Synthesis and desilylation of some bis(trimethylsilyl)alkenes and polymers bearing bis(silyl)alkenyl groups

Article abstract of DOI:10.1016/j.jorganchem.2009.03.011

The synthesis of various vinylbis(silanes) from some aryl and heteroaryl aldehydes and (Me₃Si)₃CLi in Et₂O is described. Friedel-Crafts reaction of 1,1-bis(trimethylsilyl)-2-(2-naphthyl)ethene with various acyl chlorides (

Full text of DOI:10.1016/j.jorganchem.2009.03.011

Journal of Organometallic Chemistry 694 (2009) 2448–2453
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Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Synthesis and desilylation of some bis(trimethylsilyl)alkenes and polymers
bearing bis(silyl)alkenyl groups
a
a
a
Kazem D. Safa a,b, , Mina Namvari , Akbar Hassanpour , Shahin Tofangdarzadeh
*
a Organosilicon Research Laboratory, Faculty of Chemistry, University of Tabriz, 51664 Tabriz, Iran
b Research Institute for Fundamental Sciences, Tabriz, Iran
a r t i c l e i n f o
a b s t r a c t
Article history:
The synthesis of various vinylbis(silanes) from some aryl and heteroaryl aldehydes and (Me3Si)3CLi in
Et2O is described. Friedel–Crafts reaction of 1,1-bis(trimethylsilyl)-2-(2-naphthyl)ethene with various
Received 21 January 2009
Received in revised form 1 March 2009
Accepted 11 March 2009
Available online 17 March 2009
acyl chlorides (RCOCl, R = Me, Et, i-Pr, i-Bu, n-pent) gave the corresponding
a-silyl-a,b-unsaturated enon-
es with high steroselectivity. Moreover, poly(styrene)-co-[2,2-bis(trimethylsilyl)ethenyl(styrene)]
E
obtained via the reaction of polymers bearing pendant enone functions and (Me3Si)3CLi, reacts with
the same acyl chlorides in the presence of catalytic amount of AlCl3 to give the new macromolecules
Keywords:
Tris(trimethylsilyl)methane
Peterson olefination
bearing
a
-silyl-
a
,b-unsaturated enones and
a
,b-unsaturated enones.
Ó 2009 Elsevier B.V. All rights reserved.
1,1-Bis(silyl)-1-alkenes
Functionalized poly(styrene)
Friedel–Crafts reactions
1. Introduction
demonstrate that these synthetic methodologies may be applied
to formylated polystyrenes.
1,1-Disilylated-1-alkenes have gained attention as intermedi-
ates in the organic and organosilicon synthesis [1–4]. They have
been recognized as useful synthetic reagents since the carbon–sil-
icon bonds are readily cleaved by various electrophiles in a regio-
and stereoselective manner [5,6].
Sterically overloaded tris(trimethylsilyl)methane and its deriva-
tives (‘trisyl’ compounds), show exceptional steric hindrance and
structural versatility and have been studied extensively in organo-
metallic chemistry [7]. More recently, these moieties have found
their place in the field of polymer chemistry and have been applied
in the preparation of novel polymeric materials [8,9].
We have recently been engaged in the development of 1,1-bis(-
silyl)-1-alkene derivatives [4,10], which are used as precursors for
the preparation of ketones as well as variety of important organosil-
icon intermediates such as acylsilanes, epoxysilanes, 1-halovinyl-
silanes, silylenolethers, (E)-alkeneylsilanes, and silylenolacetates
[1]. We also reported a convenient and steroseletive route for the
2. Results and discussion
Tris(trimethylsilyl)methyllithium, made in almost quantitative
yield from the reaction between tris(trimethylsilyl)methane and
methyllithium [11–13], reacts with some non-enolisable alde-
hydes such as 2-naphthaldehyde, 2-thiophenealdehyde, 5-methyl-
furfural, 3-pyridinaldehyde, p-chlorobenzaldehyde and 2,6-
dichlorobenzaldehyde with the formation of a series of 1,1-bis(tri-
methylsilyl)-2-arylalkenes containing heteroaryl and chloro sub-
stituents in the aromatic ring. The Peterson reaction readily gives
the appropriate vinylbis(silanes) (Table 1).
a-Silyl-a,b-unsaturated enones are usually prepared by Zr-pro-
moted ene-yne cyclization–carbonylation [14–17], Pd-catalyzed
acylation of a-silylalkenylmetals [18], and the Grignard reaction
of vinylsilanes with carbonyl compounds [19] with poor selectivity
and expensive reagents. More recently, we have reported a conve-
synthesis of
ylsilyl)-2-phenylethene [6]. In an effort to extend the range of
1,1-bis(silyl)-1-alkenes and -silyl- ,b-unsaturated enones, new
a-silyl-a,b-unsaturated enones from 1,1-bis(trimeth-
nient and selective route for the synthesis of
a-silyl-a,b-unsatu-
rated enones from 1,1-bis(trimethylsilyl)-2-phenylethene [6]. To
investigate the generality of this reaction, 1,1-bis(trimethylsilyl)-
2-(2-naphthyl)ethene was treated under optimum conditions
(0 °C, 120 min AlCl3/RCOCl = 1.5) with various acyl chlorides
(RCOCl, R = Me, Et, i-Pr, i-Bu, n-pent) in the presence of AlCl3 as a
catalyst. The optimum reaction conditions, were discovered
through the reaction of vinylbis(silane) 1 with acetyl chloride,
using the same amount of AlCl3, in three different reaction times
a
a
1,1-bis(trimethylsilyl)-1-alkenes were prepared and the reactions
of 1,1-bis(trimethylsilyl)-2-(2-naphthyl)ethene were studied. We
* Corresponding author. Address: Organosilicon Research Laboratory, Faculty of
Chemistry, University of Tabriz, 51664 Tabriz, Iran. Tel.: +98 411 3393124; fax: +98
411 3340191.
E-mail address: dsafa@tabrizu.ac.ir (K.D. Safa).
0022-328X/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2009.03.011

K.D. Safa et al. / Journal of Organometallic Chemistry 694 (2009) 2448–2453
2449
Table 1
Table 2
Synthesis of 1,1-bis(trimethylsilyl)-2-arylethenes via Peterson olefination.
The effect of reaction time and amount of AlCl3 in the reaction of 1 with acetyl
chloride.
Ar
SiMe3
(Me3Si)3CLi / THF
Ar-CHO
Entry
Time (min)
AlCl3 (mequiv.)
Product 7 (%)a
Product 8 (%)a
Et2O
reflux
1
2
3
60
120
180
15.3
15.3
15.3
35
78
39
29
17
55
H
SiMe3
a
Ar
Time (h)
3
Product structure
Yield (%)
91
The yields have been obtained by GC–MS.
can also be applied in the desiylation of containing bis(trimethyl-
silyl)alkenyl groups.
SiMe3
SiMe3
The method reported earlier [4] for the modification of formy-
lated polymer precursors via Peterson protocol has been applied
for the preparation of poly(styrene)-co-[2,2-bis(trimethylsilyl)eth-
enyl(styrene)] (PSi) (Scheme 1). Linear poly(styrene) (P) random
homopolymer (P) was obtained by solution free radical polymer-
H
(1)
18
18
69
75
SiMe3
SiMe3
S
S
ization at 70( 1) °C using a,
a0-azobis(isobutyronitrile) (AIBN) as
an initiator. The formyl groups were introduced by direct electo-
philic substitution of polymer P using methyl dichloromethyl
ether (Cl2CHOMe) in the presence of tin (IV) chloride in nitroben-
zene. The percentage of formyl groups in the side chain of the
formylated polymer PCHO can be determined by 1H NMR
(49 mol%). Polymer PSi was prepared by the reaction of its formyl
precursor with organolithium reagent (Me3Si)3CLi. After modifica-
tion of polymer PCHO with (Me3Si)3CLi, all signals from formyl
groups at 9.91 ppm disappeared and the signals from SiMe3
groups were detected at 0.20 ppm (Fig. 1). Moreover, the FT-IR
spectra of the obtained copolymer PSi did not show a sharp peak
at 1696 cmꢀ1 which indicates the absence of –CHO groups. It is
worth noting that the reaction of polymer PSi under the same
reaction conditions with acyl chlorides led to the desilylated
products PCOR. As an example, Fig. 1 shows the 1H NMR spectrum
of the polymer PCOCH3. In addition to the peaks at 1.50–2.27 ppm
corresponding to the CH and CH2 groups in the backbone of the
polymer, a singlet at 2.35 ppm assigned to CH3CO, is observed.
It is interesting to compare the integrated intensities of the peaks
assigned to CH3CO and –SiMe3 as they contain important infor-
mation about the incorporation of CH3CO groups to the side chain
of the polymer.
H
(2)
H3C
H3C
SiMe3
SiMe3
O
O
H
(3)
N
7
85
N
SiMe3
H
SiMe3
(4)
Cl
Cl
3
3
86
81
SiMe3
SiMe3
The percentage of formyl in PCHO side chain was calculated by
measuring the integrate peak areas of the formyl proton and total
aliphatic protons. The expression in Eq. (1) was used to determine
the composition of polymers, where m1 is the mole fraction of for-
myl styrene and 1 ꢀ m1 is that of styrene. Both formyl styrene and
styrene contain five aliphatic protons.
H
(5)
Cl
Cl
SiMe3
Cl
H
SiMe3
Cl
IA Integrated peak area of formyl protons
(6)
¼
ð1Þ
Ia
Integrated peak area of aliphatic
Since all –CHO groups are converted into bis(silyl) groups in PSi,
m1 and m2 are still the same. In PCOCH3, X and Y are calculated by
the following equation:
(Table 2). It was found that after 1 h, the reaction was incomplete,
and that longer reaction times gave higher yields of the
unsaturated enone.
a-silyl-a,b-
IA Integrated peak area of SiMe3 group
A ¼
A ¼
¼
Ia
Integrated peak area of CH3CO
In all cases, the monodesilylation of 1,1-bis(trimethylsilyl)-2-
(2-naphthyl)ethene was complete within two hours giving -si-
lyl- ,b-unsaturated enones as the major product (by GC–MS). Sub-
9X
3X þ 3Y
a
ð2Þ
a
stitution of the second silyl group by hydrogen usually required a
longer time (3 h) and an increase in the amount of AlCl3. In these
reactions, high stereoselectivity was observed and only E stereoiso-
mers were obtained. Moreover, in the case of i-Bu and n-pent
substituted products (entries e and d, Table 3), desilylation was
accompanied with the formation of trace of the corresponding Z
stereoisomers (7% and 3% yields respectively (by GC–MS)). As an
extension to the present study, we have found out that our method
The polymer PCOCH3 shows approximately a 3:6 ratio between the
peaks at 2.35 and 0.15 ppm, suggesting that nearly 34% of the side
chain of the polymer are changed into
one groups. The percentage of -silyl-
,b-unsaturated enone groups in polymers are listed in Table 4.
a-silyl-a,b-unsaturated en-
a
a,b-unsaturated enone and
a
The FT-IR spectra of all polymers PCOR showed two peaks around
1667, 1972 cmꢀ1 due to C@O stretching.

2450
K.D. Safa et al. / Journal of Organometallic Chemistry 694 (2009) 2448–2453
Table 3
The Friedel–Crafts reaction of 1 with acyl chlorides 2a–e.
O
SiMe3
AlCl3
H
O
+
RCOCl
+
R
CH2Cl2
o
H
SiMe3
R
H
H
SiMe3
0 C
1
7
8
Entry
a
RCOCl 2
7 (%)
8 (%)
E
Z
72 (7a)
–
15 (8a)
O
H3C
Cl
b
c
65 (7b)
–
–
7
26 (8b)
21 (8c)
23 (8d)
O
CH3CH2
Cl
74 (7c)
64 (7d)
68 (7e)
O
Cl
d
O
Cl
e
3
30 (8e)
O
H3C-(CH2)4
Cl
(a) Reactions carried out on 3.4 mmol scale of 1 in the presence of 15.3 mequiv. in CH2Cl2 (20 ml) at 0 °C for 2 h. (b) AlCl3/RCOCl = 1.5.
Scheme 1. Synthesis route for preparation of PCHO, Psi and PCOR polymers.
variety of acyl chlorides to give the corresponding
urated enones and
a
-silyl-
a
,b-unsat-
3. Conclusion
a
,b-unsaturated enones in high yields with high
steroselectivities. These compounds have potential for conversion
into new materials with a variety of chemically reactive groups.
We have developed a method for the facile generation and reac-
tion of some 1,1-bis(silyl) alkenes and studied their reactions with a

K.D. Safa et al. / Journal of Organometallic Chemistry 694 (2009) 2448–2453
2451
Fig. 1. The 1H NMR spectra of (a) PCHO, (b) PSi and (c) PCOCH
.
3
quadrupole mode 5973N instrument, operating at 70 eV. The FT-
IR spectra were recorded on a Bruker-Tensor 270 spectrometer.
Elemental analyses were carried out with an Elementar vario EL
III instrument.
4. Experimental
4.1. Solvents and reagents
The reactions were carried out under dry argon. Solvents were
dried by standard methods. Substrates for the preparation of
tris(trimethylsilyl)methyllithium, viz. Me3SiCl (Merck), Li (Merck),
CHCl3 (Merck), all the aldehyde derivatives (Merck), dichlorometh-
yl ether (Merck) and tin (IV) chloride (Merck) were used as re-
ceived. All acyl chlorides were purchased from Merck and
distilled before use. AlCl3 was used after sublimation.
4.3. General procedure for the synthesis of vinylbis(silanes)
Tris(trimethylsilyl)methyllithium (15 mmol) and aldehyde
(15 mmol) in dry THF (50 ml) were refluxed for a specific time
mentioned in Table 1 and then poured into water (50 ml) and ex-
tracted twice with 50 ml of ether. The combined organic layers
were dried (Na2SO4) and filtered. The solvent was evaporated
and the residue was then purified by preparative TLC (silica gel)
to give the corresponding vinylbis(silane).
4.2. Spectra
The 1H NMR and 13C NMR spectra were recorded with a Bruker
FT-400 MHz spectrometer at room temperature and CDCl3 as a sol-
vent. The mass spectra were obtained with a GC-Mass Agilent,
4.3.1. Preparation of 1,1-bis(trimethylsilyl)-2-(2-naphthyl)ethene (1)
A white solid: Rf = 0.44 (n-hexane); Yield: 91%; m.p. 40–42 °C;
FT-IR (KBr cmꢀ1): 3051 (Ar–H), 1553, 1497 (C@C), 1248, 835 (Si–
CH3); 1H NMR (400 MHz, CDCl3): d ꢀ0.00 (s, 9H, SiMe3), 0.27 (s,
9H, SiMe3), 7.35–7.83 (m, 7H, Ar), 7.92 (s, 1H, vinyl); 13C NMR
(CDCl3): d ꢀ0.4 (SiMe3), 1.0 (SiMe3), 122.3–153.8 (Ar and C@C);
m/z (EI): 298 (50%, [M]+), 283 (64%, [MꢀMe]+), 209 (64%), 185
(100%), 73 (51%, [SiMe3]+). Anal. Calc. for C18H26Si2: C, 72.5; H,
8.7. Found: C, 72.1; H, 8.3%.
Table 4
The molar compositions of PCOR polymers.
Xa (%)
Ya (%)
m2 (%)
PCOCH
34
31
33
32
31
15
18
14
17
18
51
51
51
51
51
3
PCOC H5
2
PCOi-Pr
PCOi-Bu
PCOn-Pent
4.3.2. Preparation of 1,1-bis(trimethylsilyl)-2-(2-thiophenyl)ethene
(2)
a
A yellowish liquid: Rf = 0.32 (n-hexane); Yield: 69%; FT-IR (KBr
X is the mole fraction of
a-silyl-a,b-unsaturated enone in polymer and Y is that
cmꢀ1): 3073 (Ar–H), 1551, 1424 (C@C), 1252, 837 (Si–CH3); 1H
of the
a,b-unsaturated enone in polymer.

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K.D. Safa et al. / Journal of Organometallic Chemistry 694 (2009) 2448–2453
NMR (400 MHz, CDCl3): d ꢀ0.28 (s, 9H, SiMe3), ꢀ0.29 (s, 9H, SiMe3),
6.45, 6.80 (m, 3H, Ar), 7.1 (s, 1H, vinyl); 13C NMR (CDCl3): d ꢀ0.5
(SiMe3), 0.61 (SiMe3), 124.4–147.8 (Ar and C@C); m/z (EI): 254
(23%, [M]+), 239 (30%, [MꢀMe]+), 181 (36%, [MꢀSiMe3]+), 141
(100%), 73 (40%, [SiMe3]+). Anal. Calc. for C12H22Si2S: C, 71.7; H,
8.7. Found: C, 71.9; H, 8.3%.
m.p. 92 °C). 7a: FT-IR (KBr cmꢀ1), 3065 (Ar–H), 1674 (C@O),
1594, 1500 (Ar and C@C), 1249, 841 (Si–CH3); 1H NMR (400 MHz,
CDCl3): d 0.26 (s, 9H, SiMe3), 2.08 (s, 3H, CH3), 6.90-7.83 (m, 8H, vi-
nyl and Ar); 13C NMR (CDCl3): d ꢀ2.6 (SiMe3), 30.2 (CH3), 124.8–
149.7 (Ar and C@C), 215.6 (C@O); m/z (EI): 268 (42%, [M]+), 253
(100%, [MꢀMe]+), 179 (58%).
Compound 8a: FT-IR (KBr cmꢀ1), 3053 (Ar–H), 1667 (C@O),
1615, 1503 (Ar and C@C), 1244, 823 (Si–CH3); 1H NMR (400 MHz,
CDCl3): d 2.43 (s, 3H, CH3), 6.8 (d, 1H, J=16 Hz, ArHC@CH), 7.50-
7.69 (m, 8H, ArCH= CH and Ar); 13C NMR (CDCl3): d -2.6 (SiMe3),
30.2 (CH3), 124.8-149.7 (Ar and C@C), 209.6 (C@O); m/z (EI): 268
(42%, [M]+), 253 (100%, [MꢀMe]+), 179 (58%).
4.3.3. Preparation of 1,1-bis(trimethylsilyl)-2-[2-(5-
methyl)furyl]ethene (3)
A yellowish liquid: Rf = 0.40 (n-hexane); Yield: 52%; FT-IR (KBr
cmꢀ1): 2955 (Ar–H), 1559, 1483 (C@C), 1250, 841 (Si–CH3); 1H
NMR (400 MHz, CDCl3): d 0.17 (s, 9H, SiMe3), 0.18 (s, 9H, SiMe3),
2.34 (s, 3H, CH3), 6.00–6.22 (d, 2H, JHH = 3 Hz, Ar), 7.16 (s, 1H, vi-
nyl); 13C NMR (CDCl3): d ꢀ0.40 (SiMe3), 0.64 (SiMe3), 12.6 (CH3),
106.8–152.4 (Ar and C@C); m/z (EI): 252 (23%, [M]+), 237 (30%,
[MꢀMe]+), 179 (36%, [MꢀSiMe3]+), 139 (100%), 73 (40%, [SiMe3]+).
Anal. Calc. for C13H24OSi2: C, 61.7; H, 10.5. Found: C, 61.3; H, 10.2%.
4.4.2. Reaction of 1 with C2H5COCl
The reaction of 1 with 2b (0.31 g). TLC on silica gel (5:1 n-hex-
ane:diethyl ether as eluant) gave 7b (Rf = 0.55) and 8b (Rf = 0.19,
m.p. 78 °C). 7b: FT-IR (KBr cmꢀ1), 3056 (Ar–H), 1673 (C@O),
1592, 1504 (Ar and C@C), 1250, 839 (Si–CH3); 1H NMR (400 MHz,
3
4.3.4. Preparation of 1,1-bis(trimethylsilyl)-2-(3-pyridyl)ethene (4)
A yellowish liquid: Rf = 0.64 (2:1 n-hexane:ethyl acetate as elu-
ent); Yield: 70%; FT-IR (KBr cmꢀ1): 3030, 3078 (Ar–H), 1253, 832
(Si–CH3), 1551, 1470 (C@C); 1H NMR (400 MHz, CDCl3): d 0.08 (s,
9H, SiMe3), 0.16 (s, 9H, SiMe3), 7.17–8.45 (m, 5H, Ar and vinyl);
13C NMR (CDCl3): d ꢀ0.7 (SiMe3), 0.9 (SiMe3), 121.5ꢀ149.3 (Ar and
C@C); m/z (EI): 249 (38%, [M]+), 248 (75%, [MꢀH]+), 234 (100%,
[MꢀMe]+), 176 (27%, [MꢀSiMe3]+), 73 (64%, [SiMe3]+). Anal. Calc.
for C13H23NSi2: C, 62.7; H, 9.6; N, 5.6. Found: C, 62.2; H, 10; N, 5.4%.
CDCl3): d 0.31 (s, 9H, SiMe3), 1.02 (t, 3H, JHH = 7, CH3), 2.34–2.36
(q, 2H, CH2), 7.03–7.86 (m, 8H, vinyl and Ar); 13C NMR (CDCl3): d
ꢀ2.5 (SiMe3), 6.98 (CH3), 35.5 (CH2), 124.8–149.6 (Ar and C@C),
212.3 (C@O); m/z (EI): 282 (17%, [M]+), 267 (20%, [MꢀMe]+), 253
(100%, [MꢀEt]+), 73 (35%, [SiMe3]+).
Compound 8b: FT-IR (KBr cmꢀ1), 3051 (Ar–H), 1667 (C@O),
1618, 1503 (Ar and C@C); 1H NMR (400 MHz, CDCl3): d 1.20 (t,
3H, JHH = 7, CH3), 2.71–2.76 (q, 2H, CH2), 6.91 (d, 1H, J = 16 Hz,
ArHC@CH), 7.50–7.96 (m, 8H, ArC@CH and Ar); 13C NMR (CDCl3):
d 7.5 (CH3), 33.1 (CH2), 122.5–141.2 (Ar and C@C), 199.8 (C@O).
4.3.5. Preparation of 1,1-bis(trimethylsilyl)-2-(4-chloro)phenylethene
(5)
4.4.3. Reaction of 1 with i-C3H7COCl
A
colorless liquid: Rf = 0.48 (n-hexane); Yield: 74%; FT-IR
The reaction of 1 with 2c (0.36 g). TLC on silica gel (4:1 n-hex-
ane:diethyl ether as eluant) gave 7c (Rf = 0.64) and 8c (Rf = 0.36,
m.p. 86-88 °C). 7c: FT-IR (KBr cmꢀ1), 3056 (Ar–H), 1671 (C@O),
1588, 1504 (Ar and C@C), 1250, 841 (Si–CH3); 1H NMR (400 MHz,
(KBr cmꢀ1): 3027 (Ar–H), 1551, 1484 (C@C), 1251, 837 (Si–CH3),
927 (C–Cl); 1H NMR (400 MHz, CDCl3): d 0.01 (s, 9H, SiMe3), 0.23
(s, 9H, SiMe3), 7.1–7.3 (d, 4H, JHH = 8 Hz, Ar), 7.7 (s, 1H, vinyl);
13C NMR (CDCl3): d ꢀ0.5 (SiMe3), 1.0 (SiMe3), 126.9–152.3 (Ar
and C@C); m/z (EI): 267 (64%, [MꢀMe]+), 193 (60%, [MꢀPhꢀC]+),
169 (71%,), 73 (100%, [SiMe3]+). Anal. Calc. for C14H23ClSi2: C,
59.8; H, 8.4. Found: C, 59.2; H, 8.2%.
3
CDCl3): d 0.31 (s, 9H, SiMe3), 1.00 (d, 6H, JHH = 7, CH (CH3)2),
2.49–2.52 (m, 1H, CH(CH3)2), 7.17–7.86 (m, 8H, vinyl and Ar); 13C
NMR (CDCl3): d ꢀ1.9 (SiMe3), 17.7 (CH (CH3)2), 39.8 (CH(CH3)2),
125.1–149.1 (Ar and C@C), 215.1 (C@O); m/z (EI): 224 (22%,
[MꢀHCOCH(CH3)2]+), 181 (100%, [ArCH@CCOH]+), 152 (29%,
[ArCHC]+).
4.3.6. Preparation of 1,1-bis(trimethylsilyl)-2-(2,6-
dichloro)phenylethene (6)
8c: FT-IR (KBr cmꢀ1), 3058 (Ar–H), 1677 (C@O), 1603, 1462 (Ar
3
A
colorless liquid: Rf = 0.28 (n-hexane); Yield: 70%; FT-IR
and C@C); 1H NMR (400 MHz, CDCl3): d 1.22 (d, 6H, JHH = 7,
(KBr cmꢀ1): 3057 (Ar–H), 1600, 1427 (C@C), 1253, 840 (Si–CH3),
930 (C–Cl); 1H NMR (400 MHz, CDCl3): d ꢀ0.10 (s, 9H, SiMe3),
0.25 (s, 9H, SiMe3), 7.1–7.3 (m, 4H, vinyl and Ar), 13C NMR (CDCl3):
CH(CH3)2), 2.96–3.00 (m, 1H, CH(CH3)2), 6.94 (s, 1H, ArHC@CH),
7.50–7.96 (m, 8H, Ar and ArHC@CH); 13C NMR (CDCl3): d 17.5
(CH(CH3)2), 38.3 (CH(CH3)2), 122.5–141.4 (Ar and C@C), 202.8
(C@O).
d
ꢀ0.6 (SiMe3), ꢀ0.5 (SiMe3), 126.4–149.2 (Ar and C@C); m/z (EI):
301 (100%, [MꢀMe]+), 227 (56%, [MꢀPhꢀC]+), 73 (72%, [SiMe3]+).
Anal. Calc. for C14H22Cl2Si2: C, 52.6; H, 6.5. Found: C, 52.4; H, 6.9%.
4.4.4. Reaction of 1 with i-C4H9COCl
The reaction of 1 with 2d (0.41 g). TLC on silica gel (8:1 n-hex-
ane:diethyl ether as eluant) gave 7d (Rf = 0.56) and 8d (Rf = 0.21).
Compound 7d: FT-IR (KBr cmꢀ1), 3056 (Ar–H), 1675 (C@O), 1589,
1505 (Ar and C@C), 1249, 841 (Si–CH3); 1H NMR (400 MHz, CDCl3):
4.4. General procedure for Friedel–Crafts reactions using 1,1-
bis(trimethylsilyl)-2-(2-naphthyl)ethene as a precursor
3
A
solution of 1,1-bis(trimethylsilyl)-2-(2-naphthyl)ethene
d 0.28 (s, 9H, SiMe3), 0.81 (d, 6H, JHH = 6 Hz, CH(CH3)2), 2.11–2.19
3
(1.0 g, 3.7 mmol) in dry CH2Cl2 (20 ml) was added during 15 min
at 0 °C under argon to a stirred solution of anhydrous aluminum
trichloride (7.1 g, 15.3 mequiv.) in dry CH2Cl2 (30 ml) containing
acyl chloride (3.36 mmol), and the mixture was stirred at 0 °C for
a further 105 min. The reaction mixture was poured into water
(50 ml) and extracted twice with 50 ml of ether. The combined or-
ganic layers were dried (Na2SO4) and filtered. The solvent was
evaporated and the residue was then purified by preparative TLC
(silica gel) to give the products.
(m, 1H, CH2CH(CH3)2), 2.22 (d, 2H, JHH = 6 Hz, COCH2CH(CH3)2),
6.98–7.90 (m, 8H, vinyl and Ar); 13C NMR (CDCl3): d ꢀ2.4 (SiMe3),
21.6 (CH(CH3)2), 22.4 (CH(CH3)2), 50.7 (CH2CH(CH3)2), 125.1–149.7
(Ar and C@C), 210.7 (C@O); m/z (EI): 310 (64%, [M]+), 295 (73%,
[MꢀMe]+), 267 (87%, [MꢀCH(CH3)2]+), 253 (100%, [MꢀCH2CH-
(CH3)2]+), 73 (59%, [SiMe3]+).
Compound 8d: FT-IR (KBr cmꢀ1), 3056 (Ar–H), 1687 (C@O),
1605, 1464 (Ar and C@C); 1H NMR (400 MHz, CDCl3): d 1.02 (d,
3
6H, JHH = 6 Hz, CH(CH3)2), 2.24-2.34 (m, 1H, CH2CH(CH3)2), 2.58
3
(d, 2H, JHH = 6 Hz, COCH2CH(CH3)2), 6.86 (s, 1H, ArHC@CH),
4.4.1. Reaction of 1 with CH3COCl
The reaction of 1 with 2a (0.27 g). TLC on silica gel (7:2 n-hex-
ane:diethyl ether as eluant) gave 7a (Rf = 0.25) and 8a (Rf = 0.27,
7.46–7.94 (m, 8H, Ar and ArCH@CH); 13C NMR (CDCl3): d 21.7
(CH(CH3)2), 24.2 (CH(CH3)2), 48.9 (CH2CH(CH3)2), 122.4–153.7 (Ar
and C@C), 199.1 (C@O).

K.D. Safa et al. / Journal of Organometallic Chemistry 694 (2009) 2448–2453
2453
4.4.5. Reaction of 1 with n-C5H11COCl
2.26 (m, Aliphatic), 1.26 (t, CH3), 2.69 (CH2), 6.69-7.96 (m,
Aromatic).
The reaction of 1 with 2e (0.47 g). TLC on silica gel (4:1 n-hex-
ane:diethyl ether as eluant) gave 7e (Rf = 0. 64) and 8e (Rf = 0.45).
Compound 7e: FT-IR (KBr cmꢀ1), 3056 (Ar–H), 1675 (C@O), 1591,
1460 (Ar and C@C), 1249, 843 (Si–CH3); 1H NMR (400 MHz, CDCl3):
4.6.3. Reaction of PSi with i-C3H7COCl
FT-IR (KBr cmꢀ1), 3054 (Ar–H), 1688, 1605 (C@O), 1251, 835
(Si–CH3); 1H NMR (400 MHz, CDCl3): d 0.10 (s, SiMe3), 1.25–2.36
(m, Aliphatic, CH(CH3)2), 2.92 (m, CH(CH3)2), 6.76-7.82 (m,
Aromatic).
3
d 0.31 (s, 9H, SiMe3), 0.80 (t, 3H, JHH = 7 Hz, CH2CH3), 1.11–1.21
(m, 4H, CH2CH2CH3), 1.53–1.60 (m, 2H, COCH2CH2CH2), 2.33 (t,
3
2H, JHH = 8 Hz, COCH2CH2), 7.03–7.86 (m, 8H, vinyl and Ar); 13C
NMR (CDCl3): d ꢀ2.4 (SiMe3), 12.8 (CH2CH3), 21.5 (CH2CH3), 22.3
(CH2CH2CH3), 30.2 (COCH2CH2CH2), 42.2 (COCH2), 124.9–149.7
(Ar and C@C), 211.6 (C@O); m/z (EI): 281 (37%, [Mꢀ(CH2)2CH3)]+),
267 (100%, [Mꢀ(CH2)3CH3)+]), 253 (66%, [Mꢀ(CH2)4CH3]+), 73
(34%, [SiMe3]+).
4.6.4. Reaction of PSi with i-C4H9COCl
FT-IR (KBr cmꢀ1), 3026 (Ar–H), 1686, 1657 (C@O), 1251, 843
(Si–CH3); 1H NMR (400 MHz, CDCl3): d 0.10 (s, SiMe3), 1.31–2.82
(m, Aliphatic, CH(CH3)2), CH2CH(CH3)2), COCH2CH(CH3)2), 6.99–
7.26 (m, Aromatic).
8e: FT-IR (KBr cmꢀ1), 3055 (Ar–H), 1685 (C@O), 1613, 1460 (Ar and
C@C); 1H NMR (400 MHz, CDCl3): d 0.98 (t, 3H, 3JHH = 7 Hz, CH2CH3),
1.39–1.42 (m, 4H, CH2CH2CH3), 1.74, 178 (m, 2H, COCH2CH2CH2),
4.6.5. Reaction of PSi with n-C5H11COCl
3
2.72 (t, 2H, JHH = 8 Hz, COCH2CH2), 6.89 (s, 1H, ArHC@CH), 7.54–
FT-IR (KBr cmꢀ1), 3024 (Ar–H), 1687, 1663 (C@O), 1250, 840
(Si–CH3); 1H NMR (400 MHz, CDCl3): d 0.12 (s, SiMe3), 1.28–2.97
(m, Aliphatic, n-C5H11), 6.99–7.95 (m, Aromatic).
7.97 (m, 8H, Ar and ArCH@CH); 13C NMR (CDCl3): d 12.9 (CH2CH3),
21.5 (CH2CH3), 22.0 (CH2CH2CH3), 30.5 (COCH2CH2CH2), 39.9 (COCH2),
122.4-153.7 (Ar and C@C), 199.6 (C@O).
Acknowledgment
4.5. Preparation of polymer bearing 1,1-bis(silyl)-1-alkene side chains
(PSi)
This work has been supported by the Research Institute for Fun-
damental Sciences, Tabriz, Iran.
(Me3Si)3CLi (15.8 mmol) was added dropwise with stirring to
solutions of copolymers PCHO (15.8 mmol) in THF at room tempera-
ture. The reaction was quenched by adding a small amount of acidic
methanol after 2 h and the reaction mixture was poured into cooled
acidic methanol to precipitate the polymer PSi. FT-IR (KBr cmꢀ1),
3025 (Ar–H), 1251, 837 (Si–CH3); 1H NMR (400 MHz, CDCl3): d
0.08 (s, SiMe3), 1.25–2.20 (m, Aliphatic), 6.50–7.72 (m, Aromatic).
References
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precursor
A solution of polymer (1.0 g, 3.4 mmol) in dry CH2Cl2 (20 ml)
was added during 15 min at 0 °C under argon to a stirred solution
of anhydrous aluminum trichloride (7.1 g, 15.3 mequiv.) in dry
CH2Cl2 (30 ml) containing acyl chloride (3.36 mmol), and the mix-
ture was stirred at 0 °C for a further 105 min. The reaction mixture
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´
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4.6.1. Reaction of PSi with MeCOCl
FT-IR (KBr cmꢀ1), 3054 (Ar–H), 1672, 1667 (C@O), 1255, 840
(Si–CH3); 1H NMR (400 MHz, CDCl3): d 0.09 (s, SiMe3), 1.23–2.22
(m, Aliphatic), 2.35 (s, COCH3), 6.65–7.86 (m, Aromatic).
4.6.2. Reaction of PSi with EtCOCl
FT-IR (KBr cmꢀ1), 3023 (Ar–H), 1670, 1663 (C@O), 1251, 834
(Si–CH3); 1H NMR (400 MHz, CDCl3): d 0.11 (s, SiMe3), 1.30–