Metal-Free, DTBP-Mediated Methylthiolation of Arylboronic Acids with Dimethyldisulfide

Article abstract of DOI:10.1055/s-0035-1562499

An efficient method for the C-S bond formation via the coupling reaction of arylboronic acids with dimethyldisulfide has been developed under the metal-free conditions. This novel protocol provides an attractive route for the synthesis of aryl methyl sulf

Full text of DOI:10.1055/s-0035-1562499

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Georg Thieme Verlag Stuttgart · New York
2016, 27, A–E
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Synlett
X.-m. Wu et al.
Letter
Metal-Free, DTBP-Mediated Methylthiolation of Arylboronic Acids
with Dimethyldisulfide
Xiang-mei Wu*
Jia-ming Lou
B(OH)2
SCH3
DTBP, CH3CN
R
+
CH3SSCH3
R
120 °C,12 h
Guo-bing Yan*
metal-free
R = H, Me, i-Pr, Ph, OMe,
F, Cl, Br, I, NO2, COMe, CN
17 examples
55–80% yield
Department of Chemistry, Lishui University,
Lishui, Zhejiang 323000, P. R. of China
lswxm7162@163.com
gbyan@lsu.edu.cn
Received: 18.04.2016
Accepted after revision: 24.05.2016
Published online: 27.06.2016
lowed by electrophilic substitution with dimethyldisulfide,
which is more attractive from an atom-economical view-
point.15 It is worthwhile to mention that visible-light-medi-
ated synthesis of aryl methyl sulfides from arenediazonium
salts and dimethyldisulfide in the presence of eosin Y, a
metal-free dye, has also been developed under mild reac-
tion conditions, which exactly conforms to green and sus-
tainable chemistry.16 Recently, DMSO has been explored as
an effective methylthiolation surrogate for this transforma-
tion. Apart from aryl halides17 and aryl carboxylic acids,
the direct C–S bond formation via C–H bond activation with
DMSO is also successful.19
DOI: 10.1055/s-0035-1562499; Art ID: st-2016-w0274-l
Abstract An efficient method for the C–S bond formation via the cou-
pling reaction of arylboronic acids with dimethyldisulfide has been de-
veloped under the metal-free conditions. This novel protocol provides
an attractive route for the synthesis of aryl methyl sulfides, due to its
operational simplicity, satisfactory yields, excellent functional-group
tolerance, as well as the mild reaction conditions.
18
Key words methylthiolation, arylboronic acids, dimethyldisulfide, aryl
methyl sulfides, di-tert-butyl peroxide
Nevertheless, generally, some or one of the items in-
cluding catalytic or stoichiometric amount of transition-
metal sources, an appropriate ligand, Lewis acid, restricted
substrates, or harsh reaction conditions were necessary in
the aforementioned protocols. Furthermore, due to the fact
that the reactions under metal-free conditions are desired
particularly in the pharmaceutical synthesis and environ-
mentally benign synthetic procedures, and arylboronic ac-
Aryl methyl sulfides are valuable structural motifs pres-
ent in many pharmaceuticals and bioactive natural mole-
cules. Besides, they also serve as useful substrates for tran-
1
sition-metal-catalyzed cross-coupling reactions, including
2
3
C–C and C–N coupling reaction as electrophiles, and the
4
carbothiolation of terminal alkynes. Undoubtedly, palladi-
5
6
7
um and other transition metals, such as nickel, copper,
8
9
cobalt, and indium catalyzed C(aryl)–S coupling of thiols
with aryl halides or pseudohalides to provide aryl sulfides
that have emerged as mild and effective protocols com-
pared with the traditional C(aryl)–S bond synthetic ap-
proaches via nucleophilic aromatic substitution, which
ids have been widely employed in the formation of carbon–
heteroatom bonds such as C–N20 and C–O,
20f,r,21
but seldom
in carbon–sulfur bond, we herein describe a transition-
metal-free C–S bond formation method via the coupling re-
action of arylboronic acid and dimethyldisulfide under
neutral conditions, which might tolerate a broad range of
substrates and functional groups.
At the outset of this experiment, we investigated the
coupling of phenylboronic acid and dimethyldisulfide with
di-tert-butyl peroxide (DTBP) as promoter and 1,2-dichlo-
roethane (DCE) as reaction medium in air, without the aid
of a transition-metal catalyst. To our delight, phenyl methyl
sulfide was obtained in 40% yield at 120 °C for 12 hours. En-
couraged by this result, further optimization of the reaction
conditions was attempted, and the results are summarized
in Table 1. Some organic and inorganic promoters were
10
generally required harsh reaction conditions and the cou-
pling reaction of arylmagnesium halides with a suitable
11
electrophilic arylsulfur reagent over the past several de-
cades. However, the formation of aryl methyl sulfides in
this fashion has not been reported so far, presumably owing
to the low boiling point of methanethiol. In general, an ef-
fective strategy for the preparation of aryl methyl sulfides
mainly consist of reduction of sulfoxides, coupling reac-
tion of aryl thiols with iodomethane, and aryl halides
with dimethyldisulfide. An alternative method is the het-
eroatom-facilitated lithiation of aromatic C–H bonds fol-
12
13
14
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Georg Thieme Verlag Stuttgart · New York — Synlett 2016, 27, A–E

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Synlett
X.-m. Wu et al.
Letter
screened for this transformation, such as tert-butyl hydro-
peroxide (TBHP), tert-butyl peroxybenzoate (TBPB), 2,3-di-
chloro-5,6-dicyano-1,4-benzoquinone (DDQ), I , and K S O
Table 1 Screening Reaction Conditions for Phenylboronic Acid and Di-
methyldisulfidea
2
2
2
8
B(OH)2
SCH3
conditions
(
Table 1, entries 2–6) It was found that DTBP was the most
.
3 3
CH SSCH
+
suitable to promote the reaction. Whereas inorganic oxi-
dants like I and K S O were nearly ineffective (Table 1, en-
2
2
2
8
Entry
Promoter
Solvent
Temp (°C)
Yield (%)b
tries 5, 6). The result of the control experiments revealed
that DTBP was crucial for this transformation, no desired
product was detected by GC–MS in the absence of any addi-
tive (Table 1, entry 7). Next, several other solvents were
tested. It was found that acetonitrile (MeCN) was the most
suitable solvent for this reaction, furnishing in 65% yield
1
2
3
4
5
6
7
8
9
DTBP
TBHP
TBPB
DDQ
DCE
DCE
DCE
DCE
DCE
DCE
DCE
MeCN
PhCl
PhH
120
120
120
120
120
120
120
120
120
120
120
120
120
80
40
10
25
38
<5
<5
0
Table 1, entry 8). Chlorobenzene, benzene, and CH Cl af-
I
2
(
2 2
forded the methylthiolation product in approximately the
same yields (Table 1, entries 9–11), whereas a small
amount of desired product was obtained using DMF and
DMSO as solvents (Table 1, entries 12, 13). We also found
that reaction temperature significantly affected the reac-
tion. At 100 °C phenylboronic acid could successfully couple
with dimethyldisulfide, but only trace amount of the de-
sired product was obtained at 80°C, and the ideal tempera-
ture for the reaction was found to be 120 °C (Table 1, entries
2 2 8
K S O
–
DTBP
DTBP
DTBP
DTBP
DTBP
DTBP
DTBP
DTBP
DTBP
65
45
35
28
10
15
<5
40
65
55
75
75
75
10
11
12
CH
2
Cl
2
DMF
13
14
15
16
DMSO
MeCN
MeCN
MeCN
MeCN
MeCN
MeCN
MeCN
8, 14–16). Finally, the amount of DTBP was also tested. We
found that the yield of the product dropped slightly with
the decrease of DTBP (Table 1, entries 8, 17, 18), and the ap-
proximately same yield was obtained when a 3.0 or 4.0
equivalent amount of DTBP was used (Table 1, entries 18
and 19). Optimization of the reaction time showed that the
reaction was almost completed within 12 hours at 120 °C as
comparable yield was obtained when the reaction was car-
ried out for 24 hours at the same temperature (Table 1, en-
try 20). On the basis of these results, it was obvious that the
optimal conditions for the methylthiolation of phenylbo-
ronic acid with dimethyldisulfide were using DTBP as pro-
moter and MeCN as solvent at 120 °C for 12 hours under air.
With the optimal reaction conditions in hand, we set
out to examine the generality of the reaction with regard to
arylboronic acids, and the results are presented in Table 2.
As expected, a variety of arylboronic acids bearing elec-
tron-donating or electron-withdrawing groups at ortho,
meta or para positions on the phenyl ring were all tolerated,
affording the corresponding products in 55–80% yields.
Specifically, phenylboronic acids with Me, i-Pr, and Ph sub-
stituents could afford the corresponding methylthiolation
products in satisfactory yields (Table 2, entries 1–5). How-
ever, phenylboronic acids with strong electron-donating
substituents such as OMe generated the desired methylthi-
olation product in a slightly lower yield (Table 2, entry 6).
And phenylboronic acids possessing halogen groups could
smoothly couple with dimethyldisulfide. Notably, in these
cases, the respective desired products were obtained in
good yields while keeping fluoro, chloro, bromo, and iodo
functional groups intact, which could conveniently extend
100
140
120
120
120
120
17
18
DTBP (1 equiv)
DTBP (3 equiv)
DTBP (4 equiv)
DTBP (3 equiv)
19
2
0c
a
Reaction conditions: phenylboronic acid (1.0 mmol), dimethyldisulfide
2.0 mmol), promoter (2 equiv), solvent (2.0 mL), under air, 12 h.
(
b
c
Isolated yield.
4 h.
2
the scope of further functionalization on the phenyl ring
(Table 2, entries 7–13). Phenylboronic acids with electron-
withdrawing substituents such as COMe and CN groups
were good coupling partners, whereas a slight decrease in
the yield of methylthiolation product was observed for
phenylboronic acid with a strong electron-withdrawing ni-
tro group (Table 2, entries 14–17). Moreover, compared
with para-substituted arylboronic acids, ortho- and meta-
substituted substrates could also be well tolerated, albeit
generating the desired products in moderate yields.
To investigate the reaction mechanism, we have per-
formed the radical-trap experiment. When stoichiometric
amount of the radical scavenger 2,2,6,6-tetramethylpiperi-
dine-N-oxide (TEMPO) was added to the reaction mixture
under the same reaction conditions, the transformation
was nearly inhibited and at the same time, the expected
arylated TEMPO was detected by GC–MS. The result sug-
gested that the methylthiolation presumably proceeded
©
Georg Thieme Verlag Stuttgart · New York — Synlett 2016, 27, A–E

C
Synlett
X.-m. Wu et al.
Letter
through a radical pathway. On the basis of the above results
and the related literatures,23 a plausible reaction pathway
for the reaction is proposed in Scheme 1.
Table 2 (continued)
Yield(%)b
Entry Arylboronic acid
Product
B(OH)2
SCH3
1
1
1
4
5
6
7
55
Table 2 Methylthiolation of Arylboronic Acid with Dimethyldisul-
fide
O2N
O2N
a,22
B(OH)2
SCH3
B(OH)2
SCH3
DTBP, CH3CN
20 °C,12 h
R
+ CH3SSCH3
R
58
72
68
1
NO2
NO2
Entry Arylboronic acid
Product
Yield(%)b
75
B(OH)2
SCH3
B(OH)2
SCH3
H3COC
H3COC
1
B(OH)2
SCH3
B(OH)2
SCH3
1
2
3
72
68
CN
CN
a
B(OH)2
SCH3
Reaction conditions: arylboronic acid (1.0 mmol), dimethyldisulfide (2.0
mmol), DTBP (3.0 mmol), MeCN (2.0 mL), 120 °C, 12 h.
b
Isolated yield.
B(OH)2
SCH3
CH3SSCH3
4
70
B(OH)2
DTBP
SCH3
R
R
R
CH3S
5
6
B(OH)2
SCH3
71
60
Scheme 1 Plausible mechanism for the coupling reaction
B(OH)2
SCH3
In conclusion, a mild and practical approach to aryl
methyl sulfides has been developed from the coupling of ar-
ylboronic acid and dimethyldisulfide under metal- and
base-free conditions. Further efforts to explore the applica-
tions of the transformation in organic synthesis are cur-
rently underway in our laboratories.
H3CO
H3CO
B(OH)2
SCH3
7
8
78
80
F
F
B(OH)2
SCH3
Cl
Cl
Acknowledgment
B(OH)2
SCH3
9
75
We are grateful for financial support from the Natural Science Foun-
dation of Zhejiang Province (No. LY13B020005) and the National Nat-
ural Science Foundation of China (No. 21572094).
Cl
Cl
B(OH)2
Cl
SCH3
Cl
1
0
63
69
Supporting Information
B(OH)2
SCH3
Supporting information for this article is available online at
http://dx.doi.org/10.1055/s-0035-1562499.
1
1
1
1
S
u
p
p
ortioIgnfrm oaitn
S
u
p
p
o
nrtogI
i
f
rm oaitn
Br
Br
B(OH)2
SCH3
References and Notes
2
3
60
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(1) (a) Kalgutkar, A. S.; Kozak, K. R.; Crews, B. C.; Marnett, L. J.
Br
Br
J. Med. Chem. 1998, 41, 4800. (b) Laufer, S. A.; Striegel, H.-G.;
Wagner, G. K. J. Med. Chem. 2002, 45, 4695. (c) Gallardo-Godoy,
B(OH)2
SCH3
I
I
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X.-m. Wu et al.
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A.; Fierro, A.; McLean, T. H.; Castillo, M.; Cassels, B. K.; Reyes-
Parada, M.; Nichols, D. E. J. Med. Chem. 2005, 48, 2407.
(11) (a) Stoll, A. H.; Krasovskiy, A.; Knochel, P. Angew. Chem. Int. Ed.
2006, 45, 606. (b) Cheng, J.-H.; Ramesh, C.; Kao, H.-L.; Wang, Y.-
J.; Chan, C.-C.; Lee, C.-F. J. Org. Chem. 2012, 77, 10369.
(12) (a) Kukushkin, V. Y. Coord. Chem. Rev. 1995, 139, 375.
(b) Fernandes, A. C.; Fernandes, J. A.; Romao, C. C.; Veiros, L. F.;
Calhorda, M. J. Organometallics 2010, 29, 5517.
(
d) Pradhan, T. K.; De, A.; Mortier, J. Tetrahedron 2005, 61, 9007.
2) (a) Dubbaka, S. R.; Vogel, P. Angew. Chem. Int. Ed. 2005, 44, 7674.
b) Prokopcová, H.; Kappe, C. O. Angew. Chem. Int. Ed. 2009, 48,
(
(
2276. (c) Eberhart, A. J.; Imbriglio, J. E.; Procter, D. J. Org. Lett.
2
011, 13, 5882. (d) Ookubo, Y.; Wakamiya, A.; Yorimitsu, H.;
(13) Basu, B.; Paul, S.; Nanda, A. K. Green Chem. 2010, 12, 767.
(14) Baldovino-Pantaleón, O.; Hernández-Ortega, S.; Morales-
Morales, D. Adv. Synth. Catal. 2006, 348, 236.
Osuka, A. Chem. Eur. J. 2012, 18, 12690. (e) Modha, S. G.; Mehta,
V. P.; Van der Eycken, E. V. Chem. Soc. Rev. 2013, 42, 5042.
(
f) Hooper, J. F.; Young, R. D.; Pernik, I.; Weller, A. S.; Willis, M. C.
(15) (a) Stanetty, P.; Koller, H.; Mihovilovic, M. J. Org. Chem. 1992, 57,
6833. (b) Pratt, S. A.; Goble, M. P.; Mulvaney, M. J.; Wuts, P. G. M.
Tetrahedron Lett. 2000, 41, 3559. (c) Fort, Y.; Rodriguez, A. L.
J. Org. Chem. 2003, 68, 4918.
Chem. Sci. 2013, 4, 1568. (g) Liu, J.-X.; Liu, Y.-J.; Du, W.-T.; Dong,
Y.; Liu, J.; Wang, M. J. Org. Chem. 2013, 78, 7293. (h) Pan, F.;
Wang, H.; Shen, P.-X.; Zhao, J.; Shi, Z.-J. Chem. Sci. 2013, 4, 1573.
(
i) Wang, L.; He, W.; Yu, Z. Chem. Soc. Rev. 2013, 42, 599. (j) Pan,
(16) Majek, M.; Wangelin, A. J. V. Chem. Commun. 2013, 49, 5507.
(17) (a) Luo, F.; Pan, C.; Li, L.; Chen, F.; Cheng, J. Chem. Commun.
2011, 47, 5304. (b) Joseph, P. J. A.; Priyadarshini, S.; Kantam, M.
L.; Sreedhar, B. Tetrahedron 2013, 69, 8276. (c) Ghosh, K.; Ranjit,
S.; Mal, D. Tetrahedron Lett. 2015, 56, 5199.
(18) (a) She, J.; Jiang, Z.; Wang, Y. Tetrahedron Lett. 2009, 50, 593.
(b) Fu, Z.; Li, Z.; Xiong, Q.; Cai, H. Eur. J. Org. Chem. 2014, 7798.
(19) (a) Chen, X.; Hao, X. S.; Goodhue, C. E.; Yu, J. Q. J. Am. Chem. Soc.
2006, 128, 6790. (b) Chu, L.; Yue, X.; Qing, F. L. Org. Lett. 2010,
12, 1644. (c) Dai, C.; Xu, Z.; Huang, F.; Yu, Z.; Gao, Y. F. J. Org.
Chem. 2012, 77, 4414. (d) Patil, S. M.; Kulkarni, S.; Mascarenhas,
M.; Sharma, R.; Roopan, S. M.; Roychowdhury, A. Tetrahedron
2013, 69, 8255. (e) Sharma, P.; Rohilla, S.; Jain, N. J. Org. Chem.
2015, 80, 4116. (f) Zou, J. F.; Huang, W. S.; Li, L.; Xu, Z.; Zheng, Z.
J.; Yang, K. F.; Xu, L. W. RSC Adv. 2015, 5, 30389. (g) Xu, Y.; Cong,
T.; Liu, P.; Sun, P. Org. Biomol. Chem. 2015, 13, 9742.
(20) (a) Chan, D. M. T.; Monaco Wang, R. P.; Winters, M. P. Tetrahe-
dron Lett. 1998, 39, 2933. (b) Lam, P. Y. S.; Clark, C. G.; Saubern,
S.; Adams, J.; Winters, M. P.; Chan, D. M. T.; Combs, A. Tetrahe-
dron Lett. 1998, 39, 2941. (c) Lam, P. Y. S.; Clark, C. G.; Saubern,
S.; Adams, J.; Averill, K. M.; Chan, D. M. T.; Combs, A. Synlett
2000, 674. (d) Collman, J. P.; Zhong, M. Org. Lett. 2000, 2, 1233.
(e) Collman, J. P.; Zhong, M.; Zeng, L.; Costanzo, S. J. Org. Chem.
2001, 66, 1528. (f) Lam, P. Y. S.; Vincent, G.; Clark, C. G.; Deudon,
S.; Jadhav, P. K. Tetrahedron Lett. 2001, 42, 3415. (g) Antilla, J. C.;
Buchwald, S. L. Org. Lett. 2001, 3, 2077. (h) Yu, S.; Saenz, J.;
Srirangam, J. K. J. Org. Chem. 2002, 67, 1699. (i) Chiang, G. C. H.;
Olsson, T. Org. Lett. 2004, 6, 3079. (j) Lan, J. B.; Chen, L.; Yu, X. Q.;
You, J. S.; Xie, R. G. Chem. Commun. 2004, 40, 188. (k) Kantam,
M. L.; Venkanna, G. T.; Sridhar, C.; Sreedhar, B.; Choudary, B. M.
J. Org. Chem. 2006, 71, 9522. (l) Chen, S.; Huang, H.; Liu, X.;
Shen, J.; Jiang, H.; Liu, H. J. Comb. Chem. 2008, 10, 358.
(m) Kirchberg, S.; Fröhlich, R.; Studer, A. Angew. Chem. Int. Ed.
2009, 48, 4235. (n) Liu, B.; Liu, B.; Zhou, Y.; Chen, W. Organome-
tallics 2010, 29, 1457. (o) Raghuvanshi, D. S.; Gupta, A. K.; Singh,
K. N. Org. Lett. 2012, 14, 4326. (p) Zhou, Y.; Xie, Y.; Yang, L.; Xie,
P.; Huang, H. Tetrahedron Lett. 2013, 54, 2713. (q) Bruneau, A.;
Brion, J.-D.; Alami, M.; Messaoudi, S. Chem. Commun. 2013, 49,
8359. (r) Zhu, C.; Falck, J. R. Adv. Synth. Catal. 2014, 356, 2395.
(s) Yoo, W.-J.; Tsukamoto, T.; Kobayashi, S. Angew. Chem. Int. Ed.
2015, 54, 6587. (t) Roy, S.; Sarma, M. J.; Kashyap, B.; Phukan, P.
Chem. Commun. 2016, 52, 1170. (u) Mandal, P. S.; Kumar, A. V.
Synlett 2016, 27, 1408.
F.; Shi, Z.-J. ACS Catal. 2014, 4, 280. (k) Otsuka, S.; Fujino, D.;
Murakami, K.; Yorimitsu, H.; Osuka, A. Chem. Eur. J. 2014, 20,
1
Wang, X.-C. Adv. Synth. Catal. 2014, 356, 325. (m) Zhu, F.; Wang,
Z.-X. Org. Lett. 2015, 17, 1601.
3146. (l) Quan, Z.-J.; Lv, Y.; Jing, F.-Q.; Jia, X.-D.; Huo, C.-D.;
(
3) (a) Ram, V. J.; Agarwal, N. Tetrahedron Lett. 2001, 42, 7127.
(b) Sugahara, T.; Murakami, K.; Yorimitsu, H.; Osuka, A. Angew.
Chem. Int. Ed. 2014, 53, 9329.
(
4) (a) Hooper, J. F.; Chaplin, A. B.; González-Rodríguez, C.;
Thompson, A. L.; Weller, A. S.; Willis, M. C. J. Am. Chem. Soc.
2
012, 134, 2906. (b) Arambasic, M.; Hooper, J. F.; Willis, M. C.
Org. Lett. 2013, 15, 5162. (c) Iwasaki, M.; Topolovčan, N.; Hu, H.;
Nishimura, Y.; Gagnot, G.; Na Nakorn, R.; Yuvacharaskul, R.;
Nakajima, K.; Nishihara, Y. Org. Lett. 2016, 18, 1642.
(
5) (a) Migita, T.; Shimizu, T.; Asami, Y.; Shiobara, J.-I.; Kato, Y.;
Kosugi, M. Bull. Chem. Soc. Jpn. 1980, 53, 1385. (b) Mann, G.;
Baranano, D.; Hartwig, J. F.; Rheingold, A. L.; Guzei, I. A. J. Am.
Chem. Soc. 1998, 120, 9205. (c) Li, G. Y.; Zheng, G.; Noonan, A. F.
J. Org. Chem. 2001, 66, 8677. (d) Itoh, T.; Mase, T. Org. Lett. 2004,
6
, 4587. (e) Mispelaere-Canivet, C.; Spindler, J.-F.; Perrioa, S.;
Beslin, P. Tetrahedron 2005, 61, 5253. (f) Fernández-Rodríguez,
M. A.; Shen, Q.; Hartwig, J. F. J. Am. Chem. Soc. 2006, 128, 2180.
(g) Dahl, T.; Tornøe, C. W.; Bang-Andersen, B.; Nielsen, P.;
Jøgensen, M. Angew. Chem. Int. Ed. 2008, 47, 1726. (h) Lee, C.-F.;
Liu, Y.-C.; Badsara, S. S. Chem. Asian J. 2014, 9, 706.
(
6) (a) Cristau, H. J.; Chabaud, B.; Chêne, A.; Christol, H. Synthesis
1
6
981, 892. (b) Percec, V.; Bae, J.-Y.; Hill, D. H. J. Org. Chem. 1995,
0, 6895. (c) Millois, C.; Diaz, P. Org. Lett. 2000, 2, 1705.
(
d) Zhang, Y.; Ngeow, K. C.; Ying, J. Y. Org. Lett. 2007, 9, 3495.
7) (a) Kwong, F. Y.; Buchwald, S. L. Org. Lett. 2002, 4, 3517.
b) Bates, C. G.; Gujadhur, R. K.; Venkataraman, D. Org. Lett.
002, 4, 2803. (c) Enguehard-Gueiffier, C.; Thery, I.; Gueiffier,
(
(
2
A.; Buchwald, S. L. Tetrahedron 2006, 62, 6042. (d) Carril, M.;
SanMartin, R.; Dominguez, E.; Tellitu, I. Chem. Eur. J. 2007, 13,
5
100. (e) Zhang, H.; Cao, W.; Ma, D. Synth. Commun. 2007, 37,
5. (f) Chen, Y.-J.; Chen, H.-H. Org. Lett. 2006, 8, 5609. (g) Verma,
2
A. K.; Singh, J.; Chaudhary, R. Tetrahedron Lett. 2007, 48, 7199.
h) Lv, X.; Bao, W. J. Org. Chem. 2007, 72, 3863.
(
(
(
8) Wong, Y.-C.; Jayanth, T. T.; Cheng, C.-H. Org. Lett. 2006, 8, 5613.
9) (a) Reddy, V. P.; Swapna, K.; Kumar, A. V.; Rao, K. R. J. Org. Chem.
2
009, 74, 3189. (b) Reddy, V. P.; Swapna, K.; Kumar, A. V.;
Swapna, K.; Rao, K. R. Org. Lett. 2009, 11, 1697.
(
10) (a) Campbell, J. R. J. Org. Chem. 1964, 29, 1830. (b) Yamamoto,
T.; Sekine, Y. Can. J. Chem. 1984, 62, 1544. (c) Lindley, J. Tetrahe-
dron 1984, 40, 1433. (d) Hickman, R. J. S.; Christie, B. J.; Guy, R.
W.; White, T. J. Aust. J. Chem. 1985, 38, 899.
(21) (a) Sagar, A. D.; Tale, R. H.; Adude, R. N. Tetrahedron Lett. 2003,
44, 7061. (b) Inamoto, K.; Nozawa, K.; Yonemoto, M.; Kondo, Y.
Chem. Commun. 2011, 47, 11775. (c) Mulla, S. A. R.; Inamdar, S.
M.; Pathan, M. Y.; Chavan, S. S. RSC Adv. 2012, 2, 12818.
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Georg Thieme Verlag Stuttgart · New York — Synlett 2016, 27, A–E

E
Synlett
X.-m. Wu et al.
Letter
(
d) Chen, L. S.; Lang, H. Y.; Fang, L.; Zhu, M. Y.; Liu, J. Q.; Yu, J. J.;
terized by their spectral and analytical data and compared with
those of the known compounds (see Supporting Information).
Typical Data for Representative Compound
Wang, L. M. Eur. J. Org. Chem. 2014, 4953. (e) LaBerge, N. A.;
Love, J. A. Eur. J. Org. Chem. 2015, 5546.
(
22) General Procedure
4-Methylthioanisole (Table 2, Entry 2)
1
Arylboronic acid (1.0 mmol), dimethyldisulfide (2.0 mmol),
DTBP (3.0 mmol), and MeCN (2.0 mL) were taken in a sealed
tube. The reaction mixture was stirred at 120 °C for 12 h in air.
After cooling to room temperature, the product was diluted
Colorless oil. H NMR (300 MHz, CDCl ): δ = 7.17–7.14 (d, J = 8.1
3
Hz, 2 H), 7.08–7.05 (d, J = 8.1 Hz, 2 H), 2.42 (s, 3 H), 2.28 (s, 3 H).
1
3
C NMR (75 MHz, CDCl ): δ = 135.0, 134.8, 129.7, 127.3, 20.9,
3
+
16.5. GC-MS (EI): m/z = 138 [M ].
with H O (5 mL) and extracted with EtOAc (4 × 10 mL). The
extracts were combined and washed by brine (3 × 10 mL), dried
(23) (a) Uchiyama, N.; Shirakawa, E.; Nishikawa, R.; Hayashi, T.
Chem. Commun. 2011, 47, 11671. (b) Yan, G. B.; Yang, M. H.; Wu,
X. M. Org. Biomol. Chem. 2013, 11, 7999. (c) Liu, D.; Li, Y.; Qi, X.;
Liu, C.; Lan, Y.; Lei, A. Org. Lett. 2015, 17, 998.
2
over MgSO , filtered, and evaporated, and purified by chroma-
4
tography on silica gel to obtain the desired products with
EtOAc–hexane (1:30 to 1:100 v/v). The products were charac-
©
Georg Thieme Verlag Stuttgart · New York — Synlett 2016, 27, A–E