Synthesis of new organosilicon compounds by CS2: Mercapto-silyl-thiones

Article abstract of DOI:10.1016/j.jorganchem.2013.07.051

A new type of chemistry of carbon disulfide proceeding by way of nucleophilic attack of tris(trimethylsilyl)methyllithium (TsiLi) at carbon of carbon disulfide is reported. The treatment of TsiLi and CS₂ with some symmetrical and unsymmetrical

Full text of DOI:10.1016/j.jorganchem.2013.07.051

Journal of Organometallic Chemistry 745-746 (2013) 214e218
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Synthesis of new organosilicon compounds by CS2:
Mercapto-silyl-thiones
*
Kazem D. Safa , Khatereh Ghorbanpour
Organosilicon Research Laboratory, Faculty of Chemistry, University of Tabriz, 51664 Tabriz, Iran
a r t i c l e i n f o
a b s t r a c t
Article history:
A new type of chemistry of carbon disulfide proceeding by way of nucleophilic attack of tris(-
trimethylsilyl)methyllithium (TsiLi) at carbon of carbon disulfide is reported. The treatment of TsiLi and
CS2 with some symmetrical and unsymmetrical benzyl halides has yielded novel multifunctional com-
pounds with SiMe3, SH and C]S groups. The obtained compounds (mercapto-silyl-thiones) have been
produced with unusual rearrangement that is apparently the first example of such migration of sulphur
to carbon atom. These reactions have high selectivity and the yields are quantitative.
Ó 2013 Elsevier B.V. All rights reserved.
Received 23 March 2013
Received in revised form
10 July 2013
Accepted 18 July 2013
Keywords:
Organosilicon
Organosulphur
Tris(trimethylsilyl)methyllithium
Carbon disulfide
Mercapto-silyl-thione
Thia-Brook rearrangement
1. Introduction
[14e16,22e24]. Therefore in the reaction of TsiLi with carbon di-
sulfide the formation of the same compounds (dithiocarboxylic
In the previous publications [1e9], we reported the preparation
and reactions of some organosilicon compounds by using a bulky
tris(trimethylsilyl)methyllithium (TsiLi), in which three organosilyl
groups are attached to the central carbon atom and cause different
behaviours of this carbon atom in the reaction with various elec-
trophiles such as aldehydes, epoxides, acyl chlorides, allyl bromide
and etc.
In continuous, to extend our investigations to the organosilicon
compounds, we decided to study the reactions of tris(-
trimethylsilyl)methyllithium with carbon disulfide in the presence
of various electrophiles. Although the treatment of silyl substituted
compounds with carbon disulfide is less known [10e12], the
chemistry of carbon disulfide has been studied extensively, and
different compounds have been synthesized by using of carbon
disulfide such as dithiocarbamates, silyl dithiocarbamates, 1,1-
dithiolates, dithiocarboxylic acids and esters [13e18]. In addition,
synthesis of a novel series of heterocycles using the reaction of
carbon disulfide has been led to a class of compounds with proven
utility in medicinal chemistry [19e21].
esters or 1,1-dithiolates) was expected, surprisingly the rear-
rangement of CS2 with TsiLi led to the formation of both mercaptan
and thiocarbonyl groups that have not previously been observed.
This is apparently the first example of such migration of sulphur to
carbon atom.
We are interested to the chemistry of these compounds, that
named as mercapto-silyl-thiones, due both to the high reactivity of
the carbon-sulphur double bond and SeH bond which make
possible the synthesis of a variety compounds containing the SieCe
S and SieCeC]S units. The chemistry of these compounds can be
considered as an important class of synthetic intermediates.
2. Results and discussion
The precursor (Me3Si)3CH was prepared from the reaction of
CHCl3, Li and Me3SiCl in THF. The organolithium reagent,
(Me3Si)3CLi, was obtained by treatment of (Me3Si)3CH with MeLi
under reflux conditions in THF [25] (Scheme 1).
In order to optimize the reaction conditions with respect to
temperature and time, we first conducted the reaction of TsiLi, CS2
and benzyl bromide, as a model reaction under an argon atmo-
sphere in various temperatures. The best temperature was found to
be ꢀ46 ꢁC (cyclohexanon/N2). The results are listed in Table 1.
As seen in Table 1, the prolonged reaction times (Entries 3 and 5)
and the elevated reaction temperatures (Entries 1, 2 and 3) resulted
Treatment of carbon disulfide with organolithium compounds
causes to the generation of dithiocarboxylic esters or 1,1-dithiolates
* Corresponding author. Tel.: þ98 411 3393124; fax: þ98 411 3340191.
E-mail address: dsafa@tabrizu.ac.ir (K.D. Safa).
0022-328X/$ e see front matter Ó 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.jorganchem.2013.07.051

K.D. Safa, K. Ghorbanpour / Journal of Organometallic Chemistry 745-746 (2013) 214e218
215
Although the precise mechanism of this reaction is not clear
at the present time, it is reasonable to assume that the reaction
path with attention to 1H and 13C NMR data [1H NMR: 0.17 (s,
18H, SiMe3), 3.14 (b.s, 1H, SH), 4.45 (s, 2H, CH2), 7.28 (m, 5H, Ar);
13C NMR: ꢀ1.13 (SiMe3), 41.07 (CH2), 54.94 (C(SiMe3)2SH),
126.28e135.23 (Ar), 213.62 (C]S)] involves the initial attack of
trisyl anion at the carbon of carbon disulfide followed by a silyl
migration from carbon to sulphur (1b) (Thia-Brook rearrange-
ment) [27,28] and the formation of carbanion 1b [29] and then
conversion to the enethiolate 1c [16,30]. The resulting product
(1) shows that the migration of sulphur to carbon of C(SiMe3)2
has been occurred. It seems likely that the obtained product (1)
forms through the intermediates 1de1g and after hydrolysis of
1g (Scheme 2).
Upon examination of a broader array of benzyl halides, a series
of symmetrical and unsymmetrical benzyl halides were used.
Totally all the products were obtained in high yields and any side
products were not observed. The results are summarized in Table 2.
TsiLi and CS2 underwent a specific rearrangement with a variety of
benzyl halides (X ¼ Cl, Br and I) at ꢀ46 ꢁC to give the corresponding
mercapto-silyl-thiones in high yields. Generally, benzyl bromides
show higher yields compared with benzyl chlorides. In the reaction
of TsiLi and CS2 with benzyl chloride and 1,4-bis(chloromethyl)
benzene no products were formed. However, with introducing of
chloro group in ortho or meta position of benzyl chloride, the cor-
responding products were formed in good yields. In these com-
pounds, the electron-withdrawing groups play important role and
lead to the participation of aryl chloride in the reaction. Further-
more, conversion of 1,4-bis(chloromethyl)benzene to 1,4-
bis(iodomethyl)benzene by using NaI in acetone causes to react
readily under these reaction conditions and gave the corresponding
1,4-adduct in good yield.
THF
(Me3Si)3CH + 6LiCl
Me3Si
3Me3SiCl + CHCl3 + 6Li
+
MeLi
(Me3Si)3CH
+ CH4
Me3Si
Me3Si
Li
Scheme 1. Preparation of tris(trimethylsilyl)methyllithium.
in lower yields of 1 due to the formation of unidentified decom-
position products. At ꢀ46 ꢁC the mixture of materials was stirred
for 15 min and the compound 1 was formed as the sole product in
98% yield. When the reaction was carried out at ꢀ78 ꢁC (ethyl ac-
etate/N2) and ꢀ94 ꢁC (n-hexane/N2), another product was quanti-
tatively formed that was unstable at room temperature, therefore it
wasn’t separable. It was completely converted to 1 during the work
up.
In our experiments when carbon disulfide was added to TsiLi
solution at ꢀ46 ꢁC, the yellowish mixture immediately changed to
the red solution indicating the formation of new anion. After 5 min,
benzyl bromide was added to the solution and the red colour of the
reaction was changed to yellow in short period of time to afford the
corresponding compound (1) in high yield. The structure of the
resulted product was established from the spectral properties.
In this reaction, it was expected to observe Thia-Brook rear-
rangement and migration of silyl group on sulphur [26e28]. Sur-
prisingly the unusual rearrangement via thia migration was
occurred and the unexpected compounds were obtained. To our
knowledge no example of this type of reaction has been reported in
the literature. The intermediates of this reaction are not stable to
separate. In order to trap the intermediates, the following three
attempts were carried out:
The resulted compounds are heat sensitive and show very
different stabilities. The compounds 1, 4, 7 and 8 are thermally
more stable than the other compounds and they are stable at
room temperature. It seems that symmetric structure, steric and
electronic effects could play role on stability of these com-
pounds. In addition, the compounds 4 and 7, after the prepara-
tion and evaporation of their solvents, were liquid and gradually
from 1 to 15 days have released their remained solvents and
converted to sticky solid. The other derivatives are liquid and
decompose gradually at room temperature, but they are long-
lived at 0 ꢁC.
1) The reaction was carried out at low temperatures (ꢀ78 ꢁC and
ꢀ94 ꢁC).
2) CS2 and benzyl bromide were added in situ to the TsiLi solution.
3) The anion resulting from initial attack of TsiLi to CS2, was
immediately protonated by hydrolysis at ꢀ46 ꢁC.
Unfortunately, we were unable to stop the rearrangement or
trap the presumed intermediates with any conditions.
3. Conclusion
Table 1
In this paper, we have reported new reaction pattern for the
RLi/CS2 system. We chose TsiLi as an organolithium and benzyl
halides (X ¼ Cl, Br and I) as electrophiles. The reaction of TsiLi with
CS2 led to the formation of new compounds with SH, C]S and
SiMe3 groups that we named them as mercapto-silyl-thiones.
These reactions took place at ꢀ46 ꢁC in short period of time.
The yields are quantitative and the selectivity of these reactions is
high. The obtained compounds have different thermal stabilities
and the compounds 1, 4, 7 and 8 are thermally more stable than
the others.
Investigation of temperature and time effects on the reaction of TsiLi, CS2 and benzyl
bromide.
Me3Si
Me3Si
Me3Si
Me3Si
HS
Me3Si
S
1) CS2/ THF
Li
2) benzyl bromide
(1)
Entry
Temperature (ꢁC)
Time (min)
(1)a (%)
1
2
3
4
5
6
7
25
0
0
ꢀ46
ꢀ46
ꢀ78
ꢀ94
15
15
120
15
120
30b
60b
e
4. Experimental
10
6
98
60
98
98
4.1. Solvents and reagents
The reactions were carried out under dry argon. Solvents and
CS2 were dried by standard methods. Substrates for the prepara-
tion of tris(trimethylsilyl)methyllithium, viz. Me3SiCl (Merck), Li
(Merck), CHCl3 (Merck), and substrate for the preparation of
a
Yields were obtained by PTLC.
Explained in the text.
b

216
K.D. Safa, K. Ghorbanpour / Journal of Organometallic Chemistry 745-746 (2013) 214e218
Scheme 2. The proposed mechanism of the reaction of TsiLi, CS2 and benzyl bromide.
mercapto-silyl-thiones, viz. benzyl halides (Merck) were used as
received.
4.4.1. 1-Mercapto-1,1-bis(trimethylsilyl)-3-phenylpropane-2-thione
(1)
A yellow liquid, 98% (Rf ¼ 0.66). FTIR (KBr, cmꢀ1): 3065 (Ar),
4.2. Spectra
2957 (CH), 1601e1453 (Ar), 1409, 1150 (C]S), 1252, 917 and 843
(CeSi), 1021 (CeS); 1H NMR (400 MHz, CDCl3):
d
0.17 (s, 18H,
The 1H NMR and 13C NMR were recorded with a Bruker FT-
400 MHz spectrometer at room temperature and CDCl3 as a solvent.
The mass spectra were obtained with a GCeMS Agilent, quadrupole
mode 5973N instrument, operating at 70 eV. The FTIR spectra were
recorded on a Bruker-Tensor 270 spectrometer.
SiMe3), 3.14 (b.s,1H, SH), 4.45 (s, 2H, CH2), 7.28 (m, 5H, Ar); 13C NMR
(CDCl3):
d
ꢀ1.13 (SiMe3), 41.07 (CH2), 54.94 (C(SiMe3)2SH), 126.28e
135.23 (Ar), 213.62 (C]S); m/z (EI): 328 (4%, [M þ 2]þ), 327 (6%,
[M þ 1]þ), 326 (24%, [M]þ), 235 (24%, [M-benzyl]þ), 203 (82%,
[HSCC(SiMe3)2]þ), 115 (45%, [HSCCSiMe2]þ), 91 (100%, [benzyl]þ),
73 (70%, [SiMe3]þ); Anal. Calcd for C15H26S2Si2: C, 55.1; H, 8.0; S,
19.6. Found: C, 54.9; H, 8.2; S, 19.8%.
4.3. Preparation of tris(trimethylsilyl)methyllithium, (Me3Si)3CLi, in
THF
4.4.2. 3-(2-Bromophenyl)-1-mercapto-1,1-bis(trimethylsilyl)
propane-2-thione (2)
The reagent was prepared as described by Grobel and co-
workers [25].
A brown liquid, 90% (Rf ¼ 0.73), FTIR (KBr, cmꢀ1): 3061 (Ar),
2957 (CH), 1566e1469 (Ar), 1435, 1151 (C]S), 1251, 916 and 844
4.4. Typical procedure for the preparation of mercapto-silyl-thiones
(1e8)
(CeSi), 1024 (CeS); 1H NMR (400 MHz, CDCl3):
d
0.14 (s, 18H,
SiMe3), 3.13 (b.s, 1H, SH), 4.56 (s, 2H, CH2), 7.11e7.55 (m, 4H, Ar); 13
C
NMR (CDCl3):
d
ꢀ1.17 (SiMe3), 41.35 (CH2), 55.18 (C(SiMe3)2SH),
To
a
stirred solution of tris(trimethylsilyl)methyllithium
123.73e134.92 (Ar), 214.03 (C]S); m/z (EI): 406 (10%, [M þ 2]þ),
404 (10%, [M]þ), 325 (23%, [M ꢀ Br]þ), 170 (100%, [C7H6Br]þ), 120
(15%, [HSCH2SiMe3]þ), 91 (20%, [benzyl]þ), 73 (5%, [SiMe3]þ).
(1 mmol) in THF, carbon disulfide (1.2 mmol) in 2 ml THF was
added at ꢀ46 ꢁC (cyclohexanone/N2) under argon atmosphere.
The mixture is stirred for 5 min and then benzyl halide (1 mmol)
(for compound 8, 0.5 mmol of 1,4-bis(iodomethyl)benzene) is
added at this temperature and the stirring is maintained
(ꢀ46 ꢁC / 0 ꢁC) to end of the reaction that followed by TLC. The
mixture is poured into water and extracted with CH2Cl2. The
organic layer was washed with water, dried with Na2SO4 and
filtered. The solvent was evaporated and the residue was purified
by preparative TLC on silica gel using n-hexane as eluent to give
the product.
4.4.3. 3-(3-Bromophenyl)-1-mercapto-1,1-bis(trimethylsilyl)
propane-2-thione (3)
A brown liquid, 84% (Rf ¼ 0.71), FTIR (KBr, cmꢀ1): 3068 (Ar),
2952 (CH), 1616e1482 (Ar), 1412, 1150 (C]S), 1250, 913 and 835
(CeSi), 1029 (CeS); 1H NMR (400 MHz, CDCl3):
d
0.16 (s, 18H,
SiMe3), 3.13 (b.s,1H, SH), 4.41 (s, 2H, CH2), 7.14e7.45 (m, 4H, Ar); 13
C
NMR (CDCl3):
d
ꢀ1.15 (SiMe3), 40.05 (CH2), 55.16 (C(SiMe3)2SH),
121.39e137.84 (Ar), 213.54 (C]S); m/z (EI): 406 (10%, [M þ 2]þ),

K.D. Safa, K. Ghorbanpour / Journal of Organometallic Chemistry 745-746 (2013) 214e218
217
Table 2
Reaction of TsiLi and CS2 with benzyl halides.
Entry
RX
Product
Timea (min)
15
Yieldb (%)
Me3Si
S
Br
Br
HS
1
98
90
Me3Si
(1)
Br
2
3
30
40
(2)
Me3Si
S
HS
Br
Br
Br
84
95
Me3Si
Br
(3)
Me3Si
HS
Me3Si
S
Br
4
20
Br
(4)
Cl
Cl
5
6
e
120
40
e
Me3Si
HS
Me3Si
S
S
Cl
87
Cl
(5)
(6)
(7)
Me3Si
HS
Me3Si
Cl
Cl
7
8
9
60
30
80
80
Cl
S
Me3Si
HS
Me3Si
Cl
Cl
Cl
Cl
Cl
Cl
-
120
20
e
Cl
I
S
Me3Si
HS
Me3Si
I
SiMe3
SH
10
90
S
SiMe
3 (8)
a
End of the reaction was followed by TLC.
Yields were obtained by PTLC.
b

218
K.D. Safa, K. Ghorbanpour / Journal of Organometallic Chemistry 745-746 (2013) 214e218
404 (10%, [M]þ), 325 (23%, [M ꢀ Br]þ), 170 (100%, [C7H6Br]þ), 120
4.4.8. 1,4-Bis[1-mercapto-1,1-bis(trimethylsilyl)-2-
thiocarbonylpropyl]benzene (8)
(15%, [HSCH2SiMe3]þ), 91 (20%, [benzyl]þ), 73 (5%, [SiMe3]þ).
A yellow crystalline solid, 90% (Rf ¼ 0.40, m.p.147e148 ꢁC), FTIR
(KBr, cmꢀ1): 3071 (Ar), 2952 (CH), 1686e1509 (Ar), 1397, 1141 (C]
S), 1247, 909 and 832 (CeSi), 1025 (CeS); 1H NMR (400 MHz,
4.4.4. 3-(4-Bromophenyl)-1-mercapto-1,1-bis(trimethylsilyl)
propane-2-thione (4)
A yellow sticky solid, 95% (Rf ¼ 0.53), FTIR (KBr, cmꢀ1): 3065
CDCl3):
d 0.19 (s, 36H, SiMe3), 3.16 (b.s, 2H, SH), 4.45 (s, 4H, CH2),
(Ar), 2953 (CH), 1636e1485 (Ar), 1402, 1157 (C]S), 1249, 913 and
7.29 (s, 4H, Ar); 13C NMR (CDCl3):
d
ꢀ1.15 (SiMe3), 40.69 (CH2),
832 (CeSi), 1029 (CeS); 1H NMR (400 MHz, CDCl3):
d
0.16 (s, 18H,
54.97 (C(SiMe3)2SH), 128.15, 134.32 (Ar), 213.60 (C]S); m/z (EI):
574 (4%, [M]þ) 503 (10%, [M þ 2-SiMe3]þ), 429 (30%, [M þ 1e
2 ꢂ (SiMe3)]þ), 253 (95%, [PhCH2C(S)CSHSiMe3]þ), 73 (100%,
[SiMe3]þ); Anal. Calcd for C24H46S4Si4: C, 50.1; H, 8.0; S, 22.3.
Found: C, 50.3; H, 8.4; S, 22.1%.
SiMe3), 3.13 (b.s,1H, SH), 4.40 (s, 2H, CH2), 7.19 (d, J ¼ 8.1 Hz, 2H, Ar),
7.42 (d, J ¼ 8.1 Hz, 2H, Ar), 213.64 (C]S); 13C NMR (CDCl3):
d 0.20
(SiMe3), 41.11 (CH2), 56.13 (C (SiMe3)2SH), 121.12e135.60 (Ar); m/z
(EI): 406 (10%, [M þ 2]þ), 404 (10%, [M]þ), 325 (23%, [M ꢀ Br]þ), 170
(100%, [C7H6Br]þ), 120 (15%, [HSCH2SiMe3]þ), 91 (20%, [benzyl]þ),
73 (5%, [SiMe3]þ); Anal. Calcd for C15H25BrS2Si2: C, 44.4; H, 6.2; S,
15.8. Found: C, 44.1; H, 6.3; S, 15.7%.
Acknowledgement
We thank Dr. R. Teimuri-Mofrad, Dr. Y. Mosaei Oskoei and Dr. A.
Hassanpour for their helpful comments.
4.4.5. 3-(2-Chlorophenyl)-1-mercapto-1,1-bis(trimethylsilyl)
propane-2-thione (5)
A brown liquid, 87%: (Rf ¼ 0.64), FTIR (KBr, cmꢀ1): 3065 (Ar),
References
2960 (CH), 1576e1474 (Ar), 1443, 1153 (C]S), 1253, 916 and 853
(CeSi), 1051 (CeS); 1H NMR (400 MHz, CDCl3):
d
0.15 (s, 18H,
SiMe3), 3.13 (b.s, 1H, SH), 4.56 (s, 2H, CH2), 7.18e7.48 (m, 4H, Ar);
13C NMR (CDCl3):
[1] K.D. Safa, K. Ghorbanpour, A. Hassanpour, S. Tofangdarzadeh, J. Organomet.
Chem. 694 (2009) 1907e1911.
[2] K.D. Safa, A. Hassanpour, S. Tofangdarzadeh, M.H. Nasirtabrizi, J. Iran. Chem.
Soc. 5 (2008) 458e463.
[3] K.D. Safa, S.P. Samani, S. Tofangdarzadeh, A. Hassanpour, J. Organomet. Chem.
693 (2008) 2004e2008.
[4] K.D. Safa, M. Namvari, A. Hassanpour, S. Tofangdarzadeh, J. Organomet. Chem.
694 (2009) 2448e2453.
d
ꢀ1.19 (SiMe3), 42.55 (CH2), 55.08
(C(SiMe3)2SH), 125.50e130.11 (Ar), 213.62 (C]S); m/z (EI): 362
(10%, [M þ 2]þ), 360 (20%, [M]þ), 358 (36%, [M ꢀ 2]þ), 147 (94%,
[Me2SiSCHC]S]þ), 115 (21%, [HSCCSiMe2]þ), 91 (20%, [benzyl]þ),
73 (92%, [SiMe3]þ).
[5] K.D. Safa, M. Shahrivar, S. Tofangdarzadeh, A. Hassanpour, Tetrahedron 63
(2007) 3189e3194.
[6] K.D. Safa, F. Mosleh, P. Kalantarzadeh, Phosphorus, Sulfur Silicon 178 (2003)
1261e1268.
4.4.6. 3-(3-Chlorophenyl)-1-mercapto-1,1-bis(trimethylsilyl)
propane-2-thione (6)
[7] K.D. Safa, H.A. Eram, M.H. Nasirtabrizi, Iran. Polym. J. 15 (2006) 249e257.
[8] K.D. Safa, O. Rafigh, M.H. Nasirtabriiz, J. Chem. Res. (S) 5 (2006) 379e383.
[9] K.D. Safa, M. Babazadeh, J. Organomet. Chem. 690 (2005) 79e83.
[10] A. Ehlend, H.D. Hausen, W. Kaim, A. Lichtblau, W. Schwarz, J. Organomet.
Chem. 501 (1995) 283e286.
[11] F. Kardon, M. Mortl, G. Magyarfalvi, Synth. Commun. 38 (2008) 192e199.
[12] L. Birkofer, K. Krebs, Tetrahedron Lett. 9 (1968) 885e888.
[13] A.D. Dunn, W.D. Rudorf, Carbon Disulphide in Organic Chemistry, Ellis Hor-
wood Limited, Chichester, 1989, pp. 1e389.
[14] S.R. Ramadas, P.S. Srinivasan, J. Ramachandran, V.V.S.K. Sastry, Synthesis
(1983) 605e622.
[15] S. Kato, M. Ishida, J. Sulfur Chem. 8 (1988) 155e312.
[16] W.D. Rudorf, Sulfur Rep. 11 (1991) 51e141.
A brown liquid, 80% (Rf ¼ 0.62 2:3), FTIR (KBr, cmꢀ1): 3068
(Ar), 2962 (CH), 1617e1482 (Ar), 1432, 1150 (C]S), 1253, 913 and
835 (CeSi), 1052 (CeS); 1H NMR (400 MHz, CDCl3):
d
0.16 (s, 18H,
SiMe3), 3.13 (b.s, 1H, SH), 4.45 (s, 2H, CH2), 7.14e7.45 (m, 4H, Ar);
13C NMR (CDCl3):
d
ꢀ1.18 (SiMe3), 41.05 (CH2), 55.16
(C(SiMe3)2SH), 123.49e137.85 (Ar), 213.61 (C]S); m/z (EI): 362
(10%, [M þ 2]þ), 360 (20%, [M]þ), 358 (36%, [M ꢀ 2]þ), 147 (94%,
[Me2SiSCHC]S]þ), 115 (21%, [HSCCSiMe2]þ), 91 (20%, [benzyl]þ),
73 (92%, [SiMe3]þ).
[17] Osamu Niyomura1, Shinzi Kato, Top Curr. Chem. 251 (2005) 1e12.
[18] N. Azizi, F. Aryanasab, L. Torkiyan, A. Ziyaei, M.R. Saidi, J. Org. Chem. 71 (2006)
3634e3635.
[19] A. Alizadeh, N. Zohreh, H. Sabahnoo, Z. Noaparast, Tetrahedron 67 (2011)
1709e1715.
4.4.7. 3-(2,6-Dichlorophenyl)-1-mercapto-1,1-bis(trimethylsilyl)
propane-2-thione (7)
A yellow sticky solid, 80% (Rf ¼ 0.46), FTIR (KBr, cmꢀ1): 3071
[20] A. Alizadeh, S. Rostamnia, N. Zohreh, R. Hosseinpour, Tetrahedron Lett. 50
(2009) 1533e1535.
(Ar), 2958 (CH), 1566e1436 (Ar), 1151 (C]S), 1253, 917 and 842
(CeSi), 1019 (CeS); 1H NMR (400 MHz, CDCl3):
d
0.18 (s, 18H,
SiMe3), 3.11 (b.s, 1H, SH), 4.66 (s, 2H, CH2), 7.12e7.34 (m, 3H, Ar);
13C NMR (CDCl3):
[21] N. Lal, L. Kumar, A. Sarswat, S. Janjir, V.L. Sharma, Org. Lett. 13 (2011) 2330e2333.
[22] D. Seyferth, R.C. Hui, Tetrahedron Lett. 25 (1984) 2623e2626.
[23] J. Chen, Q. Song, Z. Xi, Tetrahedron Lett. 43 (2002) 3533e3535.
[24] A. Commerçon, G. Ponsinet, Tetrahedron Lett. 26 (1985) 5131e5132.
[25] T. Grobel, D. Seebach, Chem. Ber. 110 (1977) 852e866.
[26] T. Kawashima, Chin. J. Chem. 23 (2005) 1267e1269.
[27] A. Wright, D. Ling, P. Boudjouk, R. West, J. Am. Chem. Soc. (1972) 4784e4785.
[28] K. Takeda, K. Sumi, S. Hagisawa, J. Organomet. Chem. 611 (2000) 449e454.
[29] L. Fleming, C.D. Floyd, J. Chem. Soc. Perkin 1 (1981) 969e976.
[30] A. Guigne, P. Metzner, Phosphorus, Sulfur Silicon 25 (1985) 97e102.
d
ꢀ1.19 (SiMe3), 39.64 (CH2), 54.94
(C(SiMe3)2SH), 127.22e135.20 (Ar), 213.92 (C]S); m/z (EI): 396
(4%, [M þ 2]þ), 394 (5%, [M]þ), 235 (23%, [(Me3Si)2SHCC]S]þ), 159
(34%, [C7H5Cl2]þ), 115 (25%, [HSCCSiMe2]þ), 73 (100%, [SiMe3]þ);
Anal. Calcd for C15H24Cl2S2Si2: C, 45.5; H, 6.1; S, 16.2. Found: C,
45.1; H, 6.2; S, 16.5%.