Hypervalent iodine in synthesis 55: An efficient method for synthesis of aryl sulfides by palladium-catalyzed reaction of hypervalent iodonium salts with mercaptans

Article abstract of DOI:10.1081/SCC-100104008

The synthesis of aryl sulfides was carried out in high yields by the palladium-catalyzed cross-coupling reaction of diaryliodonium salts with mercaptans at room temperature in THF.

Full text of DOI:10.1081/SCC-100104008

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HYPERVALENT IODINE IN
SYNTHESIS 55: AN EFFICIENT
METHOD FOR SYNTHESIS
OF ARYL SULFIDES BY
PALLADIUM-CATALYZED
REACTION OF HYPERVALENT
IODONIUM SALTS WITH
MERCAPTANS
Li Wang a & Zhen-Chu Chen b
a Department of Chemistry , Zhejiang University ,
(Xi-Xi Campus), Hangzhou, 310028, P. R. China
b Department of Chemistry , Zhejiang University ,
(Xi-Xi Campus), Hangzhou, 310028, P. R. China
Published online: 09 Nov 2006.
To cite this article: Li Wang & Zhen-Chu Chen (2001) HYPERVALENT IODINE
IN SYNTHESIS 55: AN EFFICIENT METHOD FOR SYNTHESIS OF ARYL SULFIDES
BY PALLADIUM-CATALYZED REACTION OF HYPERVALENT IODONIUM SALTS WITH
MERCAPTANS, Synthetic Communications: An International Journal for Rapid
Communication of Synthetic Organic Chemistry, 31:8, 1227-1232, DOI: 10.1081/
SCC-100104008
To link to this article: http://dx.doi.org/10.1081/SCC-100104008

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SYNTHETIC COMMUNICATIONS, 31(8), 1227–1232 (2001)
HYPERVALENT IODINE IN SYNTHESIS
55: AN EFFICIENT METHOD FOR
SYNTHESIS OF ARYL SULFIDES BY
PALLADIUM-CATALYZED REACTION
OF HYPERVALENT IODONIUM SALTS
WITH MERCAPTANS
Li Wang and Zhen-ChuChen *
Department of Chemistry, Zhejiang University
(Xi-Xi Campus) Hangzhou, 310028, P. R. China
ABSTRACT
The synthesis of aryl sulfides was carried out in high
yields by the palladium-catalyzed cross-coupling reaction of
diaryliodonium salts with mercaptans at room temperature in
THF.
Aryl sulfides have received considerable interest because of their anti-
microbial activity and application in organic synthesis.1,2 Although there are
many methods for the preparation of sulfides, the one most widely used for
the preparation of aryl sulfides is the arylation of mercaptans with aryl
halides.2 Due to aryl halides’ low reactivity, the reaction usually needs
more time, high temperatures, and generally gives poor yields. Recently,
transition metal catalyzed cross-coupling reaction of sulfur nucleophiles
with organic electrophiles (i.e., aryl halides and triflates) is recognized to
* Corresponding author.
1227
Copyright & 2001 by Marcel Dekker, Inc.
www.dekker.com

1228
WANG AND CHEN
be a powerful tool for preparing aryl sulfides.3–9 However, it still has some
disadvantages, such as longer reaction time, high temperature, and use of
either a strong base or specific sulfur nucleophiles.
As an alternative to organic electrophiles, we have reported the palla-
dium-catalyzed cross-coupling reaction of hypervalent iodonium salts with
organoboron compounds10,11 and Grignard reagents.12 It showed that
diaryliodonium salts are efficient electrophilic arylation agents,13–16 and
it prompted us to extend the palladium-catalyzed arylation to mercaptans
for an efficient synthesis method of aryl sulfides. Here we report
the palladium-catalyzed cross-coupling of diaryliodonium salts with
mercaptans (Scheme 1).17
Scheme 1.
We have found that, in the presence of sodium carbonate, palladium-
catalyzed cross-coupling of diaryliodonium salts with mercaptans takes
place smoothly, reaching completion within 1 h at room temperature in
THF. The results are summarized in Table 1. All products gave satisfactory
1
m.p., IR, and H NMR spectra. The reaction was found to be general and
applicable to aliphatic or aromatic mercaptans. Several diaryliodonium salts
containing various substituents, such as methoxy, methyl, chloro, and nitro
groups, were successfully reacted. The present method is suitable not only
for the synthesis of symmetric aryl sulfides, but also for the synthesis of
unsymmetric aryl sulfides.
In conclusion, we have provided a simple efficient synthesis method of
aryl sulfides by palladium-catalyzed cross-coupling of diaryliodonium salts
with mercaptans. It has some advantages over previous methods, such as
mild reaction conditions, fast reaction rates, and good yields. Furthermore,
the range of applications of diaryliodonium salts as electrophilic arylating
agents in organic synthesis has been extended.
EXPERIMENTAL
1H NMR spectra were recorded on a PMX-60spectrometer, using
CCl4 as the solvent with TMS as an internal standard. IR spectra were
determined on a PE-683 Spectrophotometer. Melting points are uncorrected.

HYPERVALENT IODINE
Table 1. The Preparation of Aryl Sulfidesa
1229
Yield
(%)b
ꢂ
Entry
Ar2IþBF4
RSH
Product
ꢂ
1
(p-CH3C6H4)2IþBF4
PhSH
(p-CH3OC6H4)2IþBF4 PhSH
p-CH3C6H4SPh
p-CH3OC6H4SPh
p-ClC6H4SPh
m-NO2C6H4SPh
PhSPh
95
91
89
86
97
93
94
83
91
88
90
ꢂ
2
ꢂ
3
(p-ClC6H4)2IþBF4
(m-NO2C6H4)2IþBF4
PhSH
PhSH
PhSH
ꢂ
4
ꢂ
5
6
Ph2IþBF4
Ph2IþBF4
ꢂ
p-CH3C6H5SH PhSC6H4CH3-p
ꢂ
7
(p-CH3C6H4)2IþBF4
p-CH3C6H5SH p-CH3C6H4SC6H4CH3-p
p-CH3C6H5SH m-NO2C6H4SC6H4CH3-p
ꢂ
8
(m-NO2C6H4)2IþBF4
ꢂ
ꢂ
9
Ph2IþBF4
C6H5CH2SH
C2H5SH
PhSCH2C6H5
C6H5SC2H5
10Ph
11
2IþBF4
ꢂ
(p-CH3C6H4)2IþBF4
C2H5SH
p-CH3C6H4SC2H5
aReagent and conditions: 1 mmol iodonium salt, 1 mmol Na2CO3, 5 mol%
Pd(PPh3)4 and 1 mmol mercaptans, in 5 mL THF at room temperature under
b
nitrogen atmosphere; Isolated yields.
General Procedure for Synthesis of Aryl Sulfides
To a stirred solution of diaryliodonium tetrafluoroborate (1 mmol), Pd
(PPh3)4 (58 mg, 5 mol%), Na2CO3 (106 mg, 2 mmol), and anhydrous THF
(5 mL) under nitrogen atmosphere was added mercaptan at room tempera-
ture. The mixture was stirred at room temperature for an hour. The solvent
was evaporated off. To the residue, a saturated NH4Cl solution (5 mL) was
added and then extracted with ether (2ꢀ10mL). The organic layer was dried
over anhydrous MgSO4 and evaporated in vacuo. The crude product was
separated by preparative thin layer chromatography on silica gel with
hexane as a developer to afford the desired product, aryl sulfide.
4-Methylphenyl Phenyl Sulfide (entry 1,6)
M.p. 15ꢁC (Lit.18 15.7ꢁC) 1H NMR 2.32 (s,3H), 7.45–6.90(m,9H)
I.R. 3045, 2920, 1587, 1490, 1442, 1400, 1210, 1090, 1020, 800, 740,
690cm ꢂ1
.

1230
WANG AND CHEN
4-Methyoxyphenyl Phenyl Sulfide (entry 2 )
1
Oil H NMR 3.80 (s,3H) 6.90–7.45 (m,9H) I.R. 3050, 1580, 1470,
1440, 1250, 1080, 1045, 830, 780, 690 cmꢂ1
.
4-Chlorophenyl Phenyl Sulfide (entry 3)
1
Oil H NMR 7.10–7.60 (m, 9H) I.R. 3050, 1585, 1485, 1385, 1075,
1000, 800, 750, 690 cmꢂ1
.
3-Nitrophenyl Phenyl Sulfide (entry 4)
M.p. 41ꢁ–42ꢁC (Lit.19 42.5ꢁC) H NMR 7.20–8.15 (m,9H) I.R. (KBr)
1
3040, 1585, 1560, 1500, 1350, 1300, 730, 700, 670 cmꢂ1
.
Diphenyl Sulfide (entry 5)
1
Oil H NMR 7.00–7.35 (m, 10H) I.R. 3050, 1580, 1470, 1440, 1080,
1030, 740, 690 cmꢂ1
.
4.40 -Dimethyldiphenyl Sulfide (entry 7)
M.p. 55ꢁ–56ꢁC (Lit.20 m.p. 57.3ꢁC) H NMR 2.34 (s,6H) 6.90–7.30
1
(m,8H) I.R. 3060, 2950, 1595, 1480, 1070, 1005, 790 cmꢂ1
.
3-Nitrophenyl 40-methylphenyl Sulfide (entry 8)
M.p. 60ꢁ–61ꢁC (Lit.21 m.p. 61ꢁC) H NMR 7.10–8.10 (m,8H) 2.30
(s,3H) I.R. 3045, 2870, 1630, 1570, 1480, 1450, 1390, 1300, 1175, 1110,
1
1070, 1005, 900, 830, 790 cmꢂ1
.
Benzyl Phenyl Sulfide (entry 9)
M.p. 38ꢁ–40ꢁC (Lit.22 m.p. 39ꢁ–40ꢁC) 1H NMR 4.00 (s, 2H) 6.95–7.40
(m,10H) I.R. 3050, 2910, 1578, 1480, 1408, 1240, 1090, 1070, 1030, 920,
740cm ꢂ1
.

HYPERVALENT IODINE
1231
Ethyl Phenyl Sulfide (entry 10)
1
Oil H NMR 1.3 (t, 3H, J 7.1 Hz) 2.90(q,2H, J7.1 Hz), and 7.2–7.4
(5H,m) I.R. 3050, 2900, 1580, 1470, 1440, 1080, 1030, 740, 690 cmꢂ1
.
Ethyl 4-Methylphenyl Sulfide (entry 11)
1
Oil H NMR 1.3 (3H, t, J 7.1 Hz), 2.30(s,3H) 2.90(q, 2H, J 7.1 Hz),
7.2–7.4 (m,4H) I.R. 3050, 2895, 1580, 1470, 1440, 1080, 1030, 740, 690 cmꢂ1
.
ACKNOWLEDGMENTS
We appreciate the financial support of the National Science
Foundation of China (Project 29472036).
REFERENCES AND NOTES
1. Reid, E.E. Organic Chemistry of Bivalent Sulfur; 1960; Vol. II, 78.
2. Comprehensive Organic Chemistry; Jones, D.N., Ed.; Pergamon Press:
Oxford, 1979; Vol. 3, 33–103.
3. Migita, T.; Shimzu, T.; Asami, Y.; Shiobara, J.; Kato, Y.; Kosugi, M.
Bull. Chem. Soc. Jpn. 1980, 53, 1385.
4. Kosugi, M.; Ogata, T.; Terada, M.; Sano, H.; Migita, T. Bull. Chem.
Soc. Jpn. 1985, 58, 3657.
5. Ciattini, P.G.; Morera, E.; Ortar, G. Tetrahedron Lett. 1995, 36, 4133.
6. Baranano, D.; Hartwig, J.F. J. Am. Chem. Soc. 1995, 117, 2937.
7. Louie, J.; Hartwig, J.F. J. Am. Chem. Soc. 1995, 117, 11598.
8. Nan, Z.; McWilliams, J.C.; Fleitz, F.J.; Armstrong, III, J.D.; Volante,
R.P. J. Org. Chem. 1998, 63, 9606.
9. Ishiyama, T.; Mori, M.; Suzuki, A.; Miyaura, N. J. Organomet. Chem.
1996, 525, 225.
10. Min, X.; Zhenchu, C. J. Chem. Res. 1999, 6, 400.
11. Min, X.; Zhenchu, C. Syn. Commun. 1999, 29, 2457.
12. Li, W.; Zhenchu, C. ‘‘Hypervalent iodine in synthesis 47: cross-coupling-
reaction of diaryliodonium salts with Grignard reagents via a novel
double metal co-catalyst’’ Syn. Commun. in press.
13. Stang, P.J. Chem. Rev. 1996, 96, 1123.
14. Varvoglis, A. Tetrahedron 1997, 53, 1179.
15. Kitamura, T.; Fujiwara, Y. Org. Prep. Proc. Int. 1997, 29, 409.

1232
WANG AND CHEN
16. Zhdankin, V.V.; Stang, P.J. Tetrahedron 1998, 54, 10927.
17. Crivello and Lam reported that, in the presence of catalytic amounts of
copper-compounds and a molar equivalent of a trialkylamine, thiophe-
nol reacts with diaryliodonium salts to give triarylsulfonium salts at
125ꢀC. Crivello, J.V.; Lam, J.H.W. Synth. Commun. 1979, 9, 151.
18. Bourgeois, E. Ber. 1895, 28, 2323.
19. Hammick, D.L.I.; Williams, R.B. J. Chem. Soc. 1938, 211.
20. Bourgeois, E. Ber. 1895, 28, 2320 .
`
21. Passerini, R. Boll. Sci. Facolta Chim. Ind. Bologna 1950, 8, 122.
22. Yoon, N.M.; Choi, J.; Ahn, J.H. J. Org. Chem. 1994, 59, 3490.
Accepted June 18, 2000