 Torr). 1H NMR
(δ, C6D6): 1.93 (m, 4H), 0.71 (m, 4H), 0.02 (s, 3H). 19F NMR
(δ, C6D6): -81.5 (t, J F,F ) 9 Hz, 3F), -115.7 (m, J F,F ) 15 Hz,
2F), -122.3 (m, 2F), -123.3 (m, 2F), -123.5 (m, 2F), -126.6
(m, 2F). 29Si{1H} NMR (δ, C6D6): 29.2. 13C{1H} NMR (δ,
1-Br om o-4-[3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-h ep t a d e-
ca flu or od ecyl(d im eth yl)silyl]ben zen e (E{1,8}). Compound
C{1,8} (21.9 g, 40.5 mmol) and p-LiC6H4Br, obtained from 12.6
g (44.5 mmol) of p-bromoiodobenzene and 27 mL (40.5 mmol)
of nBuLi solution in n-pentane (80 mL), yielded 23.3 g (35.2
mmol, 87% based on C{1,8}) of the title compound. Bp: 145-
150 °C (0.1 Torr). Mp: 38 °C. 1H NMR (δ, C6D6): 7.31 (m, 2H),
1
2
C6D6): 118.8 (tt, J C,F ) 255 Hz, J C,F ) 30.6 Hz), 118.1 (qt,
1J C,F ) 289 Hz, J C,F ) 33.0 Hz), 112.3 (tquin, J C,F ) 268 Hz,
6.89 (m, 2H), 1.84 (m, 2H), 0.75 (m, 2H), -0.06 (s, 6H, 2J Si,H
)
2
1
2J C,F ) 32.0 Hz), 112.1 (tquin, J C,F ) 271.3 Hz, J C,F ) 31.8
6.4 Hz). 13C{1H} NMR (δ, C6D6): 136.3, 135.6, 131.9, 125.0,
1 2 1
1
2
1
2
Hz), 111.3 (tquin, J C,F ) 272 Hz, J C,F ) 31.7 Hz), 109.4 (tqt,
1J C,F ) 260 Hz, 2J C,F ) 30.5 Hz), 26.0 (t, 2J C,F ) 23.8 Hz), 7.73,
-0.38.
119.3 (tt, J C,F ) 254 Hz, J C,F ) 31.1 Hz), 118.0 (qt, J C,F )
288 Hz, 2J C,F ) 33.0 Hz), 112.7, 112.7, 111.9, 111.9 (tm), 111.2
2
1
(tm), 109.1 (tm), 26.5 (t, J C,F ) 23.8 Hz), 5.56 (s, J C,Si ) 50.7
1
Br om o[b is(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-h ep t a d e-
ca flu or od ecyl)]m eth ylsila n e C{2,8}. A solution of 24.6 g
(26.2 mmol) of B{2,8} in 400 mL of n-hexane was treated with
2.7 mL (8.4 g, 52 mmol) of Br2, yielding 21.3 g (20.9 mmol,
80% based on B{2,8}) of the title compound after recrystalli-
zation in benzene. Mp: 55 °C. Anal. Calcd for C21H11BrF34Si:
C, 24.77; H, 1.08; Br, 7.85; F, 63.50; Si, 2.75. Found: C, 24.87;
Hz), -3.65 (s, J C,Si ) 53.1 Hz).
1
Sid e P r od u ct 1,4-[C8F 17(CH2)2SiMe2]2C6H4. H NMR (δ,
CDCl3): 7.48 (s, 4H), 1.99 (m, 4H), 0.96 (m, 4H), 0.31 (s, 12H).
T r i s [4-{d i m e t h y l(3,3,4,4,5,5,6,6,7,7,8,8,8-t r i d e c a -
flu or ooct yl)silyl}p h en yl]p h osp h in e (D{1,6}) t h r ou gh
Rou te a . Compound E{1,6} (6.1 g, 11 mmol) in 50 mL of
n-hexane was treated with 14.5 mL (21.7 mmol) of tBuLi (1.50
M solution in n-hexane) at -78 °C. The reaction mixture was
allowed to reach room temperature and then stirred for 15 h.
The white precipitate formed was washed with n-pentane (2
× 20 mL) and suspended in diethyl ether (50 mL). Solids were
removed by centrifuge, and the clear solution was evaporated
to dryness, affording 4.89 g of the lithiated aryl compound,
which contained 1 equiv of diethyl ether (1H NMR). This
material (4.19 g) in a mixture of n-hexane (30 mL) and THF
(5 mL) was treated with PCl3 (0.25 mL, 2.84 mmol) in n-hexane
(5 mL) at -78 °C. After 1 h, the reaction mixture was allowed
to warm to room temperature and stirred for another 15 h.
Volatiles were removed in vacuo after filtration, and the white
residue was extracted with n-pentane (3 × 20 mL). The volume
of the combined n-pentane phases was reduced to 10 mL, and
the extract was stored at -10 °C. The mother liquor was
decanted, and the white precipitate was dried in vacuo.
Yield: 2.85 g (1.93 mmol, 62% based on E{1,6}). Mp: 89 °C.
Anal. Calcd for C48H42F39Si3P: C, 39.1; H, 2.85; F, 50.3; Si,
5.71; P, 2.10. Found: C, 39.3; H, 2.87; F, 50.1; Si, 5.80; P, 2.08.
1H NMR (δ; C6D6/C6F6, 1:1 (v/v)): 7.33 (m, 2H), 7.25 (m, 2H),
2.04 (m, 2H), 0.97 (m, 2H), 0.26 (s, 6H). 31P{1H} NMR (δ; C6D6/
C6F6, 1:1 (v/v)): -4.66. 29Si{1H} NMR (δ; C6D6/C6F6, 1:1 (v/
1
H, 1.15; Br, 7.67; F, 63.62; Si, 2.69. H NMR (δ, C6D6): 2.00
2
(m, 4H), 0.84 (m, 4H), 0.12 (s, J Si,H ) 6.6 Hz, 3H). 19F NMR
(δ, C6D6): -81.0 (m, 3F), -115.2 (m, 2F), -121.7 (m, 6F),
-122.5 (m, 2F), -122.9 (m, 2F), -126.0 (m, 2F). 29Si{1H} NMR
(δ, C6D6): 29.1. 13C{19F} NMR (δ, C6D6): 118.7 (m), 117.9 (q,
1J C,F ) 272 Hz), 112.0, 111.7, 111.6, 111.1, 109.8 (m), 25.9 (tt,
1J C,H ) 131 Hz, 2J C,H ) 5.5 Hz), 7.61 (tm, 1J C,H ) 122 Hz), -0.31
1
(qm, J C,H ) 123 Hz).
Br om o[t r is(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-h ep t a d e-
ca flu or od ecyl)]sila n e (C{3,8}). A biphase liquid system of
12.6 g (8.72 mmol) of B{3,8} in 40 mL of FC-72 and 30 mL of
n-hexane was treated with 1.0 mL (3.12 g, 19.5 mmol) of Br2,
yielding 11.6 g (8.00 mmol, 91.7% based on B{3,8}) of pure
C{3,8}. Mp: 93 °C. 1H NMR (δ; C6D6/C6F6, 3:1 (v/v)): 2.21 (m,
6H), 1.13 (m, 6H). 19F NMR (δ; C6D6/C6F6, 3:1 (v/v)): -81.6
(m, 3F), -116.0 (m, 2F), -121.9 (m, 6F), -122.8 (m), -123.1
(m, 2F), -126.3 (m, 2F). 29Si{1H} NMR (δ; C6D6/C6F6, 3:1 (v/
v)): 30.1.
1-Br om o-4-[{2-(p er flu or oa lk yl)et h yl}d im et h ylsilyl]-
ben zen es a n d 1-Br om o-4-(tr im eth ylsilyl)ben zen e. Gen -
er a l P r oced u r e. p-LiC6H4Br was obtained from p-bromoiodo-
benzene and 1 equiv of nBuLi (1.5 M solution in n-hexane)
diluted in n-pentane at 0 °C. After 1 h, the suspension was
centrifuged, and the liquid was decanted off from the white
precipitate. The corresponding chlorosilane dissolved in 10 mL
of THF was added at -78 °C to a suspension of p-LiC6H4Br in
n-pentane. The reaction mixture was allowed to warm to room
temperature and was stirred overnight. After the reaction was
quenched with saturated NH4Cl(aq), the water phase was
extracted with two 20-mL portions of n-pentane. The combined
organic phases were dried over MgSO4. Fractional distillation
afforded the pure products. Compounds 1,4-(RMe2Si)2C6H4 (R
) Me, (CH2)2C6F13, (CH2)2C8F17) were obtained as colorless
solids.
v)): -1.69. 19F NMR (δ, C6D6): -81.4 (tt, J F,F ) 9.7 Hz, J F,F
)
2.5 Hz, 3F), -115.8 (m, 2F), -122.2 (m, 2F), -123.2 (m, 2F),
-123.3 (m, 2F), -126.5 (m, 2F). 13C{1H} NMR (δ, C6D6): 139.4
(d, 1J P,C ) 12.7 Hz), 138.7 (1J Si,C ) 65 Hz), 134.3 (d, 3J P,C ) 6.7
2
1
2
Hz), 134.1 (d, J P,C ) 18.9 Hz), 119.3 (tt, J C,F ) 254 Hz, J C,F
1
2
) 30.5 Hz), 118.1 (qt, J C,F ) 289 Hz, J C,F ) 33.3 Hz), 112.3
1
2
1
(tquin, J C,F ) 268 Hz, J C,F ) 32.0 Hz), 112.1 (tquin, J C,F
)
)
2
1
2
271 Hz, J C,F ) 31.8 Hz), 111.3 (tquin, J C,F ) 272 Hz, J C,F
1
2
31.7 Hz), 109.4 (tqt, J C,F ) 260 Hz, J C,F ) 30.5 Hz), 26.6 (t,
2J C,F ) 23.5 Hz), 5.62 (s, J C,Si ) 50.9 Hz), -3.51 (s, J C,Si
)
1
1
53.1 Hz). 13C{19F} NMR (δ, C6D6): 139.4 (dt, J P,C ) 12.8 Hz),
1
1
138.6, 134.2 (dm), 119.3 (s), 118.1 (q, J C,F ) 269 Hz), 112.3,
2
1
1-Br om o-4-[d im et h yl(3,3,4,4,5,5,6,6,7,7,8,8,8-t r id eca -
flu or ooctyl)silyl]ben zen e (E{1,6}). Compound C{1,6} (3.58
g, 7.57 mmol) and p-LiC6H4Br, obtained from 2.4 g (8.48 mmol)
of p-bromoiodobenzene and 5.6 mL (8.4 mmol) of nBuLi
solution in n-pentane (40 mL), yielded 3.53 g (6.29 mmol, 83%
based on C{1,6}) of the title compound. Bp: 104 °C (0.1 Torr).
1H NMR (δ; C6D6/C6F6, 1:1 (v/v)): 7.25 (m, 2H), 7.12 (m, 2H),
2.02 (m, 2H), 0.94 (m, 2H), 0.22 (s, 6H). 19F NMR (δ, C6D6):
-81.4 (m, 3F), -116.4 (m, 2F), -122.5 (m, 2F), -123.5 (m, 2F),
-123.8 (m, 2F), -126.7 (m, 2F). 29Si{1H} NMR (δ; C6D6/C6F6,
1:1 (v/v)): -1.51. 13C{1H} NMR (δ, C6D6): 136.3, 135.6, 131.9,
112.1, 111.3, 109.5 (q, J C,F ) 25.1 Hz), 26.6 (tm, J C,H ) 125
1 1
Hz), 5.57 (t, J C,H ) 121 Hz), 4.34 (q, J C,H ) 121 Hz).
Tr is[4-{(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-h ep t a d eca -
flu or od ecyl)d im et h ylsilyl}p h en yl]p h osp h in e (D{1,8})
th r ou gh Rou te a . A solution of 4.36 g (6.59 mmol) of E{1,8}
in 30 mL of n-hexane was treated with 4.39 mL (6.58 mmol)
of nBuLi solution at 0 °C and stirred for 15 h at room
temperature. The voluminous white precipitate that separated
was washed with n-hexane (20 mL) and dried in vacuo to
afford 2.74 g of lithiated product. Alternatively, 9.28 g (14.0
mmol) of E{1,8} in 50 mL of n-hexane and 18.7 mL (28.1
mmol) of tBuLi solution at -78 °C afforded, through a similar
workup, 7.07 g of a 1:1 mixture of the lithiated aryl compound
and LiBr. Lithiated E{1,8} (2.74 g, 4.65 mmol) in a mixture
1
2
125.0, 119.3 (tt, J C,F ) 255 Hz, J C,F ) 29.8 Hz), 118.2 (qt,
1J C,F ) 287 Hz, 2J C,F ) 31.7 Hz), 112.3 (tquin, 1J C,F ) 268 Hz),
112.2 (tquin, J C,F ) 270 Hz, J C,F ) 32.5 Hz), 111.3 (tquin,
1
2

Fluorous Triphenylphosphine Derivatives
J . Org. Chem., Vol. 65, No. 13, 2000 3893
of n-hexane (30 mL) and THF (5 mL) was treated with 0.135
mL (1.55 mmol) of PCl3 in n-hexane (5 mL) at -78 °C. A
workup similar to that for D{1,6} yielded 1.59 g of D{1,8} (0.89
mmol, 41% based on E{1,8}). Alternatively, 7.07 g of the 1:1
mixture of lithiated E{1,8} and LiBr was suspended in
n-pentane (100 mL) and treated with P(OMe)3 (0.41 mL, 3.48
mmol) at 0 °C, yielding 4.00 g of D{1,8} (2.25 mmol, 48% based
on E{1,8}), through a workup procedure similar to that for
D{1,6}. Mp: 101 °C. Anal. Calcd for C54H42F51Si3P: C, 36.52;
H, 2.34; F, 54.6; Si, 4.74; P, 1.75. Found: C, 36.6; H, 2.41; F,
(m, 3F), -115.9 (m, 2F), -121.9 (m, 2F), -122.9 (m, 2F),
-123.2 (m, 2F), -126.3 (m, 2F).
Tr is[4-{b is(3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-h e p t a -
d eca flu or od ecyl)m eth ylsilyl}p h en yl]p h osp h in e (D{2,8}).
Compound C{2,8} (23.2 g, 22.8 mmol) in 130 mL of diethyl
ether added to a suspension of P(C6H4-p-Li)3, obtained from
3.42 g (6.85 mmol) of P(C6H4-p-Br)3 in 200 mL of diethyl ether
and 27.4 mL (41.1 mmol) of tBuLi solution, yielded 21.0 g (6.84
mmol, 90% based on C{2,8}) of the title compound. Mp: 72
°C. Anal. Calcd for C81H45F102Si3P: C, 31.65; H, 1.46; F, 63.10;
Si, 2.73; P, 1.00. Found: C, 31.71; H, 1.41; F, 62.91; Si, 2.72;
1
54.4; Si, 4.85; P, 1.86. H NMR (δ; C6D6/C6F6, 1:1 (v/v)): 7.34
(m, 2H), 7.25 (m, 2H), 2.04 (m, 2H), 0.98 (m, 2H), 0.27 (s, 6H).
31P{1H} NMR (δ; C6D6/C6F6, 1:1 (v/v)): -4.67. 29Si{1H} NMR
(δ; C6D6/C6F6, 1:1 (v/v)): -1.69. 13C{19F} (δ, C6D6): 139.4 (dt,
1
P, 1.08. H NMR (δ; C6D6/C6F6, 1:1 (v/v)): 7.30 (m, 4H), 2.03
(m, 4H), 1.02 (m, 4H), 0.25 (s, 3H). 31P{1H} NMR (δ; C6D6/
C6F6, 1:1 (v/v)): -4.70. 29Si{1H} NMR (δ; C6D6/C6F6, 1:1 (v/
v)): 0.23. 13C{19F} NMR (δ; C6D14/FC-72, 1:1 (v/v)): 140.4 (dt,
2
1J P,C ) 12.7 Hz, J C,H ) 6.1 Hz), 138.6 (m), 134.3 (dm), 134.1
1
(dm), 119.3 (m), 118.1 (q, J C,F ) 268 Hz), 112.3, 112.2, 111.8,
2
1J P,C ) 14.0 Hz, J C,H ) 6.7 Hz), 136.1 (m), 134.3 (dm), 119.0
2
1
111.7, 111.1, 109.3 (qm, J C,F ) 26 Hz), 26.5 (tt, J C,H ) 129
(m), 118.4 (q, 1J C,F ) 262 Hz), 112.4, 112.3, 112.0, 111.4, 109.8
2
1
1
Hz, J F,F ) 5.5 Hz), 5.58 (t, J C,H ) 121 Hz), -3.51 (q, J C,H
)
2
1
1
(qm, J C,F ) 26 Hz), 26.5 (tm, J C,H ) 131 Hz), 3.98 (t, J C,H
)
119 Hz). 19F NMR (δ, C6D6): -81.4 (m, 3F), -116.7 (m, 2F),
-122.2 (m, 6F), -123.0 (m, 2F), -123.7 (m, 2F), -126.8 (m,
2F).
123 Hz), -6.98 (q, J C,H ) 120 Hz). 19F NMR (δ; C6D6/C6F6,
1:1 (v/v)): -82.4 (m, 3F), -117.0 (m, 2F), -122.8 (m, 6F),
-123.7 (m, 2F), -124.1 (m, 2F), -127.2 (m, 2F).
1
Tr is[4-{(2-((p er flu or oa lk yl)et h yl)silyl}p h en yl]p h os-
p h in es (D{n ,x}) th r ou gh Rou te b. Gen er a l P r oced u r e.
P(C6H4-p-Br)3 was dissolved in diethyl ether and treated with
6 equiv of tBuLi (1.5 M in n-hexane) at -78 °C. After 10 min,
when a voluminous white precipitate had formed, a solution
of the fluorous bromosilane C{n ,x} in diethyl ether was added.
The reaction mixture was allowed to reach room temperature
and was stirred for another 15 h. In case the phosphines did
not precipitate quantitatively, the reaction mixture was fil-
tered, and the product was dried in vacuo. All volatiles of the
filtrate were removed in vacuo, and the residue was extracted
in 50 mL of FC-72. The remainder of the product was isolated
from the filtrate by removal of the volatiles in vacuo. Minor
amounts of impurities were removed by washing with n-
pentane.
T r i s [4-{d i m e t h y l(3,3,4,4,5,5,6,6,7,7,8,8,8-t r i d e c a -
flu or ooctyl)silyl}p h en yl]p h osp h in e (D{1,6}). Compound
C{1,6} (6.09 g, 13.8 mmol) added to a suspension of P(C6H4-
p-Li)3, obtained from 2.30 g (4.61 mmol) of P(C6H4-p-Br)3 in
50 mL of hexane/diethyl ether (3:1, v/v) and 18.4 mL (27.7
mmol) of tBuLi solution, yielded 5.23 g (3.53 mmol, 77% based
on C{1,6}) of the title compound, after quenching of the
reaction with degassed water (20 mL), phase separation, and
extraction with diethyl ether (30 mL).
T r is [4-{t r is (3,3,4,4,5,5,6,6,7,7,8,8,9,9,10,10,10-h e p -
ta d eca flu or od ecyl)silyl}p h en yl]p h osp h in e (D{3,8}). Com-
pound C{3,8} (17.2 g, 11.9 mmol) in 200 mL of diethyl ether
added to a suspension of P(C6H4-p-Li)3, obtained from 1.78 g
(3.57 mmol) of P(C6H4-p-Br)3 in 200 mL of diethyl ether and
t
14.2 mL (21.4 mmol) of BuLi solution, yielded 15.3 g (3.50
mmol, 88% based on C{3,8}) of the title compound. Mp: 124
°C. Anal. Calcd for C108H48F153Si3P: C, 29.67; H, 1.10; F, 66.56;
Si, 1.92; P, 0.71. Found: C, 29.66; H, 1.15; F, 66.38; Si, 1.96;
1
P, 0.74. H NMR (δ; C6D6/C6F6, 1:1 (v/v)): 7.35 (m, 4H), 2.07
(m, 6H), 1.09 (m, 6H). 31P{1H} NMR (δ; C6D6/C6F6, 1:1 (v/v)):
-4.49. 29Si{1H} NMR (δ; C6D6/C6F6, 1:1 (v/v)): 1.24. 19F NMR
(δ; C6D6/C6F6, 1:1 (v/v)): -80.9 (m, 3F), -115.4 (m, 2F), -121.4
(m, 6F), -122.3 (m, 2F), -122.6 (m, 2F), -125.8 (m, 2F).
Solu bility Stu d ies. Saturated solutions in the appropriate
solvent were prepared by stirring a suspension of the fluorous
phosphine for 2 h at 25 °C. A sample (3.000 ( 0.002 mL) was
taken after allowing the solution to settle. The total weight of
the saturated solution was determined. All solvent was
removed in vacuo (0.1 mbar, 15 h), after which the weight was
constant within (0.001 g, and the weight of the residue was
determined.
Deter m in a tion of P a r tition Coefficien ts. The partition
coefficients were determinded by dissolving a known amount
of phosphine (typically between 11 and 60 µmol) in a fluorous
biphasic system consisting of c-C6F11CF3 (2.000 ( 0.002 mL)
and either n-pentane, n-octane, or toluene (2.000 ( 0.002 mL).
The resulting mixture was stirred at 25 °C until all of the solid
had dissolved, and the mixture had equilibrated in a water/
ice bath (1 h). An aliquot (0.500 ( 0.002 mL) was removed
from each layer by syringe. Analysis by ICP-AAS on phos-
phorus gave the amount of phosphine present, with an
accuracy of (0.3 ppm. A conservative estimate of the experi-
mental error in the partition coefficient is (1 in the last digit.
T r is [4-{m e t h y l(b is (3,3,4,4,5,5,6,6,7,7,8,8,8-t r id e c a -
flu or ooctyl))silyl}p h en yl]p h osp h in e (D{2,6}). Compound
C{2,6} (9.43 g, 11.6 mmol) in 150 mL of diethyl ether added
to a suspension of P(C6H4-p-Li)3, obtained from 2.09 g (4.19
mmol) of P(C6H4-p-Br)3 in 100 mL of diethyl ether and 16.6
t
mL (24.9 mmol) of BuLi solution, yielded 9.37 g (3.79 mmol,
98% based on C{2,6}) of the title compound. Mp: 67 °C. Anal.
Calcd for C69H45F78Si3P: C, 33.50; H, 1.82; F, 59.97; Si, 3.40;
P, 1.25. Found: C, 33.64; H, 1.95; F, 60.11; Si, 3.32; P, 1.22.
1H NMR (δ; C6D6/C6F6, 1:1 (v/v)): 7.32 (m, 6H), 7.28 (m, 6H),
2.02 (m, 12H), 1.01 (m, 12H), 0.24 (s, 9H). 31P{1H} NMR (δ;
C6D6/C6F6, 1:1 (v/v)): -4.62. 29Si{1H} NMR (δ; C6D6/C6F6, 1:1
(v/v)): 0.24. 19F NMR (δ; C6D6/C6F6, 1:1 (v/v)): -81.5 (m, 3F),
-116.0 (m, 2F), -122.0 (m, 2F), -123.0 (m, 2F), -123.3 (m,
2F), -126.4 (m, 2F). 13C{1H} NMR (δ; C6D6/C6F6, 1:1 (v/v)):
Ack n ow led gm en t. We thank H. Kleijn and Dr. J .
T. B. H. J astrzebski (Utrecht University) for valuable
advise and Elf Atochem and U-Cat (Utrecht) for finan-
cial support.
1
139.0 (m), 138.3, 134.4 (dm), 119.4 (s), 118.5 (q, J C,F ) 271
Hz), 112.6, 112.5, 111.7, 109.9, 26.6 (tm, 1J C,H ) 130 Hz), 4.06
1
1
(t, J C,H ) 120 Hz), -6.45 (q, J C,H ) 120 Hz).
Tr is[4-{tr is(3,3,4,4,5,5,6,6,7,7,8,8,8-tr id eca flu or ooctyl)-
silyl}p h en yl]p h osp h in e (D{3,6}). Compound C{3,6} (16.4
g, 14.3 mmol) in 100 mL of diethyl ether added to a suspension
of P(C6H4-p-Li)3, obtained from 2.38 g (4.77 mmol) of P(C6H4-
p-Br)3 in 100 mL of diethyl ether and 19.1 mL (28.6 mmol) of
tBuLi solution, yielded 14.2 g (4.09 mmol, 86% based C{3,6})
Su p p or tin g In for m a tion Ava ila ble: Improved synthetic
procedures for known compounds C{1,6}, C{1,8}, Grignards
A{x} (x ) 6, 8), C{3,6}, and tris(p-bromophenyl)phosphine;
1H NMR spectra of compounds B{2,6}, C{2,6}, C{3,8}, E{1,6},
1,4-[C6F13(CH2)2SiMe2]2C6H4, E{1,8}, and 1,4-[C8F17(CH2)2-
SiMe2]2C6H4; 13C NMR spectra of compounds B{2,6}, C{2,6},
E{1,6},1,4-[C6F13(CH2)2SiMe2]2C6H4,E{1,8},and1,4-[C8F17(CH2)2-
SiMe2]2C6H4; and 19F and 29Si NMR spectra of compounds B-
{2,6}, C{2,6}, C{3,8}, and E{1,6}. This material is available
free of charge via the Internet at http://pubs.acs.org.
of the title compound. Mp: 50-55 °C. Anal. Calcd for C90H48F117
-
Si3P: C, 31.2; H, 1.40; F, 64.1; Si, 2.43; P, 0.89. Found: C,
33.9; H, 1.68; F, 60.7; Si, 2.66; P, 0.96. 1H NMR (δ; C6D6/C6F6,
1:1 (v/v)): 7.35 (m, 4H), 2.05 (m, 6H), 1.08 (m, 6H). 31P{1H}
NMR (δ; C6D6/C6F6, 1:1 (v/v)): -4.49. 29Si{1H} NMR (δ; C6D6/
C6F6, 1:1 (v/v)): 1.25. 19F NMR (δ; C6D6/C6F6, 1:1 (v/v)): -81.5
J O991548V