Straightforward and highly efficient catalyst-free regioselective reaction of thiol to β-nitrostyrene: a concise synthesis of vinyl sulfide and nitro sulfide

Article abstract of DOI:10.1016/j.tet.2009.02.074

Under catalyst-free reaction conditions, solvent-mediated addition of thiol 2 to β-nitrostyrene 1 proceeded with regioselective control to afford either adduct 3 or vinyl sulfide 4 in good to excellent yield. Thermodynamic and autocatalytic reaction mecha

Full text of DOI:10.1016/j.tet.2009.02.074

Tetrahedron 65 (2009) 3878–3885
Contents lists available at ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Straightforward and highly efficient catalyst-free regioselective reaction of thiol
to b-nitrostyrene: a concise synthesis of vinyl sulfide and nitro sulfide
Cheng-Ming Chu y, Zhijay Tu y, Pohsi Wu, Chieh-Chieh Wang, Ju-Tsung Liu,
*
Chun-Wei Kuo, Yu-Hsuan Shin, Ching-Fa Yao
Department of Chemistry, National Taiwan Normal University 88, Sec. 4, Tingchow Road, Taipei, Taiwan 116, Taiwan ROC
a r t i c l e i n f o
a b s t r a c t
Article history:
Under catalyst-free reaction conditions, solvent-mediated addition of thiol 2 to
b-nitrostyrene 1
Received 30 October 2008
Received in revised form 24 February 2009
Accepted 27 February 2009
Available online 5 March 2009
proceeded with regioselective control to afford either adduct 3 or vinyl sulfide 4 in good to excellent
yield. Thermodynamic and autocatalytic reaction mechanisms were proposed to rationalize the products
thus formed.
Ó 2009 Elsevier Ltd. All rights reserved.
Ar
1. Introduction
neat, rt
RS
NO2
SR
b
-Nitrostyrenes are versatile building blocks in organic
Ar
3
synthesis reactions.1 Conjugated nitroalkenes are excellent
Michael acceptors due to the strong electron-withdrawing
nature of the nitro group. Many classes of compounds have
been prepared via classical Michael addition using conjugated
nitroalkanes. Recently, it was discovered that substitution of
+
RSH
NO2
Ar
1
2
N2 or dry air
reflux in
toluene or
p-xylene
4
(major product)
b
-nitrostyrenes to generate corresponding alkenes is facilitated
by an electrophilic carbon-centered radical process.2,3 Based on
these preliminary results, we try to expand the scope of pro-
tocols to further applications. After intensive investigation, we
determined that, under catalyst-free reaction conditions, nu-
1a: Ar = Ph
2a: R = Ph
1b: Ar = 1-naphthalenyl
1c: Ar = 4-ClC6H4
1d: Ar = 4-FC6H4
1e: Ar = 4-MeOC6H4
1f: Ar = 2-NO2C6H4
1g: Ar = 2-furyl
2b: R = C6H5CH2
2c: R = c-C6H11
2d: R = t-C4H9
2e: R = C6H13
2f: R = C3H7
2g: R = HOC2H4
2h: R = 2-naphthalenyl
2i: R = 4-MeOC6H4
2j: R = 4-NO2C6H4
cleophilic addition of thiol radicals to
in a regiospecific manner, resulting in an efficient production of
vinyl sulfides.
b-nitrostyrenes proceeds
1h: Ar = 2-thienyl
Vinyl sulfides are versatile synthons in organic syntheses.4–6
Because there are only a few systems available for the synthesis of
vinyl sulfides, including addition of thiols to alkynyl analogues,7
transition metal-mediated cross coupling of vinyl halides with
various thiols,8 and other unusual methods,9 development of new
methods for the synthesis of vinyl sulfides is urgently needed.
Herein, we report a novel procedure to synthesize vinyl sulfides in
high yield. As shown in Scheme 1, execution of this novel procedure
is quite simple.
Scheme 1.
2. Results and discussion
Table 1 lists representative examples of reaction yield under
various reaction conditions. Our initial efforts focused primarily on
the efficiency of various solvents. Reactions were performed using
1 equiv of b-nitrostyrene 1a and 3 equiv of thiophenol 2a under
catalyst-free conditions. The results of these experiments demon-
strate that regioselective differences were highly attributed to dif-
ferences between protic and aprotic solvents. For example, ethanol
(entry 5) and toluene (entry 15) afforded 3aa and 4aa, respectively,
in quantitative yield. The temperature-dependent substitution re-
action proceeded with obvious regioselectivity in nearly every
aprotic solvent except for DMSO (entry 11), which produced a large
amount of diphenyl disulfide at high-temperature. A further
* Corresponding author. Tel./fax: þ886 2 29309092.
E-mail address: cheyaocf@ntnu.edu.tw (C.-F. Yao).
Both authors contributed equally to this work.
y
0040-4020/$ – see front matter Ó 2009 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2009.02.074

C.-M. Chu et al. / Tetrahedron 65 (2009) 3878–3885
3879
Table 1
Reaction of
catalysta
substitution are depicted in Scheme 2. During the nucleophilic
reaction, hydrogen bond formation between the sulfhydryl hy-
b-nitrostyrene 1a with thiophenol 2a in various solvents in absence of
drogen of the thiol and the nitro oxygen atom of the
styrene increases electrophilicity of the -carbon. In other words,
hydrogen bond formation simultaneously activates both the
-nitrostyrene and the thiol. In this way, an intramolecular nu-
cleophilic attack at the -site of the nitrostyrene by the sulfur
b-nitro-
Ph
Ph
Ph
dry air
5 mL solvent
reflux
b
+
NO2
+
NO2
PhSH
PhS
SPh
4aa
b
1a
2a
3aa
b
Entry
Solvent
Time
1 h
3aa (%)b
4aa (%)/[sel.]b
atom followed by a series of proton rearrangement, results in
conjugate addition. During the radical substitution reaction,
a suitable initiator such as triplet oxygen, or perhaps the process
of thermolysis, initiates the liberation of a thiyl radical. Another
proposed route is the formation of a carrier-benzylic radical when
the initiator first reacts with toluene first. The resulting benzylic
radical can abstract the hydrogen from thiol 2 to generate a thiyl
1
2
3
4
5
6
7
8
Neat/rt/O2
Neat/rt/airc
Neat/rt/air/TEMPO
Neat/rt/argon
EtOH
HOAc
MeCN
CH2Cl2
THF
EtOAc
DMSO
C6H6
1,4-Dioxane
Toluene/argon
Toluene
82
98
89
85
98
95
75
10
8
15
12
15
25
d
d
tr
d
30 min
d
1 h
1 h
3 h
3 h
3 h
3 h
3 h
3 h
3 h
3 h
3 h
3 h
3 h
3 h
d
d
2/[5.3:1]
5/[4.0:1]
15/[6.5:1]
2/[5.4:1]
9/[5.8:1]
39/[6.3:1]
46/[4.8:1]
61/[5.1:1]
75/[6.5:1]
97/[6.5:1]
98/[6.1:1]
12/[8.0:1]
radical.11 Thus, a thiyl moiety will attack at the
-nitrostyrene to form the stable benzylic radical followed by the
a-position of
9
b
10
11
12
13
14
15
16
loss of a NO2 radical. A reddish-brown corrosion was always ob-
served on the septa during the course of the reaction. However,
the outcome of the geometric isomers was quite different from
previously established examples with carbon-centered radicals.2
The E-isomers are exclusively obtained when
b-nitrostyrene is
Toluene/TEMPO
conducted with carbon-centered radicals using a similar process.
Once the intermediate A forms, the relatively sulfur group, which
is relatively larger compared with the general carbon group, will
retard the rapid rotation of the single bond, resulting in the for-
mation of E/Z isomers after the release of NO2. Moreover, the
sulfur atom helps with reduction of the steric hindrance between
the aryl and alkyl groups.
a
Conditions: a solution of 2.0 mmol of b-nitrostyrene 1a and 6 mmol of thio-
phenol 2 in 5 mL of indicated solvent was refluxed under dry atmosphere.
b
Yields and the ratio of trans/cis isomers were determined by 1H NMR and GC.
In the presence of normal atmosphere.
c
examination was also done by mixing toluene with the radical
scavenger, TEMPO, which markedly inhibited formation of the
substituted product 4aa (entry 16). In addition, when the reaction
was carried out in the absence of solvent, it did not proceed effi-
ciently (entry 3). Thus, the mechanism for this reaction pathway
appears to involve an autocatalytic/nucleophilic reaction of the
thiol. In fact, these results helped us to determine that 1,4-addition
Autocatalytic addition is generally applicable to thiols, as
shown in Table 2. In fact, the rate of thiol reaction with a com-
mon
thiols to form hydrogen bonds. For example, the reaction with
thiophenol was faster than reactions with -toluenethiol and
b-nitrostyrene was influenced by the ability of the various
a
alkyl thiol (entries 1–5). As the sulfhydryl hydrogen atom of
aliphatic thiols is less acidic than that of aromatic thiols,12
hydrogen bond formation between the sulfhydryl hydrogen atom
of thiols to b-nitrostyrenes proceeds efficiently in the absence of
acid/base catalysts, which contrasts with other methods that are
unsatisfactory due to multiple limitations.10
and the nitro oxygen atom of
aliphatic thiols.
b-nitrostyrene was reduced in
While the exact reaction mechanism remains unidentified,
plausible mechanisms for autocatalytic addition and radical
The application of the new method to the radical substitution of
-nitrostyrene with thiols in the absence of a catalyst to generate
b
vinyl sulfide was also examined. The method was compatible with
Ar
β
O
N
(a)
RSH
Ar
Ar
NO2
NO2
H
S
R
O
Table 2
1
Autocatalytic addition of thiols 2 to
b
-nitrostyrenes 1 in the absence of solventa
Ar
Ar
air
neat, rt
+
RSH
Ar
O
NO2
RS
NO2
3
N
O
H
1
2
SR
SR
3
Entry
1
2
Time
Product 3
Yieldsb (%)
1
2
3
4
5
6
7
8
1a
1a
1a
1a
1a
1b
1c
1d
1e
1e
1e
1e
1g
1h
2a
2b
2c
2e
2f
2a
2a
2a
2a
2b
2c
2e
2a
2a
30 min
2 h
32 h
36 h
10 h
1 h
30 min
30 min
7 h
3aa
3ab
3ac
3ae
3af
3ba
3ca
3da
3ea
3eb
3ec
3ee
3ga
3ha
96
92
92
91
93
94
93
95
93
96
94
96
90
93
Δ
(b)
+
RSH
2
Initiator
RS
Δ
Initiator
+
CH2
RS
CH3
or
+
+
CH3
RSH
9
CH2
RS
10
11
12c
13c
14
3 h
18 h
24 h
72 h
1 h
Ar
Ar
H
-NO2
Ar
H
+
SR
NO2
SR
NO2
1
A
4
a
Conditions: the mixture of 2.0 mmol of b-nitrostyrene 1 and 4 mmol of thiol 2
stirred under normal atmosphere.
Scheme 2. Plausible reaction mechanisms and roles of (a) nucleophilic thiol in
autocatalytic addition and (b) electrophilic thiyl radical in the pathway with
b
Yields are for isolated, chromatographically pure products.
Ethanol (0.5 mL) was added.
c
b-nitrostyrenes.

3880
C.-M. Chu et al. / Tetrahedron 65 (2009) 3878–3885
Table 3
Ar
Ar
AIBN
Benzene
reflux 12 h
Radical substitution of various thiols 2 with
b
-nitrostyrenes 1 in the absence of
Ar
Ar
RS
+
RSH
catalysta
NO2
SR
1
2
4
Ar
dry Air
+
NO2
+
NO2
RSH
5 mL solvent
reflux
SR
1
2
3
4
S
4aa
S
4ad
S
4ae
Yields (%)b
a
Entry
1
2
Solvent/time
98% (9.4:1)
82% (4.1:1)
85% (5.5:1)
3
4aa/[sel.]
1
2
3
4
5
6
7
8
1a
1a
1a
1a
1a
1a
1a
1a
1b
1c
1d
1e
1e
1e
1e
1e
1g
1h
2a
2b
2c
2d
2e
2fc
2i
Toluene/3 h
p-Xylene/7 h
p-Xylene/10 h
p-Xylene/6 h
p-Xylene/24 h
p-Xylene/12 h
Toluene/2.5 h
p-xylene/3 h
Toluene/3 h
Toluene/4 h
Toluene/4 h
Toluene/3 h
p-Xylene/10 h
p-Xylene/10 h
p-Xylene/12 h
p-Xylene/14 h
Toluene/1 h
Toluene/1 h
3aa/d
3ab/8
3ac/6
3ad/d
3ae/20
3af/3
3ai/d
3aj/29
3ba/d
3ca/tr
3da/tr
3ea/d
3eb/19
3ec/tr
3ed/d
3ee/7
4aa/93[5.6:1]
4ab/69[3.5:1]
4ac/80[4.2:1]
4ad/70[3.4:1]
4ae/52[12:1]
4af/30[5.2:1]
4ai/92[5.9:1]
4aj/65[4.2:1]
4ba/95[5.4:1]
4ca/85[5.7:1]
4da/96[4.8:1]
4ea/94[12.9:1]
4eb/62[3.4:1]
4ec/93[3.4:1]
4ed/60[3.6:1]
4ee/55[5.1:1]
4ga/92[2.3:1]
4ha/94[1.9:1]
S
S
S
4ba
4bb
4bc
98% (12.0:1)
90% (4.4:1)
85% (3.8:1)
2j
9
2a
2a
2a
2a
2b
2c
2d
2e
2a
2a
OH
S
S
10
11
12
13
14
15
16
17
18
S
4bg
4bh
4bf
97% (4.9:1)
87% (4.1:1)
95% (6.3:1)
MeO
MeO
Cl
S
3ga/d
3ha/d
S
S
4ca
4ea
4ed
a
Conditions: a solution of 2.0 mmol of b-nitrostyrene 1 and 6 mmol of thiol 2 in
98% (4.2:1)
98% (6.1:1)
90% (4.3:1)
5 mL of purified solvent was refluxed as indicated period.
b
Isolation yields and the ratio of trans/cis isomers were determined by 1H NMR
NO2
and GC.
c
S
S
O
S
Thiol (10 mmol, 5 equiv) was used.
S
4ga
4ha
4fa
94% (1.8:1)
80% (1.7:1)
96% (8.9:1)
Scheme 3. Substitution of
AIBN. Conditions: a solution of 2.0 mmol of
b
-nitrostyrenes 1 with various thiols 2 in the presence of
-nitrostyrene 1, 6 mmol of thiol 2, and
various functional substituents on the phenyl group of
b
b
-nitrostyrene, including alkyl, halo, and even heteroaryl groups
6 mmol of AIBN in 13 mL of benzene was refluxed for 12 h. (a) thiol (10 mmol, 5 equiv)
was used. (b) Isolation yields and the trans/cis isomers were determined by 1H NMR
and GC.
(Table 3). The para-site of halo-substituted -nitrostyrene reacted
b
efficiently with thiophenol, and the vinyl sulfide products were
obtained in 85–96% yields (entries 10–11). For substituted thio-
phenol 2a and 4-methoxybenzenethiol 2i, bearing electron-
donating groups, provided the corresponding vinyl sulfide 4aa in
93% and 4ai in 92% isolated yields. However, an absence of the
activating substituent lowered the radical product yields. Thus,
4-nitrobenzenethiol 2j yielded corresponding vinyl sulfide 4aj and
nitro sulfide 3aj in 65% and 29% yields, respectively (entries 1 and
7–8).
In general, the lower reactivity and boiling point of aliphatic
thiols increased the formation of dialkyl disulfide during the re-
action, resulting in poor product yield and regioselectivity. For ex-
ample, 5 equiv of 1-propanethiol 2f (bp¼67–68 ꢀC) were converted
to vinyl sulfide 4af in 30% isolated yield under refluxing p-xylene
(entry 6). Similarly, 4ae and 4ee were isolated in moderate yields
from the reaction of 1-hexanethiol 2e with the nitrostyrenes 1a and
1e, respectively (entries 5 and 16).
Ph
Ph
Ph
Ph
PhS
neat
dry air
p-xylene 5 mL,
reflux, 3 h
Ph
Ph
PhSH
PhSH
+
rt, 6 d
NO2
NO2
3ia (67%)
SPh
1i
4ia (98%)
neat
rt, 7 h
dry air
toluene 5 mL,
reflux, 3 h
+
No reaction
NO2
NO2
SPh
3ja (95%)
1j
Scheme 4.
3. Conclusion
Addition of the initiator, AIBN, dramatically improved the effi-
ciency and regioselectivity of the reaction. All the reactions can be
completed under refluxing for 12 h in benzene. Thus, addition of
AIBN significantly improved the efficiency and reactivity of the low-
boiling-point thiols, as exemplified in Scheme 3.
In summary, we have demonstrated either substitution of
the nitro group by appropriate electrophilic thiyl radicals, or
a novel protocol for the autocatalytic addition of thiols to
b
-nitrostyrene under mild and neutral conditions. Of note, the
The thiyl radical derived from 2a also reacted with
a
-diphenyl
high regioselectivity of this method did not require a catalyst.
It is also noteworthy that the present reaction opens the
possibility of a synthetic vinyl sulfide crossover to the tran-
sition-metal-catalyzed addition of alkyne or a vinyl halide
coupling reaction with thiols. Although peroxide-initiated re-
actions of mercaptans with various substrates have been
reported, addition of excess AIBN is the more facile method
and results in absolute regioselective formation of vinyl sul-
fide derivatives.
nitrostyrene 1i to efficiently produce 4ia. However, the sterically
hindered nitrostyrene was not a good substrate for the nucleophilic
thiol derived from 2a (Scheme 4), giving the expected sulfide 3ia in
moderate yield. So far, attempts to extend the substitution reaction
to the general nitroalkene, 1-nitro-1-cyclohexene 1j, with the thiyl
radical 2a have failed. This result may be explained by the forma-
tion of a stable benzylic radical, i.e., intermediate A, as shown in
Scheme 2.

C.-M. Chu et al. / Tetrahedron 65 (2009) 3878–3885
3881
4. Experimental section
4.1. General methods
117 (14),105 (25),104 (100),103 (16), 91 (16), 77 (22), 55 (17). HRMS
calcd for C14H21NO2S 267.1288, found 267.1292.
4.2.4. (2-Nitro-1-phenylethyl)propyl sulfide (3af)
All reactions were performed in oven-dried glassware and some
reactions were carried out under a positive pressure of argon when
the reactions were sensitive to moisture or oxygen. Analytical thin
layer chromatography was performed with E. Merck silica gel 60F
glass plates and flash chromatography by use of E. Merck silica gel
60 (230–400 mesh). GC was measured by SHIMADZU GC-14B. MS
or HRMS were measured by JEOL JMS-D300 or JEOL JMS-
HX110 spectrometer. 1H and 13C NMR spectra were recorded with
a Bruker Avance EX 400 FT NMR.
1H NMR (400 MHz, CDCl3)
d 7.37–7.25 (m, 5H), 4.754 (d like,
J¼7.79 Hz, 2H), 4.56 (dd, J¼7.8, 8.0 Hz, 1H), 2.42 (t, J¼7.2 Hz, 2H),
1.57 (sext, J¼7.2 Hz, 2H), 0.93 (t, J¼7.2 Hz, 3H); 13C NMR (100 MHz,
CDCl3)
d 137.72, 129.20, 128.60, 127.82, 79.59, 46.73, 33.88, 22.74,
13.52. m/z (relative intensity) 225 (Mþ, 2),179 (3), 137 (11),136 (30),
134 (21), 105 (23), 104 (100), 103 (25), 91 (15), 86 (50), 84 (76), 78
(17), 77 (24), 51 (46). HRMS calcd for C11H15NO2S 225.0818, found
225.0828.
Compounds 1a, 1c–1e, 1g–1h, 1j, thiols 2a–2h, and solvents
were obtained from commercial sources and were purified before
used if necessary. Compound 1b,13a 1f,13b and 1i,13c were prepared
according to the literature procedures and all spectral data were
consistent with the literature reports.
4.2.5. (2-Nitro-1-phenylethyl)(4-nitrophenyl)sulfide (3aj)
1H NMR (400 MHz, CDCl3)
d
8.14 (dt, J¼8.9, 1.5 Hz, 2H), 7.45 (dt,
J¼8.9, 2.0 Hz, 2H), 7.40–7.32 (m, 5H), 5.12 (dd, J¼8.3, 7.1 Hz, 1H),
4.86 (dd, J¼13.2, 8.4 Hz, 1H), 4.77 (dd, J¼13.2, 7.0 Hz, 1H); 13C NMR
(100 MHz, CDCl3)
d 147.11, 142.29, 135.58, 130.90, 129.57, 129.41,
127.83, 124.42, 78.65, 49.11. m/z (relative intensity) 304 (Mþ, 18),
257 (16), 155 (100), 149 (78), 125 (49), 104 (52), 91 (38), 66 (15).
4.2. Method A: general procedure for the autocatalytic
addition of thiophenol 2a to
solvent-free condition to generate (2-nitro-1-phenylethyl)
phenyl sulfide (3aa)
b
-nitrostyrene 1a under
4.2.6. (1-(Naphthalen-1-yl)-2-nitroethyl)phenyl sulfide (3ba)
1H NMR (400 MHz, CDCl3)
d
8.26 (d, J¼8.5 Hz, 1H), 7.91 (d,
J¼8.0 Hz, 1H), 7.82 (d, J¼8.2 Hz, 1H), 7.64 (tt, J¼6.9, 1.2 Hz, 1H), 7.55
(tt, J¼7.1, 0.8 Hz, 1H), 7.37–7.24 (m, 6H), 7.22 (d, J¼7.1 Hz, 1H), 5.71
(t, J¼7.4 Hz, 1H), 5.08 (dd, J¼13.3, 8.4 Hz, 1H), 4.93 (dd, J¼13.3,
In a typical experiment b-nitrostyrene 1a (0.298 g, 2.0 mmol)
and thiophenol 2a (0.41 mL, 4 mmol) were mixed together in
a 10 mL round bottle flask, and the solution vigorously stirred at
room temperature under an air atmosphere for 30 min. After
completion of the reaction (monitored by TLC and GC), the crude
products were purified by a flash column chromatography on silica
gel with ethyl acetate–hexane (4:100, v/v) to afford 96% yield of 3aa
as a white solid whose spectral data are consistent with the liter-
7.2 Hz, 1H); 13C NMR (100 MHz, CDCl3)
d 134.40, 134.36, 131.93,
131.81, 130.83, 129.55, 129.48, 129.44, 129.15, 127.17, 126.41, 125.18,
124.62, 122.87, 78.15, 45.21. m/z (relative intensity) 309 (Mþ, 12),
200 (14), 154 (100), 153 (65), 152 (55), 138 (41), 134 (24), 110 (64),
109 (31), 86 (53), 84 (90), 77 (24), 66 (24), 65 (21), 51 (51). HRMS
calcd for C18H15NO2S 309.0818, found 309.0827.
ature report:14 mp 73–74 ꢀC. 1H NMR (400 MHz, CDCl3)
(m, 10H), 7.34–7.21 (m, 3H), 4.93–4.83 (m, 2H), 4.75 (dd, J¼11.9,
5.3 Hz, 1H); 13C NMR (100 MHz, CDCl3)
136.48, 133.97, 132.09,
129.57, 129.20, 129.01, 128.85, 127.85, 78.74, 50.07. m/z (relative
intensity) 259 (Mþ, 11), 212 (10), 149 (11), 135 (28), 125 (26), 110
(71), 104 (100),103 (27), 77 (50), 66 (27), 65 (26), 51 (33). HRMS
calcd for C14H13NO2S 259.0662, found 259.0676.
d
7.43–7.27
4.2.7. (1-(4-Chlorophenyl)-2-nitroethyl)phenyl sulfide (3ca)
1H NMR (400 MHz, CDCl3)
d
7.39–7.28 (m, 7H), 7.20 (d, J¼8.5 Hz,
2H), 4.86 (dd, J¼9.2, 6.0 Hz, 1H), 4.82–4.75 (m, 1H), 4.73 (dd, J¼12.5,
6.0 Hz, 1H); 13C NMR (100 MHz, CDCl3)
135.13, 134.74, 134.18,
d
d
131.58, 129.66, 129.40, 129.27, 129.20, 78.52, 49.47. m/z (relative
intensity) 293 (Mþ, 7), 246 (11), 218 (66),185 (12),183 (16),140 (30),
138 (100), 136 (21), 125 (27), 110 (37), 109 (61), 102 (23), 101 (21), 75
(15). HRMS calcd for C14H12ClNO2S 293.0272, found 293.0278.
4.2.1. Benzyl(2-nitro-1-phenylethyl)sulfide (3ab)
1H NMR (400 MHz, CDCl3)
d
7.38–7.22 (m, 10H), 4.71–4.60 (m,
4.2.8. (1-(4-Fluorophenyl)-2-nitroethyl)phenyl sulfide (3da)
2H), 4.42 (dd, J¼8.8, 6.9 Hz, 1H), 3.69 (d, J¼13.6 Hz, 1H), 3.60 (d,
1H NMR (400 MHz, CDCl3)
d
7.40–7.20 (m, 7H), 7.00 (tt, J¼8.6,
J¼13.6 Hz, 1H); 13C NMR (100 MHz, CDCl3)
d
137.23, 137.08, 129.22,
2.0 Hz, 2H), 4.89 (dd, J¼9.4, 6.2 Hz, 1H), 4.82–4.75 (m, 1H), 4.72 (dd,
129.11, 128.89, 128.69, 127.97, 127.71, 79.25, 46.10, 36.19. m/z (rela-
tive intensity) 273 (Mþ, 2), 104 (25), 91 (100), 77 (18), 65 (17), 51
(11). HRMS calcd for C15H15NO2S 273.0818, found 273.0822.
J¼12.8, 6.2 Hz, 1H); 13C NMR (100 MHz, CDCl3)
d 164.05 (d,
JC–F¼247 Hz), 134.10, 132.34 (d, JC–F¼3 Hz), 131.71, 129.65 (d,
JC–F¼8 Hz), 129.63, 129.18, 116.29 (d, JC–F¼21 Hz), 78.72, 49.34. m/z
(relative intensity) 277 (Mþ, 11), 230 (8), 168 (7), 135 (11), 125 (14),
122 (100), 121 (12), 110 (25), 109 (29), 101 (13), 96 (10), 75 (7), 65
(11). HRMS calcd for C14H12FNO2S 277.0567, found 277.0578.
4.2.2. Cyclohexyl(2-nitro-1-phenylethyl)sulfide (3ac)
1H NMR (400 MHz, CDCl3)
d 7.35–7.25 (m, 5H), 4.73–4.70 (m,
2H), 4.63 (dd, J¼8.8, 6.9 Hz, 1H), 2.62–2.54 (m, 1H), 1.97–1.81 (m,
2H), 1.77–1.65 (m, 2H), 1.62–1.50 (m, 1H), 1.40–1.15 (m, 5H); 13C
4.2.9. (1-(4-Methoxyphenyl)-2-nitroethyl)phenyl sulfide (3ea)15
NMR (100 MHz, CDCl3)
d
138.28, 129.17, 128.48, 127.74, 80.00, 45.30,
1H NMR (400 MHz, CDCl3)
d
7.42–7.30 (m, 5H), 7.21 (d, J¼8.7 Hz,
44.12, 33.61, 33.59, 25.99, 25.89, 25.79. m/z (relative intensity) 256
(Mþ, 3), 235 (11), 219 (4), 137 (50), 136 (30), 104 (100), 81 (58), 77
(24), 67 (24), 55 (58). HRMS calcd for C14H19NO2S 265.1131, found
265.1141.
2H), 6.86 (d, J¼8.6 Hz, 2H), 4.88 (dd, J¼9.6, 5.8 Hz, 1H), 4.83–4.76
(m, 1H), 4.70 (dd, J¼12.4, 5.7 Hz, 1H), 3.79 (s, 3H); 13C NMR
(100 MHz, CDCl3)
d 159.94, 133.83, 132.35, 129.57, 129.05, 128.91,
128.28, 114.60, 78.97, 55.51, 49.54. m/z (relative intensity) 289 (Mþ,
3), 180 (20), 154 (8), 138 (9), 135 (10),134 (100), 119 (14),110 (23), 91
(15), 77 (13), 65 (13), 57 (8), 51 (7). HRMS calcd for C15H15NO3S
289.0767, found 289.0772.
4.2.3. Hexyl(2-nitro-1-phenylethyl)sulfide (3ae)
1H NMR (400 MHz, CDCl3)
d 7.40–7.26 (m, 5H), 4.74 (d like,
J¼7.9 Hz, 2H), 4.56 (dd, J¼7.6, 8.1 Hz, 1H), 2.43 (t, J¼7.3 Hz, 2H), 1.51
(quint, J¼7.3 Hz, 2H), 1.35–1.13 (m, 6H), 0.86 (t, J¼7.2 Hz, 3H); 13C
4.2.10. Benzyl(1-(4-methoxyphenyl)-2-nitroethyl)sulfide (3eb)
NMR (100 MHz, CDCl3)
d
137.65, 129.13, 128.53, 127.77, 79.48, 46.70,
1H NMR (400 MHz, CDCl3)
d
7.35–7.22 (m, 5H), 7.20 (d, J¼8.6 Hz,
31.81, 31.40, 29.23, 28.51, 22.60, 14.13. m/z (relative intensity) 267
2H), 6.88 (d, J¼8.6 Hz, 2H), 4.69–4.57 (m, 2H), 4.39 (dd, J¼8.8,
7.0 Hz, 1H), 3.80 (s, 3H), 3.68 (d, J¼13.6 Hz, 1H), 3.59 (d, J¼13.6 Hz,
(Mþ, 2), 237 (4), 221 (3), 220 (3), 205 (4), 149 (10), 136 (18), 134 (14),

3882
C.-M. Chu et al. / Tetrahedron 65 (2009) 3878–3885
1H); 13C NMR (100 MHz, CDCl3)
d
159.80, 137.22, 129.18, 129.11,
4.3. Method B: general procedure for the radical substitution
of thiophenol 2a with -nitrostyrene 1a to generate
phenyl(styryl)sulfane (4aa)
129.00, 128.90, 127.69, 114.60, 79.48, 55.51, 45.64, 36.15. m/z (rela-
tive intensity) 303 (Mþ, 5), 256 (4), 202 (6), 193 (34), 180 (14), 178
(10), 135 (9), 134 (100), 115 (22), 91 (69), 71 (17), 65 (14), 57 (25), 55
(11). HRMS calcd for C16H17NO3S 303.0924, found 303.0930.
b
b
-Nitrostyrene 1a (0.298 g, 2.0 mmol) and anhydrous toluene
(5 mL) were charged into a 25 mL round bottom flask. A stir bar and
heating mantle were added; then a 15 cm Liebig condenser with
10 ꢀC chilling water and drying tube were attached to the flask. The
solution was preheated to reflux (150 ꢀC) for 3 min, and thiophenol
2a (0.62 mL, 6 mmol) was charged into flask. After 3 h, the orange
reaction mixture was allowed to cool to room temperature, and the
solvent was removed in vacuo. Flash column chromatography
(SiO2; ethyl acetate/hexane, 0.5:100) of the residue offered 93%
yield of 4aa as an (E)/(Z) (6:1 by NMR) mixture of colorless oil
whose spectral data are consistent with the literature report.8f,16
4.2.11. Cyclohexyl(1-(4-methoxyphenyl)-2-nitroethyl)sulfide (3ec)
1H NMR (400 MHz, CDCl3)
d
7.27 (d, J¼8.7 Hz, 2H), 6.88 (d,
J¼8.7 Hz, 2H), 4.68 (d like, J¼7.5 Hz, 2H), 4.59 (t like, J¼7.8 Hz, 1H),
3.77 (s, 3H), 2.60–2.52 (m, 1H), 1.97–1.80 (m, 2H), 1.76–1.63 (m, 2H),
1.62–1.50 (m, 1H), 1.39–1.14 (m, 5H); 13C NMR (100 MHz, CDCl3)
d
159.54, 129.99, 128.83, 114.45, 80.07, 55.37, 44.68, 43.89, 33.56,
33.51, 25.94, 25.84, 25.76. m/z (relative intensity) 295 (Mþ, 4), 240
(4), 180 (10), 166 (4), 135 (9), 134 (100), 119 (7), 91 (7), 77 (5), 65 (4),
55 (8). HRMS calcd for C15H21NO3S 295.1237, found 295.1237.
(E)-isomer: 1H NMR (400 MHz, CDCl3)
d
7.43 (d, J¼7.9 Hz, 2H), 7.36–
4.2.12. Hexyl(1-(4-methoxyphenyl)-2-nitroethyl)sulfide (3ee)
7.22 (m, 8H), 6.91 (d, J¼15.5 Hz, 1H), 6.75 (d, J¼15.4 Hz, 1H); 13C
1H NMR (400 MHz, CDCl3)
d
7.27 (d, J¼8.6 Hz, 2H), 6.89 (d,
NMR (100 MHz, CDCl3) d 136.56, 135.25, 131.84, 129.87, 129.19,
J¼8.6 Hz, 2H), 4.73 (d like, J¼7.9 Hz, 2H), 4.52 (t like, J¼7.9 Hz, 1H),
3.81 (s, 3H), 2.44 (t, J¼7.4 Hz, 2H), 1.53 (quint, J¼7.3 Hz, 2H), 1.37–
1.18 (m, 6H), 0.87 (t, J¼7.3 Hz, 3H); 13C NMR (100 MHz, CDCl3)
128.72, 127.62, 126.98, 126.05, 123.43. m/z (relative intensity) 212
(Mþ, 100), 212 (10), 211 (65), 178 (40), 167 (35), 135 (22), 134 (22),
126 (36), 110 (10), 103 (12), 91 (20), 77 (25), 65 (8), 51 (18).
d
159.77, 129.50, 129.00, 114.59, 79.78, 55.51, 46.27, 31.85, 31.49,
29.34, 28.61, 22.67, 14.18. m/z (relative intensity) 297 (Mþ, 4), 180
(10), 179 (8), 135 (12), 134 (100), 132 (12), 119 (8), 117 (6), 91 (7), 77
(6), 65 (5), 55 (4). HRMS calcd for C15H23NO3S 297.1393, found
297.1388.
4.3.1. Benzyl(styryl)sulfane (4ab)17
1H NMR (400 MHz, CDCl3)
d 7.46–7.16 (m,10H, (E) isomer and (Z)
isomer), 6.73 (d, J¼15.5 Hz, 1H, (E) isomer), 6.55 (d, J¼15.5 Hz, 1H,
(E) isomer), 6.43 (d, J¼10.9 Hz, 1H, (Z) isomer), 6.26 (d, J¼10.9 Hz,
1H, (Z) isomer), 4.01 (d, J¼6.0 Hz, 2H, (E) isomer and (Z) isomer); 13C
4.2.13. 2-(2-Nitro-1-(phenylthio)ethyl)furan (3ga)
NMR (100 MHz, CDCl3) d 137.62 ((Z) isomer), 137.47, 137.18, 137.10
1H NMR (400 MHz, CDCl3)
d
7.40–7.15 (m, 6H), 6.29 (dd, J¼3.2,
((Z) isomer), 129.21 ((Z) isomer), 129.05, 128.91 ((Z) isomer), 128.90,
128.84, 128.44 ((Z) isomer), 128.25, 127.63 ((Z) isomer), 127.56,
127.22, 126.95 ((Z) isomer), 126.22 ((Z) isomer), 126.14 ((Z) isomer),
125.83,124.59, 39.77 ((Z) isomer), 37.63. m/z (relative intensity) 226
(Mþ, 22),178 (4),135 (14),134 (15), 92 (9), 91 (100), 89 (3), 77 (3), 65
(16), 63 (2), 51 (3). HRMS calcd for C15H14S 226.0811, found
226.0817.
1.9 Hz, 1H), 6.13 (d, J¼3.2 Hz, 1H), 4.98 (dd, J¼8.8, 6.8 Hz, 1H), 4.86
(dd, J¼8.8, 13.2 Hz, 1H), 4.71 (dd, J¼13.2, 6.6 Hz, 1H); 13C NMR
(100 MHz, CDCl3)
d 194.11, 143.14, 134.82, 130.93, 129.45, 129.35,
110.82, 108.84, 76.44, 43.54. m/z (relative intensity) 249 (Mþ, 4), 218
(7), 203 (30), 140 (10), 110 (24), 109 (66), 94 (100), 77 (12), 69 (13),
66 (27), 65 (47), 63 (11), 51 (14). HRMS calcd for C12H11NO3S
249.0460, found 249.0464.
4.3.2. Cyclohexyl(styryl)sulfane (4ac)8f
4.2.14. 2-(2-Nitro-1-(phenylthio)ethyl)thiophene (3ha)
1H NMR (400 MHz, CDCl3)
d
7.49 (d, J¼7.4 Hz, 2H, (Z) isomer),
1H NMR (400 MHz, CDCl3)
d
7.43–7.26 (m, 6H), 6.91 (dd,
7.32 (t, J¼7.5 Hz, 2H, (Z) isomer), 7.32–7.27 (m, 4H, (E) isomer),
7.23–7.14 (m, 1H, (E) isomer and (Z) isomer), 6.78 (d, J¼15.6 Hz, 1H,
(E) isomer), 6.59 (d, J¼15.6 Hz, 1H, (E) isomer), 6.44 (d, J¼11.0 Hz,
1H, (Z) isomer), 6.35 (d, J¼11.0 Hz,1H, (Z) isomer), 3.03–2.94 (m,1H,
(E) isomer), 2.94–2.84 (m, 1H, (Z) isomer), 2.12–2.01 (m, 2H, (E)
isomer and (Z) isomer),1.84–1.74 (m, 2H, (E) isomer and (Z) isomer),
1.68–1.57 (m, 1H, (E) isomer and (Z) isomer), 1.50–1.21 (m, 5H, (E)
J¼5.0, 3.7 Hz, 1H), 6.85 (d, J¼3.4 Hz, 1H), 5.20 (dd, J¼8.8, 6.6 Hz,
1H), 4.83 (dd, J¼8.9, 13.1 Hz, 1H), 4.71 (dd, J¼13.1, 6.6 Hz, 1H);
13C NMR (100 MHz, CDCl3)
d 139.56, 134.28, 131.59, 129.58,
129.30, 127.14, 126.51, 126.23, 79.25, 45.53. m/z (relative in-
tensity) 265 (Mþ, 5), 220 (4), 219 (13), 218 (31), 185 (8), 156 (19),
154 (9), 135 (6), 110 (100), 109 (40), 84 (8), 77 (6), 69 (7), 66 (11),
65 (19), 51 (5). HRMS calcd for C12H11NO2S2 265.0226, found
265.0239.
isomer and (Z) isomer); 13C NMR (100 MHz, CDCl3)
d 137.41, 137.37
((Z) isomer), 128.88, 128.85 ((Z) isomer), 128.81, 128.40 ((Z) isomer),
127.10, 126.70 ((Z) isomer), 126.12 ((Z) isomer), 125.80, 125.26 ((Z)
isomer), 124.27, 47.99 ((Z) isomer), 45.56, 33.89 ((Z) isomer), 33.83,
26.24, 25.90, 25.83 ((Z) isomer). m/z (relative intensity) 218 (Mþ,
41), 207 (8), 163 (11), 137 (12), 136 (100), 135 (52), 94 (30), 91 (29),
4.2.15. (2-Nitro-1,1-diphenylethyl)phenyl sulfide (3ia)
1H NMR (400 MHz, CDCl3)
d
7.36–7.25 (m, 11H), 7.13 (t, J¼7.8 Hz,
2H), 7.00 (d, J¼7.2 Hz 2H), 5.18 (s, 2H); 13C NMR (100 MHz, CDCl3)
d
140.82,137.74,130.04,129.77,129.06, 128.85,128.23,128.01, 82.70,
83 (11), 77 (14), 65 (11), 55 (30), 51 (10). HRMS calcd for C14H18
218.1129, found 218.1130.
S
61.62. m/z (relative intensity) 335 (Mþ, 2), 288 (3), 226 (85), 181
(35), 180 (100), 179 (73), 178 (74), 165 (77), 152 (18), 110 (37), 109
(21), 89 (16), 77 (16), 76 (14). HRMS calcd for C20H17NO2S 335.0975,
found 335.0977.
4.3.3. tert-Butyl(styryl)sulfane (4ad)8f
1H NMR (400 MHz, CDCl3)
d
7.56 (d, J¼7.2 Hz, 2H, (Z) isomer),
7.43–7.31 (m, 4H, (E) isomer, and 2H, (Z) isomer), 7.27–7.20 (m, 1H,
(E) isomer and (Z) isomer), 6.94 (d, J¼15.4 Hz, 1H, (E) isomer), 6.78
(d, J¼15.4 Hz, 1H, (E) isomer), 6.54 (d, J¼11.2 Hz, 1H, (Z) isomer),
6.50 (d, J¼11.2 Hz, 1H, (Z) isomer), 1.47 (s, 9H, (Z) isomer), 1.45 (s,
4.2.16. (2-Nitrocyclohexyl)phenyl sulfide (3ja)
1H NMR (400 MHz, CDCl3)
d 7.47–7.41 (m, 2H), 7.33–7.25 (m,
3H), 4.59 (dt, J¼9.7, 4.2 Hz, 1H), 3.86–3.81 (m, 1H), 2.23–2.01 (m,
3H), 1.94–1.73 (m, 3H), 1.58–1.48 (m, 1H), 1.44–1.30 (m, 1H); 13C
9H, (E) isomer); 13C NMR (100 MHz, CDCl3)
d 137.36 ((Z) isomer),
NMR (100 MHz, CDCl3)
d
134.35, 133.30, 129.32, 128.16, 85.79,
137.24, 132.19, 128.89 ((Z) isomer), 128.79, 128.33 ((Z) isomer),
127.43, 126.71 ((Z) isomer), 126.07, 125.55 ((Z) isomer), 123.62 ((Z)
isomer), 122.24, 44.66 ((Z) isomer), 44.51, 31.21, 30.95 ((Z) isomer).
m/z (relative intensity) 192 (Mþ, 35), 136 (100), 135 (70), 91 (37), 77
(6), 65 (5), 57 (26), 51 (5).
51.07, 30.98, 26.61, 22.88, 21.50. m/z (relative intensity) 237 (Mþ,
11), 218 (10), 125 (68), 123 (12), 110 (22), 109 (23), 81 (100), 79
(19), 77 (12), 65 (13). HRMS calcd for C12H15NO2S 237.0818, found
237.0827.

C.-M. Chu et al. / Tetrahedron 65 (2009) 3878–3885
3883
4.3.4. Hexyl(styryl)sulfane (4ae)
1H NMR (400 MHz, CDCl3)
d 137.33, 134.72, 133.68, 130.76, 128.87, 128.75, 128.48, 127.58,
d
7.49 (d, J¼7.3 Hz, 2H, (Z) isomer),
127.38, 126.98, 126.02, 125.85, 125.64, 125.47, 123.82, 123.29, 37.53.
7.35 (t, J¼7.6 Hz, 2H, (Z) isomer), 7.32–7.27 (m, 4H, (E) isomer),
7.23–7.14 (m, 1H, (E) isomer and (Z) isomer), 6.75 (d, J¼15.6 Hz, 1H,
(E) isomer), 6.48 (d, J¼15.6 Hz, 1H, (E) isomer), 6.44 (d, J¼10.9 Hz,
1H, (Z) isomer), 6.26 (d, J¼10.9 Hz, 1H, (Z) isomer), 2.80 (t, J¼7.4 Hz,
2H), 1.69 (quint, J¼7.4 Hz, 2H), 1.44 (quint, J¼7.4 Hz, 2H), 1.37–1.24
m/z (relative intensity) 276 (Mþ, 68), 186 (42), 185 (100), 184 (94),
152 (60), 141 (21), 92 (17), 91 (87). HRMS calcd for C19H16
276.0967, found 276.0965.
S
4.4.1. Cyclohexyl(2-(naphthalen-1-yl)vinyl)sulfane (4bc)
(m, 4H), 0.90 (t, J¼6.9 Hz, 3H); 13C NMR (100 MHz, CDCl3)
d
137.40,
(E)-isomer: 1H NMR (400 MHz, CDCl3)
7.85–7.75 (m, 1H), 7.74 (d, J¼8.1 Hz, 1H), 7.54–7.36 (m, 4H), 7.34 (d,
J¼15.3 Hz, 1H), 6.82 (d, J¼15.3 Hz, 1H), 3.07–2.96 (m, 1H), 2.14–2.02
(m, 2H), 1.86–1.73 (m, 2H), 1.67–1.57 (m, 1H), 1.55–1.19 (m, 5H); 13C
d
8.10 (d, J¼7.9 Hz, 1H),
128.83, 128.41 ((Z) isomer), 126.96, 126.88, 125.66, 125.58, 32.85,
31.59, 29.63, 28.71, 22.75, 14.23. m/z (relative intensity) 220 (Mþ,
100),136 (67),135 (54),134 (10), 91 (26), 77 (5), 65 (3), 51 (3). HRMS
calcd for C14H20S 220.1286, found 220.1285.
NMR (100 MHz, CDCl3)
127.09, 126.19, 125.98, 125.95, 125.81, 124.02, 123.36, 45.68, 33.85,
26.24, 25.88. (Z)-isomer: 1H NMR (400 MHz, CDCl3)
8.06–8.01 (m,
d 135.11, 133.88, 130.95, 128.66, 127.66,
4.3.5. (4-Methoxyphenyl)(styryl)sulfane (4ai)18
d
1H NMR (400 MHz, CDCl3)
d
7.58 (d, J¼7.7 Hz, 2H, (Z) isomer),
1H), 7.86–7.80 (m, 1H), 7.76 (d, J¼8.2 Hz, 1H), 7.67 (d, J¼7.1 Hz, 1H),
7.53–7.43 (m, 3H), 7.08 (d, J¼10.7 Hz, 1H), 6.60 (d, J¼10.7 Hz, 1H),
2.94–2.82 (m, 1H), 2.09–2.02 (m, 2H), 1.83–1.75 (m, 2H), 1.66–1.59
7.46 (d, J¼8.6 Hz, 2H, (E) isomer), 7.33–7.29 (d, J¼4.3 Hz, 4H, (E)
isomer), 7.28–7.21 (m, 1H, (E) isomer), 6.95 (d, J¼8.6 Hz, (E) isomer),
6.88 (d, J¼15.4 Hz, (E) isomer), 6.56 (d, J¼15.4 Hz, (E) isomer), 6.45
(d, J¼10.8 Hz, (Z) isomer), 3.85 (s, 3H, (E) isomer), 3.84 (s, 3H, (Z)
(m, 1H), 1.49–1.17 (m, 5H); 13C NMR (100 MHz, CDCl3)
d 133.67,
133.56, 131.39, 128.57, 128.02, 127.47, 126.24, 125.83, 125.66, 125.23,
124.11,122.58, 47.10, 33.73, 26.05, 25.64. m/z (relative intensity) 268
(Mþ, 22), 186 (24), 1858 (57), 184 (100), 153 (33), 152 (62), 1395 (19),
115 (13), 83 (47), 55 (48). HRMS calcd for C18H20S 268.1286, found
268.1278.
isomer); 13C NMR (100 MHz, CDCl3)
d 159.71, 136.88, 133.61, 129.09,
128.78, 127.33, 125.96, 125.88, 115.05, 55.50. m/z (relative intensity)
243 (Mþ,100), 241 (43), 227 (36), 221 (62), 197 (95), 178 (10), 165
(20), 151 (19), 134 (6), 121 (52), 103 (2).
4.3.6. (4-Nitrophenyl)(styryl)sulfane (4aj)
4.4.2. (2-(Naphthalen-1-yl)vinyl)(phenyl)sulfane (4bf)
1H NMR (400 MHz, CDCl3)
d
8.19–8.14 (d, J¼8.9 Hz, 2H, (E) iso-
(E)-isomer: 1H NMR (400 MHz, CDCl3)
d
8.10 (d, J¼8.0 Hz, 1H),
mer, and m, 2H, (Z) isomer), 7.54–7.49 (m, 4H, (Z) isomer), 7.45–7.31
(m, 7H, (E) isomer, and 3H, (Z) isomer), 7.03 (d, J¼15.36 Hz, 1H, (E)
isomer), 6.87 (d, J¼15.36 Hz, 1H, (E) isomer, and 1H, (Z) isomer),
6.52 (d, J¼10.52 Hz, 1H, (Z) isomer); 13C NMR (100 MHz, CDCl3)
7.85–7.80 (m, 1H), 7.74 (d, J¼8.1 Hz, 1H), 7.53–7.38 (m, 4H), 7.24 (d,
J¼15.4 Hz, 1H), 6.78 (d, J¼15.4 Hz, 1H), 2.85 (t, J¼7.3 Hz, 2H), 1.79
(sext, J¼7.3 Hz, 2H), 1.07 (t, J¼7.4 Hz, 3H); 13C NMR (100 MHz,
CDCl3) d 135.11, 133.91, 130.93, 128.69, 128.40, 127.57, 126.18, 125.98,
d
146.71, 145.97, 138.16, 135.80, 129.09, 128.95, 127.23, 126.74,
125.85, 124.20, 123.98, 123.33, 35.10, 23.15, 13.64. m/z (relative in-
124.32, 118.36. m/z (relative intensity) 257 (Mþ, 100), 213 (7), 210
tensity) 228 (Mþ, 61), 185 (100), 184 (75), 153 (43), 152 (66), 141
(48), 184 (6), 179 (12), 178 (43), 166 (36), 135 (20), 103 (8).
(22), 139 (18), 115 (16), 57 (24), 55 (13). HRMS calcd for C15H16
228.0973, found 228.0976.
S
4.3.7. (2-(Naphthalen-1-yl)vinyl)(phenyl)sulfane (4ba)19a
(E)-isomer: 1H NMR (400 MHz, CDCl3)
d
8.06 (dt, J¼7.2, 1.9 Hz,
4.4.3. 2-(2-(Naphthalen-1-yl)vinylthio)ethanol (4bg)
1H), 7.82 (dt, J¼7.1, 2.3 Hz, 1H), 7.75 (d, J¼8.2 Hz, 1H), 7.56 (d,
J¼7.2 Hz, 1H), 7.51–7.36 (m, 6H), 7.32 (tt, J¼7.6, 1.8 Hz, 2H), 7.24 (tt,
J¼7.4, 2.0 Hz, 1H), 6.94 (d, J¼15.1 Hz, 1H); 13C NMR (100 MHz,
(E)-isomer: 1H NMR (400 MHz, CDCl3)
d
8.09 (d, J¼7.9 Hz, 1H),
7.86–7.81 (m, 1H), 7.77 (d, J¼8.1 Hz, 1H), 7.54–7.41 (m, 4H), 7.37 (d,
J¼15.3 Hz, 1H), 6.74 (d, J¼15.3 Hz, 1H), 3.90 (t, J¼6.0 Hz, 2H), 3.06 (t,
CDCl3)
d
135.34, 134.26, 133.77, 130.92, 129.93, 129.30, 128.94,
J¼6.0 Hz, 2H), 1.96 (br s, 1H); 13C NMR (100 MHz, CDCl3)
d 134.50,
128.64, 128.20, 127.11, 126.31, 126.26, 126.01, 125.69, 123.78, 123.71.
m/z (relative intensity) 262 (Mþ, 100), 229 (23), 228 (21), 218 (40),
185 (25), 184 (22), 155 (29), 153 (63), 152 (100), 151 (26), 128 (21),
127 (36), 110 (24), 109 (39), 77 (20), 65 (20), 57 (26). HRMS calcd for
C18H14S 262.0811, found 262.0814.
133.77, 130.77, 128.64, 127.84, 126.93, 126.25, 125.99, 125.88, 125.75,
123.79, 123.42, 61.27, 36.06. (Z)-isomer: 1H NMR (400 MHz, CDCl3)
d
8.02–7.97 (m,1H), 7.87–7.81 (m,1H), 7.78 (d, J¼8.2 Hz,1H), 7.65 (d,
J¼7.12 Hz, 1H), 7.53–7.45 (m, 3H), 7.13 (d, J¼10.5 Hz, 1H), 6.47 (d,
J¼10.5 Hz, 1H), 3.77 (t, J¼5.9 Hz, 2H), 2.90 (t, J¼5.9 Hz, 2H), 2.03 (br
s, 1H); 13C NMR (100 MHz, CDCl3)
d 133.70, 133.22, 131.35, 128.68,
4.4. Method C: general procedure for the radical substitution
of a-toluenethiol 2b with (E)-1-(2-nitrovinyl)naphthalene 1b
in the peroxide of AIBN to generate benzyl(2-(naphthalen-1-
yl)vinyl)sulfane (4bb)
128.61, 127.93, 126.35, 126.12, 125.92, 125.25, 124.54, 124.11, 61.52,
38.02. m/z (relative intensity) 230 (Mþ, 59), 185 (88), 184 (64), 165
(30), 153 (68), 152 (100), 141 (20), 115 (19), 71 (26), 69 (24), 57 (43),
55 (30). HRMS calcd for C14H14OS 230.0760, found 230.0765.
a
-Toluenethiol 2b (0.7 mL, 6.0 mmol), 2,20-azobis(2-methyl-
4.4.4. (2-(Naphthalen-1-yl)vinyl)(naphthalen-2-yl)sulfane (4bh)
propionitrile) (AIBN, 0.99 g, 6 mmol), and anhydrous benzene
(8 mL) were charged into a 25 mL round bottom flask. A stir bar and
heating mantle were added; then a 15 cm Liebig condenser with
10 ꢀC chilling water and additional funnel were attached to the
flask. The solution was preheated to reflux (100 ꢀC) for 1 min, and
a solution (E)-1-(2-nitrovinyl)naphthalene 1b (0.40 g, 2 mmol) in
5 mL of dry benzene was added dropwise (one drop every 5–10 s).
After 12 h, the reaction mixture was allowed to cool to room tem-
perature, and the solvent was removed in vacuo. Flash column
chromatography (SiO2; ethyl acetate/hexane, 1:100) of the residue
offered 90% yield of 4bb as an (E)/(Z) (4.4:1 by NMR) mixture of
1H NMR (400 MHz, CDCl3)
d
8.12 (d, J¼7.8 Hz, 1H), 7.92–7.73 (m,
6H), 7.65–7.41 (m, 8H), 7.31 (d, J¼10.6 Hz, 0.1H, (Z) isomer), 7.06 (d,
J¼15.2 Hz, 1H, (E) isomer), 6.88 (d, J¼10.6 Hz, 0.1H, (Z) isomer); 13C
NMR (100 MHz, CDCl3)
d 134.41, 134.07, 133.92, 132.84, 132.48,
131.08, 129.51, 129.03, 128.78, 128.41, 128.34, 128.01, 127.75, 127.53,
126.95, 126.49, 126.34, 126.17, 126.14, 125.84, 123.93, 123.92. m/z
(relative intensity) 312 (Mþ, 100), 279 (56), 278 (24), 185 (41), 184
(43), 153 (34), 152 (89), 57 (31). HRMS calcd for C22H16S 312.0967,
found 312.0966.
4.4.5. (4-Chlorostyryl)(phenyl)sulfane (4ca)19a
colorless oil. (E)-isomer: 1H NMR (400 MHz, CDCl3)
d
7.96–7.91 (m,
(E)-isomer: 1H NMR (400 MHz, CDCl3)
d 7.43–7.39 (m, 2H), 7.36–
1H), 7.83–7.79 (m, 1H), 7.73 (d, J¼8.0 Hz, 1H), 7.49–7.21 (m, 10H),
7.31 (m, 2H), 7.29–7.21 (m, 5H), 6.88 (d, J¼15.4 Hz, 1H), 6.65 (d,
6.76 (d, J¼15.2 Hz, 1H), 4.10 (s, 2H); 13C NMR (100 MHz, CDCl3)
J¼15.4 Hz, 1H); 13C NMR (100 MHz, CDCl3)
d 135.10, 134.73, 133.15,

3884
C.-M. Chu et al. / Tetrahedron 65 (2009) 3878–3885
130.25, 129.79, 129.27, 128.87, 127.27, 127.15, 124.71. m/z (relative
intensity) 246 (Mþ, 100), 218 (28), 211 (41), 210 (24), 201 (23), 178
(50), 166 (18), 165 (23), 134 (28), 121 (24), 109 (27), 71 (19), 57 (33).
HRMS calcd for C14H11ClS 246.0265, found 246.0264.
55.32, 55.28 ((Z) isomer), 47.67 ((Z) isomer), 45.45, 33.75 ((Z) iso-
mer), 33.69, 26.11, 25.80, 25.72 ((Z) isomer). m/z (relative intensity)
248 (Mþ, 55), 219 (17), 166 (100), 151 (63), 135 (29), 121 (26), 107
(8), 91 (11), 77 (12), 55 (23). HRMS calcd for C15H20OS 248.1235,
found 248.1242.
4.4.6. (4-Fluorostyryl)(phenyl)sulfane (4da)7i
1H NMR (400 MHz, CDCl3)
d
7.52–7.44 (m, 6H, (Z) isomer), 7.42
4.4.10. tert-Butyl(4-methoxystyryl)sulfane (4ed)
(d, J¼8.2 Hz, 2H, (E) isomer), 7.37–7.23 (m, 5H, (E) isomer), 7.07 (t,
J¼8.6 Hz, 2H, (Z) isomer), 6.99 (t, J¼8.6 Hz, 2H, (E) isomer), 6.88 (d,
J¼15.4 Hz, 1H, (E) isomer), 6.70 (d, J¼15.4 Hz, 1H, (E) isomer), 6.56
(d, J¼10.7 Hz,1H, (Z) isomer), 6.48 (d, J¼10.7 Hz,1H, (Z) isomer); 13C
1H NMR (400 MHz, CDCl3)
d
7.45 (d, J¼8.6 Hz, 2H, (Z) isomer),
7.30 (d, J¼8.6 Hz, 2H, (E) isomer), 6.90 (d, J¼8.6 Hz, 2H, (Z) iso-
mer), 6.86 (d, J¼8.6 Hz, 2H, (E) isomer), 6.70 (s, 2H, (E) isomer),
6.45 (d, J¼11.1 Hz, 1H, (Z) isomer), 6.32 (d, J¼11.1 Hz, 1H, (Z) iso-
mer), 3.81 (s, 3H, (E) isomer and (Z) isomer), 1.42 (s, 9H, (Z) iso-
NMR (100 MHz, CDCl3)
d
163.71 (d, JC–F¼246 Hz), 163.10 (d,
JC–F¼247 Hz, (Z) isomer), 136.13 ((Z) isomer), 135.29, 132.99 (d,
JC–F¼3 Hz), 132.86 (d, JC–F¼3 Hz, (Z) isomer), 130.79, 130.67
(d, JC–F¼8 Hz, (Z) isomer), 130.27 ((Z) isomer), 130.09, 129.39, 129.26
((Z) isomer), 127.78 (d, JC–F¼8 Hz), 127.48 ((Z) isomer), 127.23,
126.40 ((Z) isomer), 125.82 (d, JC–F¼2 Hz, (Z) isomer), 123.35 (d,
JC–F¼2 Hz),115.94 (d, JC–F¼22 Hz),115.56 (d, JC–F¼22 Hz, (Z) isomer).
m/z (relative intensity) 230 (Mþ, 100), 229 (28), 196 (19), 185 (21),
165 (13), 139 (11), 121 (17), 109 (20). HRMS calcd for C14H11FS
230.0560, found 230.0571.
mer), 1.39 (s, 9H, (E) isomer); 13C NMR (100 MHz, CDCl3)
d 159.33,
158.41 ((Z) isomer), 133.13, 130.33 ((Z) isomer), 130.26, 130.17 ((Z)
isomer), 127.41, 125.36 ((Z) isomer), 121.09 ((Z) isomer), 119.28,
114.27, 113.79 ((Z) isomer), 5.53, 55.48 ((Z) isomer), 44.59 ((Z)
isomer), 44.51, 31.18, 30.98 ((Z) isomer). m/z (relative intensity)
222 (Mþ, 29), 166 (100), 165 (26), 151 (12), 150 (11), 135 (24), 121
(21), 77 (6), 57 (15), 51 (3). HRMS calcd for C13H18OS 222.1078,
found 222.1078.
4.4.11. Hexyl(4-methoxystyryl)sulfane (4ee)
4.4.7. (4-Methoxystyryl)(phenyl)sulfane (4ea)19
1H NMR (400 MHz, CDCl3)
d
7.45 (d, J¼8.6 Hz, 2H, (Z) isomer),
1H NMR (400 MHz, CDCl3)
d
7.50 (d, J¼8.7 Hz, 2H, (Z) isomer),
7.24 (d, J¼8.6 Hz, 2H, (E) isomer), 6.90 (d, J¼8.6 Hz, 2H, (Z) isomer),
6.85 (d, J¼8.6 Hz, 2H, (E) isomer), 6.57 (d, J¼15.6 Hz, 1H, (E) iso-
mer), 6.46 (d, J¼11.1 Hz, 1H, (E) isomer), 6.39 (d, J¼10.8 Hz, 1H, (Z)
isomer), 6.12 (d, J¼10.8 Hz, 1H, (Z) isomer), 3.81 (s, 3H, (Z) isomer),
3.80 (s, 3H, (E) isomer), 2.77 (t, J¼7.4 Hz, 2H, (E) isomer and (Z)
isomer), 1.68 (quint, J¼7.4 Hz, 2H, (E) isomer and (Z) isomer), 1.43
(quint, J¼7.4 Hz, 2H, (E) isomer and (Z) isomer), 1.35–1.25 (m, 4H,
(E) isomer and (Z) isomer), 0.89 (t, J¼6.9 Hz, 3H, (E) isomer and (Z)
7.45 (d, J¼7.3 Hz, 2H, (Z) isomer), 7.39 (d, J¼7.4 Hz, 2H, (E) isomer),
7.35–7.25 (m, 4H, (E) isomer, and 1H, (Z) isomer), 7.25–7.18 (m, 1H,
(E) isomer, and 2H, (Z) isomer), 6.93 (d, J¼8.7 Hz, 2H, (Z) isomer),
6.86 (d, J¼8.7 Hz, 2H, (E) isomer), 6.77 (d, J¼15.4 Hz,1H, (E) isomer),
6.72 (d, J¼15.4 Hz, 1H, (E) isomer), 6.56 (d, J¼10.6 Hz, 1H, (Z) iso-
mer), 6.38 (d, J¼10.6 Hz, 1H, (Z) isomer); 13C NMR (100 MHz, CDCl3)
d
159.55, 136.13, 132.92, 130.35 ((Z) isomer), 130.04 ((Z) isomer),
129.56, 129.42, 129.31 ((Z) isomer), 129.26, 127.56, 127.40 ((Z) iso-
mer), 127.19 ((Z) isomer), 126.77, 123.40 ((Z) isomer), 120.24, 114.32,
113.93 ((Z) isomer), 55.50. m/z (relative intensity) 242 (Mþ, 23), 218
(39), 152 (21), 135 (100), 121 (14), 110 (20), 109 (39), 107 (18), 92
(20), 77 (38), 65 (23). HRMS calcd for C15H14OS 242.0760, found
242.0767.
isomer); 13C NMR (100 MHz, CDCl3)
d 158.73, 158.22 ((Z) isomer),
130.17 ((Z) isomer), 130.02 ((Z) isomer), 129.95, 127.09, 126.68,
125.11 ((Z) isomer), 124.94 ((Z) isomer), 122.63, 114.09, 113.66 ((Z)
isomer), 55.33, 55.29 ((Z) isomer), 35.85 ((Z) isomer), 32.89, 31.41,
30.22 ((Z) isomer), 29.51, 28.51, 28.32 ((Z) isomer), 22.56,14.04. m/z
(relative intensity) 251 (Mþ1, 26), 250 (Mþ, 100), 248 (22), 166
(88), 165 (53), 151 (47), 150 (46), 135 (45), 134 (65), 121 (52), 91
(14), 89 (13), 77 (16), 55 (15). HRMS calcd for C15H22OS 250.1391,
found 250.1370.
4.4.8. Benzyl(4-methoxystyryl)sulfane (4eb)20
1H NMR (400 MHz, CDCl3)
d
7.41 (d, J¼8.7 Hz, 2H, (Z) isomer),
7.37–7.22 (m, 5H, (E) isomer and (Z) isomer), 7.19 (d, J¼8.6 Hz, 2H,
(E) isomer), 6.88 (d, J¼8.7 Hz, 2H, (Z) isomer), 6.82 (d, J¼8.6 Hz, 2H,
(E) isomer), 6.56 (d, J¼15.5 Hz, 1H, (E) isomer), 6.51 (d, J¼15.5 Hz,
1H, (E) isomer), 6.38 (d, J¼10.8 Hz, 1H, (Z) isomer), 6.12 (d,
J¼10.8 Hz, 1H, (Z) isomer), 3.97 (s, 2H, (E) isomer and (Z) isomer),
3.79 (s, 3H, (Z) isomer), 3.78 (s, 3H, (E) isomer); 13C NMR (100 MHz,
4.4.12. (2-Nitrostyryl)(phenyl)sulfane (4fa)
1H NMR (400 MHz, CDCl3)
d
8.04 (d, J¼8.2 Hz, 1H, (Z) isomer),
7.93 (d, J¼8.2 Hz, 1H, (E) isomer), 7.77 (d, J¼7.7 Hz, 1H, (Z) isomer),
7.69 (d, J¼7.9 Hz, 1H, (Z) isomer), 7.64 (t like, J¼7.7 Hz, 1H, (Z) iso-
mer), 7.58–7.25 (m, 8H, (E) isomer, and 5H, (Z) isomer), 7.09 (d,
J¼15.3 Hz, 1H, (E) isomer), 7.01 (d, J¼10.6 Hz, 1H, (Z) isomer), 6.98
(d, J¼15.4 Hz,1H, (E) isomer), 6.71 (d, J¼10.6 Hz,1H, (Z) isomer); 13C
CDCl3)
d 159.08, 158.51 ((Z) isomer), 137.65, 130.22 ((Z) isomer),
130.05, 129.98 ((Z) isomer), 129.18 ((Z) isomer), 129.03, 128.86 ((Z)
isomer), 128.82, 128.69, 127.55 ((Z) isomer), 127.45, 127.05, 125.76
((Z) isomer), 123.62 ((Z) isomer), 121.73, 114.25, 113.85 ((Z) isomer),
55.50, 39.67 ((Z) isomer), 37.85. m/z (relative intensity) 256 (Mþ,
79), 165 (71), 150 (65), 134 (15), 122 (14), 121 (19), 91 (100), 65 (18).
HRMS calcd for C16H16OS 256.0922, found 256.0919.
NMR (100 MHz, CDCl3)
d 147.20, 137.02, 133.49, 133.23, 133.02 ((Z)
isomer), 132.35, 131.59, 131.32, 131.23 ((Z) isomer), 130.37 ((Z) iso-
mer), 130.28 ((Z) isomer), 129.62, 129.48 ((Z) isomer), 128.20,
127.86, 127.69 ((Z) isomer), 125.03, 124.96 ((Z) isomer), 123.92,
123.65 ((Z) isomer).
4.4.9. Cyclohexyl(4-methoxystyryl)sulfane (4ec)
4.4.13. 2-(2-(Phenylthio)vinyl)furan (4ga)21
1H NMR (400 MHz, CDCl3)
d
7.43 (d, J¼8.6 Hz, 2H, (Z) isomer),
(E)-isomer: 1H NMR (400 MHz, CDCl3)
d
7.40 (dt like, J¼7.1,
7.22 (d, J¼8.6 Hz, 2H, (E) isomer), 6.88 (d, J¼8.6 Hz, 2H, (Z) isomer),
6.82 (d, J¼8.6 Hz, 2H, (E) isomer), 6.61 (d, J¼15.5 Hz, 1H, (E) iso-
mer), 6.55 (d, J¼15.5 Hz, 1H, (E) isomer), 6.37 (d, J¼10.9 Hz, 1H, (Z)
isomer), 6.18 (d, J¼10.9 Hz, 1H, (Z) isomer), 2.95–2.87 (m, 1H, (E)
isomer), 2.88–2.80 (m, 1H, (Z) isomer), 2.05–1.98 (m, 2H, (E) iso-
mer and (Z) isomer), 1.81–1.73 (m, 2H, (E) isomer and (Z) isomer),
1.64–1.56 (m, 1H, (E) isomer and (Z) isomer), 1.48–1.20 (m, 5H, (E)
1.4 Hz, 2H), 7.34–7.26 (m, 3H), 7.22 (tt like, J¼7.4, 1.2 Hz, 1H), 6.84
(d, J¼15.3 Hz, 1H), 6.48 (d, J¼15.3 Hz, 1H), 6.33 (dd, J¼3.3, 1.8 Hz,
1H), 6.14 (d, J¼3.2 Hz, 1H); 13C NMR (100 MHz, CDCl3)
d 152.22,
142.16, 134.94, 130.11, 129.29, 127.16, 122.29, 119.70, 111.55, 107.51.
(Z)-isomer: 1H NMR (400 MHz, CDCl3)
d 7.48–7.42 (m, 3H), 7.33 (t,
J¼7.1 Hz, 2H), 7.26 (tt like, J¼7.3, 1.2 Hz, 1H), 6.55 (d, J¼3.4 Hz, 1H),
6.46 (dd, J¼3.4, 1.9 Hz, 1H), 6.46 (d, J¼10.8 Hz, 1H), 6.39 (d,
isomer and (Z) isomer); 13C NMR (100 MHz, CDCl3)
((Z) isomer), 130.14 ((Z) isomer), 130.02, 129.27, 126.90, 124.76 ((Z)
isomer), 123.37 ((Z) isomer), 121.22, 114.10, 113.67 ((Z) isomer),
d
158.89,158.22
J¼10.8 Hz, 1H); 13C NMR (100 MHz, CDCl3)
d 152.15, 141.78, 135.91,
130.28, 129.26, 127.38, 124.30, 115.16, 111.72, 109.94. m/z (relative
intensity) 202 (Mþ, 100), 173 (23), 157 (18), 141 (15), 121 (14), 91

C.-M. Chu et al. / Tetrahedron 65 (2009) 3878–3885
3885
Chem. 1996, 518, 69–77; (c) Russell, G. A.; Yao, C.-F. Heteroat. Chem. 1992, 3,
209–218; (d) Han, Y.; Huang, Y.-Z.; Zhou, C.-M. Tetrahedron Lett. 1996, 37, 3347–
3350.
(24), 77 (15), 69 (45), 64 (27), 57 (21). HRMS calcd for C12H10OS
202.0447, found 202.0452.
4. Trost, B. M.; Lavoie, A. C. J. Am. Chem. Soc. 1983, 105, 5075–5090.
5. Miller, R. D.; Hassig, R. Tetrahedron Lett. 1985, 26, 2395–2398.
4.4.14. 2-(2-(Phenylthio)vinyl)thiophene (4ha)22
(E)-isomer: 1H NMR (400 MHz, CDCl3)
d
7.40 (dt, J¼7.4, 1.3 Hz,
6. (a) Cookson, R. C.; Persons, P. J. J. Chem. Soc., Chem. Commun. 1976, 990a; (b)
Takeda, T.; Fujiwara, T. Chem. Lett. 1982, 11, 1113–1116; (c) Morris, T. H.;
Smith, E. H.; Walsh, R. J. Chem. Soc., Chem. Commun. 1987, 964–965; (d)
Magnus, P.; Quagliato, D. J. Org. Chem. 1985, 50, 1621–1626; (e) Mizuno, H.;
Domon, K.; Masuya, K.; Tanino, K.; Kuwajima, I. J. Org. Chem. 1999, 64,
2648–2656; (f) Domon, K. M. K.; Tanino, K.; Kuwajima, I. Synlett 1996,
157–158.
7. (a) Ichinose, Y.; Wakamatsu, K.; Nozaki, K.; Birbaum, J. L.; Oshima, K.; Utimoto,
K. Chem. Lett. 1987, 1647–1650; (b) Benati, L.; Montevecchi, P. C.; Spagnolo, P.
J. Chem. Soc., Perkin Trans. 1 1991, 2103–2109; (c) Benati, L.; Capella, L.; Mon-
tevecchi, P. C.; Spagnolo, P. J. Chem. Soc., Perkin Trans. 1 1995, 1035–1038;
(d) Beauchemin, A.; Gareau, Y. Phosphorus, Sulfur Silicon Relat. Elem. 1998, 139,
187–192; (e) Mcdonald, J. W.; Corbin, J. L.; Newton, W. E. Inorg. Chem. 1976, 15,
2056–2061; (f) Kuniyasu, H.; Ogawa, A.; Sato, K. I.; Ryu, I.; Kambe, N.; Sonoda,
N. J. Am. Chem. Soc. 1992, 114, 5902–5903; (g) Backvall, J. E.; Ericsson, A. J. Org.
Chem. 1994, 59, 5850–5851; (h) Koelle, U.; Rietmann, C.; Tjoe, J.; Wagner, T.;
Englert, U. Organometallics 1995, 14, 703–713; (i) Ogawa, A.; Ikeda, T.; Kimura, K.;
Hirao, T. J. Am. Chem. Soc. 1999, 121, 5108–5114; (j) Sugoh, K.; Kuniyasu, H.; Sugae,
T.; Ohtaka, A.; Takai, Y.; Tanaka, A.; Machino, C.; Kambe, N.; Kurosawa, H. J. Am.
Chem. Soc. 2001, 123, 5108–5109.
2H), 7.32 (tt, J¼7.3, 1.0 Hz, 2H), 7.24 (tt, J¼7.0, 1.2 Hz, 1H), 7.14 (d,
J¼5.0 Hz, 1H), 6.96 (dd, J¼5.0, 3.6 Hz, 1H), 6.91 (d, J¼3.1 Hz, 1H),
6.86 (d, J¼15.2 Hz, 1H), 6.71 (d, J¼15.2 Hz, 1H); 13C NMR
(100 MHz, CDCl3)
d 141.45, 135.10, 129.86, 129.25, 127.57, 127.07,
125.54, 125.31, 124.43, 122.51. (Z)-isomer: 1H NMR (400 MHz,
CDCl3)
d
7.46 (d, J¼7.7 Hz, 2H), 7.38–7.30 (m, 3H), 7.26 (t,
J¼7.4 Hz, 1H), 6.17 (d, J¼3.4 Hz, 1H), 7.06 (dd, J¼4.9, 3.8 Hz, 1H),
6.84 (d, J¼10.3 Hz, 1H), 6.40 (d, J¼10.3 Hz, 1H); 13C NMR
(100 MHz, CDCl3)
d 140.02, 135.81, 129.92, 129.26, 128.03, 127.20,
126.95, 126.22, 123.00, 121.55. m/z (relative intensity) 218 (Mþ,
100), 185 (33), 184 (30), 173 (34), 121 (23), 109 (10), 97 (15), 77
(7), 69 (7), 65 (13), 51 (8). HRMS calcd for C12H10S2 218.0218,
found 218.0220.
8. (a) Murahashi, S.; Yamamura, M.; Yanagisawa, K.; Mita, N.; Kondo, K. J. Org.
Chem. 1979, 44, 2408–2417; (b) Foa, M.; Santi, R.; Garavaglia, F. J. Organomet.
Chem. 1981, 206, C29–C32; (c) Baranano, D.; Mann, G.; Hartwig, J. F. Curr. Org.
Chem. 1997, 1, 287–305; (d) Rane, A. M.; Miranda, E. I.; Soderquist, J. A. Tetra-
hedron Lett. 1994, 35, 3225–3226; (e) Li, G. Y. J. Org. Chem. 2002, 67, 3643–3650;
(f) Bates, C. G.; Saejueng, P.; Doherty, M. Q.; Venkataraman, D. Org. Lett. 2004, 6,
5005–5008; (g) Commercon, A.; Normant, J.; Villieras, J. J. Organomet. Chem.
1975, 93, 415–421; (h) Yatsumonji, Y.; Okada, O.; Tsubouchi, A.; Takeda, T.
Tetrahedron 2006, 62, 9981–9987.
4.4.15. (2,2-Diphenylvinyl)(phenyl)sulfane (4ia)
1H NMR (400 MHz, CDCl3) 7.45–7.21 (m, 15H), 6.86 (s, 1H); 13
d C
NMR (100 MHz, CDCl3)
d 141.66, 141.28, 139.38, 136.69, 129.96,
129.72, 129.32, 128.59, 128.51, 128.02, 127.50, 127.40, 126.98, 124.30.
m/z (relative intensity) 288 (Mþ, 85), 287 (36), 178 (55), 165 (24),
109 (17), 105 (100), 77 (31), 57 (27). HRMS calcd for C20H16
288.0967, found 288.0967.
S
9. (a) Aucagne, V.; Tatibouet, A.; Rollin, P. Tetrahedron 2004, 60, 1817–1826; (b)
Stephan, E.; Olaru, A.; Jaouen, G. Tetrahedron Lett. 1999, 40, 8571–8574; (c)
Ishida, M.; Iwata, T.; Yokoi, M.; Kaga, K.; Kato, S. Synthesis 1985, 632–634; (d)
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Acknowledgements
10. Synthesis of nitro sulfide by the conjugate addition of aromatic thiol to b-ni-
This work was a collaborative effort with Dr. Kak-Shan Shia,
Division of Biotechnology and Pharmaceutical Research, National
Health Research Institutes, whose input was invaluable. We
gratefully acknowledge the financial support provided by the Na-
tional Science Council of the Republic of China and National Taiwan
Normal University (TOP001).
trostyrenes in neat under catalyst and heating conditions was reported.
However, in most cases, these are preparing in the presence of expensive or
toxic catalyst and the scope of substrate is also not well-investigated: (a)
Mustafa, A.; Hamid, A.; Harhash, E.; Kamel, M. J. Am. Chem. Soc. 1955, 77, 3860–
3862; (b) Cason, L. F.; Wanser, C. C. J. Am. Chem. Soc. 1951, 73, 142–145; (c)
´
Menand, M.; Dalla, V. Synlett 2005, 95–98.
11. Thiol compounds have pKa value in the range of 7–11 and are very good radical
carriers during the course of radical reactions. Due to the softness character of
thiyl radicals a large number of versatile synthesis involving thiol radicals were
developed. In addition, the interception of radical process by reaction at ben-
zylic positions under thermolysis is well-known: Renaud, P.; Sibi, M. P. Radicals
in Organic Synthesis; Wiley-VCH Verlag GmbH: D69469 Weinheim, Federal
Republic of Germany, 2001; Vols. 1 and 2.
12. The approximate pKa value of thiophenol is in the range of 7. Relatively, a pKa of
10–11 for alkyl thiol has also been reported: March, J. Advanced Organic
Chemistry: Reactions, Mechanisms, and Structure, 4th ed.; Wiley & Sons: New
York, NY, 1992; Chapter 8.
Supplementary data
Supplementary data associated with this article can be found in
the online version, at doi:10.1016/j.tet.2009.02.074.
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