a
Table 3 The oxidative-trifluoromethylation of styrenes
Medicinal Chemistry of Fluorine, John Wiley & Sons, Hoboken,
2
008.
(a) K. Sato, M. Higashinagata, T. Yuki, A. Tarui, M. Omote,
I. Kumadaki and A. Ando, J. Fluorine Chem., 2008, 129, 51;
2
(
b) C.-P. Zhang, H.-P. Cao, Z.-L. Wang, C.-T. Zhang,
Q.-Y. Chen and J.-C. Xiao, Synlett., 2010, 1089; (c) L. Chu and
F.-L. Qing, J. Am. Chem. Soc., 2010, 132, 7262.
b
Entry
Ar
Yield (%)
3 (a) L. M. Yagupolskii, N. V. Kondratenko and G. N. Timofeeva,
J. Org. Chem. USSR, 1984, 20, 103; (b) T. Umemoto and
S. Ishihara, J. Am. Chem. Soc., 1993, 115, 2156; (c) J.-J. Yang,
R. L. Kirchmeier and J. M. Shreeve, J. Org. Chem., 1998, 63, 2656;
1
2
3
4
5
6
7
8
9
m-NO
2
C
6
H
4
(1b)
(1c)
21 (2b)
25 (2c)
23 (2d)
33 (2e)
21 (2f)
31 (2g)
30 (2h)
31 (2i)
39 (2j)
31 (2k)
Complex
p-NO
m-PhC
p-PhC
o-ClC
p-ClC
p-BrC
p-MeC
p-MeOC
1-Naphthyl (1k)
n-C 17 (1l)
2
C
6
H
4
6
H
4
(1d)
(1e)
(
d) E. Magnier, J.-C. Blazejewski, M. Tordeux and C. Wakselman,
6 4
H
Angew. Chem., Int. Ed., 2006, 45, 1279; (e) Y. Mace,
B. Raymondeau, C. Pradet, J.-C. Blazejewski and E. Magnier,
Eur. J. Org. Chem., 2009, 1390; (f) S. Noritake, N. Shibata,
S. Nakamura, T. Toru and M. Shiro, Eur. J. Org. Chem., 2008,
6
H
H
4
(1f)
(1g)
(1h)
6
4
6 4
H
6
H
4
(1i)
3
465; (g) A. Matsnev, S. Noritake, Y. Nomura, E. Tokunaga,
6
4
H (1j)
S. Nakamura and N. Shibata, Angew. Chem. Int. Ed., 2010, 49, 572.
(a) P. Eisenberger, S. Gischig and A. Togni, Chem.–Eur. J., 2006,
1
1
0
1
4
8
H
1
2, 2579; (b) I. Kieltsch, P. Eisenberger and A. Togni, Angew.
a
+
À
The molar ratio of 1b–l : [Ph
b
is 1 : 2 : 6. Isolated yield.
2
SCF
3
]
[OTf] : HOCH SO
2
2
NaÁ2H
2
O
Chem., Int. Ed., 2007, 46, 754; (c) P. Eisenberger, I. Kieltsch,
N. Armanino and A. Togni, Chem. Commun., 2008, 1575;
(
d) R. Koller, K. Stanek, D. Stolz, R. Aardoom, K. Niedermann,
R. Koller and A. Togni, Angew. Chem., Int. Ed., 2009, 48, 4332.
(a) X. Wang, L. Truesdale and J.-Q. Yu, J. Am. Chem. Soc., 2010,
5
6
1
32, 3648; (b) C.-P. Zhang, Z.-L. Wang, Q.-Y. Chen, C.-T. Zhang,
Y.-C. Gu and J.-C. Xiao, Angew. Chem., Int. Ed., 2011, 50, 1896;
c) Y. Ye, N. D. Ball, J. W. Kampf and M. S. Sanford, J. Am. Chem.
(
Soc., 2010, 132, 14682.
(a) M. A. McClinton and D. A. McClinton, Tetrahedron, 1992, 48,
6
(
555; (b) N. O. Brace, J. Fluorine Chem., 1999, 93, 1;
c) W. R. Dolbier Jr, Chem. Rev., 1996, 96, 1557; (d) G. G. Furin,
Russ. Chem. Rev., 2000, 69, 491; (e) W.-Y. Huang, W. Wang and
B.-N. Huang, Huaxue Xuebao, 1986, 44, 488; (f) W.-Y. Huang,
J.-T. Liu, Y.-B. Xie and X.-Q. He, Chin. J. Chem., 1994, 12, 528;
Scheme 1 Proposed mechanism for the oxidative-trifluoromethyl-
ation of styrenes by S-(trifluoromethyl)diphenylsulfonium salt.
(
g) Z. Wang and X. Lu, Tetrahedron, 1995, 51, 2639; (h) X. Lu,
S. Ma and J. Zhu, Tetrahedron Lett., 1988, 29, 5129; (i) T. Yajima,
H. Nagano and C. Saito, Tetrahedron Lett., 2003, 44, 7027;
reaction was run under a nitrogen atmosphere, however, none
of the product was formed (entry 8, Table 1). It seems that the
(
j) Y. Takeyama, Y. Ichinose, K. Oshima and K. Utimoto,
oxygen atom in these products comes from O
In summary, we have discovered that S-(trifluoromethyl)-
diphenylsulfonium triflate can react with Na or
HOCH SO Na under suitable conditions to generate the
2
.
Tetrahedron Lett., 1989, 30, 3159; (k) B.-N. Huang, F.-H. Wu and
C.-M. Zhou, J. Fluorine Chem., 1995, 75, 1.
(a) P. Sartori and W. Habel, J. Fluorine Chem., 1980, 16, 265;
7
8
2 2 4
S O
(
(
b) P. Sartori and W. Habel, J. Fluorine Chem., 1981, 18, 131;
c) P. S. Bhadury, S. Singh, M. Sharma and M. Palit, J. Anal. Appl.
2
2
CF3 radical without further reduction. Based on this, a
convenient method for the synthesis of a-trifluoromethylated
ketones has been successfully developed. We propose that the
S-(trifluoromethyl)diphenylsulfonium triflate is reduced by
Pyrolysis, 2007, 78, 288; (d) B. R. Langlois, T. Billard,
J.-C. Mulatier and C. Yezeguelian, J. Fluorine Chem., 2007, 128,
8
51.
(a) Y. Kamitori, M. Hojo, R. Masuda, S. Ohara, Y. Kawamura and
T. Ebisu, Synthesis, 1989, 43; (b) K. Sato, M. Omote, A. Ando
and I. Kumadaki, Org. Lett., 2004, 6, 4359; (c) K. Sato,
M. Higashinagata, T. Yuki, A. Tarui, M. Omote, I. Kumadaki
and A. Ando, J. Fluorine Chem., 2008, 129, 51; (d) H. A. Schenck,
P. W. Lenkowski, I. Choudhury-Mukherjee, S.-H. Ko, J. P. Stables,
M. K. Patel and M. L. Brown, Bioorg. Med. Chem., 2004, 12, 979;
(e) I. Choudhury-Mukherjee, H. A. Schenck, S. Cechova,
T. N. Pajewski, J. Kapur, J. Ellena, D. S. Cafiso and
M. L. Brown, J. Med. Chem., 2003, 46, 2494; (f) T. Shono,
N. Kise and H. Oka, Tetrahedron Lett., 1991, 32, 6567;
Na
S
2 2
O
4
or HOCH
2 2
SO Na via a SET mechanism, and that
the CF
3
radical is the key intermediate which reacts with
styrene to produce, after oxidation, a-trifluoromethylated
ketones. Investigations into the details of the oxidation process
in this reaction are currently underway.
Notes and references
(
g) A. D. Allen, G. Angelini, C. Paradisi, A. Stevenson and
1
(a) P. Kirsch, Modern Fluoroorganic Chemistry: Synthesis,
Reactivity, Applications, Wiley-VCH, Weinheim, 2004;
b) K. Uneyama, Organofluorine Chemistry, Blackwell, Oxford,
T. T. Tidwell, Tetrahedron Lett., 1989, 30, 1315; (h) A. J. Laurent
and S. Lesniak, Tetrahedron Lett., 1992, 33, 3311; (i) N. Roques,
WO 0158833 (A1), 2001; (j) N. Kamigata, K. Udodaira and
T. Shimizu, Phosphorus, Sulfur Silicon Relat. Elem., 1997, 129, 155.
(
2006; (c) J.-P. Begue and D. Bonnet-Delpon, Bioorganic and
6
634 Chem. Commun., 2011, 47, 6632–6634
This journal is c The Royal Society of Chemistry 2011