Nickel-catalyzed carbonylation of thioacetates with aryl iodides via CO insertion and C–S bond cleavage

Article abstract of DOI:10.1177/17475198211028114

Aryl thioesters are synthesized via nickel-catalyzed carbonylation of thioacetates with aryl iodides. Alkyl thioacetates undergo coupling with carbon monoxide and aryl iodides to produce the desired aryl thioesters in moderate yields. This catalytic carbonylative coupling process provides a cost-effective and direct approach for the preparation of useful thioesters.

Full text of DOI:10.1177/17475198211028114

1028114CHL0010.1177/17475198211028114Journal of Chemical ResearchMai et al.
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Nickel-catalyzed carbonylation of
thioacetates with aryl iodides via
CO insertion and C–S bond cleavage
https://doi.org/10.1177/17475198211028114
DOI: 10.1177/17475198211028114
journals.sagepub.com/home/chl
Wen-Peng Mai1 , Hong-Da Sui2, Ming-Xiu Lv1 and Kui Lu3
Abstract
Aryl thioesters are synthesized via nickel-catalyzed carbonylation of thioacetates with aryl iodides. Alkyl thioacetates
undergo coupling with carbon monoxide and aryl iodides to produce the desired aryl thioesters in moderate yields.
This catalytic carbonylative coupling process provides a cost-effective and direct approach for the preparation of useful
thioesters.
Keywords
carbonylation, C–S bond cleavage, disulfides, nickel, thioacetates
Date received: 10 February 2021; accepted: 9 June 2021
the synthesis of thioesters.16–19 Herein, we report a novel
Introduction
process for the synthesis of aryl thioesters via nickel-
The thioester unit is a very useful and powerful building
catalyzed carbonylation of thioacetates or dialkyl disulfides
block in organic chemistry1 and is also an important com-
with aryl iodides under mild conditions.
ponent of many natural products2 and agrochemicals.3
Specifically, thioesters have often been employed as inter-
mediates for the synthesis of amides, esters, and ketones.4–8
In addition, thioesters also serve as important intermediates
in the biosynthesis of polyketides and nonribosomal poly-
peptides.9 Due to their many applications, numerous syn-
thetic methods have been developed for the preparation of
thioesters, for example, palladium-catalyzed carbonylation
of aryl halides and alcohols,10 palladium-catalyzed carbon-
ylation of thioacetates and aryl iodides,11 palladium-cata-
lyzed intermolecular transthioetherification of aryl halides
with thioethers,12 condensation of carboxylic acids and
alcohols,13 copper-catalyzed esterification of disulfides
and acyl chlorides,14 and decarboxylative coupling of
α-oxocarboxylic acids and disulfides.15 These methods
suffer from certain disadvantages such as harsh conditions,
high costs, formation of by-products, and the use of excess
reagents. More recently, new progress was reported in this
field, in which some novel protocols were developed for
Results and discussion
In previous work, Kim et al.11 reported aryl thioacetates
as the source of sulfur in the palladium-catalyzed
1School of Materials and Chemical Engineering, Henan University of
Engineering, Zhengzhou, P.R. China
2School of Chemistry and Chemical Engineering, Henan University of
Technology, Zhengzhou, P.R. China
3School of Chemical Engineering and Food Science, Zhengzhou Institute
of Technology, Zhengzhou, P.R. China
Corresponding authors:
Wen-Peng Mai, School of Materials and Chemical Engineering, Henan
University of Engineering, Zhengzhou 450006, Henan, P.R. China.
Email: maiwp@yahoo.com
Kui Lu, School of Chemical Engineering and Food Science, Zhengzhou
Institute of Technology, Zhengzhou 450044, Henan, P.R. China.
Email: luckyluke@haue.edu.cn
Creative Commons Non Commercial CC BY-NC: This article is distributed under the terms of the Creative Commons
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reproduction and distribution of the work without further permission provided the original work is attributed as specified on the SAGE and
Open Access pages (https://us.sagepub.com/en-us/nam/open-access-at-sage).

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Journal of Chemical Research
Table 1. Optimization of the reaction conditionsa.
Entry
1a:2a
Ni source
Ligandb
Solvent
Yield 3aa/4aa(%)c
1
2
3
4
5
6
7
8
1:1
1:2
1:3
1:3
1:3
1:3
1:3
1:3
1:3
1:3
1:3
1:3
1:3
1:2
1:1.5
1:3
NiCl2∙DME
NiCl2∙DME
NiCl2∙DME
NiBr2
NiBr2
NiBr2
NiBr2
NiI2
NiI2
NiI2
NiBr2
NiBr2
NiBr2
NiBr2
NiBr2
NiBr2
DTBPy
DTBPy
DTBPy
Bpy
Bpy
Bpy
Bpy
Bpy
DTBPy
Phen
Bpy
DMF
DMF
DMF
DMF
DMAc
Toluene
dioxane
DMF
5/25
15/11
23/6
45/10
33/16
0/20
0/13
43/11
40/7
23/20
58/8
46/12
69/8
60/10
65/5
0
9
DMF
DMF
10
11
12
13d
14d
15d
16
DMF/H2O (10:1)
DMF/H2O (5:1)
DMF/H2O (10:1)
DMF/H2O (10:1)
DMF/H2O (10:1)
DMF/H2O (10:1)
Bpy
Bpy
Bpy
Bpy
Bpy
aReaction conditions: 1a (0.5mmol), 2a (as needed), Ni (0.05mmol), ligand (0.1mmol), Zn (2.0 equiv.) in solvent (3mL), 110°C, and 15h.
bDTBPy: 4,4’-di-tert-butyl-2,2’-bipyridine, Bpy: 2,2’-bipyridine, Phen: 1,10-phenanthroline.
cGC yield.
d1atm CO balloon.
carbonylation of aryl iodides for the formation of thioesters (1atm) was introduced into the system, the GC ratio of 3aa
under CO (8atm). Inspired by this result, we tried to use to 4aa was improved to 6:1 (Table 1, entries 13–15). The
nickel as the catalyst for this transformation under 1atm of Zn powder plays an important role in this transformation,
CO; however, the reaction did not occur at all. To our and no product was observed at all (Table 1, entry 16).
surprise, alkyl thioacetates were compatible with the Ni
To investigate the scope of this transformation, many
catalyst, unlike aryl thioacetates under the same conditions. aryl iodides were examined for the formation of the cor-
Thus, we chose iodobenzene (1a) and S-ethyl ethanethioate responding aryl thioester under the optimized reaction con-
(2a) as model substrates in order to find optimized condi- ditions and the results are shown in Table 2. Both aryl
tions for the carbonylation (Table 1). Using NiCl2 (10mol%) iodides which have electron-donating and electron-with-
as the catalyst, DTBPy (4,4’-di-tert-butyl-2,2’-bipyridine) drawing groups were found to react with thioacetates and
as the ligand, and DMF as the solvent, thioether 4aa was gave the products in moderate yields. Generally, those
detected as the main product (Table 1, entry 1). Interestingly, with electron-donating groups on the aryl ring favored the
the amount of product 3aa increased as the ratio of 1a:2a transformation. For example, 1-iodo-4-methoxybenzene
decreased (Table 1, entries 1–3). The GC yield of product (1e) and 1-fluoro-4-iodobenzene (1b) both reacted with
3aa was improved to 45% when NiBr2 was used as the cat- S-ethyl ethanethioate (2a) under the optimized conditions,
alyst instead of NiCl2 under the same conditions (Table 1, leading to the corresponding products in 73% and 47%
entry 4). Other solvents such as DMAc, toluene, and diox- yields, respectively (Table 2, 3ba and 3ea). Similarly, iodo-
ane were also screened using NiBr2 as the catalyst; how- benzene (1a) and 1-iodo-4-methylbenzene (1f) provided
ever, no improvement in the yield of 3aa was observed the desired products in yields of 69% and 62%, respec-
(Table 1, entries 5–7). On changing the NiBr2 to NiI2, about tively. 1-chloro-3-iodobenzene (1c) and 1-fluoro-4-iodo-
a 40% GC yield of product 3aa was observed when using 2-methylbenzene (1d) provided the expected products in
Bpy (2,2’-bipyridine) or DTBPy as the ligand (Table 1, about 55% yields when using S-ethyl ethanethioate (2a).
entries 8 and 9). When Phen (1,10-phenanthroline) was
When S-propyl ethanethioate (2b) was selected as the
used as the ligand, the ratio of product 3aa to 4aa was substrate, different aryl iodides could also participate in
almost 1:1 (Table 1, entry 10). To our delight, the product this reaction with 2b. 1-Iodo-4-methoxybenzene (1e) and
yield of 3aa was improved to 58% when DMF and H2O 1-iodo-4-(trifluoromethyl)benzene (1g) produced the
were used as co-solvents (Table 1, entry 11). The yield of products 3eb and 3gb in 70% and 42% yields, respec-
3aa was not improved when the amount of H2O was tively. However, only a 33% isolated yield of 3ib was
increased in the co-solvent (Table 1, entry 12). When CO obtained when using 1-iodo-2-methoxybenzene (1i) as the

Mai et al.
3
Table 2. The scope of the aryl iodides and thioacetatesa,b.
aReactions were carried out using 1 (1.0 mmol), 2 (1.5 mmol), NiBr2 (0.05 mmol), bpy (0.1 mmol), Zn (2.0 mmol), 1 atm CO balloon,
DMF/H2O (2 mL:0.2 mL), 110 °C, and 15 h.
bIsolated yield.
substrate. Moreover, 1-chloro-3-iodo-2-methylbenzene compatible with the present reaction conditions and the
(1h), 1-fluoro-4-iodo-2-methylbenzene (1d), and 4-iodo-1,1’- corresponding product 3ee was obtained in 45% yield;
biphenyl (1j) gave the corresponding products 3hb, however, other S-aryl ethanethioates were not compatible
3db, and 3jb in yields of about 50%. To our delight, the with this reaction.
heteroaromatic iodide 3-iodothiophene (1k) reacted with
To study further the mechanism of this transformation,
2b to produce the desired product 3kb in 42% yield. For alkyl sulfides were selected as one of the substrates to carry
other S-alkyl ethanethioates (2c–d), containing func- out the reaction under the optimized conditions. To our
tional groups such as fluorine and furan, the reactions delight, the results showed that the yields of the desired
gave the desired products 3ec and 3ed in moderate products were higher in comparison with those obtained
yields. To our surprise, S-aryl ethanethioate 2e was when alkyl ethanethioates were employed as substrates

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Journal of Chemical Research
conditions, and a simple procedure. Unfortunately, this
one-pot protocol for the formation of S-thioesters was
unsuccessful with S-aryl ethanethioates as substrates as
used in our previous work.20
Experimental
All experiments were carried out using a Schlenk flask
open to air. Aryl iodides and thioacetates were purchased
from commercial suppliers and were used as received,
unless otherwise noted. All solvents and other commer-
cially available reagents were purchased from TCI com-
pany and used directly. Reactions were monitored by TLC
(Qingdao Haiyang Chemical Co., Ltd., Silica gel 60 F254).
Products were detected using a UV-Vis lamp (254nm).
Column chromatography was performed on Qingdao
Haiyang Chemical Co., Ltd., Silica Gel 60 (200–300 mesh).
Scheme 1. Alkyl sulfides as substrates.
1
The H and 13C NMR spectra were obtained on a Bruker
1
400MHz NMR Fourier transform spectrometer. H NMR
data are reported as: chemical shift (δ ppm), multiplicity,
coupling constant (Hz), and integration. 13C NMR data are
reported in terms of chemical shift (δ ppm), multiplicity,
and coupling constant (Hz) where applicable. The spectra
are referenced against the internal non-deuterated solvent
(CDCl3, δ 1H=7.26ppm, 13C=77.0ppm). Data are reported
as follows: s=singlet, d=doublet, t=triplet, q=quartet, and
m=multiplet. ESI-MS spectra were recorded on a Bruker
Esquire 3000 instrument.
Scheme 2. Plausible reaction mechanism.
(Scheme 1). For example, dibutylsulfane and S-butyl
ethanethioate reacted with 1-iodo-3,5-dimethylbenzene
under the same conditions, leading to the same product in
71% and 63%, respectively. These results indicated that
insertion of Ni(I) into the S–S bond is easier and that the
insertion of CO occurred after C–S or S–S bond cleavage.
Based on the above the experimental data and previous
work,17 a plausible reaction mechanism is proposed in
Scheme 2. First, an Ni(0) species is formed by reduction
with Zn powder, then, the species inserts into the Ph–I bond
of the iodobenzene to form the intermediate A. Next, spe-
cies B is produced rapidly in the presence of excess Zn.
Intermediate B reacts with S-propyl ethanethioate and the
Ni(I) inserts into the C–S bond of S-propyl ethanethioate,
leading to the intermediate C. In the next step, the CO
inserts into the species C, meanwhile, acetyl group was
removed leading to the intermediate D. In the end, the spe-
cies D gives the desired product 3aa and Ni(I) via the
reductive elimination. Finally, the catalytic cycle is contin-
ued through Ni(0)–Ni(I)–Ni(II) form by the assistance of
Zn.
General procedures for the one-pot
synthesis of thioesters 3
A Schlenk flask equipped with a magnetic stir bar was
charged with S-alkyl thioacetate 2 (1.5mmol), aryl iodides
1 (1.0mmol), NiBr2 (21.8mg, 0.1mmol), bipyridine
(31.2mg, 0.2mmol), and Zn powder (130mg, 2.0mmol).
Next, the reaction flask was degassed and backfilled with
CO three times, and then DMF/H2O (2:0.2mL) were
injected sequentially. The mixture was stirred at 110°C
for 15h. When the reaction was complete, brine (30mL)
was added and the aqueous layer was extracted with
EtOAc (2×20mL). The combined organic layer was
dried and evaporated and the residue was purified by
flash chromatography on silica gel (eluent:petroleum
ether/EtOAc=100:1 to 50:1, v/v) to furnish the desired
product 3.
S-ethyl benzothioate (3aa): Yield: 114mg (69%); yellow-
1
ish liquid (lit.13). H NMR (400 MHz, CDCl3): δ 7.80
(d, J=8.0Hz, 2H), 7.58-7.57 (m, 1H), 7.49-7.45 (m, 2H),
3.13-3.08 (m, 3H), 1.38 (t, J=8.0Hz, 2H). 13C NMR
(101MHz, CDCl3): δ 14.75, 23.44, 127.16, 128.56, 133.20,
137.30, 192.08. HRMS (EI): m/z [M+H]+ calcd for
C9H11OS: 167.0531; found: 167.0533.
Conclusion
In conclusion, we have established a novel nickel-catalyzed
carbonylation of aryl iodides and thioacetates for the syn-
thesis of thioesters. Numerous aryl iodides reacted to give
the desired S-alkyl thioesters in moderate yields under
1atm of CO. This methodology is also useful with dialkyl
sulfides and afforded the corresponding products in moder-
ate yields under the same conditions. Advantageously, the
reaction occurs in one pot, using a cheap catalyst, mild
S-ethyl 4-fluorobenzothioate (3ba): Yield: 86mg (47%);
1
yellowish liquid (lit.21). H NMR (400 MHz, CDCl3):
δ 8.03-7.99 (m, 2H), 7.14 (t, J = 8.0 Hz, 2H), 3.13-3.07
(m, 2H), 1.38 (t, J=8.0Hz, 3H). 13C NMR (101MHz,

Mai et al.
5
CDCl3): δ 14.73, 23.57, 115.56 (d, JC-F = 22 Hz), 129.63 CDCl3): δ 7.56 (d, J=8.0Hz, 1H), 7.50 (d, J=8.0Hz, 1H),
(d, JC-F =9Hz), 133.64, 167.12 (d, JC-F =252Hz), 190.57. 7.20 (t, J=8.0Hz, 1H), 3.06 (t, J=8.0Hz, 2H), 2.47 (s, 3H),
HRMS (EI): m/z [M+H]+ calcd for C9H10FOS: 185.0436; 1.77-1.72 (m, 2H), 1.07 (t, J=8.0Hz, 3H). 13C NMR
found: 185.0432.
(101MHz, CDCl3): δ 13.40, 16.76, 22.91, 31.82, 126.14,
126.51, 131.83, 133.88, 140.71, 194.74. HRMS (EI): m/z
S-ethyl 3-chlorobenzothioate (3ca): Yield: 106mg (53%); [M+H]+ calcd for C11H14ClOS: 229.0454; found:
colorless liquid. 1H NMR (400 MHz, CDCl3): δ 7.95 229.0450.
(s, 1H), 7.87 (d, J=8.0Hz, 1H), 7.39 (t, J=8.0Hz, 1H),
3.14-3.08 (m, 2H), 1.38 (t, J=8.0Hz, 3H). 13C NMR S-(4-fluoro-3-methylphenyl)butanethioate (3db): Yield:
(101MHz, CDCl3): δ 14.66, 23.68, 125.29, 127.22, 129.88, 106mg (50%); yellowish liquid. 1H NMR (400MHz,
133.11, 134.52, 138.76, 190.90. HRMS (EI): m/z [M+H]+ CDCl3): δ 7.87-7.82 (m, 2H), 7.10 (t, J=8.0Hz, 1H), 3.07
calcd for C9H9ClOS: 200.0063; found: 200.0058.
(t, J=8.0Hz, 2H), 2.35 (d, J=4.0Hz, 3H), 1.75-1.70 (m,
2H), 1.06 (t, J=8.0Hz, 3H). 13C NMR (101MHz, CDCl3):
S-ethyl 4-fluoro-3-methylbenzothioate
(3da): Yield: δ 13.42, 14.53 (d, JC-F =3.0Hz), 22.99, 31.02, 115.35 (d,
1
109mg (55%); colorless liquid. H NMR (400 MHz, JC-F =23Hz), 125.49 (d, JC-F =18Hz), 127.06, 130.80,
CDCl3): δ 7.85-7.81 (m, 2H), 7.06 (t, J= 8.0 Hz, 1H), 133.32, 163.19, 165.70, 190.82. HRMS (EI): m/z [M+H]+
3.11-3.05 (m, 2H), 2.33 (s, 3H), 1.38-1.34 (m, 3H). 13C calcd for C11H14FOS: 213.0749; found: 213.0745.
NMR (101MHz, CDCl3): δ 14.47, 14.50, 14.75, 23.51,
115.35 (d, JC-F =25Hz), 125.49 (d, JC-F =18Hz), 127.03, S-propyl 2-methoxybenzothioate (3ib): Yield: 69mg
1
130.76, 133.32 (d, JC-F =3.0Hz), 165.70 (d, JC-F =252Hz), (33%); yellowish liquid. H NMR (400MHz, CDCl3): δ
190.74. HRMS (EI): m/z [M+H]+ calcd for C10H12FOS: 7.80-7.78 (m, 1H), 7.49-7.46 (m, 1H), 7.04-6.99 (m, 2H),
199.0593; found: 199.0588.
3.94 (s, 3H), 3.04 (t, J=8.0Hz, 2H), 1.75-1.70 (m, 2H),
1.06 (t, J=8.0Hz, 3H). 13C NMR (101MHz, CDCl3): δ
S-ethyl 4-methoxybenzothioate (3ea): Yield: 143mg 13.56, 22.82, 31.41, 55.84, 112.00, 120.35, 127.41, 129.65,
(73%); yellow liquid (lit.13). 1H NMR (400MHz, CDCl3): 133.37, 157.59, 191.42. HRMS (EI): m/z [M+H]+ calcd
δ 7.96 (d, J = 8.0 Hz, 2H), 6.93 (t, J = 8.0 Hz, 2H), 3.88 for C11H15O2S: 211.0793; found: 211.0790.
(d, J=8.0Hz, 3H), 3.09-3.05 (m, 2H), 1.37-1.33 (m, 3H).
13C NMR (101MHz, CDCl3): δ 14.90, 23.29, 55.46, 113.71, S-propyl (1,1’-biphenyl)-4-carbothioate (3jb): Yield:
129.28, 130.16, 163.66, 190.55. HRMS (EI): m/z [M+H]+ 118mg (46%); yellow solid. 1H NMR (400MHz, CDCl3): δ
calcd for C10H13O2S: 197.0636; found: 197.0633.
8.08 (d, J=8.0Hz, 2H), 7.70-7.64 (m, 4H), 7.51-7.42 (m,
3H), 3.11 (t, J=8.0Hz, 2H), 1.78-1.73 (m, 2H), 1.08 (t,
S-ethyl 4-methylbenzothioate (3fa): Yield: 112mg (62%); J=8.0Hz, 3H). 13C NMR (101MHz, CDCl3): δ 13.47,
1
yellow liquid (lit.14). H NMR (400MHz, CDCl3): δ 7.90 23.03, 30.97, 127.21, 127.27, 127.75, 128.23, 128.96,
(d, J=12Hz, 2H), 7.27 (t, J=8.0Hz, 2H), 3.12-3.06 (m, 136.02, 139.89, 145.98, 191.67. HRMS (EI): m/z [M+H]+
2H), 2.43 (s, 3H), 1.37 (t, J=8.0Hz, 3H). 13C NMR calcd for C16H17OS: 257.1000; found: 257.0997.
(101MHz, CDCl3): δ 14.83, 21.67, 23.34, 127.23, 129.23,
134.75, 144.05, 191.74 HRMS (EI) m/z [M+H]+ calcd for S-propyl thiophene-3-carbothioate (3kb): Yield: 78mg
C10H13OS 181.0687; found: 181.0685.
(46%); yellow liquid. 1H NMR (400MHz, CDCl3): δ 8.13-
8.12 (m, 1H), 7.57-7.55 (m, 1H), 7.36-7.28 (m, 1H), 3.06 (t,
S-propyl 4-methoxybenzothioate (3eb): Yield: 147mg J=8.0Hz, 2H), 1.75-1.69 (m, 2H), 1.05 (t, J=8.0Hz, 3H).
(70%); yellowish liquid (lit.13). 1H NMR (400MHz, 13C NMR (101MHz, CDCl3): δ 13.42, 23.08, 30.76, 126.04,
CDCl3): δ 7.98 (d, J=8.0Hz, 2H), 6.95 (d, J=8.0Hz, 2H), 126.32, 130.26, 141.18, 185.77. HRMS (EI): m/z
3.88 (s, 3H), 3.06 (t, J=8.0Hz, 2H), 1.74-1.69 (m, 2H), [M+H]+ calcd for C8H11OS2: 187.0251; found: 187.0250.
1.05 (t, J=8.0Hz, 3H). 13C NMR (101MHz, CDCl3): δ
13.47, 23.12, 30.81, 55.49, 113.71, 129.33, 130.20, 163.65, S-(2-fluoroethyl) 4-methoxybenzothioate (3ec): Yield:
190.65. HRMS (EI): m/z [M+H]+ calcd for C11H15O2S 84mg (39%); yellow liquid. 1H NMR (400MHz, CDCl3): δ
211.0793; found: 211.0787.
7.99 (d, J=8.0Hz, 2H), 6.97 (d, J=8.0Hz, 2H), 4.67 (t,
J=8.0Hz, 1H), 4.55 (t, J=8.0Hz, 1H), 3.90 (s, 3H), 3.44-
S-propyl 4-(trifluoromethyl)benzothioate (3gb): Yield: 3.36 (m, 2H). 13C NMR (101MHz, CDCl3): δ 28.71, 28.93,
104mg (42%); yellowish liquid. 1H NMR (400MHz, 55.55, 82.87 (d JC-F =170Hz), 113.88, 129.46, 129.55,
CDCl3): δ 8.10 (d, J=8.0Hz, 2H), 7.74 (d, J=8.0Hz, 2H), 164.04, 189.32. HRMS (EI): m/z [M+H]+ calcd for
3.11 (t, J=8.0Hz, 2H), 1.77-1.72 (m, 2H), 1.06 (t, J=8.0Hz, C10H12FO2S: 215.0542; found: 215.0537.
3H). 13C NMR (101MHz, CDCl3): δ 13.41, 22.84, 31.22,
122.21 (t, JC-F =271Hz), 125.71 (d, JC-F =8.0Hz), 134.68 S-(furan-2-ylmethyl) 4-methoxybenzothioate (3ed): Yield:
(d, JC-F =32Hz), 140.00, 191.21. HRMS (EI): m/z [M+H]+ 139mg (56%); yellow liquid. 1H NMR (400MHz, CDCl3):
calcd for C11H12F3OS: 249.0561; found: 249.0558.
δ 7.98 (d, J=8.0Hz, 2H), 7.37 (d, J=8.0Hz, 1H), 6.96-6.93
(m, 2H), 6.34-6.31 (m, 2H), 4.36 (s, 2H), 3.89 (s, 3H). 13
C
S-propyl 3-chloro-2-methylbenzothioate (3hb): Yield: NMR (101MHz, CDCl3): δ 25.63, 55.54, 108.01, 110.65,
103mg (45%); colorless liquid. 1H NMR (400MHz, 113.83, 129.54, 142.23, 150.73, 163.92, 189.20. HRMS

6
Journal of Chemical Research
(EI): m/z [M+H]+ calcd for C13H13O3S: 249.0585; found:
249.0583.
Supplemental material
Supplemental material for this article is available online.
S-(2-methylfuran-3-yl) 4-methoxybenzothioate (3ee): Yield: References
112mg (45%); yellowish liquid. 1H NMR (400MHz,
1. Horst BT, Feringa BL and Minnaard AJ. Chem Commun
CDCl3): δ 8.04 (d, J=8.0Hz, 2H), 7.44 (d, J=4.0Hz, 1H),
6.99 (d, J=8.0Hz, 2H), 6.43 (d, J=4.0Hz, 1H), 3.91 (s,
3H), 2.33 (s, 3H). 13C NMR (101MHz, CDCl3): δ 12.02,
55.56, 103.66, 113.93, 115.28, 129.29, 129.76, 141.09,
156.68, 164.00, 188.01. HRMS (EI): m/z [M+H]+ calcd
for C13H13O3S: 249.0585; found: 249.0580.
2007; 43: 489.
2. Kumar KSA, Bavikar SN, Spasser L, et al. Angew Chem Int
Ed 2011; 50: 6137.
3. Liu XL, Shi Y, Kang JS, et al. ACS Med Chem Lett 2015; 6:
660.
4. Ueda M, Seki K and Imai YS. Synthesis 1981; 1981: 991.
5. Burhardt MN, Taaning RH and Skrydstrup T. Org Lett 2013;
15: 948.
6. Tokuyama H, Yokoshima S, Yamashita T, et al. Tetrahedron
Lett 1998; 39: 3189.
7. Liebeskind LS and Srogl J. J Am Chem Soc 2000; 122:
11260.
8. Modha SG, Mehta VP and Van der Eycken EV. Chem Soc
Rev 2013; 42: 5042.
9. Keating TA and Walsh CT. Curr Opin Chem Biol 1999; 3:
598.
10. Yan K, Yang D, Wei W, et al. Org Biomol Chem 2015; 13:
7323.
S-butyl 3,5-dimethylbenzothioate (3lf): Yield: 140mg
(63%); colorless liquid. 1H NMR (400 MHz, CDCl3): δ
7.60 (s, 2H), 7.21 (s, 1H), 3.08 (t, J = 8.0 Hz, 2H), 2.39
(s, 6H), 1.67-1.64 (m, 2H), 1.51-1.45 (m, 2H), 0.97
(t, J=8.0Hz, 3H). 13C NMR (101MHz, CDCl3): δ 13.63,
21.19, 22.05, 28.70, 31.64, 124.92, 134.85, 137.37, 138.27,
192.45. HRMS (EI): m/z [M+H]+ calcd for C13H19OS:
223.1157; found: 223.1155.
Declaration of conflicting interests
11. Kim M, Yu S, Kim JG, et al. Org Chem Front 2018; 5: 2447.
12. Li Y, Bao G and Wu XF. Chem Sci 2020; 11: 2187.
13. Gopinath P, Vidyarini RS and Chandrasekaran S. Eur J Org
Chem 2009; 2009: 6043.
The author(s) declared no potential conflicts of interest with
respect to the research, authorship, and/or publication of this
article.
14. Azeredo JB, Godoi M, Schwab RS, et al. Eur J Org Chem
2013; 2013: 5188.
Funding
15. Rong G, Mao J, Liu D, et al. RSC Adv 2015; 5: 26461.
16. Qi X, Bao ZP, Yao XT, et al. Org Lett 2020; 22: 6671.
17. Feng Y, Yang S, Zhao S, et al. Org Lett 2020; 22: 6734.
18. Qiao Z and Jiang X. Org Lett 2016; 18: 1550.
19. Chung J, Seo UR, Chun S, et al. Chem Cat Chem 2016; 8:
318.
20. Mao P, Sui HD, Yuan JW, et al. Chemistry Select 2020; 5:
9908.
21. Ochiai H, Uetake Y, Niwa T, et al. Angew Chem Int Ed 2017;
56: 2482.
The author(s) disclosed receipt of the following financial support
for the research, authorship, and/or publication of this article: The
authors greatly acknowledge financial support from the Henan
University of Engineering for the Youth Doctoral Funding (no.
2015017) and the Henan Province Key Research and Development
and Promotion Special (212102310258).
ORCID iD
Wen-Peng Mai
https://orcid.org/0000-0003-0097-6727