Air-initiated hydrosilylation of unactivated alkynes and alkenes and dehalogenation of halohydrocarbons by tris(trimethylsilyl)silane under solvent-free conditions

Article abstract of DOI:10.1016/j.jorganchem.2008.03.019

A highly efficient air-initiated hydrosilylation of unactivated alkynes and alkenes and dehalogenation of halohydrocarbons with tris(trimethylsilyl)silane ((TMS)₃SiH) as a reducing agent has been established under solvent-free conditions. These observations demonstrate that the potential and versatility of air to function as a competent initiator for Si-H bond activations. It can rival organic initiators and metal catalysts in its efficiency and is a superior initiating system from economic, environmentally sound and practical perspectives.

Full text of DOI:10.1016/j.jorganchem.2008.03.019

Journal of Organometallic Chemistry 693 (2008) 2188–2192
Contents lists available at ScienceDirect
Journal of Organometallic Chemistry
journal homepage: www.elsevier.com/locate/jorganchem
Air-initiated hydrosilylation of unactivated alkynes and alkenes
and dehalogenation of halohydrocarbons by tris(trimethylsilyl)silane
under solvent-free conditions
Jialiang Wang a, Zhenyu Zhu a, Wen Huang a, Mingli Deng a, Xigeng Zhou a,b,
*
a Department of Chemistry, Shanghai Key Laboratory of Molecular Catalysis and Innovative Material, Fudan University, Shanghai 200433, People’s Republic of China
b State Key Laboratory of Organometallic Chemistry, Shanghai 200032, People’s Republic of China
a r t i c l e i n f o
a b s t r a c t
Article history:
A highly efficient air-initiated hydrosilylation of unactivated alkynes and alkenes and dehalogenation of
halohydrocarbons with tris(trimethylsilyl)silane ((TMS)3SiH) as a reducing agent has been established
under solvent-free conditions. These observations demonstrate that the potential and versatility of air
to function as a competent initiator for Si–H bond activations. It can rival organic initiators and metal cat-
alysts in its efficiency and is a superior initiating system from economic, environmentally sound and
practical perspectives.
Received 18 December 2007
Received in revised form 8 March 2008
Accepted 21 March 2008
Available online 28 March 2008
Keywords:
Air
Ó 2008 Elsevier B.V. All rights reserved.
Hydrosilylation
Dehalogenation
Solvent-free
Radical reaction
1. Introduction
and cleaner methods to activate the Si–H bonds under mild
conditions.
The addition of Si–H bond to alkynes is one of the most impor-
tant reactions for the preparation of the corresponding vinyl
silanes, which are versatile building blocks in organic synthesis
[1]. On the other hand, from the various procedures and reagents
that have been developed for reductive dehalogenation, the silanes
also represent an important family due to their low toxicity, fewer
by-products and compatibility with a wide range of solvents [2].
Nevertheless, silanes are known to be the poor reducing agents,
due to their low ability to donate hydrogen atoms or hydrides
[3]. In general, the Si–H bond needs to be activated by organome-
tallic complexes [4], radical initiators [5] or irradiation [6] in these
processes. Although quite efficient, organometallic complexes are
usually expensive and/or water-sensitive while organic radical
initiators generally require the elevated temperature [7]. Further-
more, in the two cases, especially for metal-based catalytic system,
a use of organic solvents is generally necessary. The concerns of
environment-pollution due to the extensive use of volatile organic
solvents and metal-containing reagents calls for more convenient
A simple and cheap approach to making the silyl radical reac-
tion process environmentally clean/green would be carried out in
the absence of any solvent, using a clean initiator instead of the
organic initiators, preferably using ubiquitously molecular oxygen
for favorable process economics. Although silanes have been
known to undergo oxidation reactions with O2 via an radical mech-
anism at least since 1992 [8], to our surprise, relatively little effort
has been devoted to the development of the reactions as an effec-
tive initiating system for silyl radical reactions. Only recently, a few
successful examples of air-induced hydrosilylation of activated
alkenes and alkynes were reported [9]. Compared with traditional
methods for activation of Si–H bonds, these reactions are cleaner,
simpler, and more economic without the need of organic radical
initiators or metal complex catalysts. However, attempts to extend
the strategy to simple alkenes and alkynes were unsuccessful [9a].
Very recently, during our research into initiating silyl radical reac-
tions by lanthanide metals [10], we accidentally observed that a
small amount of air (dioxygen) could induce the addition of
(TMS)3SiH to phenylacetylene to give the corresponding anti-
Markovnikov hydrosilylation product in a good yield. To probe
the scope of air-induced silyl radical reactions and to understand
factors controlling required selectivity and mildening reaction con-
ditions, in this paper we present an extension of air-initiated
hydrosilylation to unactivated alkynes and alkenes. Furthermore,
* Corresponding author. Address: Department of Chemistry, Shanghai Key
Laboratory of Molecular Catalysis and Innovative Material, Fudan University,
Shanghai 200433, People’s Republic of China. Tel.: +86 21 6564 3769; fax: +86 21
6564 1740.
E-mail address: xgzhou@fudan.edu.cn (X. Zhou).
0022-328X/$ - see front matter Ó 2008 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2008.03.019

J. Wang et al. / Journal of Organometallic Chemistry 693 (2008) 2188–2192
2189
we found that air is also an efficient initiator for radical dehalogen-
ation of halohydrocarbons using (TMS)3SiH.
observation [13]. The presence of cyclohexenyl did not interfere
with the outcome of the reaction of alkyne (Table 2, entry 5),
although the sole C–C double bond has been found to be reactive
to (TMS)3SiH under the similar conditions (vide infra). However,
the aliphatic alkynes, bearing ether groups, reacted sluggishly
and gave the desired products in moderate to good yields (Table
2, entries 6 and 7). The selective hydrosilylation of propargylic
alcohols in a general sense was a challenging problem due to the
competitive formation of the endo-dig cyclization products [14].
Significantly, in the present case C6H5CH(OH)C„CH reacted with
(TMS)3SiH to give the highly selective hydrosilylation product
albeit moderate yield (Table 2, entry 8). Furthermore, treatment
of 1,6-heptadiyne with 1 equiv. of (TMS)3SiH also gave the selec-
tive mono-hydrosilylation product in respectable yield (Table 2,
entry 11).
These successful results encouraged us to extend the method to
the hydrosilylation of unactivated alkenes. Table 3 summarizes the
results. Similar to those described for the hydrosilylation of
alkynes, the reaction of (TMS)3SiH with unactivated alkenes was
also markedly promoted by a catalytic amount of air under mild
conditions to give the corresponding anti-Markovnikov addition
products in moderate to good yields (Table 3). The electron-with-
drawing or electron-donating substituent in benzene ring seems
to have little effect in the yields (Table 3, entries 1, 5 and 6). It is
worth mentioning that both the use of a slight excess of (TMS)3SiH
(1.1 equiv.) and the control of the catalytic amount of air are the
keys to the success of these hydrosilylation reactions to prevent
the oligomerization of alkynes/alkenes and the formation of
siloxane.
2. Results and discussion
Phenylacetylene was used as model substrate to optimize the
reaction conditions. As shown in Table 1, under pure argon atmo-
sphere (using standard Schlenk technique), the reaction between
phenylacetylene and (TMS)3SiH in THF did not take place even at
60 °C for 48 h (Table 1, entry 1). When 2.0 mL air was introduced
into the vial, the hydrosilylation product was obtained in 87% yield
at ambient temperature for 2 h (Table 1, entry 2). However, when
the reaction was carried out under air atmosphere (Table 1, entries
3 and 4), the yield of the addition product was low due to the
predominant formation of (Me3SiO)2SiHSiMe3 [8,11], indicating
that the ratio of reagents, particularly air/silane, is important for
the reaction. In addition, we examined the effect of solvents, H2O
was found to be an effective solvent for this transformation despite
not being substrates-soluble (Table 1, entry 6) [12]. But the reac-
tion proceeded more quickly under solvent-free conditions and
afforded Z-isomer in the highest yield (Table 1, entry 7). Signifi-
cantly, the selectivity and yield obtained in the present system
are comparable to those observed in the Et3B/O2 initiating system,
and no solvent is needed [13]. To the best of our knowledge, only a
few reports are available about solvent-free silyl radical reactions
in the literature [9]. Among various silanes examined, (EtO)3SiH,
Et3SiH and Ph2MeSiH are inefficient substrates even with
prolonged heating (Table 1, entries 13–15).
To explore the generality of this reaction, we then tested the
hydrosilylation of various alkynes under optimum reaction condi-
tions. The results are summarized in Table 2. All reactions gave
anti-Markovnikov addition products in moderate to excellent
yields. The reactivity of alkynes is controlled by the nature of the
substituents. Aromatic acetylenes undergo most readily the hydro-
silylation to give the Z-isomers in high yields and with excellent
regio- and stereoselectivity, whereas straight chain alkyl groups
seem to negatively effect the percentage distribution of isomers
(Table 2, entries 9 and 10). This is consist with the previously
It is well-known that tris(trimethylsily1)silane can function as a
free radical reducing agent for organic halides. However, the reac-
tions generally need to be initiated by UV photolysis or by the ther-
mal decomposition of organic initiators in the presence of solvents
[15]. To further explore the scope and limitations of the air-in-
duced silyl radical reactions, we then turned our attention to the
reaction of (TMS)3SiH with a variety of organic halides. Several sol-
vents and conditions were tried and we have found that optimum
results were obtained by using 1–2 mol% of O2 based on halides. As
Table 1
Hydrosilylation of phenylacetylene under different conditionsa
Ph
Ph
SiR3
+
Ph
+ R3SiH
SiR3
E
Z
Entry
Silane
Additive
Solvent
T (°C)
Time (h)
Yieldb (%)
Z/Ec
1
2
(Me3Si)3SiH
(Me3Si)3SiH
(Me3Si)3SiH
(Me3Si)3SiH
(Me3Si)3SiH
(Me3Si)3SiH
(Me3Si)3SiH
(Me3Si)3SiH
(Me3Si)3SiH
(Me3Si)3SiH
(Me3Si)3SiH
(Me3Si)3SiH
(EtO)3SiH
–
THF
THF
THF
THF
Toluene
H2O
Solvent-free
Solvent-free
Solvent-free
Solvent-free
Solvent-free
Solvent-free
Solvent-free
Solvent-free
Solvent-free
60
r.t.
70
r.t.
r.t.
r.t.
r.t.
0
r.t.
r.t.
r.t.
r.t.
60
60
60
48
2
48
2
2
1
0.5
1
1
0.5
0.5
0.5
12
12
12
NR
87
24
40
86
86
93
82
79
71
89
65
NR
NR
NR
–
air (2 mL)
–
–
98/2
98/2
98/2
98/2
98/2
99/1
98/2
98/2
98/2
98/2
98/2
–
3d
4d
5
Air (2 mL)
Air (2 mL)
Air (2 mL)
Air (2 mL)
Air (0.5 mL)
Air (8 mL)
Dioxygen (0.5 mL)
Dioxygen (8 mL)
Air (2 mL)
6
7
8
9
10
11
12
13
14
15
Et3SiH
Ph2MeSiH
Air (2 mL)
Air (2 mL)
–
–
a
Reaction conditions: phenylacetylene (1.0 mmol), silane (1.1 mmol), solvent (2 mL) in argon atmosphere.
Isolated yield.
Determined by GC–MS.
In air atmosphere.
b
c
d

2190
J. Wang et al. / Journal of Organometallic Chemistry 693 (2008) 2188–2192
Table 2
Table 4
Air-initiated addition of (TMS)3SiH to terminal alkynesa
Air-initiated dehalogenation of halohydrocarbonsa
Si(TMS)3
argon/air
sovlent-free
argon/air
sovlent-free
R
+
+
(TMS)3SiH
R
Si(TMS)3
RX + (TMS)3SiH
RH
R
Z
E
Entry
RX
GC-yield (%)
Entry
R
Time (h)
Yield (%)b
Z/Ec
1
CH3(CH2)9Br
87
0
2b
3c
4
CH3(CH2)9Br
CH3(CH2)9Br
CH3(CH2)5Br
CH3(CH2)11Br
PhCH2Br
1
2
3
4
C6H5
p-MeC6H4
0.5
1
1
1
3
6
6
6
2
93
91
90
90
86
80
65
55
83
86
75
99/1
99/1
99/1
99/1
99/1
82/18
99/1
99/1
82/18
70/30
98/2
26
81
89
91
49
76
p-F, m-MeC6H3
p-amylC6H4
1-Cyclohexenyl
p-tBuC6H4OCH2
C6H5CH2OCH2
C6H5CH(OH)
CH3(CH2)4CH2
CH3CH2CH2CH2
HCCCH2CH2CH2
5
6
7
8
5
PhBr
BrCH2COOCH2CH3
6d
7d
8d
9
O
O
Br
9
80
10
2
6
11d
Br
a
Reaction conditions: alkyne (1.0 mmol), (TMS)3SiH (1.1 mmol) and air (2 mL) in
argon atmosphere at room temperature.
10
86
b
O
Isolated yield.
Determined by GC–MS.
The reaction was carried out at 60 °C.
c
11
12d
13
14
15
PhI
85
84
55
36
<5
d
PhI
PhCH2Cl
Chlorocyclohexane
PhCl
a
Reaction conditions: halohydrocarbon (1.0 mmol), (TMS)3SiH (1.1 mmol) and
Table 3
air (2.0 mL) in argon atmosphere at 60 °C for 6 h.
Air-initiated addition of (TMS)3SiH to alkenesa
b
The reaction was carried out under pure argon.
The reaction was carried out under air without sealing the vial.
c
R1
R2
R1
R2
Si(TMS)3
argon/air
sovlent-free
d
H2O as solvent.
+ (TMS)3SiH
Entry
Alkenes
Time (h)
Isolated yield (%)b
1
Styrene
Styrene
Styrene
a-Methylstyrene
p-Methylstyrene
p-Fluorostyrene
1-Decene
2
2
2
6
4
4
6
6
79
76
0
74
73
76
75
77
Br
argon/air
2c
3d
4
+
+
+
60 οC 6 h
sovlent-free
(TMS)3SiH
90%
6%
2%
5
6
7
8
Scheme 1.
Allyl phenyl ether
a
Reaction conditions: alkene (1.0 mmol), (TMS)3SiH (1.1 mmol) and air (2.0 mL)
in argon atmosphere at 60 °C.
cates that the present dehalogenation reaction proceeded via a
radical chain pathway (Scheme 1).
b
Isolated yield.
H2O as solvent.
The reaction was carried out under pure argon.
c
d
Chatgilialoglu has demonstrated that reaction of (TMS)3SiH
with adventitious dioxygen could lead to the generation of
(TMS)3SiÁ radical [8,11]. Based on the results described above, these
reactions were considered to proceed by a radical mechanism. The
initiation step included an autoxygenation reaction of (TMS)3SiH
by in situ dioxygen and a hydrogen abstraction reaction to gener-
ate a silyl radical. The air-induced radical mechanism is supported
by the two facts that all the reactions are retarded by addition of a
radical inhibitor, such as 1,4-benzoquinone, and that no reactions
take place under pure argon.
shown in Table 4, the reaction is general for different organic
halides, and in most cases gives the corresponding dehalogenated
products in moderate to excellent yields. Generally, chlorides, bro-
mides, and iodides tend to display an increasing reactivity in the
order of RCl < RBr < RI, which may be envisaged from their overall
behavior in Table 4 (Table 4, entries 7, 11 and 15). And for a partic-
ular halogen atom, aryl halides were less reactive toward
(TMS)3SiH than alkyl halides (Table 4, entries
5
and 7).
3. Conclusion
A (TMS)3SiH/O2-promoted coupling reaction of aryl iodides with
arenes was recently reported [16]. However, in that case O2 is stoi-
chiometric as a H-acceptor and plays a different role. All these
demonstrate the potential of diverse applications of silanes/dioxy-
gen system in organic synthesis. Significantly, the presence of func-
tionalities such as ester or ether groups in the starting materials
did not interfere with the outcome of the reaction (Table 4, entries
8–10). The results represent the first example of air-induced
dehalogenatation under solvent-free condition.
To explore the scope, we also examined the reaction of 6-bro-
mo-1-hexene. As expected, this reaction gave the methylcyclopen-
tane as the major product together with a small amount of
cyclohexane and simple reduction product [17]. This further indi-
We have demonstrated that air is also a highly promising initi-
ator for the solvent-free hydrosilylation of unactivated alkynes and
alkenes as well as the solvent-free dehalogenation of halohydro-
cans by (TMS)3SiH with their good selectivity and yields. These
reactions are clean, simple, economic, highly efficient, and environ-
mentally friendly, as just the addition of a catalytic amount of air is
required, which avoids the need for a special workup procedure
and makes this method compatible with sensitive, highly function-
alized molecules. The results obtained in this work should provide
useful data for the design of new silyl radical chain reactions in
organic synthesis. Further development on this methodology is
currently under way in our laboratory.

J. Wang et al. / Journal of Organometallic Chemistry 693 (2008) 2188–2192
2191
9H), 0.15 (s, 27H). GC/MS m/z: 436 (M+), 174 ((TMS)2Si)+, 73
4. Experimental
(TMS)+.
All silanes, alkynes and alkenes were purchased from Aldrich.
The 1H NMR spectra were recorded in CDCl3 on a Bruker AV 400
(400 MHz for 1H) spectrometer. 13C NMR spectra were recorded
in CDCl3 on a Bruker AV 400 (100 MHz for 13C) with TMS as the
internal standard with complete decoupling. Chemical shifts are
reported in ppm, and J values are given in Hz. GC–MS were
obtained on a Hewlett–Packard 6890/5973 instrument.
4.7. (Z)-3-Benzyloxyl-1-[tris(trimethylsilyl)]-1-propene
1H NMR (CDCl3, 400 MHz) d 7.30–7.40 (m, 5H), 6.54–6.61 (m,
1H), 5.80 (d, 1H, J = 13.6 Hz), 4.54 (s, 2H), 4.04 (d, 2H, J = 6.3 Hz),
0.14 (s, 27H). 13C NMR (CDCl3, 100 MHz) d 144.78, 138.89,
128.55, 128.50, 128.22, 124.55, 72.99, 71.63, 0.94. GC/MS m/z:
321 (M+À73), 73 (TMS)+.
4.1. General procedure for the addition of (TMS)3SiH to alkynes
4.8. (Z)-1-Phenyl-3-[tris(trimethylsilyl)]allyl alcohol
To a 10 mL vial was added alkynes (1.0 mmol) and (TMS)3SiH
(1.1 mmol) under argon, then 2 mL air was introduced into the
vial via syringe. The vial was sealed, and then the mixture was
stirred at the corresponding temperature for 0.5–6 h. After com-
pletion of the reaction (monitored by TLC), the reaction of mix-
ture was purified by flash chromatographed on silica gel using
hexane/ethyl acetate as the eluent. All products were identified
by comparison of their 1H NMR and MS spectra with those of
authentic samples [13], or showed satisfactory analytical data
and expected spectra.
1H NMR (CDCl3, 400 MHz) d 7.30–7.40 (m, 5H), 6.55–6.60
(m, 1H), 5.90 (d, 1H, J = 13.3 Hz), 5.16 (d, 1H, J = 9.2 Hz), 1.74 (br
1H), 0.13 (s, 27H). 13C NMR (CDCl3, 100 MHz) d 148.17, 142.85,
130.04, 128.66, 126.67, 124.57, 67.54, 1.53. GC/MS m/z: 378
(M+À2), 174 ((TMS)2Si)+, 73 (TMS)+.
4.9. (Z)-1-[Tris(trimethylsilyl)silyl]-1-heptene-6-yne
1H NMR (CDCl3, 400 MHz) d 6.34-6.40 (m, 1H), 5.54 (d, 1H,
J = 12.8 Hz), 2.20-2.26 (m, 4H), 1.93 (t, 1H, J = 2.7 Hz), 1.60–1.65
(m, 2H), 0.14 (s, 27H). 13C NMR (CDCl3, 100 MHz) d 148.06,
121.26, 82.24, 68.17, 34.58, 28.22, 18.51, 1.30. GC/MS m/z: 340
(M+), 267 (M+À73), 174 ((TMS)2Si)+, 73 (TMS)+.
4.2. (Z)-1-(p-Tolyl)-2-[tris(trimethylsilyl)silyl]ethene
1H NMR (CDCl3, 400 MHz) d 7.37 (d, 1H, J = 14.5 Hz), 7.22 (d,
2H), 7.08 (d, 2H), 5.82 (d, 1H, J = 14.5 Hz), 2.30 (s, 3H), 0.12 (s,
4.10. General procedure for the addition of (TMS)3SiH to alkenes
27H). 13C NMR (CDCl3, 100 MHz)
d 146.63, 137.80, 132.16,
129.17, 128.09, 123.06, 21.38, 1.41. GC–MS m/z: 364 (M+), 174
To a 10 mL vial was added alkenes (1.0 mmol) and (TMS)3SiH
(1.1 mmol) under argon, then 2 mL air was introduced into the vial
via syringe. The vial was sealed, and then the mixture was stirred
at 60 °C for 2–6 h. After the completion of the reaction (monitored
by TLC), the reaction of mixture was purified by flash chromatog-
raphy on silica gel using hexane/ethyl acetate as the eluent.
((TMS)2Si)+, 73 (TMS)+.
4.3. (Z)-1-(4-Fluoro-3-methylphenyl)-2-[tris(trimethylsilyl)silyl]ethene
1H NMR (CDCl3, 400 MHz) d 7.32 (d, 1H, J = 14.5 Hz), 7.14
(s, 1H), 6.93–7.08 (m, 2H), 5.83 (d, 1H, J = 14.5 Hz), 2.27 (s, 3H),
0.12 (s, 27H). 13C NMR (CDCl3, 100 MHz) d 162.03, 159.57,
145.78, 136.70, 131.20, 126.87, 124.67, 123.97, 114.84, 14.64,
1.36. GC/MS m/z: 382 (M+), 174 ((TMS)2Si)+, 73(TMS)+.
4.11. 1-(p-Tolyl)-2-[tris(trimethylsilyl)silyl]ethane
1H NMR (CDCl3, 400 MHz) d 6.92–7.12 (m, 4H), 2.62–2.66
(m, 2H), 2.34 (s, 3H), 1.06–1.10 (m, 2H), 0.21 (s, 27H). 13C NMR
(CDCl3, 100 MHz) d 129.21, 129.00, 127.56, 127.31, 35.19, 21.20,
10.92, 1.45. GC/MS m/z: 366 (M+), 174 ((TMS)2Si)+, 73 (TMS)+.
4.4. (Z)-1-(p-Amylphenyl)-2-[tris(trimethylsilyl)silyl]ethene
1H NMR (CDCl3, 400 MHz) d 7.46 (d, 1H, J = 14.2 Hz), 7.30 (d, 2H,
J = 7.32 Hz), 7.16 (d, 2H, J = 7.32 Hz), 5.90 (d, 1H, J = 14.2 Hz), 2.64 (t,
J = 7.56 Hz, 2H), 1.60–1.69 (m, 2H), 1.30–1.38 (m, 4H), 0.94 (t,
J = 7.32 Hz, 3H), 0.12 (s, 27H). 13C NMR (CDCl3, 100 MHz) d 146.72,
142.14, 138.22, 128.50, 128.03, 123.30, 35.82, 31.49, 31.36, 22.71,
14.22, 1.42. GC/MS m/z: 420 (M+), 174 ((TMS)2Si)+, 73 (TMS)+.
4.12. 1-(p-Fluorophenyl)-2-[tris(trimethylsilyl)silyl]ethane
1H NMR (CDCl3, 400 MHz) d 7.12–7.14 (m, 2H), 6.95–6.98
(m, 2H), 2.64–2.67 (m, 2H), 1.07–1.11 (m, 2H), 0.24 (s, 27H). 13C
NMR (CDCl3, 100 MHz) d 162.35, 128.98, 128.91, 115.25, 34.77,
10.88, 1.38. GC/MS m/z: 370 (M+), 174 ((TMS)2Si)+, 73 (TMS)+.
4.5. (Z)-1-(1-Cyclohexenyl)-2-[tris(trimethylsilyl)silyl]ethene
4.13. Phenyl 3-[tris(trimethylsilyl)]propyl ether
1H NMR (CDCl3, 400 MHz) d 6.67 (d, 1H, J = 14.3 Hz), 5.74 (t,
1H), 5.40 (d, 1H, J = 14.3 Hz), 2.07–2.13 (m, 4H), 1.58–1.68 (m,
4H), 0.17 (s, 27H). 13C NMR (CDCl3, 100 MHz) d 149.42, 138.92,
124.95, 118.61, 28.47, 25.38, 22.61, 22.13, 1.33. GC/MS m/z: 354
(M+), 174 ((TMS)2Si)+, 73(TMS)+.
1H NMR (CDCl3, 400 MHz) d 7.24–7.27 (m, 2H), 6.85–6.92
(m, 3H), 3.89 (t, 2H, J = 6.8 Hz,), 1.83–1.87 (m, 2H), 0.86–0.90
(m, 2H), 0.15 (s, 27H). 13C NMR (CDCl3, 100 MHz) d 159.18,
129.51, 120.57, 114.63, 70.70, 28.82, 3.69, 1.30. GC/MS m/z: 382
(M+), 315 (M+À73), 174 ((TMS)2Si)+, 73 (TMS)+.
4.6. 1-[Tris(trimethylsilyl)]allyl 4-tbutylphenyl ether
4.14. General procedure for the dehalogenation of halohydrocarbons
by (TMS)3SiH
1H NMR (CDCl3, 400 MHz) Z-isomer d 7.35 (d, 2H, J = 8.7 Hz),
6.90 (d, 2H, J = 8.7 Hz), 6.73–6.78 (m, 1H), 5.98 (d, 1H,
J = 13.3 Hz), 4.55 (d, 2H, J = 6.4 Hz), 1.36 (s, 9H), 0.15 (s, 27H). E-
isomer d 7.35 (d, 2H, J = 8.7 Hz), 6.90 (d, 2H, J = 8.7 Hz), 6.53–6.61
(m, 1H), 5.70 (d, 1H, J = 18.3 Hz), 4.76 (d, 2H, J = 6.3 Hz), 1.36 (s,
To a 10 mL vial was added halohydrocarbons and (TMS)3SiH un-
der argon, then 2 mL air was introduced into the vial via syringe.
The vial was sealed and heated at 60 °C for 6 h and then analyzed

2192
J. Wang et al. / Journal of Organometallic Chemistry 693 (2008) 2188–2192
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This work is supported by the NNSF of China, NSF of Shanghai
and Shanghai Leading Academic Discipline Project for financial
support (B108).
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