A highly efficient method for the silylation of alcohols, phenols, and naphthols using HMDS in the presence of zinc oxide (ZnO) as economical heterogeneous catalyst

Article abstract of DOI:10.1080/10426500701569406

Variety alcohols, phenols, and naphthols were effectively converted into their corresponding trimethylsilyl ether with hexamethyldisilazane in the presence of zinc oxide under very mild and ambient conditions with short reaction time in good to excellent yields.

Full text of DOI:10.1080/10426500701569406

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A Highly Efficient Method for
the Silylation of Alcohols,
Phenols, and Naphthols Using
HMDS in the Presence of Zinc
Oxide (ZnO) as Economical
Heterogeneous Catalyst
a
a
Hamid Reza Shaterian & Majid Ghashang
a
Department of Chemistry, Faculty of Sciences ,
University of Sistan and Baluchestan , Zahedan, Iran
Published online: 20 Feb 2008.
To cite this article: Hamid Reza Shaterian & Majid Ghashang (2007) A Highly
Efficient Method for the Silylation of Alcohols, Phenols, and Naphthols Using
HMDS in the Presence of Zinc Oxide (ZnO) as Economical Heterogeneous Catalyst,
Phosphorus, Sulfur, and Silicon and the Related Elements, 183:1, 194-204, DOI:
10.1080/10426500701569406
To link to this article: http://dx.doi.org/10.1080/10426500701569406
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Phosphorus, Sulfur, and Silicon, 183:194–204, 2008
Copyright © Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426500701569406
A Highly Efficient Method for the Silylation of Alcohols,
Phenols, and Naphthols Using HMDS in the Presence of
Zinc Oxide (ZnO) as Economical Heterogeneous Catalyst
Hamid Reza Shaterian and Majid Ghashang
Department of Chemistry, Faculty of Sciences, University of Sistan
and Baluchestan, Zahedan, Iran
Variety alcohols, phenols, and naphthols were effectively converted into their cor-
responding trimethylsilyl ether with hexamethyldisilazane in the presence of zinc
oxide under very mild and ambient conditions with short reaction time in good to
excellent yields.
Keywords Alcohols; hexamethyldisilazane; phenols; trimethylsilylation; zinc oxide
INTRODUCTION
Catalytic technologies play a key role in the economic development and
development of the chemicals industry and add to around 20% of world
1
Gross national product (GNP). A major emerging and challenging part
of heterogeneous catalysis is that of environmental pollution control,
with contraction legislation on the release of waste and toxic emissions
1
having serious implications for the chemical industry. Many of these
processes were focused on product yield, disregarding the environmen-
tal impact of inorganic waste and toxic by-products formed during the
1
reaction. Tightening legislation on the emission of hazardous pollu-
tants is driving the industry toward the implementation of innovative
“
clean technology,” including the use of alternative heterogeneously cat-
2
alyzed processes. In this research, ZnO as the solid heterogeneous
Lewis acid catalyst deserve special mention, this catalyst is safe, easy
to handle, environmentally benign, presents fewer disposal problems.
Received 18 June 2007; accepted 22 June 2007.
We are thankful to the Sistan and Baluchestan University Research Council for the
partial support of this research.
Address correspondence to Hamid Reza Shaterian, Department of Chemistry, Faculty
of Sciences, University of Sistan and Baluchestan, PO Box 98135-674, Zahedan, Iran.
E-mail: hrshaterian@hamoon.usb.ac.ir
1
94

Silylation in the Presence of Zinc Oxide
195
Zinc oxide has been demonstrated to be efficient catalyst for several
3
important reactions such as Friedel-Crafts Acylation Reaction and
4
one-pot preparation of β-acetamido ketones.
The preparation of silyl ethers could carry out by treatment of
alcohols with silyl chlorides or silyl triflates in the presence of an
organic base.5
–12
However, some of these methods frequently suf-
fered from drawbacks such as lack of reactivity or the difficulty in
removal of amine salts. 1,1,1,3,3,3-Hexamethyldisilazane (HMDS) is
a stable, commercially available, and cheap reagent for trimethylsi-
lylation of hydrogen-labile substrates, giving NH3 as the only by-
5
–9
product.
Even though the handling of this reagent is easy, the
low silylation power of HMDS is the main drawback to its applica-
tion; therefore, there are a variety of catalysts for activating of this
reagent, such as (CH3)3SiCl,13 K-10 montmorillonite, sulfonic acids,
14
15
18
16
17
zirconium sulfophenyl phosphonate, ZnCl2, Envirocat EPZGO,
tungstophosphoric acid, iodine, lithium perchlorate, cupric sulfate
pentahydrate, H–β zeolite, MgBr2, lithium perchlorate supported
on silica gel, Al(HSO4)3, Al(OTF)3, magnesium triflate, copper
19
20
21
2
2
23
24
2
5
26
27
28
2
9
30
31
triflate, silica chloride, and silica-HClO4.
In most of these cases, however, a long reaction time, drastic reac-
tion conditions, or tedious workup is needed. In addition, many of these
reagents are moisture sensitive or expensive. The lack of a facile and
effective synthetic methodology for the silylation of hydroxyl groups
prompted us to develop a convenient and practical procedure for the
protection of hydroxyl groups in the presence of heterogeneous cata-
lyst conditions. The use of heterogeneous catalysts under solvent-free
conditions is becoming very popular as it has many advantages: re-
duced pollution, reusability, high selectivity, low cost, and simplicity in
process and in handling. In the present research for functional group
transformation, we wish to describe a new protocol for the mild and
rapid trimethylsilylation of a wide variety of hydroxyl groups using
HMDS and a catalytic amount of zinc oxide as solid Lewis acid cata-
lyst. The trimethylsilylation is easily carried out at room temperature
(
Scheme 1).
SCHEME 1

1
96
H. R. Shaterian and M. Ghashang
RESULTS AND DISCUSSION
A wide range of structurally diverse and functionalized phenols and al-
cohols underwent silylation by this process to provide the corresponding
TMS ethers in good to excellent isolated yields as shown in Table I (En-
tries 1–22). Phenols and benzylic alcohols mostly reacted faster than
aliphatic alcohols whereas primary alcohols generally are faster than
secondary and tertiary alcohols. Generally, in the all cases of benzyl,
primary, secondary and tertiary alcohols the reactions were completed
within less than 135 min in solvent-free condition accompanied by evo-
lution of NH3 gas from the reaction mixture. Inspection of the data in
Table I clearly shows that different types of hindered secondary and
tertiary alcohols were successfully converted to the corresponding silyl
ethers at ambient conditions (Table I).
The suggested mechanism of the ZnO catalyzed silylation of hydroxyl
groups is shown in Scheme 2.
In this mechanism, however operation process chart (OPC) of cata-
lyst in this works is unknown nonetheless according to the observations
such as evolution of NH3 in the reaction conditions, we have suggested
that an acid-base interaction between empty π orbital of Zn in ZnO as
catalyst and nitrogen in HMDS polarizes N Si bond of HMDS to pro-
duce a reactive silylating agent (I). A rapid reaction with alcohol then
ensues, leading to the ammonium silylating species (II) with concomi-
tant release of the corresponding silyl ether. Irreversible cleavage of (II)
with alcohol leading to the fast evolution of ROTMS and also formation
SCHEME 2

Silylation in the Presence of Zinc Oxide
197
of the unstable complexes of ZnO with ammonia (III). Irreversible clea-
vage of this complex with HMDS, leading to the fast evolution of NH3.
Release of ZnO as catalyst from intermediate (III), re-enters catalytic
cycle (Scheme 2).
In conclusion, we have demonstrated that zinc oxide is a new, ef-
ficient catalyst for trimethylsilylation of a variety of hydroxyl groups
using HMDS under mild and efficient conditions. This method is impor-
tant from an environmental point-of-view and economic considerations
because it produces little waste. It also has excellent activity on an
industrial scale. Simple work-up procedure, including filtering the cat-
alyst and purification of products using short pad column of silica gel
followed evaporation of the solvent is another advantage of this method.
EXPERIMENTAL
All reagents were purchased from Merck and Aldrich and used with-
out further purification. All yields refer to isolated products after pu-
rification. Products were characterized by comparison with authentic
1
samples and by spectroscopy data (IR, H NMR spectra) and melt-
ing point. The NMR spectra were recorded on a Bruker Avance DPX
500 and 300 MHz instrument. The spectra were measured in CDCl3
relative to TMS (0.00 ppm). IR spectra were recorded on a Perkin-
Elmer 781 spectrophotometer. Melting points were determined in open
capillaries with a BUCHI 510 melting point apparatus and are un-
corrected. TLC was performed on Silica-gel polygram SIL G/UV 254
plates.
General Procedure for Silylation of Alcohols Using HMDS
Catalyzed with ZnO
To a stirred solution of alcohol (1 mmol), HMDS (0.7 mmol) ZnO (0.05 g)
was added at room temperature and the mixture was stirred at appro-
priate time specified in Table I. The reaction was followed by TLC (n-
hexane–EtOAc, 9:1). After completion of the reaction, the catalyst was
filtrated and residue was passed through a short pad of silica gel. Then,
the pad column was washed with n-hexane (2 × 10 mL). Evaporation
of the solvent under reduced pressure gave pure product(s) (Table I).
The desired pure product(s) was characterized by comparison of their
1
4–31
physical data with those of known compounds.
The spectral data
of some representative Trimethylsilyl ethers are given below:

1
98
H. R. Shaterian and M. Ghashang
TABLE I Silylation of Alcohols, Phenols and Naphthols with HMDS
in the Presence of ZnO as Catalyst under Solvent-Free Condition at
Ambient Conditions
Molar ratio
Substrate/H
MDS
Time
(min)
Yield
(%)
Entry
1
Substrate
Product
1/0.7
1/0.7
5
95
2
3
5
95
1/0.7
1/1.3
5
6
91
93
4
5
1/0.7
5
90
6
7
1/0.7
1/1.3
5
5
93
88
8
1/0.7
5
96
(
Continued on next page)

Silylation in the Presence of Zinc Oxide
199
TABLE I Silylation of Alcohols, Phenols and Naphthols with HMDS
in the Presence of ZnO as Catalyst under Solvent-Free Condition at
Ambient Conditions (Continued)
Molar ratio
Substrate/H
MDS
Time
(min)
Yield
(%)
Entry
9
Substrate
Product
1/0.7
11
92
1
1
0
1
1/0.7
15
89
1/0.7
7
89
1
1
2
3
1/0.7
1/0.7
85
89
85
87
1
4
1/0.7
120
91
1
5
1/0.8
131
89
1
1
6
7
1/0.8
1/0.7
110
125
95
95
1
8
1/1.3
91
90
(
Continued on next page)

2
00
H. R. Shaterian and M. Ghashang
TABLE I Silylation of Alcohols, Phenols and Naphthols with HMDS
in the Presence of ZnO as Catalyst under Solvent-Free Condition at
Ambient Conditions (Continued)
Molar ratio
Substrate/H Time Yield
Entry
Substrate
Product
MDS
(min)
(%)
1
9
1/0.7
135
94
2
2
0
1
1/0.7
1/0.7
89
95
93
121
2
2
1/0.7
120
97
a
Yields refer to the pure isolated products. All known products have been reported
1
previously in the literature and were characterized by comparison of IR and H NMR
spectra with authentic samples.
1
4–31
Trimethyl(benzyloxy) Silane (Entry 1, Table I)
1
H NMR (CDCl3 500 MHz): δ = 7.36–7.35 (5H, m), 4.72 (2H, s), 0.19
(
1
9H, s), ppm; IR (CCl4): 3050, 2957, 1496, 1454, 1377, 1250, 1207, 1096,
027, 842, 727, 695 cm .
−1
Trimethylphenoxy Silane (Entry 2, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 7.31 (t, 2H, J = 8.0 Hz), 7.02 (t,
1
3
6
H, J = 7.3 Hz), 6.92 (d, 2H, J = 7.8 Hz), 0.34 (s, 9H) ppm; IR (CCl4):
039, 2960, 1596, 1492, 1252, 1164, 1070, 1024, 1002, 918, 843, 759,
−1
92 cm
.
Trimethyl(4-methyl phenoxy) Silane (Entry 3, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 7.08 (d, 2H,J = 8.0 Hz), 6.80 (d,
2
1
H,J = 8.1 Hz), 2.33 (s, 3H), 0.32 (s, 9H) ppm; IR (CCl4): 2960, 1613,
1
−
509, 1251, 1168, 1103, 916, 846, 754 cm
.
Trimethyl(4-amino phenoxy) Silane (Entry 4, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 6.61 (d, 2H, J = 8.5 Hz), 6.51 (d, 2H,
13
J = 6.5 Hz), 3.34 (s, 2H), 0.22 (s, 9H) ppm; C NMR (CDCl3,125 MHz):

Silylation in the Presence of Zinc Oxide
201
δ = 147.6, 140.4, 120.6, 116.7, 0.2 ppm; IR (CCl4): 3357, 2952, 1624,
−1
1
509, 1244, 1120, 911, 846, 754 cm .
Trimethyl(1-naphtaleneoxy) Silane (Entry 5, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 8.25 (dd, 1H, J = 6.12 and 3.4 Hz),
7
7
1
.88 (dd, 1H, J = 6.01 and 3.4 Hz), 7.56–7.54 (m, 3H), 7.41 (t, 1H, J =
.7 Hz), 6.97 (d, 1H, J = 7.4 Hz), 0.44(s, 9H) ppm; IR (CCl4): 3050, 2959,
579, 1507, 1461, 1390, 1272, 1154, 1093, 1051, 1015, 914, 848, 796, 771
−
1
cm
.
Trimethyl(2-naphtaleneoxy) Silane (Entry 6, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 7.85–7.78 (m, 3H), 7.50, (J = 5.0 Hz),
7
.41 (t, 1H, J = 6.9 Hz), 7.31 (d, 1H, J = 2.1 Hz), 7.18 (dd, 1H, J = 8.8
and 2.3 Hz), 0.41(s, 9H) ppm; IR (CCl4): 3057, 2959, 1631, 1590, 1508,
−
1
1
460, 1349, 1254, 1173, 1122, 978, 926, 855, 746 cm .
Bistrimethyl(4,4’-biphenoxy) Silane (Entry 7, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 7.44 (d, 4H, J = 8.6 Hz), 6.91 (d, 4H,
13
J = 8.5 Hz), 0.32 (s, 18H) ppm; C NMR (CDCl3, 125 MHz): δ = 154.3,
1
1
34.2, 127.7, 120.2, 0.28 ppm; IR (CCl4): 3060, 2960, 1603, 1490, 1255,
−1
169, 1102, 923, 841, 759 cm
.
Trimethyl(4-methoxybenzyloxy) Silane (Entry 8, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 7.29 (d, 2H, J = 8.4 Hz), 6.91 (d,
1
3
2
(
H, J = 8.4 Hz), 4.66 (s, 2H), 3.81 (s, 3H), 0.18 (s, 9H) ppm; C NMR
CDCl3, 125 MHz): δ = 158.9, 133.1, 128.1, 113.7, 64.4, 55.2, 0.3 ppm;
IR (CCl4): 3040, 2956, 1613, 1587, 1512, 1464, 1376, 1300, 1248, 1171,
−1
1
085, 840, 751 cm .
Trimethyl(2-phenylethoxy) Silane (Entry 9, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 7.33–7.23 (m, 5H), 3.81 (t, 2H, J =
7
2
8
.3 Hz), 2.87 (t, 2H, J = 7.3 Hz), 0.11(s, 9H) ppm; IR (CCl4): 3064, 3028,
955, 2899, 1604, 1479, 1474, 1454, 1383, 1250, 1207, 1094, 1030, 928,
−1
42, 740, 698 cm
.
Trimethyl(diphenylmethoxy) Silane (Entry 10, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 7.41–7.23 (m, 10H), 5.80 (s, 1H),
0
1
.12 (s, 9H) ppm; IR (CCl4): 3063, 3027, 2957, 2863, 1598, 1492, 1453,
354, 1303, 1251, 1187, 1090, 1061, 1027, 917, 885, 740, 700 cm
−
1
.
Trimethyl(α-methylbenzyloxy) Silane (Entry 11, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 7.40–7.34 (m, 4H), 7.28 (t, 1H, J =
.9 Hz), 4.93 (q, 1H, J = 6.3 Hz), 1.51 (d, 3H, J = 6.3 Hz), 0.15 (s, 9H)
6

2
02
H. R. Shaterian and M. Ghashang
ppm; IR (CCl4): 3063, 3027, 2972, 2927, 2868, 1688, 1603, 1492, 1450,
−
1
1369, 1250, 1206, 1090, 1032, 999, 959, 841, 757, 699 cm
.
Trimethyl Butoxy Silane (Entry 12, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 3.58 (t, 2H, J = 6.5 Hz), 1.52 (qui,
H, J = 5.9 Hz), 1.33 (six, 2H, J = 5.4 Hz), 0.92 (t, 3H, J = 7.3 Hz), 0.11
2
−
1
(
s, 9H) ppm; IR (CCl4): 2959, 1384, 1250, 1095, 900, 792 cm .
Trimethyl Isopentyloxy Silane (Entry 13, Table 1)
1
H NMR (CDCl3, 500 MHz): δ = 3.59 (t, 2H, J = 6.8 Hz), 1.73–1.64
m, 1H), 1.42 (q, 2H, J = 6.8 Hz), 0.90 (d, 6H, J = 6.6 Hz), 0.10 (s, 9H)
(
−
1
ppm; IR (CCl4): 2959, 1464, 1385, 1250, 1092, 991, 794 cm
.
Trimethyl Cyclohexyloxy Silane (Entry 14, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 3.57–3.51 (m, 1H), 1.79–1.70 (m,
4
2
H), 1.53–1.50 (m, 1H), 1.29–1.13 (m, 5H), 0.10 (s, 9H) ppm; IR (CCl4):
933, 2857, 1450, 1375, 1249, 1092, 1049, 996, 887, 839, 748 cm
−
1
.
Trimethyl (Tert-butoxy) Silane (Entry 15, Table I)
1
H NMR (CDCl3, 300 MHz): δ = 1.23 (s, 9H), 0.05 (s, 9H), ppm; 13C
NMR (CDCl3, 75 MHz): δ = 58.1, 31.1, 1.4 ppm; IR (CCl4): 2977, 1363,
−1
1
250, 1051, 794 cm .
Trimethyl(tetrahydro-2-furylmethoxy) Silane
(
Entry 16, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 3.91–3.83 (m, 1H), 3.79–3.73 (m,
1
1
7
1
H), 3.70–3.63 (m, 1H), 3.46 (t, 2H, J = 4.9 Hz), 1.84–1.73 (m, 3H),
.59–1.50 (m, 1H), 0.02 (s, 9H) ppm; 13C NMR (CDCl3, 125 MHz): δ =
9.4, 68.1, 65.1, 27.6, 25.5, 0.6 ppm; IR (CCl4): 2933, 1450, 1375, 1249,
−1
092, 1049, 996, 887, 839, 748 cm
.
Trimethyl[5-methyl-2-(1-methylethyl) cyclohexyl]oxy Silane
(
Entry 17, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 3.39 (six, 1H, J = 4.3 Hz), 2.14 (six,
1
1
0
H, J = 2.2 Hz), 1.85–1.83 (m, 1H), 1.64–1.56 (m, 2H), 1.43–1.32 (m,
H), 1.17–1.11 (m, 1H), 1.06–0.93 (m, 2H), 0.89 (d, 6H, J = 6.7 Hz),
1
3
.86–0.76 (m, 1H), 0.72 (d, 3H, J = 6.8 Hz), 0.10 (s, 9H) ppm; C NMR
(
1
CDCl3, 125 MHz): δ = 72.4, 50.0, 45.4, 34.5, 31.6, 25.2, 22.9, 22.2, 21.2,
−
1
5.9, 0.5 ppm; IR (CCl4): 2955, 1455, 1249, 1069, 931, 886, 839 cm .

Silylation in the Presence of Zinc Oxide
203
Bistrimethyl(1,4-butanedioxy) Silane (Entry 18, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 3.59 (t, 4H, J = 5.7 Hz), 1.55 (qui,
H, J = 3.0 Hz), 0.10(s, 18H) ppm; IR (CCl4): 2956, 1250, 1094, 840
4
cm
−
1
.
Trimethyl(tricyclo[3,3,1,13,7] doc-1-yloxy) Silane (Entry 19,
Table I)
1
H NMR (CDCl3, 500 MHz): δ = 2.10 (s, 3H), 1.76 (d, 6H, J = 2.9
1
3
Hz), 1.60 (d, 6H, J = 2.5 Hz), 0.13(s, 9H), ppm; C NMR (CDCl3, 125
MHz): δ = 71.3, 46.0, 36.2, 30.9, 3.0 ppm; IR (CCl4): 2908, 1453, 1353,
−
1
1
304, 1240, 1132, 1093, 1016, 964, 871, 837, 752 cm .
Trimethyl(1-octyloxy) Silane (Entry 20, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 3.56 (t, 2H, J = 6.7 Hz), 1.52 (qui,
H, J = 6.8 Hz), 1.31–1.28 (m, 10H), 0.88 (t, 3H, J = 6.5 Hz), 0.10 (s,
2
9
−
1
H) ppm; IR (CCl4): 2928, 2857, 1250, 1099, 840, 746 cm
.
Trimethyl[(1-methylheptyl)oxy] Silane (Entry 21, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 3.75 (six, 1H, J = 5.7 Hz), 1.44–1.26
(
m, 10H), 1.12 (d, 3H, J = 6.0 Hz), 0.88 (t, 3H, J = 6.6 Hz), 0.10 (s, 9H)
ppm; IR (CCl4): 2958, 2929, 2858, 1458, 1375, 1249, 1135, 1084, 1049,
−1
9
56, 830, 794, 747 cm .
Trimethyl[(3β)-Choest-4-en-3-yl]oxy Silane (Entry 22, Table I)
1
H NMR (CDCl3, 500 MHz): δ = 5.32 (t, 1H, J = 2.2 Hz), 3.51–3.45
1
3
(
m, 1H), 2.29–0.86 (m, 40H), 0.67 (s, 3H), 0.12 (s, 9H) ppm; C NMR
(
CDCl3, 125 MHz): δ = 141.4, 121.3, 72.3, 56.8, 56.1, 50.2, 42.7, 42.3,
3
2
1
9.8, 39.5, 37.4, 36.5, 36.2, 35.7, 32.0, 31.95, 31.9, 28.2, 28.0, 24.2, 23.8,
2.7, 22.5, 21.0, 19.3, 18.7, 11.8, 0.2 ppm; IR (KBr): 2950, 1466, 1380,
−1
249, 1085, 958, 897, 840, 754 cm
.
REFERENCES
[1] R. A. Sheldon, Chemistry & Industry, 1, 12 (1997).
[2] J. H. Clark and D. J. MacQuarrie, Chem. Comm., 853 (1998).
[3] M. Hosseini Sarvari and H. Sharghi, J. Org. Chem., 69, 6953 (2004).
[4] M. T. Maghsoodlou, A. Hassankhani, H. R. Shaterian, S. M. Habibi-Khorasani, and
E. Mosaddegh, Tetrahedron Lett., 48, 1729 (2007).
[
[
[
5] G. Van Look, G. Simchen, and J. Heberle, Silylation Agents (Fluka, Buchs,
Switzerland, 1995).
6] T. W. Greene and P. G. M. Wuts, Protective Groups in Organic Synthesis (Wiley, New
York, 1999), 3rd ed.
7] M. Lalonde and T. H. Chan, Synthesis, 817 (1985).

2
04
H. R. Shaterian and M. Ghashang
[
[
8] P. J. Kocienski, In Protective Groups, R. Enders, R. Noyori, and B. M. Trost, Eds.
Thieme, Stuttgart, 1994).
9] M. A. Brook, Silicon in Organic, Organometallic, and Polymer Chemistry (Wiley,
(
New York, 2000).
[
10] G. A. Olah, B. G. B. Gupta, S. C. Narang, and R. Malhotra, J. Org. Chem., 44, 4272
1979).
(
[
[
[
[
[
11] B. A. D’Sa, D. McLeod, and J. G. Verkade, J. Org. Chem., 62, 5057 (1997).
12] B. A. D’Sa and J. G. Verkade, J. Am. Chem. Soc., 118, 12,832 (1996).
13] J. Cossy and P. Pale, Tetrahedron Lett., 28, 6039 (1987).
14] Z. H. Zhang, T. S. Li, F. Yang, and C. G. Fu, Synth. Commun., 28, 3105 (1998).
15] D. Boerner, G. Koerner, F. Spieker, and M.Wiemann, German Patent, DE 2757936
(
1978).
[
16] M. Curini, F. Epifano, M. C. Marcotullio, O. Rosati, and U. Costantino, Synth. Com-
mun., 29, 541 (1999).
[17] H. Firouzabadi and B. Karimi, Synth. Commun., 23, 1633 (1993).
[18] B. P. Bandgar and P. P. Wadgaonkar, Synth. Commun., 27, 2069 (1997).
[19] H. Firouzabadi, N. Iranpoor, K. Amani, and F. Nowrouzi, J. Chem. Soc. Perkin Trans.
1
2601 (2002).
[
[
[
[
[
[
[
[
[
20] B. Karimi and B. Golshani, J. Org. Chem., 65, 7228 (2000).
21] N. Azizi and M. R. Saidi, Organometallics, 23, 1457 (2004).
22] B. Akhlaghinia and S. Tavakoli, Synthesis, 1775 (2005).
23] V. H. Tillu, V. H. Jadhav, H. B. Borate, and R. D. Wakharkar, Arkivoc, 83 (2004).
24] M. M. Mojtahedi, H. Abbasi, and M. S. Abaee, J. Mol. Catal. A: Chem., 250, 6 (2006).
25] N. Azizi, R. Yousefi, and M. R. Saidi, J. Organometallic Chem., 691, 817 (2006).
26] F. Shirini, M. A. Zolfigol, and M. Abedini, Bull. Chem. Soc. Jpn., 78, 1982 (2005).
27] H. Firouzabadi, N. Iranpoor, S. Sobhani, and S. Gassamipour, Synthesis, 595 (2005).
28] H. Firouzabadi, N. Iranpoor, S. Sobhani, and S. Gassamipour, J. Organometallic
Chem., 689, 3197 (2004).
[
[
[
29] H. Firouzabadi, N. Iranpoor, S. Sobhani, S. Gassamipour, and Z. Amoozgar, Tetra-
hedron Lett., 44, 891 (2003).
30] F. Shirini, M. A. Zolfigol, and K. Mohammadi, Phosphorus, Sulfur, Silicon, Relat.
Elem., 178, 1567 (2003).
31] H. R. Shaterian, F. Shahrekipoor, and M. Ghashang, J. Mol. Catal. A: Chem., 272,
142 (2007).