New aspects of the chemistry of CS 2: Synthesis of mercapto-triorganosilyl- thiones by use of tris(trimethylsilyl)methyllithium

Article abstract of DOI:10.1080/17415993.2013.830726

Tris(trimethylsilyl)methyllithium (TsiLi) reacts with CS2 via cleavage of the C=S double bond and unexpected rearrangement to give sulfur-containing organosilicon compounds. The intermediate, from the reaction between TsiLi and CS2 is not stable but it ha

Full text of DOI:10.1080/17415993.2013.830726

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New aspects of the chemistry
of CS2: synthesis of mercapto-
triorganosilyl-thiones by use of
tris(trimethylsilyl)methyllithium
Kazem D. Safa a & Khatereh Ghorbanpour a
a Organosilicon Research Laboratory, Faculty of Chemistry,
University of Tabriz , 51664 Tabriz, Iran
Published online: 09 Sep 2013.
To cite this article: Kazem D. Safa & Khatereh Ghorbanpour , Journal of Sulfur Chemistry (2013):
New aspects of the chemistry of CS2: synthesis of mercapto-triorganosilyl-thiones by use of
tris(trimethylsilyl)methyllithium, Journal of Sulfur Chemistry, DOI: 10.1080/17415993.2013.830726
To link to this article: http://dx.doi.org/10.1080/17415993.2013.830726
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Journal of Sulfur Chemistry, 2013
http://dx.doi.org/10.1080/17415993.2013.830726
New aspects of the chemistry of CS2: synthesis of
mercapto-triorganosilyl-thiones by use of
tris(trimethylsilyl)methyllithium
Kazem D. Safa∗ and Khatereh Ghorbanpour
Organosilicon Research Laboratory, Faculty of Chemistry, University of Tabriz, 51664 Tabriz, Iran
(Received 29 May 2013; accepted 28 July 2013)
Tris(trimethylsilyl)methyllithium (TsiLi) reacts with CS2 via cleavage of the C=S double bond and unex-
pected rearrangement to give sulfur-containing organosilicon compounds. The intermediate, from the
reaction between TsiLi and CS2 is not stable but it has been trapped by various alkyl halides to give
mercaptobis-(trimethylsilyl)-thiones. These reactions are quantitative and high yields in short periods of
time have been obtained.
Keywords: organosilicon-sulfur;tris(trimethylsilyl)methyllithium;carbondisulfide;mercapto-trimethylsilyl-
thione; alkyl halide
1. Introduction
The chemistry of carbon disulfide has been studied extensively. Most reactions proceed via ini-
tial nucleophilic attack at carbon.[1–9] According to the literature,[1–4,9–12] the reaction of
carbon disulfide with organolithium compounds leads to the formation of intermediates of two
types: 1,1-dithioenolates RHC = C(SLi)2 and dithiocarboxylates RC(S)SLi. 1,1-Dithioenolates
are ambidentate nucleophiles which react with electrophiles at both sulfur atoms. Dithiocarboxy-
lates in the presence of electrophiles are converted into dithiocarboxylic acid esters, compounds
−
−
containing one or more C C(S)S C groups. Despite the many research publications during the
past decade or so that have been concerned with the synthetic applications of CS2, there are few
reports on the reaction of organosilicon compounds with CS2.[13–15]Therefore, we wish to report
reactionsofcarbondisulfideproceedingbywayofnucleophilicattackoftris(trimethylsilyl)methyl
anion at the carbon of carbon disulfide.
We have recently used bulky tris(trimethylsilyl)methyllithium (TsiLi) [16] as a reagent in var-
ious reactions such as the preparation of vinylsilanes, epoxysilanes, halovinylsilanes, silylethers,
etc. In addition, we have investigated its behavior with various electrophiles such as aldehydes,
∗Corresponding author. Email: dsafa@tabrizu.ac.ir
© 2013 Taylor & Francis

2
K.D. Safa and K. Ghorbanpour
epoxides, benzyl, allyl and alkyl halides.[17–25] With this in mind we have examined the reac-
tion of TsiLi with CS2 in the presence of various electrophiles in an effort to synthesize products
from attack at sulfur. Surprisingly, rearrangement occurred and new organosilicon compounds
with thiocarbonyl and mercapto groups were produced. The conversion of carbon disulfide into
compounds containing mercapto and thiocarbonyl groups has not previously been observed.
The chemistry of these compounds is considered to be important because compounds containing
three different functional groups – trimethylsilyl, mercapto and thiocarbonyl – may be obtained.
We name them mercaptobis-(trimethylsilyl)-thiones.
2. Results and discussion
The present report deals with the reaction of tris(trimethylsilyl)methyllithium, carbon disulfide
and alkyl halides to give mercaptobis(trimethylsilyl)-thiones (1) (Scheme 1).
Scheme 1. Reaction of TsiLi and CS2 with alkyl halides.
Initially, we chose TsiLi as an organolithium compound and MeI as electrophile. When CS2
was added to a solution of TsiLi in THF, generated from the reaction of TsiH with MeLi [16]
(Scheme 2), at −46◦C (cyclohexanone/N2) and the mixture stirred at the same temperature for
5 min, the color immediately changed from yellow to red, indicating the formation of new anion.
Iodomethane was added and the color changed again (back to yellow). The mixture was stirred for
5 min at −46◦C and compound 1a was formed as the sole product in 98% yield (Scheme 3). Its
structure was determined from 13C and 1H NMR spectra. A singlet assigned to two trimethylsilyl
groups and a broad singlet assigned to the mercapto (SH) proton were detected at 0.14 ppm and
3.18 ppm, respectively. In addition, in the 13C NMR spectrum a very weak peak at 213.6 ppm
confirmed the presence of the C=S group.
Scheme 2. Preparation of tris(trimethylsilyl)methyllithium.
We attempted to separate the intermediate in the reaction of TsiLi with CS2 but we could not
isolate it. Therefore, we decided to trap it with various electrophiles. Although the mechanism is
not yet clear, the pathway for the formation of mercaptobis-(trimethylsilyl)-thiones is assumed
to be C-to-S migration of the SiMe3 group, then the formation of carbanion (b) (thia-Brook
rearrangement) [26–29] and, after that, conversion to the enethiolate (c).[9,10] The resulting
product (1) shows that the migration of sulfur to the central carbon of C(SiMe3)2 has occurred. It

Journal of Sulfur Chemistry
3
Scheme 3. Preparation of 1-mercapto-1,1-bis(trimethylsilyl)propane-2-thione (1a).
seems likely that the product (1) forms through the intermediates (d)–(g) and after hydrolysis of
(g) (Scheme 4).
Scheme 4. The proposed mechanism of the reaction of TsiLi, CS2 and alkyl iodide.
To try to stop the rearrangement, we carried out the reaction with MeI at −78◦C and in a
one-pot reaction but we obtained the same product (1a) in poor yield. To investigate the effect
of temperature, the reaction was also carried out at 0◦C. A brown solution containing several
unidentified products with an unpleasant smell was formed.
After optimizing the reaction conditions, we examined the generality of these conditions in
reactions of several symmetrical and unsymmetrical alkyl halides. The results are summarized
in Table 1. Progress of the reactions was conveniently monitored by TLC. In all cases, reactions
were continued until complete consumption of the initial compounds. Table 1 shows the end time
of the reactions and the yields.
Generally, primary alkyl iodides gave higher yields than secondary and tertiary alkyl iodides.
2-Propyl iodide after 1 h gave a poor yield and none of the desired product was detected in
the reaction with tert-butyl iodide. Reactions of ethyl bromide and n-butyl bromide were also
investigated. Reaction of TsiLi and CS2 with alkyl iodides proceeded rapidly, but no reactions
were observed with alkyl bromides.
Furthermore, treatment of TsiLi and CS2 with allyl bromide, benzyl bromide and propargyl
halides was investigated. In contrast to the alkyl bromides, the reactions of allyl and benzyl

4
K.D. Safa and K. Ghorbanpour
Table 1. Reaction of TsiLi and CS2 with various halides.
Entry
1
RX
Product
Timea (min)
5
Yieldb (%)
98
CH3I
(1a)
2
CH3CH2I
10
98
(1b)
(1c)
3
4
CH3CH2Br
CH3(CH2)2I
–
60
15
–
90
5
CH3CHICH3
60
Low yield
(1d)
6
7
PhCH2CH2Br
PhCH2CH2I
–
–
–
60
20
–
85
(1e)
(1f)
8
9
CH3(CH2)3Br
CH3(CH2)3I
60
20
–
85
10
11
(CH3)3CI
CH3(CH2)4I
120
30
–
85
(1g)
(1h)
12
13
CH3(CH2)5I
30
45
85
80
ICH2CH2CH2I
(1i)
14
ICH2(CH2)2CH2I
60
80
98
(1j )
H
Me3Si
HS
S
C
Br
Cl
H2C
HC
15
16
15
Me3Si
CH2CH CH2
(1k)
C
–
120
–
(Continued)

Journal of Sulfur Chemistry
5
Table 1. Continued.
Entry
17
RX
Product
Timea (min)
Yieldb (%)
–
Unidentified compounds
–
C
I
HC
18
15
98
Br
(1l)
aThe reactions were followed by TLC.
bYields obtained by preparative thin layer chromatography (PTLC).
bromides as well as alkyl iodides were quantitative and high yields in short periods of time were
obtained. Propargyl chloride and iodide did not show good results. All the products are stable at
0◦C for a long time and for several months at room temperature.
3. Conclusion
We have described a novel, efficient and quantitative preparation of a variety of multifunctional
mercaptobis(trimethylsilyl)-thiones from the reaction of TsiLi and CS2 with alkyl, allyl and ben-
zyl halides in THF at −46◦C. The intermediate from the reaction between TsiLi and CS2 was
trapped rapidly by alkyl iodides, allyl and benzyl bromide but no reaction was observed with alkyl
bromides.
4. Experimental
4.1. Solvents and reagents
The reactions were carried out under dry argon. Solvents and CS2 were dried by standard meth-
ods. Substrates for the preparation of tris(trimethylsilyl)methyllithium, namely Me3SiCl (Merck),
Li (Merck), CHCl3 (Merck) and substrates for the preparation of mercaptobis(trimethyl)silyl-
thiones, namely alkyl halides, benzyl and allyl bromide (Merck), n-hexane (Merk) for TLC, were
used as received. Tris(trimethylsilyl)methyllithium, (Me3Si)3CLi, was prepared as described by
Grobel et al.[16] Commercially unavailable alkyl iodides were prepared from alkyl chlorides and
bromides as described in the literature.[30]
4.2. Instrumentation
The 1H 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 GC-massAgilent quadrupole mode
5973N instrument, operating at 70 eV. The Fourier transform infrared spectroscopy (FTIR) spectra
were recorded on a Bruker-Tensor 270 spectrometer. Elemental analyses were obtained with a
Vario EL III instrument.
4.3. Typical procedure for the preparation of mercaptobis(trimethylsilyl)-thiones (1a–1l)
To a stirred solution of tris(trimethylsilyl)methyllithium (1 mmol) in THF, carbon disulfide
(1.2 mmol) in THF (2 ml) was added at −46◦C (cyclohexanone/N2) under an argon atmosphere.

6
K.D. Safa and K. Ghorbanpour
The mixture was stirred for 5 min and then electrophile (1 mmol) (for compounds 1i and 1j,
0.5 mmol of electrophile) was added at this temperature and the stirring was maintained as the
mixture was allowed to warm from −46◦C to 0◦C. The progress of the reaction was followed by
TLC with n-hexane as solvent. The mixture was poured into water and extracted with CH2Cl2. The
organic layer was washed with water, dried with Na2SO4 and filtered. The solvent was evaporated
from the filtrate and the residue was purified by preparative TLC on silica gel with n-hexane as
eluent.
4.3.1. 1-Mercapto-1,1-bis(trimethylsilyl)propane-2-thione (1a)
Yellow liquid, 98% (Rf = 0.50). FTIR (KBr, cm−1): 2957 (CH), 1413, 1153 (C=S), 1252, 920 and
−
−
837 (C Si), 1023 (C S); 1H NMR (400 MHz, CDCl3): δ 0.14 (s, 18H, SiMe3), 2.55 (s, 3H, CH3),
3.18 (b.s, 1H, SH); 13C NMR (CDCl3): δ −1.21 (SiMe3), 19.76 (CH3), 55.33 (C(SiMe3)2SH),
+
+
−
213.62 (C=S, very weak); m/z (EI): 250 (10%, [M] ), 235 (42%, [M CH3] ), 203 (70%,
[HSCC(SiMe3)2]+), 163 (19%, [HSCC(SH)SiMe3]+), 115 (61%, [HSCCSiMe2]+), 73 (100%,
[SiMe3]+).Anal. Calcd for C9H22S2Si2: C, 43.1; H, 8.8; S, 25.6. Found: C, 43.4; H, 8.6; S, 25.4%.
4.3.2. 1-Mercapto-1,1-bis(trimethylsilyl)butane-2-thione (1b)
Yellow liquid, 98% (Rf = 0.70). FTIR (KBr, cm−1): 2960 (CH), 1407, 1152 (C=S), 1251, 918
1
−
−
and 842 (C Si), 1022 (C S); H NMR (400 MHz, CDCl3): δ 0.15 (s, 18H, SiMe3), 1.27 (t, J =
7.4 Hz, 3H, CH3), 3.14 (q, J = 7.4 Hz, 3H, CH2 and SH); 13C NMR (CDCl3): δ −1.18 (SiMe3),
11.79 (CH3), 30.33 (CH2), 55.22 (C(SiMe3)2SH), 213.62 (C=S, very weak); m/z (EI): 264 (18%,
+
+
+
+
−
[M] ), 249 (20%, [M CH3] ), 203 (68%, [HSCC(SiMe3)2] ), 163 (19%, [HSCC(SH)SiMe3] ),
115 (59%, [HSCCSiMe2]+), 73 (100%, [SiMe3]+). Anal. Calcd for C10H24S2Si2: C, 45.4; H, 9.1;
S, 24.2. Found: C, 45.6; H, 8.9; S, 24.3%.
4.3.3. 1-Mercapto-1,1-bis(trimethylsilyl)pentane-2-thione (1c)
Yellow liquid, 90% (Rf = 0.64). FTIR (KBr, cm−1): 2960 (CH), 1405, 1151 (C=S), 1251, 918
1
−
−
and 840 (C Si), 1022 (C S); H NMR (400 MHz, CDCl3): δ 0.09 (s, 18H, SiMe3), 0.99 (t,
J = 7.3 Hz, 3H, CH3), 1.61–1.70 (m, 2H, CH2), 3.13 (t, J = 7.2 Hz, 3H, CH2 and SH); 13C NMR
(CDCl3): δ −1.16 (SiMe3), 12.53 (CH3), 20.30 and 38.09 (2 × CH2), 55.40 (C(SiMe3)2SH),
213.62 (C=S, very weak); m/z (EI): 278 (5%, [M]+), 277 (10%, [M-1]+), 235 (20%,
+
+
+
−
[M CH2CH2CH3] ), 221 (25%, [S = CC(SH)(SiMe3)2] ), 163 (39%, [HSCC(SH)SiMe3] ),
115 (37%, [HSCCSiMe2]+), 73 (100%, [SiMe3]+). Anal. Calcd for C11H26S2Si2: C, 47.4; H, 9.4;
S, 23.0. Found: C, 47.1; H, 9.6; S, 22.9%.
4.3.4. 1-Mercapto-3-methyl-1,1-bis(trimethylsilyl)butane-2-thione (1d)
Yellow liquid with low yield (Rf = 0.60), FTIR (KBr, cm−1): 2960 (CH), 1406, 1151 (C=S),
+
+
−
−
1252, 919 and 83+9 (C Si), 1022 (C S); m/z (EI): 278 (+4%, [M] ), 277 (8%, [M-1] ), 235 (19%,
+
−
[M CH(CH3)2] ), 221 (25%, [S = CC(SH)(SiMe3)2] ), 163 (39%, [HSCC(SH)SiMe3] ), 115
(37%, [HSCCSiMe2]+), 73 (100%, [SiMe3]+).
4.3.5. 1-Mercapto-4-phenyl-1,1-bis(trimethylsilyl)butane-2-thione (1e)
Yellow liquid, 85%: (Rf = 0.53), FTIR (KBr, cm−1): 3064 (Ar), 2959 (CH), 1600–1450 (Ar),
1
−
−
1311, 1158 (C=S), 1250, 916 and 839 (C Si), 1023 (C S); H NMR (400 MHz, CDCl3): δ
0.18 (s, 18H, SiMe3), 3.19 (t, J = 7.8 Hz, 3H, CH2 and SH), 3.43 (t, J = 7.8 Hz, 2H, CH2),

Journal of Sulfur Chemistry
7
7.19–7.35 (m, 5H, Ar); 13C NMR (CDCl3): δ −1.17 (SiMe3), 33.17 (CH2), 39.32 (CH2), 55.40
(C(SiMe3)2SH), 125.39–127.59 (Ar), 213.62 (C=S, very weak); m/z (EI): 340 (3%, [M]+),
+
+
+
−
339 (10%, [M-1] ), 263 (20%, [M Ph] ), 221 (25%, [S = CC(SH)(SiMe3)2] ), 115 (52%,
[HSCCSiMe2]+), 91 (22%, [benzyl]+), 73 (100%, [SiMe3]+). Anal. Calcd for C16H28S2Si2: C,
56.4; H, 8.3; S, 18.8. Found: C, 56.5; H, 8.7; S, 18.7%.
4.3.6. 1-Mercapto-1,1-bis(trimethylsilyl)hexane-2-thione (1f)
Yellow liquid, 85% (Rf = 0.70), FTIR (KBr, cm−1): 2958 (CH), 1405, 1151 (C=S), 1252, 918
1
−
−
and 841 (C Si), 1022 (C S); H NMR (400 MHz, CDCl3): δ 0.15 (s, 18H, SiMe3), 0.92 (t,
J = 7.3 Hz, 3H, CH3), 1.36–1.46 (m, 2H, CH2), 1.57–1.64 (m, 2H, CH2), 3.15 (t, J = 7.4 Hz,
3H, CH2 and SH); 13C NMR (CDCl3): δ −1.17 (SiMe3), 12.66 (CH3), 21.15, 28.82 and 35.93
(3 × CH2), 55.40 (C(SiMe3)2SH), 213.62 (C=S, very weak); m/z (EI): 292 (3%, [M]+), 291
+
+
+
−
(6%, [M-1] ), 235 (10%, [M CH2CH2CH2CH3] ), 221 (25%, [S = CC(SH)(SiMe3)2] ), 163
(35%, [HSCC(SH)SiMe3]+), 115 (51%, [HSCCSiMe2]+), 73 (100%, [SiMe3]+). Anal. Calcd for
C12H28S2Si2: C, 49.2; H, 9.6; S, 21.9. Found: C, 49.4; H, 9.5; S, 22.0%.
4.3.7. 1-Mercapto-1,1-bis(trimethylsilyl)heptane-2-thione (1g)
Yellow liquid, 85% (Rf = 0.68), FTIR (KBr, cm−1): 2958 (CH), 1407, 1151 (C=S), 1252,
1
−
−
918 and 836 (C Si), 1022 (C S); H NMR (400 MHz, CDCl3): δ 0.15 (s, 18H, SiMe3),
0.88 (t, J = 7.0 Hz, 3H, CH3), 1.25–1.40 (m, 4H, 2 × CH2), 1.58–1.65 (m, 2H, CH2), 3.14 (t,
J = 7.4 Hz, 3H, CH2 and SH); 13C NMR (CDCl3): δ −1.18 (SiMe3), 12.93 (CH3), 21.19, 26.44,
30.12 and 36.16 (4 × CH2), 55.15 (C(SiMe3)2SH), 213.62 (C=S, very weak); m/z (EI): 306
+
+
+
−
(5%, [M] ), 291 (10%, [M CH3] ), 236 (10%, [M + 1-CH2CH2CH2CH2CH3] ), 203 (67%,
[HSCC(SiMe3)2]+), 163 (18%, [HSCC(SH)SiMe3]+), 115 (53%, [HSCCSiMe2]+), 73 (100%,
[SiMe3]+). Anal. Calcd for C13H30S2Si2: C, 50.9; H, 9.8; S, 20.9. Found: C, 51.2; H, 9.9; S,
20.8%.
4.3.8. 1-Mercapto-1,1-bis(trimethylsilyl)octane-2-thione (1h)
Yellow liquid, 85% (Rf = 0.82), FTIR (KBr, cm−1): 2955 (CH), 1408, 1151 (C=S), 1251, 918
1
−
−
and 842 (C Si), 1022 (C S); H NMR (400 MHz, CDCl3): δ 0.15 (s, 18H, SiMe3), 0.88 (m,
5H, CH2CH3), 1.25–1.74 (m, 6H, 3 × CH2), 3.15 (t, J = 7.4 Hz, 3H, CH2 and SH); 13C NMR
(CDCl3): δ −1.17 (SiMe3), 13.00 (CH3), 21.51, 26.71, 27.65, 30.35 and 36.23 (5 × CH2),
55.17 (C(SiMe3)2SH), 213.62 (C=S, very weak); m/z (EI): 320 (5%, [M]+), 305 (10%,
+
+
+
−
[M CH3] ), 236 (10%, [M + 1-CH2CH2CH2CH2CH2CH3] ), 203 (100%, [HSCC(SiMe3)2] ),
163 (22%, [HSCC(SH)SiMe3]+), 115 (63%, [HSCCSiMe2]+), 73 (99%, [SiMe3]+). Anal. Calcd
for C14H32S2Si2: C, 52.4; H, 10.0; S, 20.0. Found: C, 52.5; H, 9.7; S, 20.1%.
4.3.9. 1,5-Dimercapto-1,1,5,5-tetrakis(trimethylsilyl)heptane-2,4-dithione (1i)
Yellow liquid, 80% (Rf = 0.55), FTIR (KBr, cm−1): 2956 (CH), 1406, 1153 (C=S), 1251, 916 and
1
−
−
841 (C Si), 1021 (C S); H NMR (400 MHz, CDCl3): δ 0.14 (s, 36H, SiMe3), 1.94–1.98 (m, 2H,
CH2), 3.13 (b.s, 2H, SH), 3.23 (t, J = 7.1 Hz, 4H, CH2); 13C NMR (CDCl3): δ −1.16 (SiMe3),
25.38 and 34.99 (3 × CH2), 55.41 (C(SiMe3)2SH), 213.62 (C=S, very weak); This compound
decomposed during GC-mass analysis to give fragments with m/z (EI): 203 ([HSCC(SiMe3)2]+),
163 ([HSCC(SH)SiMe3]+), 115 ([HSCCSiMe2]+), 73 ([SiMe3]+). Anal. Calcd for C19H44S4Si4:
C, 44.4; H, 8.6; S, 25.0. Found: C, 44.6; H, 8.8; S, 25.3%.

8
K.D. Safa and K. Ghorbanpour
4.3.10. 1,5-Dimercapto-1,1,5,5-tetrakis(trimethylsilyl)octane-2,4-dithione (1j)
Yellow liquid, 80% (Rf = 0.50, m.p.: 72–74◦C), FTIR (KBr, cm−1): 2954 (CH), 1403, 1151
1
(C=S), 1250, 917 and 839 (C–Si), 1021 (C–S); H NMR (400 MHz, CDCl3): δ 0.14 (s, 36H,
SiMe3), 1.71–1.74 (m, 4H, CH2), 3.12 (b.s, 2H, SH), 3.18 (t, 4H, CH2); 13C NMR (CDCl3): δ
−1.16 (SiMe3), 26.20 and 35.46 (4 × CH2), 55.27 (C(SiMe3)2SH), 213.62 (C=S, very weak);
this compound decomposed during GC-mass analysis to give fragments with m/z (EI): 203
([HSCC(SiMe3)2]+), 163 ([HSCC(SH)SiMe3]+), 115 ([HSCCSiMe2]+), 73 ([SiMe3]+). Anal.
Calcd for C20H46S4Si4: C, 45.5; H, 8.8; S, 24.3. Found: C, 45.6; H, 8.9; S, 24.5%.
4.3.11. 1-Mercapto-1,1-bis(trimethylsilyl)pent-4-ene-2-thione (1k)
Yellow liquid, 98% (Rf = 0.73), FTIR (KBr, cm−1): 3084 (CHvinyl), 2954 (CH), 1637 (C=C),
1
−
−
1418, 1153 (C=S), 1250, 917 and 840 (C Si), 1021 (C S); H NMR (400 MHz, CDCl3): δ
0.15 (s, 18H, SiMe3), 3.13 (b.s, 1H, SH), 3.84 (d, J = 6.8 Hz, 2H, CH2), 5.11 (d, J = 10.0 Hz,
1H, CH2), 5.25 (d, J = 17.0 Hz, 1H, CH2), 5.77–5.87 (m, 1H, CH); 13C NMR (CDCl3): δ −1.17
(SiMe3), 39.20 (CH2), 55.40 (C(SiMe3)2SH), 117.31 (CH2vinyl), 130.84 (CHvinyl), 213.60 (C=S,
+
+
+
−
−
veryweak);m/z (EI):276(13%, [M] ), 249(15%, [M CH = CH2] ), 203(13%, [M SiMe3] ),
163 (30%, [HSCC(SH)SiMe3]+), 115 (22%, [HSCCSiMe2]+), 73 (100%, [SiMe3]+), 28 (29%,
[CH = CH2]+). Anal. Calcd for C11H24S2Si2: C, 47.7; H, 8.7; S, 23.2. Found: C, 47.5; H, 8.8; S,
23.1%.
4.3.12. 1-Mercapto-1,1-bis(trimethylsilyl)-3-phenylpropane-2-thione (1l)
Yellow liquid, 98% (Rf = 0.66). FTIR (KBr, cm−1): 3065 (Ar), 2957 (CH), 1601–1453 (Ar),
1
−
−
1409, 1150 (C=S), 1252, 917 and 843 (C Si), 1021 (C S); H NMR (400 MHz, CDCl3): δ 0.17
(s, 18H, SiMe3), 3.14 (b.s, 1H, SH), 4.45 (s, 2H, CH2), 7.28 (m, 5H, Ar); 13C NMR (CDCl3):
δ −1.13 (SiMe3), 41.07 (CH2), 54.94 (C(SiMe3)2SH), 126.28–135.23 (Ar), 213.62 (C=S, very
weak); m/z (EI): 328 (4%, [M + 2]+), 327 (6%, [M + 1]+), 326 (24%, [M]+), 235 (24%, [M-
benzyl]+), 203 (82%, [HSCC(SiMe3)2]+), 115 (45%, [HSCCSiMe2]+), 91 (100%, [benzyl]+),
73 (70%, [SiMe3]+). Anal. Calcd for C15H26S2Si2: C, 55.1; H, 8.0; S, 19.6. Found: C, 54.9; H,
8.2; S, 19.8%.
Acknowledgement
We thank Dr J.D. Smith for helpful comments
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