Synthesis of β-amino-α,β-unsaturated ketone derivatives via sequential rhodium-catalyzed sulfur ylide formation/rearrangement

Article abstract of DOI:10.1021/acs.joc.5b00521

In the presence of a Rh(II) catalyst and β-(methylthio)-α,β-unsaturated ketones, 1-sulfonyl-1,2,3-triazoles can be converted into functionalized β-amino-α,β-unsaturated ketones via formation of α-imino rhodium carbene/sulfur ylide and subsequent rearrangement. The products decompose to useful 2-methylthiopyrrole derivatives conveniently in high yield.

Full text of DOI:10.1021/acs.joc.5b00521

Note
pubs.acs.org/joc
Synthesis of β‑Amino-α,β-unsaturated Ketone Derivatives via
Sequential Rhodium-Catalyzed Sulfur Ylide Formation/
Rearrangement
Jun He, Zengming Man, Yinping Shi, and Chuan-Ying Li*
Department of Chemistry, Zhejiang Sci-Tech University, Xiasha West Higher Education District, Hangzhou 310018, China
S
* Supporting Information
ABSTRACT: In the presence of a Rh(II) catalyst and β-
(methylthio)-α,β-unsaturated ketones, 1-sulfonyl-1,2,3-triazoles
can be converted into functionalized β-amino-α,β-unsaturated
ketones via formation of α-imino rhodium carbene/sulfur ylide
and subsequent rearrangement. The products decompose to
useful 2-methylthiopyrrole derivatives conveniently in high yield.
ransition-metal carbenoids are versatile intermediates in
modern synthetic chemistry that undergo a wide variety of
Imino carbenoid derived from 1-sulfonyl-1,2,3-triazole could
also be trapped by heteroatoms such as sulfur,9 oxygen,10 and
nitrogen,11 and subsequent [2,3]-sigmatropic rearrangement or
cycloaddition resulted in the formation of heterocycles or
compounds bearing heteroatom-substituted quaternary carbon
atoms. We envisioned that if we used β-methylthio-α,β-
unsaturated ketone 2 to react with in situ generated α-imino
carbenoid B (Scheme 1), sulfur ylide C may be formed, and
subsequent Michael addition of nitrogen would furnish
zwitterionic intermediate D, which would lead to the formation
of 3 by cleavage of carbon sulfur bond and reformation of
carbon carbon double bond. Thus, the unusual insertion of
three atoms into the carbon sulfur bond would be realized.
To test the above hypothesis, 3-oxobis(methylthio)ketene
acetal 2a was synthesized conveniently from acetophenone,
carbon disulfide, and iodomethane.12 Compound 2a was
treated with triazole 1a in the presence of 1 mol % of
Rh2(OAc)4 in refluxing DCE (Table 1, entry 1). After 5 h,
compound 3aa was obtained as a single isomer in 81% yield.
The use of Rh2(Oct)4 substantially improved the reaction
(entry 2). Rh2(esp)2 and Rh2(piv)4 worked almost equally well
(entries 3 and 4), while Rh2(s-ntv)4 and Rh2(TFA)4 led to
much decreased yield (entries 5 and 6). High temperature was
necessary to achieve high yield (entries 7 and 9). Among the
different solvent we examined (entries 2 and 8−10), 1,2-DCE
was proven to be the best. Fine tuning the ratio of 1a and 2a
did not improve the yield of 3aa (entries 11 and 12).
T
chemical transformations leading to the formation of complex
molecules.1 Although diazo compounds and N-tosylhydrazones
are traditional precursors for metal carbenes,2 nondiazo
approaches to metal carbenes have attracted considerable
attention recently.3 In 2008, Fokin and Gevorgyan demon-
strated that in the presence of rhodium(II) catalyst 1-sulfonyl-
1,2,3-triazole underwent transannulation with nitrile to furnish
imidazole.4 Noticeably, the author proposed a Dimroth-type
equilibrium and denitrogenative decomposition of the open
chain form A, which led to the formation of critical
intermediate α-imino carbenoid B (Scheme 1). This report
Scheme 1. Mechanistic Hypothesis
In order to explore the scope of this novel transformation, a
wide range of 1-sulfonyl-1,2,3-triazoles underwent the rhodium-
catalyzed reaction with 2a (Table 2). Gratifyingly, in most
cases, this procedure worked well and the corresponding
product 3 could be obtained in moderate to good yield.
Moreover, this reaction is compatible with all kinds of
functional groups including fluoro, chloro, bromo, trifluor-
omethyl, methoxycarbonyl, cyano, methoxy, and thienyl groups.
opens a new era for triazole chemistry,5 and many novel
transformations based on the electrophilic activity of carbene
carbon and nucleophilic ability of imino nitrogen atom have
been explored by Fokin, Gevorgyan, Murakami, Davies, and
other groups.6 In our related research,7 we used ketene silyl
acetal, nitrosobenzene, and a tethered carbonyl group to trap α-
imino rhodium carbenoid, and 3-pyrrolin-2-one,7a N-acylami-
dine,7b and furan derivatives7c were obtained, respectively. Ylide
formation and subsequent reactions8 are among the most
important transformations of transition metal carbenoids. α-
Received: March 8, 2015
Published: April 9, 2015
© 2015 American Chemical Society
4816
DOI: 10.1021/acs.joc.5b00521
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The Journal of Organic Chemistry
Note
a
For the aryl group with different substitution patterns (R1 in
triazole 1), the o-methoxy-substituted substrate 1l led to the
formation of 3la in 76% yield (entry 11). Likely due to the
steric hindrance of o-group, the yield of 3la is lower than
corresponding meta- or para-isomers (entries 10 and 12). Of
note is that the resulting products 3 were obtained exclusively
as single isomers, except in the case of 3pa (entry 15), for
which two inseparable isomers (1:0.8) were obtained in 88%
yield.
Table 1. Optimization of Reaction Conditions
This reaction also permitted the use of a variety of different
β-(methylthio)-α,β-unsaturated ketones (Table 3). For 3-
Table 3. Reaction Scope with β-(Methylthio)-α,β-
a
unsaturated Ketones
b
entry
catalyst
solvent
time (h)
yield (%)
1
2
3
4
5
6
Rh2(OAc)4
Rh2(Oct)4
Rh2(esp)2
Rh2(piv)4
Rh2(s-ntv)4
Rh2(TFA)4
Rh2(Oct)4
Rh2(Oct)4
Rh2(Oct)4
Rh2(Oct)4
Rh2(Oct)4
Rh2(Oct)4
DCE
DCE
DCE
DCE
DCE
DCE
DCE
toluene
DCM
CHCl3
DCE
DCE
5.0
4.5
81
96
91
95
53
b
entry
2 (R1, R2, R3)
time (h)
yield (%)
4.0
1
2
3
4
5
6
7
8
9
2b (o-MeC6H4, SMe, H)
2c (p-MeOC6H4, SMe, H)
2d (p-ClC6H4, SMe, H)
2e (p-BrC6H4, SMe, H)
2f (2-thienyl, SMe, H)
2g (Me, SMe, H)
1.6
4.5
2.8
1.3
0.9
2.0
5.2
2.0
2.4
3ab (89)
3ac (86)
3ad (77)
3ae (76)
3af (84)
4.3
9.0
c
10.0
7.0
N.R.
d
7
N.R.
34
c
8
1.3
3ag (59)
d
9
11.0
11.0
1.7
N.R.
42
2h (Me, SMe, Me)
2i (Ph, Ph, H)
3ah (63)
e
10
3ai (82)
e
11
91
2j (Ph, H, H)
3aj (86)
f
12
4.0
93
a
In the presence of 0.002 mmol of Rh2(Oct)4, 0.2 mmol of triazole 1a
and 0.2 mmol of 2 were reacted in 2 mL of refluxing DCE under N2.
Average of two runs. Two inseparable isomers were obtained
(1:0.35). Two inseparable isomers were obtained (1:0.35). Two
inseparable isomers were obtained (1:0.4).
a
0.2 mmol of 1a, 0.2 mmol of 2a, and 0.002 mmol of rhodium(II)
catalyst dissolved in 2 mL of refluxing solvent under N2. Average of
two runs. No reaction. The reaction temperature was 70 °C. 0.3
mmol of 1a and 0.2 mmol of 2a were used. 0.2 mmol of 1a and 0.3
b
b
c
c
d
e
d
e
f
mmol of 2a were used.
oxobis(methylthio)keteneacetals bearing different aromatic
rings (entries 1−5), 3ab−af were obtained in 76−89% yield.
The presence of chloro or bromo on the aromatic rings had a
negative effect on the process (entries 3 and 4). Alkyl ketones
2g and 2h were also suitable nucleophilic reagents, leading to
the formation of 3ag and 3ah in moderate yield, although two
inseparable isomers were obtained in these cases (entries 6 and
7, the molar ratio of the isomers is 1:0.35). This reaction also
worked well for 2i and 2j, which have only one methylthio
group at the β-position (entries 8 and 9). Compound 2i
delivered a 1:0.4 mixture of the desired 3ai, while 3aj was
isolated as the trans-isomer.
When we optimized the reaction conditions, we found that if
we prolonged the reaction time, 2-(methylthio)-4-phenyl-1-
tosyl-1H-pyrrole 4aa could be isolated in about 10% yield. We
were interested in this transformation and tried to improve the
yield of 4aa. Finally, we found that 4aa was obtained in 90%
yield when 3aa was heated in refluxing toluene for 2.5 h (Table
4, entry 1). For most of the β-amino-α,β-unsaturated ketones
we tested, the corresponding substituted pyrroles could be
obtained in high yield. The mixture of the E- and Z-isomer led
to the formation of 4 smoothly (Table 4, entries 3, 6, 7, and 8).
When treated with 20% hydrochloric acid in THF at 30 °C, 3af
furnished compound 6 in 70% yield, together with 2-
methylthioenamine 7 in 40% yield (eq 1).
a
Table 2. Reaction Scope with 1-Sulfonyl-1,2,3-triazoles
b
entry
1 (R1, R2)
time (h)
yield (%)
1
1b (p-FC6H4, Ts)
4.5
2.0
4.0
5.5
4.3
7.5
1.5
1.5
2.3
1.4
2.3
1.6
3.8
0.7
4.4
2.4
7.0
3ba (77)
3ca (85)
3da (88)
3ea (72)
3fa (72)
3ga (53)
3ha (94)
3ia (84)
3ja (77)
3ka (86)
3la (76)
3ma (87)
3na (98)
3oa (55)
2
1c (p-ClC6H4, Ts)
1d (p-BrC6H4, Ts)
1e (p-CF3C6H4, Ts)
1f (p-MeOOCC6H4, Ts)
1g (p-NCC6H4, Ts)
1h (p-MeC6H4, Ts)
1i (p-EtC6H4, Ts)
1j (p-tBuC6H4, Ts)
1k (p-MeOC6H4, Ts)
1l (o-MeOC6H4, Ts)
1m (m-MeOC6H4, Ts)
1n (m-FC6H4, Ts)
1o (2-thienyl, Ts)
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
c
1p (Ph, Ms)
3pa (88)
1q (Ph, p-BrC6H4SO2)
1r (Ph, p-MeOC6H4SO2)
3qa (82)
3ra (64)
a
In the presence of 0.002 mmol of Rh2(Oct)4, 0.2 mmol of triazole 1
and 0.2 mmol of 2a were reacted in 2 mL of refluxing DCE under N2.
Average of two runs. Two inseparable isomers were obtained
(1:0.8).
b
c
In summary, α-imino rhodium carbenes derived from 1-
sulfonyl-1,2,3-triazoles are efficiently trapped with β-(methyl-
thio)-α,β-unsaturated ketones, and the in situ generated sulfur
ylides undergo rearrangement to afford β-amino-α,β-unsatu-
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DOI: 10.1021/acs.joc.5b00521
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The Journal of Organic Chemistry
Note
a
reported in ppm relative to the carbon resonance of CDCl3 (77.00
ppm). High-resolution mass spectra (HRMS) were recorded using the
ESI mode (TOF). All of the substituted acetophenones were
commercially purchased, and the S-ethyl ester13 and dithioacetals 214
were prepared according to the reported methods in the literature.
Preparation of α-Oxo Ketene Dithioacetal 2. General
Procedure for Preparation of Substituted 3,3-Bis(methylthio)-1-
phenylprop-2-en-1-ones 2.14 To a stirred solution of NaH (800 mg,
20 mmol) in THF (20 mL) at 0 °C was added appropriately
substituted acetophenone (10 mmol) dropwise, the suspension was
stirred for 20 min, and CS2 (11 mmol) was added dropwise. The
reaction mixture (RM) was allowed to stir for 30 min, and MeI (25
mmol) was added dropwise. The RM was slowly brought up to room
temperature (rt) and stirring continued for another 3 h with
monitoring by TLC. The RM was poured into ice-cold water,
extracted with ethyl acetate, dried with Na2SO4, and concentrated
under reduced pressure. The crude was recrystallized with dichloro-
methane and petroleum ether to give the desired product 2. The
compound 2a,14 2b,14 2c,14 2d,14 2e,14 2f,15 2g,15 and 2h15were
reported in the literature.
Table 4. Synthesis of Pyrrole 4
3,3-Bis(methylthio)-1-phenylprop-2-en-1-one (2a): yellow solid,
1
1.36 g; yield 61%; H NMR (400 MHz, chloroform-d) δ 7.92 (d, J =
7.2 Hz, 2H), 7.52−7.42 (m, 3H), 6.77 (s, 1H), 2.57 (s, 3H), 2.54 (s,
3H).
3,3-Bis(methylthio)-1-(o-tolyl)prop-2-en-1-one (2b): yellow solid,
1
1.53 g; yield 64%; H NMR (400 MHz, chloroform-d) δ 7.48 (d, J =
7.2 Hz, 1H), 7.33−7.30 (m, 1H), 7.23−7.21 (m, 2H), 6.41 (s, 1H),
2.54 (s, 3H), 2.49 (s, 3H), 2.48 (s, 3H).
1-(4-Methoxyphenyl)-3,3-bis(methylthio)prop-2-en-1-one (2c):
1
yellow solid, 1.50 g; yield 59%; H NMR (400 MHz, chloroform-d)
δ 7.92 (d, J = 8.8 Hz, 2H), 6.93 (d, J = 8.8 Hz, 2H), 6.75 (s, 1H), 3.86
(s, 3H), 2.56 (s, 3H), 2.53 (s, 3H).
1-(4-Chlorophenyl)-3,3-bis(methylthio)prop-2-en-1-one (2d): yel-
1
low solid, 1.13 g; yield 44%; H NMR (400 MHz, chloroform-d) δ
7.86 (d, J = 8.8 Hz, 2H), 7.41 (d, J = 8.8 Hz, 2H), 6.70 (s, 1H), 2.57
(s, 3H), 2.54 (s, 3H).
1-(4-Bromophenyl)-3,3-bis(methylthio)prop-2-en-1-one (2e): yel-
1
low solid, 1.29 g; yield 43%; H NMR (400 MHz, chloroform-d) δ
7.78 (d, J = 8.4 Hz, 2H), 7.57 (d, J = 8.4 Hz, 2H), 6.70 (s, 1H), 2.57
(s, 3H), 2.54 (s, 3H).
3,3-Bis(methylthio)-1-(thiophene-2-yl)prop-2-en-1-one (2f):
1
brown solid, 1.24 g; yield 54%; H NMR (400 MHz, chloroform-d)
δ 7.66 (d, J = 3.6 Hz, 1H), 7.55 (d, J = 4.8 Hz, 1H), 7.10 (t, J = 4.4 Hz,
1H), 6.62 (s, 1H), 2.56 (s, 3H), 2.53 (s, 3H).
4,4-Bis(methylthio)but-3-en-2-one (2g): yellow solid, 0.83 g, yield
51%; 1H NMR (400 MHz, chloroform-d) δ 6.04 (s, 1H), 2.47 (s, 3H),
2.43 (s, 3H), 2.20 (s, 3H).
a
0.2 mmol of 3 was dissolved in 2 mL of dry toluene, and then the
3-Methyl-4,4-bis(methylthio)but-3-en-2-one (2h): yellow viscous
reaction mixture was stirred at 110 °C for 2.5 h.
1
liquid, 0.96 g; yield 54%; H NMR (400 MHz, chloroform-d) δ 2.39
(s, 3H), 2.33 (s, 3H), 2.30 (s, 3H), 2.11 (s, 3H).
Procedure for the Preparation of 3-(Methylthio)-1,3-diphenyl-
prop-2-en-1-one 2i.16 To a stirred suspension of NaH (160 mg, 4.0
mmol) in DMF (25 mL) under an N2 atmosphere was added dropwise
a solution of aryl methyl ketone (3.7 mmol) and aryl dithioester13
(800 mg, 4.4 mmol) in DMF (15 mL) at 0 °C, and the reaction
mixture was further stirred at room temperature for 1 h. After
complete formation of monothiodiketone (monitored by TLC), the
reaction mixture was cooled to 0 °C, followed by dropwise addition of
methyl iodide (4.4 mmol) and further stirring at room temperature for
2 h (monitored by TLC). The mixture was then poured into water (40
mL) and extracted with EtOAc (3 × 40 mL). The combined organic
extracts were washed with H2O (3 × 40 mL) followed by brine (1 ×
40 mL) and dried over anhydrous Na2SO4. The solvent was removed
under reduced pressure to give crude products 2i, which were purified
by column chromatography using PE/EtOAc (40:1) as eluent to give
the desired product 2i.16 The compound 2i was reported in the
literature.
rated ketones in mostly good to excellent yields. The
transformation is featured with broad scope and a formal
insertion of three atoms into C−S bond. The synthetic
potential of the reaction is highlighted by the synthesis of 2-
(methylthio)pyrrole derivatives.
EXPERIMENTAL SECTION
■
General Information. For proton nuclear magnetic resonance (1H
NMR) spectra, the chemical shift (δ) is reported in parts per million
(ppm) downfield relative to tetramethylsilane (TMS, 0.0 ppm) or
CDCl3 (7.26 ppm). Coupling constants (J) are reported in hertz.
Multiplicities are reported using the following abbreviations: s, singlet;
d, doublet; t, triplet; q, quartet; m, multiplet; br, broad. For carbon-13
nuclear magnetic resonance (13C NMR) spectra, the chemical shift is
3-(Methylthio)-1,3-diphenylprop-2-en-1-one (2i): yellow solid,
1
0.39 g; yield 42%; H NMR (400 MHz, chloroform-d) δ 7.98 (d, J
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Note
= 7.2 Hz, 2H), 7.52 (t, J = 7.4 Hz, 1H), 7.46−7.42 (m, 5H), 7.34 (d, J
= 6.8 Hz, 2H), 7.11 (s, 1H), 1.96 (s, 3H).
4-(4-Ethylphenyl)-1-tosyl-1H-1,2,3-triazole (1i): white solid, 0.98 g;
yield 60%; 1H NMR (400 MHz, chloroform-d) δ 8.27 (s, 1H), 8.02 (d,
J = 7.6 Hz, 2H), 7.73 (d, J = 7.6 Hz, 2H), 7.38 (d, J = 7.2 Hz, 2H),
7.26 (d, J = 7.2 Hz, 2H), 2.67 (d, J = 7.2 Hz, 2H), 2.44 (s, 3H), 1.25 (t,
J = 7.2 Hz, 3H).
Procedure for the Preparation of (E)-3-(Methylthio)-1-phenyl-
prop-2-en-1-one 2j.17 To a stirred suspension of nickel chloride
hexahydrate (1.706 g, 7.2 mmol) in ethanol (10 mL) was added
sodium borohydride (340 mg, 9.0 mmol), in small portions (15 min)
and the mixture was further stirred for 10 min. A solution of ketene
S,S-acetal 2a (650 mg, 2.7 mmol) in ethanol (5 mL) was added to the
black suspension, and the mixture was further stirred at room
temperature for 10 min. It was then heated under reflux on an oil bath
with stirring for 48 h until the starting material has disappeared
completely (TLC). The mixture was filtered hot through a sintered
funnel, and the black residue was washed with boiling chloroform (3 ×
30 mL). The combined filtrate was washed with water (2 × 40 mL),
and the organic layer was dried with sodium sulfate and evaporated to
give a yellow viscous liquid, which was passed through a silica gel
column. Elution with PE/EtOAc (30:1) as eluent gave the desired
product 2j. The compound 2j was reported in the literature.
4-(4-(tert-Butyl)phenyl)-1-tosyl-1H-1,2,3-triazole (1j): white solid,
1.05 g; yield 59%; 1H NMR (400 MHz, chloroform-d) δ 8.27 (s, 1H),
8.02 (d, J = 8.4 Hz, 2H), 7.75 (d, J = 8.4 Hz, 2H), 7.46 (d, J = 8.4 Hz,
2H), 7.39 (d, J = 8.4 Hz, 2H), 2.45 (s, 3H), 1.33 (s, 9H).
4-(4-Methoxyphenyl)-1-tosyl-1H-1,2,3-triazole (1k): white solid,
1.39 g; yield 85%; 1H NMR (400 MHz, chloroform-d) δ 8.22 (s, 1H),
8.01 (d, J = 8.4 Hz, 2H), 7.75 (d, J = 8.4 Hz, 2H), 7.37 (d, J = 8.8 Hz,
2H), 6.95 (d, J = 8.8 Hz, 2H), 3.83 (s, 3H), 2.43 (s, 3H).
4-(2-Methoxyphenyl)-1-tosyl-1H-1,2,3-triazole (1l): yellow solid,
1.14 g; yield 69%; 1H NMR (400 MHz, chloroform-d) δ 8.57 (s, 1H),
8.32 (d, J = 7.6 Hz, 1H), 8.02 (d, J = 8.0 Hz, 2H), 7.39−7.31 (m, 3H),
7.10−7.02 (t, J = 7.6 Hz, 1H), 6.98 (d, J = 8.4 Hz, 1H), 3.97 (s, 3H),
2.43 (s, 3H).
4-(3-Methoxyphenyl)-1-tosyl-1H-1,2,3-triazole (1m): white solid,
1.29 g; yield 65%; 1H NMR (400 MHz, chloroform-d) δ 8.31 (s, 1H),
8.03 (d, J = 8.4 Hz, 2H), 7.43−7.31 (m, 5H), 6.92 (d, J = 7.6 Hz, 1H),
3.86 (s, 3H), 2.45 (s, 3H).
4-(3-Fluorophenyl)-1-tosyl-1H-1,2,3-triazole (1n): white solid, 0.48
g; yield 30%; 1H NMR (400 MHz, chloroform-d) δ 8.32 (s, 1H), 8.03
(d, J = 7.6 Hz, 2H), 7.57 (t, J = 10.2 Hz, 2H), 7.44−7.35 (m, 3H), 7.07
(t, J = 8.6 Hz, 1H), 2.46 (s, 3H).
(E)-3-(Methylthio)-1-phenylprop-2-en-1-one (2j): yellow viscous
liquid, 78 mg; yield 16%; H NMR (400 MHz, chloroform-d) δ 7.98
1
(d, J = 14.4 Hz, 1H), 7.92 (d, J = 8.4 Hz, 2H), 7.55 (t, J = 7.4 Hz, 1H),
7.49−7.44 (m, 2H), 6.80 (d, J = 14.4 Hz, 1H), 2.46 (s, 3H).
General Procedures for Formation of 1-Sulfonyl-1,2,3-
triazoles 1.5b A scintillation vial was charged with copper(I)
thiophene-2-carboxylate (CuTC, 0.095 g, 0.5 mmol, 0.1 equiv in
regards to alkyne), toluene (20 mL), and the alkyne (5.0 mmol, 1
equiv). The reaction mixture was cooled in an ice−water bath.
Subsequently, the sulfonyl azide (5.0 mmol, 1 equiv) was added slowly
as the limiting reagent to avoid a runaway exotherm, and the reaction
mixture allowed to warm to room temperature and stirred overnight.
The reaction was diluted with saturated aq NH4Cl and extracted into
DCM (2 × 20 mL). The combined organics were dried (Na2SO4) and
filtered through Celite. The eluent was concentrated in vacuo. The
obtained crude product was purified by SiO2 column chromatography
(PE/EA = 30:1) to give the desired product 1. The compounds 1a,5b
1b,18 1c,9b 1d,5a 1e,19 1f,7a 1g,6j 1h,19 1i,20 1j,21 1k,19 1l,22 1m,11a 1n,21
1p,23 1q,5b and 1r4were reported in the literature.
4-Phenyl-1-tosyl-1H-1,2,3-triazole (1a): white solid, 1.42 g; yield
95%; 1H NMR (400 MHz, chloroform-d) δ 8.32 (s, 1H), 8.02 (d, J =
8.0 Hz, 2H), 7.82 (d, J = 8.0 Hz, 2H), 7.48−7.34 (m, 5H), 2.44 (s,
3H).
4-(4-Fluorophenyl)-1-tosyl-1H-1,2,3-triazole (1b): white solid, 0.82
g; yield 52%; 1H NMR (400 MHz, chloroform-d) δ 8.28 (s, 1H), 8.04
(d, J = 8.0 Hz, 2H), 7.81 (t, J = 8.0 Hz, 2H), 7.40 (d, J = 8.0 Hz, 2H),
7.13 (t, J = 8.0 Hz, 2H), 2.46 (s, 3H).
4-(Thiophene-2-yl)-1-tosyl-1H-1,2,3-triazole (1o): white solid, 0.37
1
g, yield 24%; mp 140−141 °C; H NMR (400 MHz, chloroform-d) δ
8.21 (s, 1H), 8.02 (d, J = 8.4 Hz, 2H), 7.45 (d, J = 3.6 Hz, 1H), 7.40
(d, J = 8.4 Hz, 2H), 7.35 (d, J = 5.2 Hz, 1H), 7.09 (t, J = 4.4 Hz, 1H),
2.45 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ 147.4, 142.5,
133.0, 130.8, 130.5, 128.7, 127.8, 126.3, 125.6, 118.1, 21.8; HRMS
+
(ESI) calcd for C13H12N3O2S2 306.0371, found 306.0366.
1-(Methylsulfonyl)-4-phenyl-1H-1,2,3-triazole (1p): white solid,
0.96 g; yield 86%; 1H NMR (400 MHz, chloroform-d) δ 8.32 (s, 1H),
7.88 (d, J = 7.6 Hz, 2H), 7.53−7.44 (m, 2H), 7.46−7.39 (m, 1H), 3.58
(s, 3H).
1-(4-Bromophenylsulfonyl)-4-phenyl-1H-1,2,3-triazole (1q): white
solid, 1.60 g; yield 88%; 1H NMR (400 MHz, chloroform-d) δ 8.32 (s,
1H), 8.02 (d, J = 8.0 Hz, 2H), 7.83 (d, J = 7.2 Hz, 2H), 7.76 (d, J = 8.0
Hz, 2H), 7.49−7.36 (m, 3H).
1-(4-Methoxyphenylsulfonyl)-4-phenyl-1H-1,2,3-triazole (1r):
1
white solid, 0.87 g; yield 55%; H NMR (400 MHz, chloroform-d)
δ 8.31 (s, 1H), 8.09 (d, J = 8.8 Hz, 2H), 7.83 (d, J = 7.2 Hz, 2H),
7.48−7.39 (m, 2H), 7.42−7.33 (m, 1H), 7.04 (d, J = 8.8 Hz, 2H), 3.89
(s, 3H).
4-(4-Chlorophenyl)-1-tosyl-1H-1,2,3-triazole (1c): white solid, 1.12
g; yield 76%; 1H NMR (400 MHz, chloroform-d) δ 8.30 (s, 1H), 8.02
(d, J = 8.4 Hz, 2H), 7.75 (d, J = 8.4 Hz, 2H), δ 7.43−7.38 (m, 4H),
2.45 (s, 3H).
General Procedure for the Synthesis of β-Amino-α,β-
unsaturated Ketone Derivatives 3. Under a nitrogen atmosphere,
DCE (1.0 mL) was added to reaction flask charged with Rh2(Oct)4
(1.6 mg, 1 mol %) and 1-sulfonyl-1,2,3-triazoles 1 (0.2 mmol). Then a
solution of α-oxo ketene dithioacetal compound 2 (0.2 mmol) in DCE
(1.0 mL) was added dropwise at room temperature. The reaction
mixture was stirred at reflux until TLC analysis showed that 2 was
completely consumed. The reaction mixture cooled to room
temperature and filtered through a short plug of silica gel. The
solution of mixture was concentrated and then purified by flash
chromatography elution with PE/DCM (1:2) as eluent to give the
corresponding product 3.
4-(4-Bromophenyl)-1-tosyl-1H-1,2,3-triazole (1d): white solid,
1
1.05 g; yield 56%; H NMR (400 MHz, chloroform-d) δ 8.32 (s,
1H), 8.03 (d, J = 8.0 Hz, 2H), 7.70 (d, J = 8.4 Hz, 2H), 7.57 (d, J = 8.4
Hz, 2H), 7.40 (d, J = 8.0 Hz, 2H), 2.46 (s, 3H).
1-Tosyl-4-(4-(trifluoromethyl)phenyl)-1H-1,2,3-triazole (1e): white
solid, 1.11 g; yield 60%; 1H NMR (400 MHz, chloroform-d) δ 8.40 (s,
1H), 8.05 (d, J = 8.0 Hz, 2H), 7.95 (d, J = 8.0 Hz, 2H), 7.70 (d, J = 8.4
Hz, 2H), 7.41 (d, J = 8.4 Hz, 2H), 2.46 (s, 3H).
Methyl 4-(1-tosyl-1H-1,2,3-triazol-4-yl)benzoate (1f): white solid,
1.37 g; yield 77%; 1H NMR (400 MHz, chloroform-d) δ 8.40 (s, 1H),
8.11 (d, J = 8.4 Hz, 2H), 8.04 (d, J = 8.0 Hz, 2H), 7.91 (d, J = 8.4 Hz,
2H), 7.41 (d, J = 8.0 Hz, 2H), 3.94 (s, 3H), 2.46 (s, 3H).
4-(1-Tosyl-1H-1,2,3-triazol-4-yl)benzonitrile (1g): white solid, 1.23
g; yield 76%; 1H NMR (400 MHz, chloroform-d) δ 8.42 (s, 1H), 8.04
(d, J = 8.0 Hz, 2H), 7.95 (d, J = 8.0 Hz, 2H), 7.73 (d, J = 8.0 Hz, 2H),
7.42 (d, J = 8.0 Hz, 2H), 2.46 (s, 3H).
4-Methyl-N-((Z)-2-(methylthio)-2-phenylvinyl)-N-((Z)-1-(methyl-
thio)-3-oxo-3-phenylprop-1-en-1-yl)benzenesulfonamide (3aa): yel-
low oil, 95 mg; yield 96%; 1H NMR (400 MHz, chloroform-d) δ 7.82
(d, J = 8.4 Hz, 2H), 7.78 (d, J = 7.6 Hz, 2H), 7.52 (t, J = 7.2 Hz, 1H),
7.46−7.33 (m, 9H), 6.74 (s, 1H), 6.68 (s, 1H), 2.47 (s, 3H), 2.45 (s,
3H), 1.81 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ 188.3, 156.7,
144.9, 138.3, 136.8, 136.2, 135.2, 132.4, 129.8, 128.6, 128.5, 128.4,
127.9, 125.0, 120.8, 21.6, 16.3, 15.5; HRMS (ESI) calcd for
+
4-p-Tolyl-1-tosyl-1H-1,2,3-triazole (1h): white solid, 1.25 g; yield
80%; 1H NMR (400 MHz, Chloro- form-d) δ 8.27 (s, 1H), 8.02 (d, J
= 8.4 Hz, 2H), 7.71 (d, J = 8.4 Hz, 2H), 7.39 (d, J = 8.0 Hz, 2H), 7.24
(d, J = 8.0 Hz, 2H), 2.45 (s, 3H), 2.38 (s, 3H).
C26H26NO3S3 496.1075, found 496.1079.
N-((Z)-2-(4-Fluorophenyl)-2-(methylthio)vinyl)-4-methyl-N-((Z)-1-
(methylthio)-3-oxo-3-phenylprop-1-en-1-yl)benzenesulfonamide
(3ba): yellow oil, 79 mg; yield 77%; 1H NMR (400 MHz, chloroform-
4819
DOI: 10.1021/acs.joc.5b00521
J. Org. Chem. 2015, 80, 4816−4823

The Journal of Organic Chemistry
Note
d) δ 7.80 (d, J = 8.4 Hz, 2H), 7.77 (d, J = 7.2 Hz, 2H), 7.52 (d, J = 7.2
Hz, 1H), 7.45−7.40 (m, 4H), 7.36 (d, J = 8.0 Hz, 2H), 7.06−7.11 (m,
2H), 6.75 (s, 1H), 6.65 (s, 1H), 2.46 (s, 3H), 2.44 (s, 3H), 1.80 (s,
3H); 13C NMR (100 MHz, chloroform-d) δ 188.4, 164.1 (q, J = 124.0
Hz), 156.5, 145.0, 138.3, 135.1 (d, J = 3.5 Hz), 132.5, 130.2, 130.1,
129.9, 128.5, 128.0, 128.0, 125.2, 120.9 (d, J = 4.6 Hz), 115.8, 115.6,
d) δ 7.72 (d, J = 8.0 Hz, 2H), 7.67 (d, J = 7.6 Hz, 2H), 7.42 (t, J = 7.0
Hz, 1H), 7.35−7.23 (m, 6H), 7.13 (d, J = 7.6 Hz, 2H), 6.66 (s, 1H),
6.55 (s, 1H), 2.58 (q, J = 7.4 Hz, 2H), 2.39 (s, 3H), 2.35 (s, 3H), 1.71
(s, 3H), 1.16 (t, J = 7.4 Hz, 3H); 13C NMR (100 MHz, chloroform-d)
δ 188.3, 156.9, 144.9, 144.8, 138.3, 136.9, 135.2, 134.0, 132.4, 129.8,
129.2, 128.4, 128.3, 128.1, 127.9, 124.5, 120.6, 28.5, 21.6, 16.3, 15.5,
+
+
21.6, 16.3, 15.6; HRMS (ESI) calcd for C26H25FNO3S3 514.0980,
15.3; HRMS (ESI) calcd for C28H30NO3S3 524.1388, found
found 514.0986.
524.1393.
N-((Z)-2-(4-Chlorophenyl)-2-(methylthio)vinyl)-4-methyl-N-((Z)-
1-(methylthio)-3-oxo-3-phenylprop-1-en-1-yl)benzenesulfonamide
(3ca): yellow oil, 89 mg; yield 85%; 1H NMR (400 MHz, chloroform-
d) δ 7.71 (d, J = 8.4 Hz, 2H), 7.65 (d, J = 7.6 Hz, 2H), 7.52 (t, J = 7.4
Hz, 1H), 7.35−7.24 (m, 8H), 6.65 (s, 1H), 6.63 (s, 1H), 2.36 (s, 3H),
2.34 (s, 3H), 1.71 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ
188.2, 156.3, 145.0, 138.2, 135.5, 135.1, 134.4, 133.8, 132.5, 129.9,
129.6, 128.8, 128.4, 127.9, 127.8, 125.7, 120.9, 21.6, 16.2, 15.6; HRMS
N-((Z)-2-(4-tert-Butylphenyl)-2-(methylthio)vinyl)-4-methyl-N-
((Z)-1-(methylthio)-3-oxo-3-phenylprop-1-en-1-yl)-
1
benzenesulfonamide (3ja): yellow oil, 84 mg; yield 77%; H NMR
(400 MHz, chloroform-d) δ 7.73 (d, J = 8.0 Hz, 2H), 7.68 (d, J = 7.6
Hz, 2H), 7.42 (t, J = 7.2 Hz, 1H), 7.33−7.30 (m, 6H), 7.25 (d, J = 8.0
Hz, 2H), 6.65 (s, 1H), 6.57 (s, 1H), 2.39 (s, 3H), 2.35 (s, 3H), 1.72 (s,
3H), 1.25 (s, 9H); 13C NMR (100 MHz, chloroform-d) δ 188.3, 157.0,
151.8, 144.8, 138.3, 136.6, 135.2, 133.7, 132.4, 129.8, 128.4, 128.1,
127.9, 125.5, 125.2, 124.6, 120.6, 34.6, 31.2, 21.6, 16.3, 15.6; HRMS
+
(ESI) calcd for C26H25ClNO3S3 530.0685, found 530.0692.
+
(ESI) calcd for C30H34NO3S3 552.1701, found 552.1706.
N-((Z)-2-(4-Bromophenyl)-2-(methylthio)vinyl)-4-methyl-N-((Z)-
1-(methylthio)-3-oxo-3-phenylprop-1-en-1-yl)benzenesulfonamide
(3da): yellow oil, 101 mg; yield 88%; 1H NMR (400 MHz,
chloroform-d) δ 7.72 (d, J = 8.0 Hz, 2H), 7.67 (d, J = 7.2 Hz, 2H),
7.43 (d, J = 8.0 Hz, 2H), 7.35−7.31 (m, 3H), 7.27−7.23 (m, 4H), 6.64
(s, 2H), 2.36 (s, 3H), 2.35 (s, 3H), 1.72 (s, 3H); 13C NMR (100 MHz,
chloroform-d) δ 188.3, 156.4, 145.0, 138.2, 136.0, 135.1, 133.7, 132.5,
131.8, 129.9, 128.4, 128.3, 127.9, 127.6, 125.8, 122.6, 120.9, 21.6, 16.3,
N-((Z)-2-(4-Methoxyphenyl)-2-(methylthio)vinyl)-4-methyl-N-
((Z)-1-(methylthio)-3-oxo-3-phenylprop-1-en-1-yl)-
1
benzenesulfonamide (3ka): yellow oil, 90 mg; yield 86%; H NMR
(400 MHz, chloroform-d) δ 7.82 (d, J = 7.6 Hz, 2H), 7.77 (d, J = 7.6
Hz, 2H), 7.51 (t, J = 7.2 Hz, 1H), 7.44−7.32 (m, 6H), 6.92 (d, J = 8.4
Hz, 2H), 6.77 (s, 1H), 6.58 (s, 1H), 3.82 (s, 3H), 2.47 (s, 3H), 2.44 (s,
3H), 1.80 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ 188.4, 160.0,
156.7, 144.8, 138.3, 137.5, 135.4, 132.4, 129.8, 129.7, 128.9, 128.4,
127.94, 127.90, 123.8, 120.7, 114.0, 55.3, 21.6, 16.3, 15.5; HRMS
+
15.7; HRMS (ESI) calcd for C26H25BrNO3S3 574.0180, found
574.0186.
+
(ESI) calcd for C27H28NO4S3 526.1180, found 526.1182.
4-Methyl-N-((Z)-2-(methylthio)-2-(4-(trifluoromethyl)phenyl)-
vinyl)-N-((Z)-1-(methylthio)-3-oxo-3-phenylprop-1-en-1-yl)-
N-((Z)-2-(2-Methoxyphenyl)-2-(methylthio)vinyl)-4-methyl-N-
1
benzenesulfonamide (3ea): yellow oil, 81 mg; yield 72%; H NMR
((Z)-1-(methylthio)-3-oxo-3-phenylprop-1-en-1-yl)-
1
benzenesulfonamide (3la): yellow oil, 80 mg; yield 76%; H NMR
(400 MHz, chloroform-d) δ 7.81 (d, J = 7.2 Hz, 2H), 7.75 (d, J = 7.2
Hz, 2H), 7.65 (d, J = 7.4 Hz, 2H), 7.59 (d, J = 7.4 Hz, 2H), 7.45−7.34
(m, 5H), 6.85 (s, 1H), 6.72 (s, 1H), 2.45 (s, 3H), 2.44 (s, 3H), 1.82 (s,
3H); 13C NMR (100 MHz, chloroform-d) δ 188.2, 156.4, 145.2, 140.9,
139.3 (q, J = 193.4 Hz), 138.1, 134.9, 132.5, 131.7, 130.0, 128.6, 128.5,
127.92, 127.90 (q, J = 1.1 Hz), 127.1, 125.6 (q, J = 1.9 Hz), 120.9,
(400 MHz, chloroform-d) δ 7.78 (d, J = 8.4 Hz, 2H), 7.70 (d, J = 7.6
Hz, 2H), 7.43 (t, J = 7.4 Hz, 1H), 7.34 (d, J = 7.6 Hz, 2H), 7.23−7.27
(m, 3H), 7.15 (d, J = 7.6 Hz, 1H), 6.89 (t, J = 7.4 Hz, 1H), 6.84 (d, J =
8.0 Hz, 1H), 6.70 (s, 1H), 6.39 (s, 1H), 3.73 (s, 3H), 2.43 (s, 3H),
2.36 (s, 3H), 1.64 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ
188.3, 157.2, 157.1, 144.6, 138.5, 135.6, 134.0, 132.3, 131.0, 130.8,
129.8, 129.7, 128.4, 127.9, 125.1, 123.6, 120.5, 120.3, 111.0, 55.6, 21.6,
+
115.7, 21.6, 16.2, 15.7; HRMS (ESI) calcd for C27H25F3NO3S3
564.0948, found 564.0954.
+
16.3, 14.6; HRMS (ESI) calcd for C27H28NO4S3 526.1180, found
Methyl 4-((Z)-2-(4-methyl-N-((Z)-1-(methylthio)-3-oxo-3-phenyl-
prop-1-en-1-yl)phenylsulfonamido)-1-(methylthio)vinyl)benzoate
(3fa): yellow oil, 80 mg; yield 72%; 1H NMR (400 MHz, chloroform-
d) δ 7.98 (d, J = 8.0 Hz, 2H), 7.73 (d, J = 8.4 Hz, 2H), 7.68(d, J = 7.6
Hz, 2H), 7.46(d, J = 8.4 Hz, 2H), 7.37−7.32 (m, 3H), 7.28 (d, J = 8.0
Hz, 2H), 6.78 (s, 1H), 6.63 (s, 1H), 3.86 (s, 3H), 2.38 (s, 3H), 2.36 (s,
3H), 1.73 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ 188.3, 166.5,
156.5, 145.1, 141.8, 138.2, 135.0, 132.5, 132.3, 130.0, 129.9, 129.7,
129.4, 128.5, 128.3, 128.0, 126.9, 120.9, 52.2, 21.6, 16.3, 15.8; HRMS
526.1182.
N-((Z)-2-(3-Methoxyphenyl)-2-(methylthio)vinyl)-4-methyl-N-
((Z)-1-(methylthio)-3-oxo-3-phenylprop-1-en-1-yl)-
1
benzenesulfonamide (3ma): yellow oil, 92 mg; yield 87%; H NMR
(400 MHz, chloroform-d) δ 7.81 (d, J = 8.4 Hz, 2H), 7.76 (d, J = 7.2
Hz, 2H), 7.52 (t, J = 7.2 Hz, 1H), 7.41 (d, J = 7.6 Hz, 2H), 7.35 (d, J =
8.0 Hz, 2H), 7.29 (d, J = 7.6 Hz, 1H), 7.05−6.98 (m, 2H), 6.92−6.88
(m, 1H), 6.72 (s, 1H), 6.71 (s, 1H), 3.83 (s, 3H), 2.47 (s, 3H), 2.45 (s,
3H), 1.83 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ 188.3, 159.7,
157.0, 144.9, 138.22, 138.16, 135.6, 135.0, 132.4, 129.8, 129.6, 129.3,
128.4, 127.9, 125.1, 120.7, 120.5, 114.0, 113.8, 55.3, 21.6, 16.3, 15.5;
+
(ESI) calcd for C28H28NO5S3 554.1129, found 554.1135.
N-((Z)-2-(4-Cyanophenyl)-2-(methylthio)vinyl)-4-methyl-N-((Z)-1-
(methylthio)-3-oxo-3-phenylprop-1-en-1-yl)benzenesulfonamide
(3ga): yellow oil, 55 mg; yield 53%; 1H NMR (400 MHz, chloroform-
d) δ 7.80 (d, J = 8.0 Hz, 2H), 7.73 (d, J = 8.0 Hz, 2H), 7.68 (d, J = 8.0
Hz, 2H), 7.60 (d, J = 8.0 Hz, 2H), 7.53 (t, J = 7.4 Hz, 1H), 7.36−7.44
(m, 4H), 6.96 (s, 1H), 6.70 (s, 1H), 2.46 (s, 3H), 2.41 (s, 3H), 1.82 (s,
3H); 13C NMR (100 MHz, chloroform-d) δ 188.1, 156.1, 145.3, 142.2,
138.0, 134.7, 132.6, 132.5, 130.0, 129.6, 128.8, 128.5, 128.2, 127.92,
127.89, 118.4, 121.1, 111.9, 21.6, 16.2, 15.9; HRMS (ESI) calcd for
+
HRMS (ESI) calcd for C27H28NO4S3 526.1180, found 526.1182.
N-((Z)-2-(3-Fluorophenyl)-2-(methylthio)vinyl)-4-methyl-N-((Z)-1-
(methylthio)-3-oxo-3-phenylprop-1-en-1-yl)benzenesulfonamide
(3na): yellow oil, 101 mg; yield 98%; 1H NMR (400 MHz,
chloroform-d) δ 7.83 (d, J = 8.4 Hz, 2H), 7.77 (d, J = 7.2 Hz, 2H),
7.54 (t, J = 7.4 Hz, 1H), 7.44 (d, J = 7.6 Hz, 2H), 7.38 (d, J = 8.0 Hz,
2H), 7.16−7.25 (m, 3H), 7.07 (t, J = 7.6 Hz, 1H), 6.82 (s, 1H), 6.74
(s, 1H), 2.48 (s, 3H), 2.47 (s, 3H), 1.85 (s, 3H); 13C NMR (100 MHz,
chloroform-d) δ 188.2, 164.0, 161.5, 156.6, 145.1, 139.4, 138.1 (q, J =
147.0 Hz), 134.9, 132.5, 130.1 (q, J = 4.2 Hz), 129.9, 129.3, 128.4,
127.9, 126.2, 123.94, 123.91, 120.7, 115.3 (q, J = 21.3 Hz), 21.6, 16.2,
+
C27H25N2O3S3 521.1027, found 521.1034.
4-Methyl-N-((Z)-2-(methylthio)-2-p-tolylvinyl)-N-((Z)-1-(methyl-
thio)-3-oxo-3-phenylprop-1-en-1-yl)benzenesulfonamide (3ha): yel-
low oil, 92 mg; yield 94%; 1H NMR (400 MHz, chloroform-d) δ 7.81
(d, J = 8.0 Hz, 2H), 7.76 (d, J = 8.0 Hz, 2H), 7.51 (t, J = 7.2 Hz, 1H),
7.41 (d, J = 7.6 Hz, 2H), 7.34 (m, 4H), 7.20 (d, J = 7.6 Hz, 2H), 6.74
(s, 1H), 6.63 (s, 1H), 2.47 (s, 3H), 2.44 (s, 3H), 2.37 (s, 3H), 1.80 (s,
3H); 13C NMR (100 MHz, chloroform-d) δ 188.4, 156.9, 144.8, 138.6,
138.3, 136.9, 135.3, 133.8, 132.4, 129.8, 129.3, 129.0, 128.4, 128.3,
127.9, 124.4, 120.6, 21.6, 21.1, 16.3, 15.5; HRMS (ESI) calcd for
+
15.7; HRMS (ESI) calcd for C26H25FNO3S3 514.0980, found
514.0986.
4-Methyl-N-((Z)-2-(methylthio)-2-(thiophene-2-yl)vinyl)-N-((Z)-1-
(methylthio)-3-oxo-3-phenylprop-1-en-1-yl)benzenesulfonamide
(3oa): yellow oil, 55 mg; yield 55%; 1H NMR (400 MHz, chloroform-
d) δ 7.83 (d, J = 8.0 Hz, 2H), 7.77 (d, J = 7.6 Hz, 2H), 7.53 (t, J = 7.4
Hz, 1H), 7.46−7.36 (m, 5H), 7.32 (d, J = 5.2 Hz, 1H), 7.21(d, J = 3.2
Hz, 1H), 7.07 (s, 1H), 6.76 (s, 1H), 2.47 (s, 3H), 2.40 (s, 3H), 2.01 (s,
3H); 13C NMR (100 MHz, chloroform-d) δ 188.3, 156.33, 156.25,
145.1, 141.7, 138.1, 135.2, 132.5, 130.0, 128.5, 128.0, 127.9, 127.6,
+
C27H28NO3S3 510.1231, found 510.1232.
N-((Z)-2-(4-Ethylphenyl)-2-(methylthio)vinyl)-4-methyl-N-((Z)-1-
(methylthio)-3-oxo-3-phenylprop-1-en-1-yl)benzenesulfonamide
1
(3ia): yellow oil, 87 mg; yield 84%; H NMR (400 MHz, chloroform-
4820
DOI: 10.1021/acs.joc.5b00521
J. Org. Chem. 2015, 80, 4816−4823

The Journal of Organic Chemistry
Note
126.2, 125.7, 120.7, 120.6, 21.6, 16.4, 16.1; HRMS (ESI) calcd for
C24H24NO3S4 502.0639, found 502.0645.
4-Methyl-N-((Z)-2-(methylthio)-2-phenylvinyl)-N-((Z)-1-(methyl-
thio)-3-oxo-3-(thiophene-2-yl)prop-1-en-1-yl)benzenesulfonamide
(3af): yellow oil, 84 mg; yield 84%; 1H NMR (400 MHz, chloroform-
d) δ 7.81 (d, J = 8.0 Hz, 2H), 7.59 (d, J = 4.8 Hz, 1H), 7.46−7.34 (m,
8H), 7.08 (t, J = 4.2 Hz, 1H), 6.67 (s, 1H), 6.61 (s, 1H), 2.48 (s, 3H),
2.45 (s, 3H), 1.80 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ
180.5, 157.0, 145.8, 144.9, 136.7, 136.0, 135.0, 133.2, 130.6, 129.9,
128.6, 128.5, 128.4, 128.0, 127.9, 124.9, 120.0, 21.6, 16.4, 15.5; HRMS
+
N-((Z)-2-(Methylthio)-2-phenylvinyl)-N-(1-(methylthio)-3-oxo-3-
phenylprop-1-en-1-yl)methanesulfonamide (3pa): yellow oil, 74
1
mg; two inseparable isomers were obtained (1:0.8); yield 88%; H
NMR (400 MHz, chloroform-d) δ 7.89 (d, J = 7.2 Hz, 1.6H), 7.86 (d,
J = 7.2 Hz, 2H), 7.48−7.43 (m, 2H), 7.42−7.32 (m, 6H), 7.31−7.22
(m, 6.4H), 7.13 (s, 0.8H), 6.86 (s, 1H), 6.68 (s, 1H), 6.54 (s, 0.8H),
3.27 (s, 3H), 3.19 (s, 2.4H), 2.45 (s, 3H), 2.39 (s, 2.4H), 1.83 (s,
2.4H), 1.79 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ 188.9,
185.9, 155.4, 153.3, 139.2, 138.7, 138.4, 136.7, 136.1, 134.4, 132.6,
132.5, 128.9, 128.7, 128.56, 128.51, 128.50, 128.48, 128.43, 128.33,
128.15, 128.12, 125.2, 123.9, 121.5, 116.2, 41.0, 40.9, 16.9, 16.6, 15.4,
+
(ESI) calcd for C24H24NO3S4 502.0639, found 502.0645.
4-Methyl-N-((Z)-2-(methylthio)-2-phenylvinyl)-N-(1-(methylthio)-
3-oxobut-1-en-1-yl)benzenesulfonamide (3ag): yellow oil, 51 mg;
1
two inseparable isomers were obtained (1:0.35), yield 59%; H NMR
(400 MHz, chloroform-d) δ 7.78 (d, J = 8.0 Hz, 0.71H), 7.76 (d, J =
8.0 Hz, 2H), 7.41−7.32 (m, 9.5H), 6.68 (s, 0.35H), 6.58 (s, 1H), 5.99
(s, 1.36H), 2.48 (s, 3H), 2.45 (s, 3H), 2.43 (s, 1H), 2.33 (s, 1H), 2.18
(s, 4H), 1.84 (s, 1H), 1.80 (s, 3H); 13C NMR (100 MHz, chloroform-
d) δ 195.7, 195.2, 155.2, 155.1, 151.6, 144.8, 137.2, 136.7, 135.92,
135.88, 134.9, 134.8, 134.4, 131.0, 129.7, 129.5, 128.6, 128.5, 128.3,
128.2, 127.9, 125.9, 124.9, 123.5, 123.4, 123.1, 30.8, 29.7, 29.2, 21.6,
16.9, 16.2, 15.5, 15.4; HRMS (ESI) calcd for C21H24NO3S3+ 434.0918,
found 434.0923.
+
15.3; HRMS (ESI) calcd for C20H22NO3S3 420.0762, found
420.0760.
4-Bromo-N-((Z)-2-(methylthio)-2-phenylvinyl)-N-((Z)-1-(methyl-
thio)-3-oxo-3-phenylprop-1-en-1-yl)benzenesulfonamide (3qa): yel-
low oil, 91 mg; yield 82%; 1H NMR (400 MHz, chloroform-d) δ 7.79
(d, J = 8.8 Hz, 2H), 7.75 (d, J = 7.6 Hz, 2H), 7.70 (d, J = 8.8 Hz, 2H),
7.56−7.52 (m, 1H), 7.47−7.37 (m, 7H), 6.75 (s, 1H), 6.59 (s, 1H),
2.49 (s, 3H), 1.80 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ
188.3, 156.2, 138.5, 138.1, 137.3, 136.4, 132.6, 132.5, 129.3, 129.0,
128.8, 128.7, 128.5, 128.4, 127.9, 124.0, 121.1, 16.4, 15.5; HRMS
4-Methyl-N-(2-methyl-1-(methylthio)-3-oxobut-1-en-1-yl)-N-((Z)-
2-(methylthio)-2-phenylvinyl)benzenesulfonamide (3ah): yellow oil,
56 mg; two inseparable isomers were obtained (1:0.35); yield 63%; 1H
NMR (400 MHz, chloroform-d) δ 7.79 (d, J = 8.0 Hz, 2H), 7.76 (d, J
= 8.0 Hz, 0.71H), 7.40−7.30 (m, 9.5H), 6.89 (s, 0.35H), 6.64 (s, 1H),
2.51 (s, 3H), 2.43 (s, 5H), 2.21 (s, 3H), 2.16 (s, 1H), 2.14 (s, 1H),
1.95 (s, 3H), 1.81 (s, 3H), 1.79 (s, 1H); 13C NMR (100 MHz,
chloroform-d) δ 203.3, 201.1, 144.9, 144.6, 144.4, 141.1, 139.0, 137.7,
136.9, 135.8, 135.6, 134.3, 133.8, 129.62, 129.57, 128.54, 128.50,
128.42, 128.32, 128.29, 127.99, 127.94, 127.7, 127.1, 126.9, 124.5,
29.4, 29.3, 21.59, 21.57, 18.9, 18.4, 18.3, 17.0, 15.7, 15.3; HRMS (ESI)
+
(ESI) calcd for C25H23BrNO3S3 560.0023, found 560.0026.
4-Methoxy-N-((Z)-2-(methylthio)-2-phenylvinyl)-N-((Z)-1-(meth-
ylthio)-3-oxo-3-phenylprop-1-en-1-yl)benzenesulfonamide (3ra):
1
yellow oil, 64 mg; yield 64%; H NMR (400 MHz, chloroform-d) δ
7.86 (d, J = 8.8 Hz, 2H), 7.78 (d, J = 7.6 Hz, 2H), 7.52 (t, J = 7.4 Hz,
1H), 7.47−7.33 (m, 7H), 7.00 (d, J = 8.8 Hz, 2H), 6.76 (s, 1H), 6.68
(s, 1H), 3.86 (s, 3H), 2.48 (s, 3H), 1.81 (s, 3H); 13C NMR (100 MHz,
chloroform-d) δ 188.3, 163.8, 157.1, 138.3, 136.8, 135.8, 132.4, 130.2,
129.5, 128.6, 128.5, 128.43, 128.40, 127.9, 125.2, 120.5, 114.4, 55.7,
+
+
16.3, 15.6; HRMS (ESI) calcd for C26H26NO4S3 512.1024, found
calcd for C22H26NO3S3 448.1075, found 448.1072.
512.1021.
4-Methyl-N-((Z)-2-(methylthio)-2-phenylvinyl)-N-(3-oxo-1,3-di-
4-Methyl-N-((Z)-2-(methylthio)-2-phenylvinyl)-N-((Z)-1-(methyl-
phenylprop-1-en-1-yl)benzenesulfonamide (3ai): yellow oil, 83 mg;
1
thio)-3-oxo-3-(o-tolyl)prop-1-en-1-yl)benzenesulfonamide (3ab):
two inseparable isomers were obtained (1:0.4); yield 82%; H NMR
1
(400 MHz, chloroform-d) δ 1H NMR (400 MHz, CDCl3) δ 7.91 (d, J
= 7.6 Hz, 2H), 7.86−7.83 (m, 1.4H), 7.74 (d, J = 7.6 Hz, 2H), 7.59 (d,
J = 8.0 Hz, 2H), 7.49 (t, J = 7.2 Hz, 1H), 7.44−7.29 (m, 9H), 7.24−
7.18 (m, 9H), 6.91 (s, 1.4H), 6.86 (s, 1H), 6.39 (s, 0.4H), 2.45 (s,
1.2H), 2.39 (s, 3H), 1.73 (s, 1.2H), 1.62 (s, 3H); 13C NMR (100
MHz, chloroform-d) δ 192.2, 187.8, 150.0, 149.0, 144.6, 144.1, 140.2,
138.3, 138.2, 138.0, 137.1, 136.3, 136.1, 135.6, 134.7, 132.5, 132.4,
130.1, 129.9, 129.5, 129.40, 129.35, 129.26, 128.7, 128.6, 128.40,
128.33, 128.29, 128.20, 128.14, 127.96, 127.87, 127.67, 127.59, 127.42,
124.0, 119.7, 116.8, 21.61, 21.57, 15.5, 15.4. HRMS (ESI) calcd for
yellow oil, 90 mg; yield 89%; H NMR (400 MHz, chloroform-d) δ
7.79 (d, J = 8.0 Hz, 2H), 7.48−7.28 (m, 9H), 7.20 (d, J = 8.4 Hz, 2H),
6.65 (s, 1H), 6.44 (s, 1H), 2.50 (s, 3H), 2.49 (s, 3H), 2.41 (s, 3H),
1.81 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ 192.3, 156.2,
156.0, 144.8, 139.0, 137.8, 136.6, 136.2, 135.0, 131.4, 130.7, 129.8,
128.6, 128.5, 128.3, 127.8, 125.3, 125.1, 123.8, 21.5, 20.7, 16.3, 15.5;
+
HRMS (ESI) calcd for C27H28NO3S3 510.1231, found 510.1232.
N-((Z)-3-(4-Methoxyphenyl)-1-(methylthio)-3-oxoprop-1-en-1-
yl)-4-methyl-N-((Z)-2-(methylthio)-2-phenylvinyl)-
1
benzenesulfonamide (3ac): yellow oil, 90 mg; yield 86%; H NMR
(400 MHz, chloroform-d) δ 7.81 (d, J = 8.0 Hz, 2H), 7.76 (d, J = 8.8
Hz, 2H), 7.45 (d, J = 7.2 Hz, 2H), 7.41−7.33 (m, 5H), 6.90 (d, J = 8.8
Hz, 2H), 6.73 (s, 1H), 6.68 (s, 1H), 3.86 (s, 3H), 2.45 (s, 3H), 2.44 (s,
3H), 1.80 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ 187.1, 163.1,
155.2, 144.8, 136.8, 136.1, 135.2, 131.2, 130.2, 129.8, 128.6, 128.5,
128.4, 127.9, 125.0, 121.1, 113.6, 55.4, 21.6, 16.2, 15.5; HRMS (EI)
+
C31H28NO3S2 526.1510, found 526.1512.
4-Methyl-N-((Z)-2-(methylthio)-2-phenylvinyl)-N-((E)-3-oxo-3-
phenylprop-1-en-1-yl)benzenesulfonamide (3aj): yellow oil, 78 mg;
yield 86%; 1H NMR (400 MHz, chloroform-d) δ 8.28 (d, J = 14.4 Hz,
1H), 7.88 (d, J = 7.6 Hz, 2H), 7.83 (d, J = 8.4 Hz, 2H), 7.55−7.41 (m,
8H), 7.34 (d, J = 8.4 Hz, 2H), 6.19 (d, J = 14.4 Hz, 2H), 2.43 (s, 3H),
1.69 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ 189.8, 148.9,
145.0, 141.7, 138.6, 135.3, 134.6, 132.2, 129.7, 129.5, 128.8, 128.39,
128.37, 128.0, 127.9, 118.0, 104.1, 21.5, 15.1; HRMS (ESI) calcd for
+
calcd for C27H28NO4S3 526.1180, found 526.1182.
N-((Z)-3-(4-Chlorophenyl)-1-(methylthio)-3-oxoprop-1-en-1-yl)-
4-methyl-N-((Z)-2-(methylthio)-2-phenylvinyl)benzenesulfonamide
(3ad): yellow oil, 81 mg; yield 77%; 1H NMR (400 MHz, chloroform-
d) δ 7.81 (d, J = 8.0 Hz, 2H), 7.71 (d, J = 8.4 Hz, 2H), 7.47−7.32 (m,
9H), 6.70 (s, 1H), 6.68 (s, 1H), 2.45 (s, 6H), 1.80 (s, 3H); 13C NMR
(100 MHz, chloroform-d) δ 187.0, 157.5, 145.0, 138.7, 136.6, 136.3,
135.1, 129.9, 129.3, 128.7, 128.6, 128.4, 127.8, 127.0, 126.5, 124.8,
+
C25H24NO3S2 450.1198, found 450.1199.
Procedure for Formation of S-Methyl-3-Oxo-3-(thiophene-
2-yl)propanethioate 6 and (Z)-4-Methyl-N-(2-(methylthio)-2-
phenylvinyl)benzenesulfonamide 7. To a solvent of 3af (100 mg,
0.2 mmol) in THF (4.0 mL) was added 20% hydrochloric acid (2
mL), and the reaction mixture was stirred at 30 °C for 2.5 h. After
completion of reaction, the reaction was filtered through a short plug
of silica gel. The solution of mixture was concentrated and then
purified by flash chromatography elution with PE/DCM (1:2) as
eluent to give the corresponding product 6 (28 mg, 70%) and 7 (25
mg, 40%) as a yellow viscous liquid.
+
120.1, 21.6, 16.3, 15.5; HRMS (ESI) calcd for C26H25ClNO3S3
530.0685, found 530.0687.
N-((Z)-3-(4-Bromophenyl)-1-(methylthio)-3-oxoprop-1-en-1-yl)-
4-methyl-N-((Z)-2-(methylthio)-2-phenylvinyl)benzenesulfonamide
(3ae): yellow oil, 87 mg; yield 76%; 1H NMR (400 MHz, chloroform-
d) δ 7.81 (d, J = 8.0 Hz, 2H), 7.64 (d, J = 8.4 Hz, 2H), 7.55 (d, J = 8.4
Hz, 2H), 7.45−7.33 (m, 7H), 6.70 (s, 1H), 6.67 (s, 1H), 2.45 (s, 6H),
1.80 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ 187.2, 157.3,
144.9, 137.1, 136.6, 136.4, 135.2, 131.7, 129.9, 129.5, 128.63, 128.60,
128.4, 127.9, 127.4, 124.8, 120.1, 21.6, 16.3, 15.5; HRMS (ESI) calcd
S-Methyl-3-oxo-3-(thiophene-2-yl)propanethioate (6): yellow
1
viscous liquid, 28 mg; yield 70%; H NMR (400 MHz, chloroform-
d) δ 7.79 (d, J = 3.2 Hz, 1H), 7.72 (d, J = 4.8 Hz, 1H), 7.16 (t, J = 4.4
+
for C26H25BrNO3S3 574.0180, found 574.0194.
Hz, 1H), 4.16 (s, 2H), 2.36 (s, 3H); 13C NMR (100 MHz,
4821
DOI: 10.1021/acs.joc.5b00521
J. Org. Chem. 2015, 80, 4816−4823

The Journal of Organic Chemistry
Note
chloroform-d) δ 191.8, 184.1, 143.2, 135.3, 133.8, 128.4, 54.5, 12.2;
HRMS (ESI) calcd for C8H9O2S2 201.0044, found 201.0042.
S-Methyl benzothioate (5a): yellow viscous liquid, 21 mg; yield
70%; H NMR (400 MHz, chloroform-d) δ 7.97 (d, J = 8.4 Hz, 2H),
1
+
7.59−7.55 (t, J = 7.4 Hz, 1H), 7.47−7.43 (m, 2H), 2.48 (s, 3H).
( Z ) - 4 - M e t h y l - N - ( 2 - ( m e t h y l t h i o ) - 2 - p h e n y l v i n y l ) -
benzenesulfonamide (7): yellow viscous liquid, 25 mg; yield 40%; 1H
NMR (400 MHz, chloroform-d) δ 7.76 (d, J = 8.0 Hz, 2H), 7.49−7.43
(m, 3H), 7.36−7.29 (m, 4H), 6.87 (d, J = 11.2 Hz, 1H), 2.42 (s, 3H),
1.93 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ 144.1, 137.0,
136.7, 129.9, 128.6, 127.6, 126.8, 126.7, 126.4, 117.9, 21.6, 16.3;
S-Methyl-4-bromobenzothioate (5b): yellow viscous liquid, 28 mg;
1
yield 60%; H NMR (400 MHz, chloroform-d) δ 7.83 (d, J = 8.4 Hz,
2H), 7.59 (d, J = 8.4 Hz, 2H), 2.48 (s, 3H).
ASSOCIATED CONTENT
■
+
HRMS (ESI) calcd for C16H18NO2S2 320.0779, found 320.0766.
S
* Supporting Information
General Procedure for Formation of Pyrrole Derivative 4
and S-Methyl Benzothioate 5. Compound 3 (0.2 mmol) was
dissolved in the dry toluene (2 mL), and then the reaction mixture was
stirred at 110 °C for 2.5 h. After completion of the reaction, the
reaction mixture cooled to the room temperature and filtered through
a short plug of silica gel. The solution of mixture was concentrated and
purified by flash chromatography (elution with PE/DCM as eluent) to
give the corresponding product 4 and 5.
NMR spectra for 1−7. This material is available free of charge
via the Internet at http://pubs.acs.org.
AUTHOR INFORMATION
Corresponding Author
*E-mail: licy@zstu.edu.cn.
■
Notes
2-(Methylthio)-4-phenyl-1-tosyl-1H-pyrrole (4aa): yellow viscous
The authors declare no competing financial interest.
1
liquid, 62 mg, yield 90%; H NMR (400 MHz, chloroform-d) δ 7.80
(d, J = 8.4 Hz, 2H), 7.64 (s, 1H), 7.39 (d, J = 8.4 Hz, 2H), 7.30−7.25
(m, 2H), 7.22−7.16 (m, 3H), 6.53 (s, 1H), 2.31 (s, 3H), 2.28 (s, 3H);
13C NMR (100 MHz, chloroform-d) δ 145.1, 135.3, 132.9, 129.7,
128.8, 127.8, 127.4, 127.3, 127.1, 125.3, 120.3, 118.1, 21.6, 20.8;
ACKNOWLEDGMENTS
■
This work was generously supported by the National Natural
Science Foundation of China (21002091, 21372204) and the
Zhejiang Sci-Tech University 521 project.
+
HRMS (ESI) calcd for C18H18NO2S2 344.0779, found 344.0777.
1-(Methylsulfonyl)-2-(methylthio)-4-phenyl-1H-pyrrole (4pa): yel-
low viscous liquid, 43 mg; yield 81%; 1H NMR (400 MHz,
chloroform-d) δ 7.57 (s, 1H), 7.48 (d, J = 7.4 Hz, 2H), 7.39−7.35
(m, 2H), 7.29−7.25 (m, 1H), 6.78 (s, 1H), 3.40 (s, 3H), 2.49 (s, 3H);
13C NMR (100 MHz, chloroform-d) δ 132.8, 128.8, 127.2, 127.1,
126.3, 125.3, 120.2, 119.2, 42.4, 21.2; HRMS (ESI) calcd for
REFERENCES
■
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+
C12H14NO2S2 268.0466, found 268.0460.
4-(4-Bromophenyl)-2-(methylthio)-1-tosyl-1H-pyrrole (4ae): yel-
low viscous liquid; 78 mg, yield 93%; 1H NMR (400 MHz,
chloroform-d) δ 7.88 (d, J = 8.4 Hz, 2H), 7.70 (s, 1H), 7.46 (d, J =
8.8 Hz, 2H), 7.33 (d, J = 8.8 Hz, 2H), 7.29 (d, J = 8.4 Hz, 2H), 6.56 (s,
1H), 2.40 (s, 3H), 2.36 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ
145.3, 135.2, 132.0, 131.8, 129.8, 127.8, 127.7, 126.8, 126.2, 120.7,
+
120.3, 117.7, 21.7, 20.7; HRMS (ESI) calcd for C18H17BrNO2S2
421.9884, found 421.9887.
2-(Methylthio)-4-(thiophene-2-yl)-1-tosyl-1H-pyrrole (4af): yellow
1
viscous liquid, 50 mg; yield 71%; H NMR (400 MHz, chloroform-d)
δ 7.88 (d, J = 8.0 Hz, 2H), 7.63 (s, 1H), 7.30 (d, J = 8.0 Hz, 2H), 7.17
(d, J = 4.8 Hz, 1H), 7.08 (d, J = 3.2 Hz, 1H), 7.01−6.99 (m, 1H), 6.49
(s, 1H), 2.41 (s, 3H), 2.36 (s, 3H); 13C NMR (100 MHz, chloroform-
d) δ 145.3, 135.2, 132.0, 131.8, 129.8, 127.84, 127.78, 126.8, 126.2,
(4) Horneff, T.; Chuprakov, S.; Chernyak, N.; Gevorgyan, V.; Fokin,
V. V. J. Am. Chem. Soc. 2008, 130, 14972.
(5) N-Sulfonyl-1,2,3-triazoles are easily available by a Cu-catalyzed
alkyne−azide cycloaddition (CuAAC) reaction: (a) Yoo, E. J.;
Ahlquist, M.; Kim, S. H.; Bae, I.; Fokin, V. V.; Sharpless, K. B.;
Chang, S. Angew. Chem., Int. Ed. 2007, 46, 1730. (b) Raushel, J.; Fokin,
V. V. Org. Lett. 2010, 12, 4952. (c) Liu, Y.; Wang, X.; Xu, J.; Zhang, Q.;
Zhao, Y.; Hu, Y. Tetrahedron 2011, 67, 6294.
+
120.7, 120.3, 117.7, 21.7, 20.7; HRMS (ESI) calcd for C16H16NO2S3
350.0343, found 350.0344.
4-Methyl-2-(methylthio)-1-tosyl-1H-pyrrole (4ag): yellow viscous
1
liquid, 39 mg; yield 69%; H NMR (400 MHz, chloroform-d) δ 7.84
(d, J = 8.4 Hz, 2H), 7.28 (d, J = 8.4 Hz, 2H), 7.17 (s, 1H), 6.14 (s,
1H), 2.40 (s, 3H), 2.30 (s, 3H), 2.01 (s, 3H); 13C NMR (100 MHz,
chloroform-d) δ 144.7, 135.8, 129.6, 127.6, 126.1, 122.5, 122.0, 121.9,
(6) For reviews, see: (a) Chattopadhyay, B.; Gevorgyan, V. Angew.
Chem., Int. Ed. 2012, 51, 862. (b) Gulevich, A. V.; Gevorgyan, V.
Angew. Chem., Int. Ed. 2013, 52, 1371. (c) Davies, H. M. L.; Alford, J.
S. Chem. Soc. Rev. 2014, 43, 5151. For selected recent reports, see:
(d) Miura, T.; Nakamuro, T.; Liang, C.-J.; Murakami, M. J. Am. Chem.
Soc. 2014, 136, 15905. (e) Kwok, S. W.; Zhang, L.; Grimster, N. P.;
Fokin, V. V. Angew. Chem., Int. Ed. 2014, 53, 3452. (f) Yang, J.-M.;
Zhu, C.-Z.; Tang, X.-Y.; Shi, M. Angew. Chem., Int. Ed. 2014, 53, 5142.
(g) Shang, H.; Wang, Y.; Tian, Y.; Feng, J.; Tang, Y. Angew. Chem., Int.
Ed. 2014, 53, 5662. (h) Schultz, E. E.; Lindsay, V. N. G.; Sarpong, R.
Angew. Chem., Int. Ed. 2014, 53, 9904. (i) Shi, Y.; Gulevich, A. V.;
Gevorgyan, V. Angew. Chem., Int. Ed. 2014, 53, 14191. (j) Jung, D. J.;
Jeon, H. J.; Kim, J. H.; Kim, Y.; Lee, S. Org. Lett. 2014, 16, 2208.
(k) Miura, T.; Funakoshi, Y.; Tanaka, T.; Yada, A.; Murakami, M. Org.
Lett. 2014, 16, 2760. (l) Ma, X.-J.; Pan, S.-F.; Wang, H.-X.; Chen, W.-
Z. Org. Lett. 2014, 16, 4554. (m) Shen, H.; Fu, J.; Gong, J.; Yang, Z.
Org. Lett. 2014, 16, 5588. (n) Zhang, Y.-S.; Tang, X.-Y.; Shi, M. Chem.
Commun. 2014, 50, 15971. (o) Lee, D. J.; Shin, J.; Yoo, E. J. Chem.
+
21.6, 20.7, 11.8; HRMS (ESI) calcd for C13H16NO2S2 282.0622,
found 282.0617.
3,4-Dimethyl-2-(methylthio)-1-tosyl-1H-pyrrole (4ah): yellow vis-
1
cous liquid, 53 mg; yield 90%; H NMR (400 MHz, chloroform-d) δ
7.82 (d, J = 8.0 Hz, 2H), 7.27 (s, 1H), 7.25 (d, J = 8.0 Hz, 2H), 2.39
(s, 3H), 2.14 (s, 3H), 1.99 (s, 3H), 1.97 (s, 3H); 13C NMR (100 MHz,
chloroform-d) δ 144.4, 136.3, 133.0, 129.5, 127.7, 122.1, 122.0, 121.0,
21.6, 21.0, 10.6, 10.2; HRMS (ESI) calcd for C14H18NO2S2+ 296.0779,
found 296.0776.
2,4-Diphenyl-1-tosyl-1H-pyrrole (4ai): yellow viscous liquid, 61
1
mg; yield 82%; H NMR (400 MHz, chloroform-d) δ 7.73 (s, 1H),
7.53 (d, J = 8.4 Hz, 2H), 7.39−7.24 (m, 10H), 7.09 (d, J = 8.4 Hz,
2H), 6.48 (s, 1H), 2.34 (s, 3H); 13C NMR (100 MHz, chloroform-d) δ
144.8, 136.9, 135.4, 133.3, 131.2, 130.8, 129.4, 128.8, 128.4, 127.5,
127.4, 127.1, 127.0, 125.5, 119.5, 114.3, 21.6; HRMS (ESI) calcd for
C23H20NO2S+ 374.1214, found 374.1217.
4822
DOI: 10.1021/acs.joc.5b00521
J. Org. Chem. 2015, 80, 4816−4823

The Journal of Organic Chemistry
Note
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