Tridentate phosphine ligands with novel linker-units

Article abstract of DOI:10.1039/b209589k

The synthesis of two novel types of tripodal phosphine ligands containing vinyl and alkynyl linker functions in their ligand backbones are reported. Using pentaerythritol (1) as the starting material the functionalized phosphines H₂C=CH-CH₂OCH₂C(CH₂PPh ₂)₃ (6), Me₃SiCξC-CH₂OCH ₂C(CH₂PPh₂)₃ (10) and HCξC-CH₂OCH₂C(CH₂PPh₂) ₃ (11) were obtained in good yield in 4-5-step syntheses. H ₂C=CH-CH₂OCH₂C(CH₂PPh ₂)₃ (6) and the silyl protected alkinyl derivative (CH₃)₃Si-CξC-CH₂OCH₂C(CH ₂PPh₂)₃ (10) were reacted with one molar equivalent of [Mo(CO)₃-(MeCN)₃] to yield the yellow-brown, air stable triphosphine-molybdenum complexes [{H₂C=CH-CH ₂OCH₂C-(CH₂PPh₂)₃}Mo(CO) ₃] (12) and [{(CH₃)₃Si-CξC-CH ₂OCH₂C(CH₂PPh₂)₃}Mo(CO) ₃] (13) the latter of which was characterized by X-ray diffraction. The Royal Society of Chemistry 2003.

Full text of DOI:10.1039/b209589k

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Tridentate phosphine ligands with novel linker-units
Ralf A. Findeis and Lutz H. Gade*
Laboratoire de Chimie Organométallique et de Catalyse, CNRS UMR 7513, Institut Le Bel,
Université Louis Pasteur, 4, rue Blaise Pascal, 67070 Strasbourg, France
Received 30th September 2002, Accepted 14th November 2002
First published as an Advance Article on the web 12th December 2002
The synthesis of two novel types of tripodal phosphine ligands containing vinyl and alkynyl linker functions in
their ligand backbones are reported. Using pentaerythritol (1) as the starting material the functionalized phosphines
᎐
᎐
H C᎐CH–CH OCH C(CH PPh ) (6), Me SiC᎐C–CH OCH C(CH PPh ) (10) and HC᎐C–CH OCH C(CH PPh )
᎐
᎐
᎐
2
2
2
2
2
3
3
2
2
2
2
3
2
2
2
2 3
(11) were obtained in good yield in 4–5-step syntheses. H C᎐CH–CH OCH C(CH PPh ) (6) and the silyl protected
᎐
2
2
2
2
2 3
᎐
alkinyl derivative (CH ) Si–C᎐C–CH OCH C(CH PPh ) (10) were reacted with one molar equivalent of [Mo(CO) -
᎐
3
3
2
2
2
2
3
3
(MeCN) ] to yield the yellow-brown, air stable triphosphine–molybdenum complexes [{H C᎐CH–CH OCH C-
᎐
3
2
2
2
᎐
(CH PPh ) }Mo(CO) ] (12) and [{(CH ) Si–C᎐C–CH OCH C(CH PPh ) }Mo(CO) ] (13) the latter of which was
᎐
2
2
3
3
3
3
2
2
2
2
3
3
characterized by X-ray diffraction.
Introduction
Results and discussion
The leaching of metal is a major practical problem in the appli-
cation of immobilized molecular catalysts which are thought
to combine the virtues of homogeneous catalysis (high
activity and selectivity, directed catalyst design) with those
of heterogeneous catalysts (e.g. facile catalyst separation and
recycling).1,2 The loss of catalyst may be suppressed to various
degrees by using polydentate ligands which form thermally and
kinetically stable complexes with the catalyst metal. Among the
large number of ligand systems, which have been employed in
this context, polydentate phosphines such as the “triphos”
ligand, MeC(CH2PPh2)3, are good examples for this capacity.3
However, their use as ligands in heterogenized metal catalysts
requires the functionalization of their backbone structure,
preferentially in the apical position. Such modified tripodal
phoshines have been employed for the physisorption of Ru and
Rh complexes on oxidic supports4 and the covalent fixation of
such catalyst precursors to polystyrene.5 These catalytic phases
have been studied in catalytic hydrogenation and hydroformyl-
ation as well as the isomerization of allylic alcohols.6 Addi-
tionally, backbone-functionalized triphos-complexes were
employed in two-phase catalysis.7
Synthesis of the tripodal phosphine ligand H C᎐CH–CH -
OCH2C(CH2PPh2)3 (6)
᎐
2
2
The synthesis of the functionalized phosphine tripods is based
in part on the previous reports by Huttner and co-workers in
this field.9–13
The starting material is pentaerythritol (1) which is
a cheap basic chemical which possesses a functionalized neo-
pentane structure and thus appears to be well suited for the
synthetic objective. The four hydroxyl functions in 1 are chem-
ically equivalent, and in order to attach a linker group to only
one of these, it had to be differentiated with respect to the
others. This is readily achieved by reaction of 1 with triethyl
orthoacetate in toluene to give the known methyl trioxa-
bicyclooctane derivative 2 (Scheme 1).16 The unreacted “apical”
OH-function was then coupled with allyl bromide as a linker
unit to give H C᎐CH–CH OCH C(CH O) CCH (3) which in
᎐
2
2
2
2
3
3
turn was hydrolyzed yielding the triol H C᎐CH–CH OCH -
᎐
2
2
2
C(CH2OH)3 (4). Functional group interconversion with SOCl2
in dry pyridine gave the trichloride 5 which was reacted with
LiPPh2 in DME to yield the target phosphine H C᎐CH–
᎐
2
CH2
OCH C(CH PPh ) (6) in good yield.
2
2
2 3
The differentiation of the OH-groups by orthoester protec-
tion requires the multistep sequence in the synthesis of 6 as
discussed above. This leads to moderate overall yields of the
triphos derivative in spite of the relatively high yields in each
individual reaction step. It was therefore desirable to devise a
shorter route to compound 6. This was possible via the 3-
chloro-2,2-bis(chloromethyl)propan-1-ol (7) which is directly
prepared from pentaerythritol (Scheme 1).17 Reaction of 7 with
allyl bromide directly gave the key intermediate 5 which was
thus accessible in large quantities.
Many previously published syntheses of tripodal phosphines
partially suffer from the non-tolerance of certain functional
groups (e.g. C–C multiple bonds)8 or the fact that the phos-
phino groups are introduced at a very early stage of the reaction
sequence, making subsequent work up more difficult.9–13 In
particular, if expensive (chiral) phosphino functions are to be
introduced in an early reaction step of the synthetic pathway,14
the loss in phosphine during the overall sequence may be
considerable. We recently developed a strategy, in which the
phosphine is introduced in the final step of the ligand-linker
synthesis which was applied to the synthesis of a tripodal phos-
phine containing an ether–alcohol function in the ligand back-
bone.15 In this paper we generalize this strategy and report the
᎐
Synthesis of the tripodal phosphine ligands Me3SiC᎐C–CH2-
᎐
᎐
OCH C(CH PPh ) (10) and HC᎐C–CH OCH C(CH PPh )
᎐
2
2
2
3
2
2
2
2 3
(11)
The direct application of the synthetic strategy outlined above
to the preparation of alkynyl-functionalized tripodal phos-
phines simply by reaction of chloro-2,2-bis(chloromethyl)-
propan-1-ol (7) with propargyl bromide proved to be unsuccess-
ful. This was due to a partial isomerization of the reaction
product to the corresponding allene derivative (eqn. (1)) under
the reaction conditions.
This undesired rearrangement could be suppressed by use of
the Me3Si-protected propargyl chloride which reacted with 7
cleanly to give the trichloride 8. Under the reaction conditions,
which involved the use of KOH as base, the alkynyl group was
efficient synthesis of triphos-derivatives containing C᎐C double
᎐
᎐
or C᎐C triple bonds in the linker unit which is attached to the
᎐
ligand framework.
T h i s j o u r n a l i s © T h e R o y a l S o c i e t y o f C h e m i s t r y 2 0 0 3
D a l t o n T r a n s . , 2 0 0 3 , 2 4 9 – 2 5 4
249

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CH2OCH2C(CH2PPh2)3 (10) selectively in the subsequent func-
tional group interconversion. Desilylation with KF/[18]crown-6
᎐
yielded the target molecule HC᎐C–CH OCH C(CH PPh )
᎐
2
2
2
2
3
(11) (Scheme 2).
Synthesis and structural characterization of the complexes
[{L}Mo(CO)3]
In order to establish the structural details and the ligand
properties of the new triphosphines H C᎐CH–CH OCH -
᎐
2
2
2
C(CH2PPh2)3 (6) and the silyl protected alkynyl derivative
᎐
(CH ) Si–C᎐C–CH OCH C(CH PPh ) (10) were reacted with
᎐
3
3
2
2
2
2 3
one molar equivalent of [Mo(CO)3(MeCN)3] to yield the yellow-
brown, air stable triphosphine–molybdenum complexes [{H C᎐
᎐
2
CH–CH2OCH2C(CH2PPh2)3}Mo(CO)3] (12) and [{(CH3)3Si–
᎐
C᎐C–CH OCH C(CH PPh ) }Mo(CO) ] (13) (Scheme 3).
᎐
2
2
2
2
3
3
The 31P NMR resonance of the coordinated phosphine
ligand is observed at δ 15.6 for complex 12 (6: δ Ϫ26.5) and at
δ 17.7 for complex 13 (10: δ Ϫ26.8). The IR ν(CO) band
patterns are consistent with facial tricoordination of the tri-
phosphine and the molecular ion peaks at m/z = 862.1 (12) and
at m/z = 930.9 (13) confirm their formulation.
Single crystals of complex 13, which were suitable for an
X-ray diffraction study, were obtained by slow diffusion of
hexanes into a CH2Cl2 solution of the compound. The molecu-
lar structure of 13 is displayed in Fig. 1 along with its principal
bond lengths and angles.
The phosphine ligand adopts the expected facial coordin-
ation mode for a molybdenum complex having a slightly dis-
torted octahedral coordination geometry. The Mo–P distances
of 2.534(1)–2.552(1) Å and the M–CO bond lengths of
1.947(4)–1.973(4) Å are within the expected range.18 Both the
P–Mo–P and the C–Mo–C angles, which lie in the ranges of
79.73(3)–85.99(3)Њ and 83.1(2)–86.7(2)Њ, respectively, are below
90Њ defining a slightly enlongated trigonal antiprismatic first
coordination sphere.
Scheme 1 The two alternative synthetic strategies for the preparation
of H2C᎐CH–CH2OCH2C(CH2PPh2)3 (6).
᎐
(1)
Conclusion
The introduction of the phosphine functions in the final step of
the synthesis of backbone-functionalized tripodal phosphine
ligands provides an efficient access to such ligands while minim-
ising the loss in phosphine. This will be the prerequisite to the
extension of this work to C3 chiral derivatives using inter alia
Burk’s 1,4-dialkylphospholane units.14 This and the fixation of
the ligands to support materials is currently under way in our
laboratory.
desilylated. The direct reaction of 8 with LiPPh2 to give the
triphosphine ligand gave a product mixture containing the
phosphine which could, however, not be isolated in pure form.
This problem was circumvented by renewed trimethylsilylation
᎐
of 8, yielding 9 which in turn gave the triphosphine Me SiC᎐C–
᎐
3
Scheme 2 Synthesis of the alkynyl-functionalized phosphines 10 and 11.
D a l t o n T r a n s . , 2 0 0 3 , 2 4 9 – 2 5 4
250

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Scheme 3 Synthesis of the complexes [{L}Mo(CO)3], 12 and 13.
1
dried Celite or by centrifugation. The H, 13C, 31P, and 29Si
NMR spectra were recorded on Bruker AC 200, Bruker Avance
250 and Bruker AMX 400 FT-NMR spectrometers. 1H and 13
C
NMR data are listed in parts per million [ppm] relative to
tetramethylsilane and were referenced using the residual proto-
nated solvent peak (1H) or the carbon resonance (13C). 29Si and
31P NMR data are listed in ppm relative to, respectively, tetra-
methylsilane and 85% H3PO4 as external standards. Infrared
spectra were recorded on a Nicolet Magna IRTM 750 spectro-
meter. Elemental analyses were carried out by the microanalyti-
cal service at the chemistry department at Strasbourg. HOCH2-
C(CH2O)3CCH3 (3),16 diphenylphosphine,19 and [(MeCN)3-
Mo(CO)3]20 were prepared according to published procedures.
All other chemicals used as starting materials were obtained
commercially and used without further purification.
Preparation of H C᎐CH–CH OCH C(CH O) CCH (3)
᎐
2
2
2
2
3
3
Allyl bromide (22.7 g = 187 mmol) was added dropwise to a
stirred suspension of 33.1 g (591 mmol) of finely powdered
KOH and 19.9 g (124.2 mmol) of 4-(hydroxymethyl)-1-methyl-
2,6,7-trioxabicyclo[2.2.2]octane in 150 ml of dmso. The reac-
tion mixture was stirred at 60 ЊC for 2 h and then cooled to
room temperature. 500 ml of water were added, the organic
layer separated and the aqueous phase extracted twice with
200 ml of Et2O. The combined organic phases were treated with
100 ml of a saturated aqueous solution of NaCl-Lösung, then
washed with 100 ml of water and finally dried over Na2SO2.
After filtration and removal of the solvent by distillation the
oily residue was fractionated at reduced pressure to give H C᎐
᎐
2
CH–CH2OCH2C(CH2O)3CCH3 (6) as a colourless liquid.
᎐
Fig. 1 Two views of the molecular structure of [{(CH3)3Si–C᎐C–
᎐
CH2OCH2C–(CH2PPh2)3}Mo(CO)3] (13). Principal bond lengths (Å)
and interbond angles (Њ): Mo–P(1) 2.540(1), Mo–C(1) 1.973(4), C(45)–
C(46) 1.476(7), Mo–P(2) 2.552(1), Mo–C(2) 1.963(5), C(46)–C(47)
1.205(6), Mo–P(3) 2.534(1), Mo–C(3) 1.947(4), C(47)–Si 1.830(5);
P(1)–Mo–P(2) 85.99(3), C(1)–Mo–C(2) 85.8(2), C(44)–O(4)–C(45)
112.0(3), P(1)–Mo–P(3) 85.63(3), C(1)–Mo–C(3) 86.7(2), C(45)–C(46)–
C(47) 174.2(5), P(2)–Mo–P(3) 79.73(3), C(2)–Mo–C(3) 83.1(2), C(46)–
C(47)–Si 172.0(4)
Yield: 21.6 g (107.9 mmol, 87%); bp: 88–89 ЊC/0.50 Torr.
1H-NMR (400.1 MHz, CDCl3, 295 K): δ = 1.37 (s, 3 H, H-1),
3.11 (s, 2 H, H-5), 3.83 (dt, 2 H, 3JHH = 5.60 Hz, 4JHH = 1.40 Hz,
H-6), 3.93 (s, 6 H, H-3), 5.09–5.18 (m, 2 H, H-8), 5.70–5.80
(m, 1 H, H-7). {1H}13C-NMR (100.6 MHz, CDCl3, 295 K):
δ = 23.6 (CH3, C-1), 35.1 (C, C-4), 68.6 (CH2, C-6), 69.7 (CH3,
C-3), 72.6 (CH2, C-5), 108.7 (C, C-2), 117.5 (CH2, C-8), 134.2
(CH, C-7). IR (film): ν = 3008 (w), 2949 (m), 2878 (m), 1738 (w),
1647 (w), 1476 (m), 1447(m), 1401 (s), 1352 (m), 1297 (s), 1263
(m), 1209 (m), 1155 (m), 1128 (s), 1055 (s), 990 (m), 929 (m), 884
(m), 864 (s), 751 (w), 714 (w) cmϪ1. C10H16O4 (200.23 g molϪ1):
calcd.: C 59.98, H 8.05; found: C 60.22, H 7.91%.
Experimental
All manipulations were performed under nitrogen (desiccant
P4O10, Granusic®, J. T. Baker) on a high vacuum line using
standard Schlenk techniques, or in a glovebox. Solvents and
solutions were transferred by needle-septa techniques. Solvents
were dried according to standard methods and saturated with
nitrogen. The deuterated solvents used for the NMR spectro-
scopic measurements were degassed by three successive “freeze–
pump–thaw” cycles and stored over 4-Å molecular sieves.
Solids were separated from suspensions by filtration through
Preparation of H C᎐CH–CH OCH C(CH OH) (4)
᎐
2
2
2
2
3
A solution of 15.1 g (75.2 mmol) of H C᎐CH–CH OCH -
᎐
2
2
2
C(CH2O)3CCH3 (3) in 40 ml of methanol and 50 ml of 2 M
HCl was stirred at ambient temperature for 6 h. Solid Na2CO3
D a l t o n T r a n s . , 2 0 0 3 , 2 4 9 – 2 5 4
251

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(12.1 g = 87.5 mmol) was carefully added in small portions to
the reaction mixture which was then stirred at room temp. for
another 18 h. The solvent was removed by distillation and the
residue extracted with methanol. After removal of the solvent
n-hexane. The resulting deep red solution was warmed to room
temperature and then stirred for another 30 min. A solution of
2.62 g (11.3 mmol) of H C᎐CH–CH OCH C(CH Cl) (5) in
᎐
2
2
2
2
3
8 ml of DME was then added dropwise to the lithium phos-
phide solution which was subsequently stirred for 24 h. All
volatiles were removed in vacuo, the residue was extracted with
20 ml of toluene and the extract washed with 3 × 10 ml of
degassed water. The organic phase was dried over Na2SO4 and
after filtration all remaining volatile components were removed
in vacuo. The crude product was taken up in methanol
in vacuo the analytically pure compound H C᎐CH–CH -
᎐
2
2
OCH2C(CH2OH)3 (4) was obtained as a soft colourless solid.
from which the pure reaction product H C᎐CH–CH OCH C-
(CH2PPh2)3 (6) was obtained as a colourless, highly viscous oil.
᎐
2
2
2
Yield: 10.3 g (58.6 mmol, 78%). 1H-NMR (300.17 MHz,
CDCl3, 295 K): δ = 3.42 (s, 2 H, H-3), 3.66 (s, 6 H, H-1), 3.94
(dt, 2 H, 3JHH = 5.6 Hz, 4JHH = 1.5 Hz, H-4), 5.14–5.26 (m, 2 H,
H-6), 5.78–5.85 (m, 1 H, H-5). {1H}13C-NMR (75.48 MHz,
CDCl3, 295 K): δ = 44.8 (C, C-2), 64.5 (CH2, C-4), 72.4 (CH2,
C-3), 72.6 (CH2, C-1), 117.4 (CH2, C-6), 133.9 (CH, C-5). IR
(film): ν = 3411 (b), 2949 (m), 2883 (m), 1647 (m), 1570 (m),
Yield: 5.15 g (7.57 mmol, 67%). 1H-NMR (300.17 MHz,
CDCl3, 295 K): δ = 2.80 (s, 6 H, H-1), 3.40 (s, 2 H, H-3), 3.54
(d, 2 H, 3JHH = 5.7 Hz, H-4), 5.08–5.21 (m, 2 H, H-6), 5.53–5.65
(m, 1 H, H-5), 7.32–7.61 (m, 30 H, aromat. H). {1H}13C-NMR
(75.48 MHz, CDCl3, 295 K): δ = 38.04 (m, CH2, C-1), 42.6
1411 (s), 1131 (m), 1083 (m), 1040 (s), 923 (m), 654 (m) cmϪ1
.
C8H16O4 (176.21 g molϪ1): calcd.: C 54.33, H 9.15; found:
C 54.68, H 9.37%.
Preparation of H C᎐CH–CH OCH C(CH Cl) (5)
᎐
2
2
2
2
3
1
(q, C, JPC = 12.2 Hz, C-2), 71.1 (s, CH2, C-4), 76.3 (q, CH2,
4JPC = 8.6 Hz, C-3), 116.0 (s, CH2, C-6), 128.0–128.2 (m,
aromat. C), 132.5–133.1 (m, aromat. C), 134.7 (s, CH, C-5),
139.4–139.5 (m, aromat. C). {1H}31P-NMR (121.51 MHz,
CDCl3, 295 K): δ = Ϫ26.5 (s). IR (film): ν = 3069 (m), 3050 (m),
2923 (m), 2851 (m), 1644 (m), 1584 (m), 1480 (s), 1433 (s), 1372
(m), 1305 (m), 1184 (m), 1093 (s), 1026 (m), 999 (m), 924 (m),
826 (m), 739 (m), 695 (m) cmϪ1. C44H43OP3 (680.75 g molϪ1):
calcd.: C 77.63, H 6.37; found: C 77.28, H 6.59%.
Method A. To a mixture of 8.92 g (50.6 mmol) of H C᎐CH–
᎐
2
CH2OCH2C(CH2OH)3 (4) and 13.2 g (167 mmol) of dry pyrid-
ine, which was stirred at 0 ЊC, were added dropwise 19.9 g
(167 mmol) of SOCl2. After completed addition, the reaction
mixture was first stirred at 0 ЊC for 30 min, then for another
30 min at room temperature and finally for 2.5 h at 110–120 ЊC.
After cooling to 0 ЊC, 150 ml of iced water was addded to the
stirred solution. The aqueous phase was extracted twice with
50 ml of CH2Cl2 and the combined organic layers were washed
with 100 ml 2 M HCl, 2 × 100 ml of water and then dried over
Na2SO4. After filtration, the solvent was removed by distillation
and the residue then fractionated under reduced pressure.
᎐
Preparation of HC᎐C–CH OCH C(CH Cl) (8)
᎐
2
2
2
3
Finely powdered KOH (6.73 g = 120 mmol) was added to a
vigorously stirred solution of 10.0 g (52.3 mmol) of 3-bromo-
The reaction product H C᎐CH–CH OCH C(CH Cl) (7) was
᎐
2
2
2
2
3
(1-trimethylsilyl)-1-propyne and 5.10
g (26.6 mmol) of
obtained as a colourless liquid. Yield: 8.08 g (34.9 mmol, 69%).
3-chloro-(2,2-chloromethyl)propan-1-ol (7) in 20 ml of dmso.
The strongly exothermic reaction was controlled with an ice
bath. After the evolution of heat had subsided, the reaction
mixture was stirred at 70 ЊC for another 30 min and then cooled
to room temperature. After addition of 150 ml of water, the
phases were separated and the aqueous phase extracted with
2 × 50 ml of CH2Cl2. The combined organic phases were
washed with 2 × 100 ml of water and then dried over Na2SO4.
After removal of the solvent by distillation, the crude product
was fractionated at reduced pressure. The desired product
Method B. Finely powdered KOH (7.83 g = 139 mmol)
was rapidly added to a vigorously stirred solution of 6.71 g
(35.0 mmol) of 3-chloro-(2,2-chloromethyl)propan-1-ol (7) and
12.7 g (105 mmol) of allyl bromide in 35 ml of dmso. The
exothermic reaction, which immediately set in, was controlled
with the aid of an ice bath, thus keeping the reaction temper-
ture below 60 ЊC. After the reaction had subsided the stirred
solution was heated at 60 ЊC for another 2 h. After cooling to
room temperature, 150 ml of water were added and the aqueous
phase extracted with 3 × 50 ml of CH2Cl2. Work up as
described above. Yield: 6.65 g (28.7 mmol, 82%).
᎐
HC᎐C–CH OCH C(CH Cl) (8) was obtained as a colourless
᎐
2
2
2
3
liquid.
bp: 78–80Њ C/0.50 Torr. 1H-NMR (300.17 MHz, CDCl3,
295 K): δ = 3.45 (s, 2 H, H-3), 3.63 (s, 6 H, H-1), 3.99 (dt, 2 H,
Yield: 3.78 g (16.5 mmol, 62%); bp: 72Њ C/0.45 Torr.
1H-NMR (300.17 MHz, CDCl3, 295 K): δ = 2.45 (t, 1 H,
4JHH = 2.4 Hz, H-6), 3.58 (s, 2 H, H-3), 3.65 (s, 6 H, H-1), 4.17
4
3JHH = 5.6 Hz, JHH = 1.5 Hz, H-4), 5.15–5.29 (m, 2 H, H-6),
4
(d, 2 H, JHH = 2.4 Hz, H-4). {1H}13C-NMR (75.48 MHz,
5.79–5.92 (m, 1 H, H-5). {1H}13C-NMR (75.48 MHz, CDCl3,
295 K): δ = 44.3 (CH2, C-1), 46.1 (C, C-2), 67.3 (CH2, C-4),
72.3 (CH2, C-3), 117.1 (CH2, C-6), 134.2 (CH, C-5). IR (film):
ν = 3081 (w), 2965 (m), 2857 (m), 1647 (m), 1474 (m), 1439 (s),
1307 (m), 1268 (m), 1136 (s), 1109 (s), 986 (m), 930 (s), 870 (m),
760 (m), 743 (m), 703 (m) cmϪ1. C8H13Cl3O (231.55 g molϪ1):
calcd.: C 41.50, H 5.66; found: C 41.18, H 5.81%.
CDCl3, 295 K): δ = 44.2 (CH2, C-1), 45.9 (C, C-2), 58.7 (CH2,
C-4), 67.4 (CH2, C-3), 75.0 (CH, C-6), 78.9 (C, C-5). IR (film):
ν = 3295 (s), 2964 (m), 2878 (m), 1470 (m), 1439 (s), 1359 (m),
1308 (m), 1270 (m), 1103 (s), 1023 (m), 956 (m), 913 (m), 871
(m), 846 (m), 809 (m), 761 (m), 743 (m), 702 (m), 641 (m) cmϪ1
.
C8H11Cl3O (229.53 g molϪ1): calcd.: C 41.86, H 4.83; found:
C 41.62, H 4.91%.
Preparation of H C᎐CH–CH OCH C(CH PPh ) (6)
᎐
2
2
2
2
2 3
᎐
Preparation of (CH ) Si–C᎐C–CH OCH C(CH Cl) (9)
᎐
3
3
2
2
2
3
To a stirred solution of 6.63 g (35.6 mmol) of HPPh2 in 25 ml
of DME, which was cooled at Ϫ10 ЊC, were added dropwise
14.2 ml (35.6 mmol) of a 2.5 molar solution of n-BuLi in
A solution of 4.40 ml (2.5 molar, 11.0 mmol) of LDA in thf/
ethylbenzene/n-hexane was added with a syringe to a stirred
D a l t o n T r a n s . , 2 0 0 3 , 2 4 9 – 2 5 4
252

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᎐
᎐
᎐
solution of 2.03 g (8.84 mmol) of HC᎐C–CH OCH C(CH Cl)
mmol) of (CH ) Si–C᎐C–CH OCH C(CH PPh ) (10) in 5 ml
᎐
2
2
2
3
3 3 2 2 2 2 3
(8) in 20 ml of thf which was cooled at Ϫ78 ЊC. After stirring
for 30 min at Ϫ78 ЊC, 2.20 ml (17.6 mmol) of trimethylchloro-
silane were added and the reaction mixture was subsequently
stirred at room temperature for 16 h. The volatiles were then
removed in vacuo and the crude product taken up in 50 ml of
Et2O. The solution was washed with 2 × 25 ml of water, the
combined aqueous phases twice extracted with 20 ml of
Et2O and the combined organic phases dried over Na2SO4.
of methanol/thf (1 : 1). The reaction mixture was stirred at
room temperature for 7 d. All volatiles were removed sub-
sequently, the residue was taken up in 10 ml of toluene, washed
with 3 × 10 ml degassed water and the organic phase was
dried over Na2SO4. The solvent was removed in vacuo and the
crude product reprecipitated at Ϫ30 ЊC from methanol giving
᎐
HC᎐C–CH OCH C(CH PPh ) (11) as a soft colourless solid.
᎐
2
2
2
2 3
After removal of the solvent in vacuo, the crude product was
᎐
fractionated at reduced pressure. The product, (CH ) Si–C᎐C–
᎐
3
3
CH2OCH2C(CH2Cl)3 (9) was obtained as a colourless liquid.
1
Yield: 713 mg (1.05 mmol, 62%). H-NMR (300.17 MHz,
4
CD2Cl2, 295 K): δ = 2.29 (t, 1 H, JHH = 2.4 Hz, H-6), 2.53
4
(m, 6 H, H-1), 3.19 (s, 2 H, H-3), 3.29 (d, 2 H, JHH = 2.4 Hz,
H-4), 7.25–7.48 (m, 30 H, aromat. H). {1H}13C-NMR
(75.48 MHz, CD2Cl2, 295 K): δ = 38.5 (m, CH2, C-1), 42.0
(q, C, 2JPC = 13.2 Hz C-2), 57.8 (s, CH2, C-4), 74.3 (s, CH, C-6),
1
Yield: 2.38 g (7.87 mmol, 89%). bp: 87 ЊC/0.50 Torr. H-
NMR (300.17 MHz, CDCl3, 295 K): δ = 0.16 (s, 9 H, H-7), 3.56
(s, 2 H, H-3), 3.63 (s, 6 H, H-1), 4.13 (s, 2 H, H-4). {1H}13C-
NMR (75.48 MHz, CDCl3, 295 K): δ = Ϫ0.3 (CH3, C-7), 44.3
(CH2, C-1), 46.0 (C, C-2), 59.4 (CH2, C-4), 67.0 (CH2, C-3),
92.2 (C, C-6), 100.7 (C, C-5). {1H} 29Si-NMR (79.49 MHz,
CDCl3, 295 K): δ = Ϫ17.8 (s). IR (Film): ν = 2961 (s), 2898 (m),
2176 (m), 1596 (w), 1470 (m), 1439 (m), 1353 (m), 1307 (m),
1250 (s), 1101 (s), 1025 (s), 995 (m), 943 (m), 844 (s), 761 (m),
703 (m), 655 (w), 620 (w) cmϪ1. C11H19Cl3OSi (301.80 g molϪ1):
calcd.: C 43.78, H 6.35; found: C 43.63, H 6.29%.
3
76.7 (q, CH2, JPC = 7.3 Hz C-3), 80.1 (s, C, C-5), 127.3–128.8
(m, CH, aromat. C), 133.3–133.6 (m, CH, aromat. C), 140.1–
140.3 (m, C, aromat. C). {1H}31P-NMR (121.51 MHz, CD2Cl2,
295 K): δ = Ϫ27.4 (s). IR (KBr): ν = 3287 (w), 3048 (w), 2922
(m), 2847 (m), 1479 (m), 1432 (s), 1262 (w), 1182 (w), 1094 (s),
1024 (m), 998 (m), 826 (w), 738 (s), 694 (s) cmϪ1. C44H41OP3
(678.73 g molϪ1): calcd.: C 77.86, H 6.09; found: C 77.61, H
6.02%.
Preparation of [{H C᎐CH–CH OCH C(CH PPh ) }Mo(CO) ]
᎐
2
2
2
2
2
3
3
(12)
᎐
Preparation of (CH ) Si–C᎐C–CH OCH C(CH PPh ) (10)
᎐
3
3
2
2
2
2 3
A solution of 287 mg (946 µmol) of [(MeCN)3Mo(CO)3] in
30 ml of CH2Cl2 was added to a solution of 644 mg (946 µmol)
To a stirred solution of 2.28 g (12.3 mmol) of HPPh2 in 20 ml
of DME, which was cooled at Ϫ30 ЊC, were added 7.6 ml of a
solution of n-BuLi in hexanes (1.6 M, 12.3 mmol). After stir-
ring the resulting deep red solution for another 30 min at room
of H C᎐CH–CH OCH C(CH PPh ) (6) in 10 ml of CH Cl .
᎐
2
2
2
2
2
3
2
2
After stirring at room temperature for 18 h, the reaction
mixture was filtered through Celite, the volume decreased to
10 ml and the product was precipitated by addition of Et2O.
The reaction product was washed with 3 × 15 ml of Et2O and
temperature, a solution of 1.17 g (3.89 mmol) of (CH3)3Si–
᎐
C᎐C–CH OCH C(CH Cl) (9) in 6 ml of DME was added drop
᎐
2
2
2
3
wise and the reaction mixture was strirred at ambient temper-
ature for another 24 h. All volatiles were removed in vacuo
and the residue was taken up in 20 ml of toluene, washed with
2 × 10 ml of degassed water and dried over Na2SO4. After
dried in vacuo, yielding H C᎐CH–CH OCH C(CH PPh ) -
᎐
2
2
2
2
2 3
Mo(CO)3 (12) as a yellow-brown microcrystalline solid.
evaporation of the solvent, the residue was redissolved in
᎐
methanol and stored at Ϫ30 ЊC to give (CH ) Si–C᎐C–CH -
᎐
3
3
2
OCH2C(CH2PPh2)3 (10) as a colourless solid.
1
Yield: 675 mg (787 µmol, 83%); mp: 247 ЊC (decomp.). H-
NMR (300.17 MHz, CD2Cl2, 295 K): δ = 2.38 (bs, 6 H, H-1),
3.38 (s, 2 H, H-3), 4.13 (d, 2 H, 3JHH = 5.2 Hz, H-4), 5.25–5.39
(m, 2 H, H-6), 5.96–6.09 (m, 1 H, H-5), 7.08–7.39 (m, 30 H,
aromat. H). {1H}13C-NMR (75.48 MHz, CD2Cl2, 295 K):
Yield: 2.28 g (2.88 mmol, 74%); mp: 102 ЊC. 1H-NMR
(300.17 MHz, CDCl3, 295 K): δ = 0.20 (s, 9 H, H-7), 2.59
(d, 6 H, H-1), 3.26 (s, 2 H, H-3), 3.37 (s, 2 H, H-4), 7.27Ϫ7.42
(m, 30 H, aromat. H). {1H}13C-NMR (75.48 MHz, CDCl3, 295
K): δ = Ϫ 0.1 (s, CH3, C-7), 38.1 (m, CH2, C-1), 42.5 (q, C, C-2),
58.1 (s, CH2, C-4), 76.0 (q, CH2, C-3), 90.6 (s, C, C-6), 101.8 (s,
C, C-5), 127.2Ϫ139.6 (m, aromat. C). {1H}31P-NMR (121.51
MHz, CDCl3, 295 K): δ = Ϫ26.8 (s). {1H} 29Si-NMR (79.49
MHz, CDCl3, 295 K): δ = Ϫ18.6 (s). IR (film): ν = 3051 (w),
2953 (w), 2895 (w), 2170 (w), 1584 (w), 1480 (m), 1432 (s), 1407
(m), 1349 (w), 1305 (w), 1249 (m), 1181 (w), 1084 (s), 1017 (m),
991 (m), 944 (w), 841(s), 738 (s), 695 (s) cmϪ1. C47H49OP3Si
(750.91 g molϪ1): calcd.: C 75.18, H 6.58; found: C 74.87, H
6.41%.
2
δ = 31.3 (m, CH2, C-1), 41.6, (q, C, JPC = 7.2 Hz, C-2), 72.6
3
(s, CH2, C-4), 83.7 (t, CH2, JPC = 8.5 Hz, C-3), 116.8 (s, CH2,
C- 6), 128.4–129.3 (m, aromat. C), 132.1–132.3 (m, aromat. C),
135.1 (s, CH, C-5), 138.9–139.4 (m, aromat. C), 221.2–221.6
(m, CO, C-8). {1H}31P-NMR (161.9 MHz, CD2Cl2, 295 K):
δ = 15.6 (s). IR (Film): ν = 3051 (w), 2901 (w), 2844 (w), 1928
(vs), 1835 (vs), 1482 (m), 1433 (m), 1260 (w), 1180 (w), 1092 (w),
1019 (m), 996 (w), 831 (w), 738 (m), 696 (s), 622 (m) cmϪ1. MS
(FAB): m/z = 862.1 [M ϩ H]ϩ. C47H43MoO4P3 (860.72 g molϪ1):
calcd.: C 65.59 H 5.04; found: C 65.48, H 4.93%.
᎐
Preparation of [{(CH ) Si–C᎐C–CH OCH C(CH PPh ) }-
᎐
3
3
2
2
2
2 3
Mo(CO)3] (13)
Same procedure as for 12, using 85.2 mg (113 µmol) of (CH3)3-
᎐
Si–C᎐C–CH OCH C(CH PPh ) (10) and 34.3 mg (113 µmol)
᎐
2
2
2
2 3
᎐
Preparation of HC᎐C–CH OCH C(CH PPh ) (11)
᎐
2
2
2
2 3
᎐
of [(MeCN) Mo(CO) ]. The reaction product (CH ) Si–C᎐C–
᎐
3
3
3 3
Solid KF (502 mg = 8.64 mmol) and 473 mg (1.79 mmol) of
[18]crown-6 were added to a stirred solution of 1.34 g (1.69
CH2OCH2C(CH2PPh2)3Mo(CO)3 (13) was obtained as a yellow-
brown microcrystalline solid.
D a l t o n T r a n s . , 2 0 0 3 , 2 4 9 – 2 5 4
253

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coefficients and the anomalous dispersion coefficients were
taken from ref. 22. Crystal data and experimental details for the
crystals of 13 are given in Table 1.
CCDC reference number 197230.
See http://www.rsc.org/suppdata/dt/b2/b209589k/ for crystal-
lographic data in CIF or other electronic format.
Yield: 92.6 mg (99.0 µmol, 88%); mp: 218 ЊC (decomp.).
1H-NMR (300.17 MHz, CD2Cl2, 295 K): δ = 0.19 (s, 9 H, H-7),
2.36 (d, 6 H, H-1), 3.46 (s, 2 H, H-3), 4.29 (s, 2 H, H-4), 7.08–
7.40 (m, 30 H, aromat. H). {1H}13C-NMR (75.48 MHz,
CD2Cl2, 295 K): δ = 0.0 (s, CH3, C-7), 31.3 (m, CH2, C-1), 41.4
Acknowledgements
We thank the Deutsche Forschungsgemeinschaft, the CNRS,
and the Institut Universitaire de France for funding and
Dr André DeCian and Natalie Gruber for carrying out the
X-ray diffraction study.
2
(q, C, JPC = 7.0 Hz C-2), 59.7 (s, CH2, C-4), 82.8 (q, CH2,
3JPC = 9.7 Hz C-3), 92.3 (s, C, C-6), 101.8 (s, CH, C-5), 128.4–
129.3 (m, aromat. C), 132.0–133.2 (m, aromat. C), 138.9–139.4
(m, aromat. C), 221.3 (m, CO, C-8). {1H}31P-NMR (121.51
MHz, CD2Cl2, 295 K): δ = 17.7 (s). {1H} 29Si-NMR (79.49
MHz, CD2Cl2, 295 K): δ = 19.6 (s). IR (film): ν = 3279 (w), 3055
(w), 2919 (w), 2839 (w), 1929 (vs), 1841 (vs), 1482 (m), 1433 (s),
1087 (m), 1025 (w), 997 (w), 841 (s), 647 (s) cmϪ1. MS (FAB):
m/z = 930.9 [M]ϩ. C50H49MoO4P3Si (930.88 g molϪ1): calcd.:
C 64.51; H 5.31; found: C 64.27, H 5.22%.
References
1 (a) B. C. Gates, Catalytic Chemistry, Wiley, New York, 1982;
(b) C. Lecuyer, F. Quignard, A. Choplin, D. Olivier and J.-M. Basset,
Angew. Chem., Int. Ed. Engl., 1991, 30, 1660; (c) T. A. Budzichowski,
S. T. Chacon, M. H. Chisholm, F. J. Feher and W. Streib, J. Am.
Chem. Soc., 1991, 113, 689.
2 (a) F. R. Hartley, Supported Metal Complexes – A New Generation
of Catalysts, D. Reidel Publishing Company, Dortrecht, 1989;
(b) Yu. I. Yermakov, B. N. Kuznetsov, V. A. Zakharov, Catalysis by
Supported Complexes, Elsevier, Amsterdam, 1981; (c) W. A.
Herrmann and C. W. Kohlpaintner, Angew. Chem., Int. Ed. Engl.,
1993, 32, 1524.
3 (a) C. Bianchini, A. Meli, M. Peruzzini, F. Vizza and F. Zanobini,
Coord. Chem Rev., 1992, 120, 193; (b) H. A. Mayer and W. C. Kaska,
Chem. Rev., 1994, 94, 1239.
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W. Oberhauser, R. Psaro, L. Sordelli and F. Vizza, J. Am. Chem.
Soc., 1999, 121, 5961; (b) C. Bianchini, V. Dal Santo, A. Meli,
W. Oberhauser, R. Psaro and F. Vizza, Organometallics, 2000, 19,
2433.
5 (a) P. Schober, G. Huttner, L. Zsolnai and A. Jacobi, J.Organomet.
Chem., 1998, 571, 279; (b) C. Bianchini, M. Frediani and F. Vizza,
Chem. Commun., 2001, 479; (c) C. Bianchini, M. Frediani,
G. Mantovani and F. Vizza, Organometallics, 2001, 20, 2660.
6 C. Bianchini, A. Meli and W. Oberhauser, New J. Chem., 2001, 25,
11.
7 (a) C. Bianchini, A. Meli, V. Patinec, V. Sernau and F. Vizza,
J Am. Chem. Soc., 1997, 119, 4945; (b) I. Rojas, F. L. Linares,
N. Valencia and C. Bianchini, J. Mol. Catal. A, 1999, 144, 1.
8 B. C. Janssen, V. Sernau, G. Huttner, A. Asam, O. Walter,
M. Büchner and L. Zsolnai, Chem. Ber., 1995, 128, 63.
9 A. Muth, A. Asam, G. Huttner, A. Barth and L. Zsolnai,
Chem. Ber., 1994, 127, 305.
10 T. Seitz, A. Muth, G. Huttner, T. Klein, O. Walter, M. Fritz and
L Zsolnai, J. Organomet. Chem., 1994, 469, 155.
11 T. Seitz, G. Huttner and M. Büchner, Z. Naturforsch., Teil B, 1994,
49, 1813.
12 G. Huttner, O. Walter and L. Zsolnai, Z. Naturforsch., Teil B, 1995,
50, 1287.
13 P. Schober, R. Soltek, G. Huttner, L. Zsolnai and K. Heinze,
Eur. J. Inorg. Chem., 1998, 1407–1415.
14 (a) M. J. Burk and R. L. Harlow, Angew. Chem., Int. Ed. Engl., 1990,
29, 1462; (b) M. J. Burk, J. E. Feaster and R. L. Harlow, Tetrahedron:
Asymmetry, 1991, 2, 569.
15 R. A. Findeis, L. H. Gade, Eur. J. Inorg. Chem., 2003, in press.
16 T. J. Dunn, W. L. Neumann, M. M. Rogic and S. R. Woulfe,
J. Org. Chem., 1990, 55, 636.
17 (a) M. Y. Etienne and R. Soulas, Bull. Soc. Chim. Fr., 1957, 978;
(b) K. M. Lynch and W. P. Dailey, J. Org. Chem., 1995, 60, 4666.
18 Cambridge Structural Data Base, Cambridge, April 2002.
19 W. Gee, R. A. Shaw and B. C. Smith, Inorg. Synth., 1967, 9, 19.
20 D. P. Tate, W. R. Knipple and J. M. Augl, Inorg. Chem., 1962, 1, 433.
21 OpenMoleN, Interactive Structure Solution, Nonius, Delft, 1997.
22 D. T. Cromer, J. T. Waber, International Tables for X-ray
Crystallography, The Kynoch Press, Birmingham, 1974.
X-Ray crystallographic study of 13
Suitable crystals of complex 13 were obtained by layering con-
centrated solutions of the compounds in dichloromethane or
chloroform with hexanes and allowing slow diffusion at room
temperature. The crystal data were collected on a Nonius
Kappa CCD diffractometer at Ϫ100 ЊC and transfered to a
DEC Alpha workstation; for all subsequent calculations the
Nonius OpenMoleN package was used.21 The structures were
solved using direct methods with absorption corrections being
part of the scaling procedure of the data reductions. After
refinement of the heavy atoms, difference Fourier maps
revealed the maxima of residual electron density close to the
positions expected for the hydrogen atoms; they were intro-
duced as fixed contributors in the structure factor calculations
with fixed coordinates (C–H: 0.95 Å) and isotropic temperature
factors (B(H) = 1.3Beq(C) Å2) but not refined. The hydrogen
atoms of the solvents were not refined. Full least-square
refinements on F 2. A final difference map revealed no signifi-
cant maxima of electron density. The scattering factor
Table 1 X-Ray experimental data of compound 13
Formula
Molecular weight
Crystal system
Space group
a/Å
b/Å
c/Å
C50 H49MoO4P3Si
930.88
Monoclinic
P21/n
10.9160(2)
22.8277(4)
17.9896(4)
97.864(5)
4440.6(1)
4
1.39
1928
0.475
294
0.71073
10365
6776
532
0.044
0.056
1.035
0.479
β/Њ
V/Å3
Z
Dcalc/ g cmϪ3
F000
µ/mmϪ1
T /K
λ/Å
Number of data measured
Number of data with I > 3σ(I )
Number of variables
R
Rw
GOF
Largest peak in final difference/e ÅϪ3
D a l t o n T r a n s . , 2 0 0 3 , 2 4 9 – 2 5 4
254