Cross-metathesis of divinylsubstituted silanes and disiloxanes in the presence of Grubbs catalysts

Article abstract of DOI:10.1016/j.jorganchem.2006.08.006

Efficient cross-metathesis of divinylsilanes and divinyldisiloxanes, carrying different electron-withdrawing substituents at silicon, with selected olefins in the presence of the first and second generation Grubbs catalyst and Hoveyda-Grubbs catalyst is d

Full text of DOI:10.1016/j.jorganchem.2006.08.006

Journal of Organometallic Chemistry 691 (2006) 5476–5481
www.elsevier.com/locate/jorganchem
Cross-metathesis of divinylsubstituted silanes and disiloxanes
in the presence of Grubbs catalysts
*
Cezary Pietraszuk, Szymon Rogalski, Mariusz Majchrzak, Bogdan Marciniec
Adam Mickiewicz University, Faculty of Chemistry, Grunwaldzka 6, 60-780 Poznan´, Poland
Received 11 July 2006; received in revised form 30 July 2006; accepted 5 August 2006
Available online 12 August 2006
Abstract
Efficient cross-metathesis of divinylsilanes and divinyldisiloxanes, carrying different electron-withdrawing substituents at silicon, with
selected olefins in the presence of the first and second generation Grubbs catalyst and Hoveyda–Grubbs catalyst is described. The reac-
tion was proved to be a valuable method for synthesis of unsaturated organosilicon derivatives and a model for the study of synthesis of
oligo- and polymeric products via ADMET copolymerization of divinylsubstituted silanes and disiloxanes with dienes.
ꢀ 2006 Elsevier B.V. All rights reserved.
Keywords: Cross-metathesis; Grubbs catalyst; Alkylidene complexes; Divinylsilanes; Divinyldisiloxanes
1. Introduction
[7] with styrenes, alkenes and numerous allyl derivatives.
Recently, we have proposed a general scheme of vinylsilane
reactivity in the presence of Grubbs catalyst [8]. Despite the
fast development in the study of reactivity of unsaturated
organosilicon compounds, there are still limited data avail-
able on the reactivity of divinylsubstituted silanes and dis-
iloxanes. Wagener reported ADMET copolymerization of
Vi2SiMe2 with 1,9-decadiene in the presence of a tungsten
alkylidene complex [9]. We previously reported the reactiv-
ity of ViSi(OEt)2OSi(OEt)2Vi in ADMET copolymeriza-
tion with 1,9-decadiene [10a,10b] and divinylbenzene [10c]
and with ROM/ADMET copolymerization with cyclooct-
adiene [10a] in the presence of Grubbs catalyst.
Now, we report on the effective transformations of divi-
nylsubstituted silanes and disiloxanes with olefins in the
presence of Grubbs type ruthenium alkylidene complexes
(Fig. 1). The reaction offers an attractive synthetic route
leading to diunsaturated organosilicon derivatives. We dis-
cuss advantages and drawbacks of cross-metathesis of
vinylsilanes with olefins as a general synthetic method for
the synthesis of vinyltrisubstituted silanes and finally
search for a mechanistic scheme of catalysis of the reaction.
On the other hand, this reaction is a model to study the
activity of divinylsilanes and divinyldisiloxanes in effective
ADMET (co)polymerization.
Olefin metathesis has become an important synthetic
tool in organic and polymer chemistry. The family of
ruthenium-based catalysts (e.g., I, II or III, Fig. 1), tolerant
of normal organic and polymer processing conditions and
preserving their catalytic properties in the presence of the
majority of functional groups has allowed a great number
of new applications [1].
Metathesis transformations have also found many
applications in organosilicon chemistry [2]. A number of
papers appeared on the metathesis reactivity of vinylsilanes
as they constitute a class of unsaturated organosilicon com-
pounds of prospective wide applicability in organic synthe-
sis [3], especially in the fast developing palladium-catalyzed
coupling of vinylsilanes with organic derivatives [4]. In
vinylsilanes stereoelectronic properties of substituents at
silicon strongly affect the reactivity of C@C double bond.
We have previously shown that Grubbs type catalysts effec-
tively catalyse the cross-metathesis (CM) of trialkoxy-, tri-
siloxy- [5], trichloro- and generally electron-withdrawing
group substituted vinylsilanes [6] and vinylsilsesquioxanes
*
Corresponding author. Tel.: +48 61 8291 366; fax: +48 61 8291 508.
E-mail address: marcinb@amu.edu.pl (B. Marciniec).
0022-328X/$ - see front matter ꢀ 2006 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2006.08.006

C. Pietraszuk et al. / Journal of Organometallic Chemistry 691 (2006) 5476–5481
5477
R
PCy3
Ru
N
N
N
N
Cl
Ph
R'
+
Si
R
Cl
Cl
Ph
Ru
Cl
Ru
A
B
Cl
PCy3
Cl
O
PCy3
R = Cl, C6F5, C6H4-CF -4
R' = C8H17, C6H4-Cl-4,3C6H4-OMe-4
First generation
Grubbs catalyst
Second generation
Grubbs catalyst
Hoveyda - Grubbs
catalyst
R
R
Si
R
R'
R'
R'
[Ru]=CHR''
(i)
(ii)
(iii)
R'
+
+
Si
R'
CH2Cl2, reflux
R
Fig. 1. Grubbs type ruthenium alkylidene complexes.
C
D
ð1Þ
2. Results and discussion
The reaction is accompanied by competitive olefin homom-
etathesis. On the contrary, no vinylsilane homometathesis
was observed. The results of the catalytic studies are sum-
marized in Table 1.
Recently, we revealed that only vinylsilanes bearing at
least two electron-withdrawing group at silicon can effi-
ciently undergo cross-metathesis with olefins [8], while
vinylsilane homometathesis was restricted only to dichlo-
roderivatives ViSiCl2R where R = alkyl, aryl, OSiMe3
[11]. Therefore, we tested a series of electron-withdrawing
groups containing divinylsilanes (Fig. 2a) and divin-
yldisiloxanes (Fig. 2b) with respect of their reactivity in ole-
fin metathesis.
Treatment of a mixture of divinylsilane and olefin in the
presence of 5–10 mol% of catalyst I, II or III in boiling
CH2Cl2 gives rise to evolution of ethene and formation
of mono- and disubstituted vinylsilanes (Eq. (1)).
When Vi2SiCl2 was used as a reaction partner very high
activity and exclusive formation of disubstituted product D
was observed in the presence of catalyst II. On the other
hand, catalyst I underwent fast decomposition in the pres-
ence of Vi2SiCl2 [12]. Cross-metathesis of other divinylsil-
anes tested with olefins resulted in a formation of both
mono- and a disubstituted product. Therefore, high efforts
were undertaken to find conditions of more selective course
of the reactions. It was found that 10-fold excess of styrene
must be used to ensure high conversion and selectivity
towards a disubstituted products. However, even then for-
mation of the monosubstituted product could not be
avoided. Interestingly, reactions of Vi2Si(C6H4–CF3–4)2
and Vi2Si(C6F5)2 with 1-decene in the presence of catalyst
I led to selective formation of monosubstituted product in
moderate yields. Introduction of additional catalyst loading
led to further improvement in the obtained yield to 63%.
The Hoveyda–Grubbs catalyst exhibited similar behaviour
to that of catalyst II in the reactions tested. 1-Decene
a
b
R
Si
R
R
Si
R
R
Si
R
O
R = Cl, C6F5
,
C6H4-CF3-4
R = C6H5-CF3-4, OEt
Fig. 2. Divinylsubstituted silanes and disiloxanes.
Table 1
Cross-metathesis of divinylsilanes with olefins
Divinylsilane R= Olefin R0= Cat. Reaction conditionsa Conversion of A (%) Yield of C (%) C E/Z Yield of D (%) Db E, E/E, Z
Cl
C8H17
C6H4–Cl–4
II
II
1:4/1/5
1:4/3/5
100
100
0
0
25/1
E
99
98
15/1
E
C6H4–CF3–4
C8H17
C8H17
C8H17
C8H17
C6H4–Cl–4
C6H4–Cl–4
C6H4–Cl–4
C6H4–Cl–4
I
1:4/5/5
1:4/3/5
1:10/3/5
1:10/3/5
1:4/5/5
42
95
100
90
10
48
80
98
88
42, 63c, 50c,d
38
4
32
10
34
15
2
25/1
25/1
25/1
25/1
E
0
57
96, 75d
56
0
14
64
96
E
II
II
III
I
15/1
15/1
15/1
–
II
II
III
1:4/5/5
E
E
1:10/5/10
1:10/3/10
1:10/5/10
E
E
E
E
C6H4–OMe–4 II
16
E
70
E
C6F5
C8H17
C8H17
C6H4–Cl–4
C6H4–Cl–4
C6H4–OMe–4 II
I
1:4/5/5
38
100
88
99
92
38
2
15
1
25/1
25/1
E
0
E
II
II
III
1:10/3/5
1:10/5/10
1:10/3/10
1:10/5/10
98, 78d
72
15/1
E
E
98
74
E
18
E
E
Reaction conditions: CH2Cl2, reflux.
a
[ViSi]:[C@C]/time (h)/catalyst conc. (mol%).
Third possible isomer Z, Z was not observed.
Another loadings of catalyst I was added after 5 h and reaction was run for next 3 h.
b
c
d
Isolated yield.

5478
C. Pietraszuk et al. / Journal of Organometallic Chemistry 691 (2006) 5476–5481
reacted more readily than styrenes in cross-metathesis with
divinylsilanes tested. The reactions with styrenes led to
selective formation of E-isomer. The cross-metathesis of
vinylsilanes with 1-decene gave a mixture of E and Z iso-
mers, with E isomer in predominant amounts. The reaction
permits synthesis of substituted silylethenes with moderate
to high yields, under mild reaction conditions.
The cross-metathesis of divinylsubstituted disiloxanes
with olefins proceeds in the presence of 5–10 mol% of cat-
alyst I, II or III in boiling CH2Cl2 producing a mixture of
mono- and disubstituted vinylsilanes and ethene (Eq. (2)).
Also in this case reaction is accompanied by competitive
olefin homometathesis. The results of the catalytic studies
are summarized in Table 2.
To achieve a high conversion of all divinyldisiloxanes
used and a satisfactory selectivity of disubstituted products
olefins must be taken at a 10-fold excess. Generally, high
stereoselectivity of cross-metathesis was observed. The
reactions led to selective formation of E-isomer (when
styrenes were used as olefins) or a mixture of isomers
with high excess of the E compound (when 1-decene was
used).
2.1. Labelling studies
There are two processes leading to formation of silylole-
fins and ethene via catalytic transformation of vinylsilanes
with olefins, i.e., silylative coupling (Eq. (3)) and cross-
metathesis (Eq. (4)) [2]. Both reactions proceed via different
mechanisms and are catalyzed by different reactive species.
C6D5
D
D
D
H
H
H
C
C
C C
+
SiR3
[Ru]
[Ru] Si
H
or
C6D5
D
D
H
H
H
D
+
C
C
C C
SiR3
ð3Þ
ð4Þ
ð2Þ
C6D5
D
D
H
H
C
+
C
C
C
Divinyltetraphenyldisiloxane exhibited almost no reactiv-
ity. Only traces of monosubstituted product were found,
irrespective of the olefin used. Introduction of the elec-
tron-withdrawing group to phenyl ring resulted in a drastic
change in reactivity. In most cases nearly quantitative
conversion of ViSi(C6H4–CF3–4)2OSi(C6H4–CF3–4)2Vi
was observed [13]. High conversion of divinyltetraethoxy-
disiloxane observed for cross-metathesis agrees well with
its previously reported activity in ADMET copolymeriza-
tion [10].
D
H
SiR3
C6D5
D
H
D
D
H
H
[Ru] CHPh
C
C
C C
+
SiR3
Therefore, in order to distinguish between the non-carbene
mechanism (Eq. (3)) and the metallacarbene mechanism
(Eq. (4)), divinylbis(pentafluorophenyl)silane and 1,3-divi-
nyl-1,1,3,3-tetraethoxydisiloxane were tested in the reac-
Table 2
Cross-metathesis of divinyldisiloxanes with olefins
Disiloxane R= Olefin R0=
Cat. Reaction conditionsa Conversion of B (%) Yield of C (%) C E/Z Yield of D (%) Db E, E/E, Z
Ph
C8H17
C6H5–Cl–4
II
II
1:4/3/5
1:4/5/5
12
4
12
4
E
E
0
0
–
–
C6H4–CF3–4
C8H17
C8H17
C8H17
C8H17
C6H4–Cl–4
C6H4–Cl–4
C6H4–OMe–4 II
I
1:4/3/5
95
98
100
100
98
51
32
8
10
25
12
20
25/1
25/1
25/1
25/1
E
44
66
92
88
15/1
15/1
15/1
15/1
E, E
E, E
E, E
I
1:10/3/5
1:10/3/5
1:10/3/5
1:10/5/10
1:10/5 /10
1:10/5 /10
II
III
II
III
73
99
98
E
87, 75c
78
E
OEt
C8H17
I
1:4/5/5
63
99
99
88
54
10
2
E
E
E
E
5
86
95
66
E, E
E, E
E, E
E, E
C6H4–Cl–4
C6H4–Cl–4
C6H4–Cl–4
I
1:4/24/5
1:10/3/5
1:10/5/5
II
III
20
Reaction conditions: CH2Cl2, reflux.
a
[ViSi]:[C@C]/time (h)/catalyst conc. [mol%].
Third possible isomer Z, Z was not observed.
Isolated yield.
b
c

C. Pietraszuk et al. / Journal of Organometallic Chemistry 691 (2006) 5476–5481
5479
tions with styrene-d8 in the presence of II. In the case of the
non-metallacarbene mechanism, the formation of styrylsi-
lane-d7, bis(styryl)silane-d14 and ethylene-d1 is to be ex-
pected (Eq. (5), in contrast, the carbene mechanism
should afford styrylsilane-d6, bis(styryl)silane-d12 and ethyl-
ene-d2 (Eq. (6)).
pentane was added to precipitate magnesium salt. The
salt was filtered off and the product was obtained by
vacuum distillation (collected fraction 145–148 ꢁC/1 mm
Hg).
The product of 97% purity was obtained with the yield
of 75%.
1
Spectroscopic data: H NMR (C6D6, d, ppm): 5.67 (dd,
C D
D
D
5
6
[Si]
+
C
C
2H, JHH = 19.8, 3.9 Hz, @CH–Si), 6.10 (dd, 2H,
JHH = 14.4, 3.9 Hz, @CH2), 6.25 (dd, 2H, JHH = 19.8,
14.4 Hz, @CH2), 7.31–7.40 (m, 8H, C6H4–CF3–4); 13C
NMR (C6D6, d, ppm): 124.3 (q, JCF = 272.1 Hz, CF3),
124.2–124.3 (m, CH–Ci–CF3), 131.7 (@CH–Si), 135.5 (s,
CH–CH–Ci–CF3), 137.3 (@CH2), 138.1 (Ci–Si), (Ci–CF3)
not found; 19F NMR (C6D6, d, ppm): ꢀ61.95 (s, CF3);
MS: m/z (rel. intensity): 47 (29), 50 (27), 51 (23), 53 (28),
57 (21), 62 (15), 63 (27), 69 (25), 75 (31), 77 (25), 81 (15),
87 (16), 89 (15), 95 (13), 103 (16), 107 (28), 108 (15), 115
(18), 125 (21), 126 (27), 127 (72), 133 (83), 134 (55), 151
(18), 153 (91), 154 (14), 165 (15), 219 (26), 226 (25), 227
(23), 173 (14), 175 (15), 183 (18), 193 (18), 201 (21), 219
(26), 226 (25), 227 (23), 252 (19), 271 (18), 319 (56), 320
(18), 344 (25), 345 (20), 353 (100), 354 (30), 372 (13).
Vi2Si(C6F5)2 was synthesized according to similar proce-
dure to that presented above.
D
D
D
D
[Ru]
[Ru] Si
H
or
[Si]
[Si]
[Si]
+
C D
C D
D
C
5
6
5
5
6
6
D
D
D
D
ð5Þ
C D
D
5
6
+
[Si]
C
C
D
D
D
D
D
[Si]
+
[Ru] CHPh
D
C D
C D
C D
6 5
5
5
6
6
D
ð6Þ
Analysis of the products formed revealed formation of
styrylsilane-d6 and bis(styryl)silane-d12 which strongly
supports the carbene mechanism of the reaction pre-
sented previously for vinylsubstituted silicon compounds
[5a,8].
1
Isolated yield 80%; H NMR (C6D6, d, ppm): 5.69 (dd,
2H, JHH = 20.2, 2.8 Hz, @CH2), 6.01 (dd, 2H, JHH = 14.2,
2.8 Hz, @CH2), 6.45 (dd, 2H, JHH = 20.2, 14.2 Hz, @CH–
Si); 13C NMR (C6D6, d, ppm): 129.7 (@CH–Si), 137.8
(@CH2), 137.5 (dm, JCF = 248.8 Hz, C6F5), 142.9 (dm,
JCF = 256.2 Hz, C6F5), 149.3 (dm, JCF = 244.8 Hz, C6F5);
19F NMR (C6D6, d, ppm): ꢀ159.44 (m, meta), ꢀ147.56
(tt, JFF = 20.6, 4.2 Hz, para), ꢀ125.14 (m, ortho); MS:
m/z (rel. intensity): 47 (44), 48 (100), 62 (19), 67 (28), 75
(29), 79 (68), 80 (17), 85 (26), 86 (29), 87 (62), 88 (20), 92
(18), 93 (60), 98 (31), 99 (33), 110 (15), 111 (53), 112 (18),
117 (88), 129 (29), 133 (32), 156 (21), 164 (15), 182 (32),
183 (46), 248 (49), 258 (17), 322 (10), 416 (2, M+).
3. Experimental
3.1. General
All manipulations were carried out under dry argon
using standard Schlenk techniques. 1H NMR and 13C
NMR spectra were recorded on a Varian Gemini 300 at
300 and 75 MHz, respectively. GC-MS analyses were made
on Varian Saturn 2100T (DB-1, 30 m capillary column).
Complexes II and III, decane, dodecane, CH2Cl2 and
C6D6, were purchased from Aldrich. Catalyst I was pre-
pared according to the literature procedure [14].
3.3. Synthesis of 1,3-divinyl-1,1,3,3-tetra-
[4-(trifluoromethyl)phenyl]disiloxane
3.2. Synthesis of divinylbis[4-(trifluoromethyl)phenyl]silane
An oven dried 100 mL flask equipped with a con-
denser with a bubbler and a magnetic stirring bar was
charged under argon with 30 mL of dry THF, 1.56 g
(6.4 · 10ꢀ2 mol) of magnesium shavings. Then the solu-
tion of 14.46 g (6.4 · 10ꢀ2 mol) Br–C6H4–CF3–4 in
20 mL of THF was added dropwise to the reacting mix-
ture. The mixture was refluxed for 3 h and cooled down
to room temperature. An oven dried 100 mL flask
equipped with a condenser with a bubbler and a mag-
netic stirring bar was charged under argon with 20 mL
of dry THF, 5.19 g (3.2 · 10ꢀ2 mol) of divinyldichlorosi-
lane. Then the solution of BrMg–C6H4–CF3–4 in THF
was added dropwise to the mixture. The reacting mixture
was stirred for 5 h and the solvent was distilled off. Then
100 mL of pentane was added to precipitate magnesium
salt. The salt was filtered off and the product
An oven dried 100 mL flask equipped with a con-
denser with a bubbler and a magnetic stirring bar was
charged under argon with 30 mL of dry THF, 0.52 g
(2.1 · 10ꢀ2 mol) of magnesium shavings. Then the
solution of Br–C6H4–CF3–4 (2.1 · 10ꢀ2 mol) in 20 mL
of THF was added dropwise to the reacting mixture.
The mixture was refluxed for 3 h and cooled down to
room temperature. An oven dried 100 mL flask equipped
with a condenser with a bubbler and a magnetic stirring
bar was charged under argon with 20 mL of dry THF,
3 g (2 · 10ꢀ2 mol) of divinyldichlorosilane. Then the
solution of BrMg–C6H4–CF3–4 in THF was added drop-
wise to the mixture. The reacting mixture was stirred for
5 h and the solvent was distilled off. Then 100 mL of

5480
C. Pietraszuk et al. / Journal of Organometallic Chemistry 691 (2006) 5476–5481
(H2C@CH–Si(C6H4–CF3–4)2Cl) was obtained by vacuum
distillation (collected fraction: 140–144 ꢁC/1 mm Hg). In
the next step a 100 mL flask equipped with a magnetic
stirring bar was charged with 20 mL of pentane, 2.75 g
(7.2 · 10ꢀ3 mol) of H2C@CH–Si(C6H4–CF3–4)2Cl, 3.0 g
(0.17 mol) of distilled water. The mixture was stirred
for 2 days at room temperature. Then the mixture was
filtered on celite. After evaporation of solvent and water
(under vacuum) product of 97% purity was obtained with
a total yield of 68%.
1.40 (m, 24H, CH2), 2.14–2.21 (m, 4H, @CH–CH2), 5.99
(dt, 2H, JHH = 18.7, 1.5 Hz, @CH–Si), 6.28 (dt, 2H,
JHH = 18.7, 6.2 Hz, @CH–CH2), 7.50 (dd, 8H, JHH = 18.7,
7.9 Hz, C6H4–CF3–4); 13C NMR (C6D6, d, ppm): 15.0
(CH3), 23.7, 29.5, 30.24, 30.35, 30.46, 32.88 (CH2), 38.05
(@CH–CH2), 123.3 (@CH–Si), 125.1–125.3 (m, CH–Ci–
CF3), 136.5 (s, CH–CH–Ci–CF3), 125.3 (q, JCF = 271.6 Hz,
CF3), 132.2 (q, JCF = 32.0, Ci–CF3), 141.0 (Ci–Si), 155.01
(@CH–CH2); 19F NMR (C6D6, d, ppm): ꢀ61.8 (s, CF3);
MS: m/z (rel. intensity): 55 (52), 57 (50), 67 (66), 69 (28), 79
(27), 81 (64), 82 (20), 83 (24), 95 (43), 97 (22), 109 (32), 115
(22), 122 (31), 123 (23), 127 (99), 128 (27), 140 (35), 147
(20), 153 (53), 165 (42), 173 (26), 179 (21), 191 (21), 265
(23), 276 (23), 319 (100), 320 (31), 310 (23), 371 (29), 372
(33), 457 (35), 483 (23), 577 (21).
1
Spectroscopic data: H NMR (C6D6, d, ppm): 5.71 (dd,
2H, JHH = 20.1, 3.6 Hz, @CH–Si), 6.03 (dd, 2H,
JHH = 15.0, 3.6 Hz, @CH2), 6.22 (dd, 2H, JHH = 20.1,
15.0 Hz, @CH2), 7.33–7.40 (m, 18H, C6H4–CF3–4); 13C
NMR (C6D6, d, ppm): 124.4 (q, JCF = 271.2 Hz, CF3),
126.0 (q, JCF = 24.7 Hz, CH–Ci–CF3), 132.7 (q,
JCF = 37.5 Hz, Ci–CF3), 133.2 (CH2), 135.2 (CH–CH–Ci–
CF3), 138.2 (@CH–Si), 138.9 (Ci–Si); 19F NMR (C6D6, d,
ppm): ꢀ62.04 (s, CF3); MS: m/z (rel. intensity): 50 (11),
75 (13), 103 (11), 115 (16), 125 (12), 126 (18), 127 (45),
133 (21), 134 (14), 153 (100), 154 (13), 183 (11), 201 (10),
271 (23).
Si(C6F5)2(CH@CHC8H17)2, isolated yield 78%; 1H
NMR (C6D6, d, ppm): 0.86–0.92 (m, 6H, CH2–CH3),
1.26 (s, 24H, CH2), 2.13–2.20 (m, 4H, @CH–CH2), 6.21
(d of broad signals 2H, JHH = 18.6 Hz, @CH–CH2), 6.41
(dt, 2H, JHH = 18.6, 6.1 Hz, @CH–Si); 13C NMR (C6D6,
d, ppm): 14.7 (CH3), 23.5, 29.0, 29.9, 30.1, 30.2, 32.6
(CH2), 37.5 (@CH–CH2), 121.18 (@CH–Si), 138.3 (dm,
JCF = 256.8 Hz, C6F5), 143.4 (dm, JCF = 255.6 Hz, C6F5),
149.7 (dm, JCF = 248.8 Hz, C6F5), 155.4 (@CH–CH2);
19F NMR (C6D6, d, ppm): ꢀ159.71–(ꢀ159.49) (m, meta),
ꢀ148.16 (tt, JFF = 20.6, 3.9 Hz, para), ꢀ125.28 (dd,
JFF = 11.8, 3.4 Hz, ortho); MS: m/z (rel. intensity): 53
(13), 55 (77), 57 (65), 67 (100), 69 (38), 79 (26), 81 (92),
82 (26), 83 (38), 95 (64), 96 (24), 97 (31), 109 (39), 111
(17), 123 (23), 137 (15), 151 (23), 259 (15), 277 (45), 278
(16), 431 (15).
3.4. Catalytic tests
An oven dried 4 mL Schlenk flask with side neck closed
with a septum, equipped with a condenser and a magnetic
stirring bar was charged under argon with 3 mL of CH2Cl2,
divinylsilane (5.9 · 10ꢀ5 mol), 1-decene or styrene (5.9 ·
10ꢀ4 mol) and 20 lL of decane or dodecane (internal stan-
dard). The reaction mixture was stirred and heated in an oil
bath to maintain a gentle reflux (ca. 43 ꢁC). Then 0.0025 g
(2.94 · 10ꢀ6 mol) of ruthenium benzylidene complex II was
added under argon. A gentle flow of argon was applied.
The reaction was followed by gas chromatography.
[(C6H4–OMe–4)HC@CH]Si(C6H4–CF3–4)2OSi(C6H4–
1
CF3–4)2[CH@CH(C6H4–OMe–4)], isolated yield 75%; H
NMR (C6D6, d, ppm): 3.30 (s, 6H, OMe), 6.56 (d, 2H,
JHH = 19.2 Hz, @CH–Si), 7.20 (d, 2H, partially hidden,
@CH–C6H4–OMe), 7.20–7.28 (m, 8H, C6H4–OMe), 7.48
(pseudo d, 8H, CH–Ci–CF3), 7.67 (pseudo d, 8H, CH–Ci–
Si); 13C NMR (C6D6, d, ppm): 54.9 (OMe), 114.5 (CH–Ci–
OMe), 118.2 (@CH–Si), 123.8 (q, JCF = 285.2 Hz, CF3),
124.9–125.1 (m, CH–Ci–CF3), 128.7 (CH–CH–Ci–OMe),
130.1 (Ci–CH@), 132.6 (q, JCF = 32.0 Hz, Ci–CF3), 135.4
(CH–CH–Ci–CF3), 150.4 (Ci–Si), 161.4 (@CH–C6H4–
OMe), 19F NMR (C6D6, d, ppm): ꢀ61.95 (s, CF3).
3.5. Procedure for the synthesis of dialkenylsilanes and
dialkenyldisiloxanes
An oven dried 20 mL Schlenk flask equipped with a con-
denser with a bubbler and a magnetic stirring bar was
charged under argon with 10 mL of CH2Cl2, vinylsilane
(2.4 · 10ꢀ4 mol) and olefin (2.4 · 10ꢀ3 mol). The reaction
mixture was stirred and heated in an oil bath (ca. 45 ꢁC)
to maintain a gentle reflux. Then 0.01 g (1.2 · 10ꢀ5 mol)
of ruthenium benzylidene complex II was added under
argon. Intensive bubbling was observed. A gentle flow of
argon was applied from the top of the column. The course
of the reaction was followed by gas chromatography. After
a given reaction time dichloromethane was distilled off and
the catalyst was separated from the mixture using small sil-
icagel column. Then the solvent and homometathesis prod-
uct of the olefin was distilled off and the pure product was
obtained.
4. Conclusions
A variety of divinylsilanes and divinyldisiloxanes have
been tested in cross-metathesis in the presence of Grubbs
catalysts. Stereoselective course of cross-metathesis of
vinylsilanes with styrenes and 1-alkenes was indicated.
Under the optimum conditions the products required were
synthesized with moderate to high yields. The reaction was
proved to be a valuable method for the synthesis of unsat-
urated organosilicon derivatives and a model for the study
of synthesis of oligo- and polymeric products via ADMET
copolymerization of divinylsubstituted silanes and disilox-
anes with dienes.
Spectroscopic data of selected products:
Si(C6H4–CF3–4)2(CH@CHC8H17)2, isolated yield 75%;
1H NMR (C6D6, d, ppm): 0.88–0.92 (m, 6H, CH3), 1.27–

C. Pietraszuk et al. / Journal of Organometallic Chemistry 691 (2006) 5476–5481
5481
[5] (a) C. Pietraszuk, B. Marciniec, H. Fischer, Organometallics 19
(2000) 913;
Acknowledgements
(b) C. Pietraszuk, H. Fischer, M. Kujawa, B. Marciniec, Tetrahedron
Lett. 42 (2001) 1175;
(c) M. Kujawa-Welten, C. Pietraszuk, B. Marciniec, Organometallics
21 (2002) 840;
(d) M. Kujawa-Welten, B. Marciniec, J. Mol. Catal., A: Chem. 190
(2002) 79.
Financial support from the European Commission
(Contract Number ICA1-CT-2002-70002) (C.P.) and the
State Committee for Scientific Research (Poland) (Project
Number 3 T09A 14526) (B.M., M.M. and S.R.) is grate-
fully acknowledged.
[6] C. Pietraszuk, B. Marciniec, H. Fischer, Tetrahedron Lett. 44 (2003)
7121.
[7] Y. Itami, B. Marciniec, M. Kubicki, Chem. Eur. J. 10 (2004) 39.
[8] C. Pietraszuk, H. Fischer, S. Rogalski, B. Marciniec, J. Organomet.
Chem. 690 (2005) 5912.
[9] K.B. Wagener, D.W. Smith Jr., Macromolecules 24 (1991)
6073.
[10] (a) C. Pietraszuk, B. Marciniec, M. Jankowska, Adv. Synth. Catal.
344 (2002) 789;
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