First transition-metal complex catalyzed addition of organic disulfides to alkenes enables the rapid synthesis of vicinal-dithioethers

Full text of DOI:10.1021/ja983497+

482
J. Am. Chem. Soc. 1999, 121, 482-483
Table 1. Effect of the Catalyst on the Synthesis of 3a by Addition
of 1a to 2aa
First Transition-Metal Complex Catalyzed Addition
of Organic Disulfides to Alkenes Enables the Rapid
Synthesis of Wicinal-Dithioethers
Teruyuki Kondo, Shin-ya Uenoyama, Ken-ichi Fujita, and
Take-aki Mitsudo*
catalyst
conv. of 1a (%)b
yield of 3a (%)c
Department of Energy and Hydrocarbon Chemistry
Graduate School of Engineering, Kyoto UniVersity
Sakyo-ku, Kyoto 606-8501, Japan
Cp2Ti(µ-SPh)2RuClCp*
Cp*RuCl(cod)
60
95
91
90
2
4
7
0
0
0
2
60
95
88
75
trace
trace
5
0
0
0
trace
0
Cp*RuCl(cod)d
CpRuCl(PPh3)2
Ru(cod)(cot)
ReceiVed October 5, 1998
The sulfur-sulfur bond in organic disulfides may be cleaved
by nucleophilic, electrophilic, and radical processes.1 Several
transition-metal complexes have also been shown to be effective
reagents for cleavage of the sulfur-sulfur bond in organic
disulfides by oxidative addition, leading to the formation of
various new sulfur-containing transition-metal complexes.2 In
catalytic reactions, however, sulfur-containing compounds have
long been known to act as catalyst poisons because of their strong
coordinating properties.3 Therefore, transition-metal complex
catalyzed transformation of organic disulfides remains open to
study.4 Recent progress in this field includes the addition and
carbonylative addition reactions of diaryl disulfides to alkynes,5
multiple insertion of isocyanides into a sulfur-sulfur bond in
diaryl disulfides,6 and carbonylation of organic disulfides to
thioesters.7 However, the catalyst systems that have been reported
so far are strictly limited to palladium and cobalt catalysts. In
addition, there has not been a previous report of an efficient
addition reaction of organic disulfides to alkenes.8
On the other hand, the preparation of a variety of mono- and
polynuclear (thiolato)ruthenium complexes has recently been the
subject of increased interest as a result of their structural diversity,
physical properties, and potential to provide unique reaction sites.9
We have also reported the synthesis of novel thiolate-bridged Ti-
Ru complexes, Cp2Ti(µ-SR)2RuClCp*10 [Cp: cyclopentadienyl,
Cp*: pentamethylcyclopentadienyl]. Therefore, the ruthenium
complex seems to be one of the most promising catalysts for the
transformation of sulfur-containing compounds.11 During our
investigation of the reactivity of Cp2Ti(µ-SR)2RuClCp* complexes
e
Ru3(CO)12
RuCl2(PPh3)3
RuH2(PPh3)4
Pd(PPh3)4
Pd(OAc)2
RhCl(PPh3)3
Pt(PPh3)4
0
a 1a (2.5 mmol), 2a (7.5 mmol), catalyst (0.10 mmol), and toluene
o
(5.0 mL) at 100 C for 8 h under an argon atmosphere. b Determined
by GLC. c Determined by GLC based on the amount of 1a charged.
d Cp*RuCl(cod) (0.050 mmol). e Ru3(CO)12 (0.033 mmol).
as well as ruthenium catalysis,12 we found the first example of
the transition-metal complex catalyzed addition of organic di-
sulfides to alkenes. We report here the development of this new
ruthenium-catalyzed reaction which enables a simple and selective
synthesis of Vicinal-dithioethers.
Treatment of diaryl and dialkyl disulfides (1a-c) with 2-nor-
bornene (2a) in the presence of 4 mol % Cp*RuCl(cod) [cod:
1,5-cyclooctadiene] in toluene at 100 °C for 8 h under an argon
atmosphere gave the corresponding Vicinal-dithioethers (3a-c)
in high isolated yields with high stereoselectivity (exo 100%) (eq
1).13 Note that dialkyl disulfides (1b, c), which are considered
(1) Kice, J. L. In Sulfur in Organic and Inorganic Chemistry; Senning,
A., Ed.; Marcel Dekker: New York, 1971; Vol. 1, p 153.
(2) (a) Linford, L.; Raubenheimer, H. G. In AdVances in Organometallic
Chemistry; Stone, F. G. A., West, R., Eds.; Academic Press: New York, 1991;
Vol. 32, pp 1-119. (b) Murray, S. G.; Hartley, F. R. Chem. ReV. 1981, 81,
365. (c) Dubois, M. R. Chem. ReV. 1989, 89, 1.
poor substrates for the palladium-catalyzed addition of disulfides
to alkynes,5a also gave the corresponding adducts (3b, c) in high
yields.
(3) (a) Hegedus, L. L.; McCabe, R. W. In Catalyst Poisoning; Marcel
Dekker: New York, 1984. (b) Hutton, A. T. In ComprehensiVe Coordination
Chemistry; Wilkinson, G., Gillard, R. D., McCleverty, J. A., Eds.; Perga-
mon: Oxford, U.K., 1984; Vol. 5, p 1151.
The effect of the catalyst was examined in the reaction of 1a
with 2a. The results are summarized in Table 1. Among the
catalysts examined, Cp*RuCl(cod) and CpRuCl(PPh3)2, showed
high catalytic activity. Other zero and divalent ruthenium
complexes, such as Ru(cod)(cot) [cot: 1,3,5-cyclooctatriene],
Ru3(CO)12, RuCl2(PPh3)3, and RuH2(PPh3)4, were almost com-
pletely ineffective. The catalytic activity of a Ti-Ru complex,
Cp2Ti(µ-SPh)2RuClCp*, was lower than that of Cp*RuCl(cod)
itself. The present reaction is characteristic of ruthenium catalysts,
(4) In contrast, the transition-metal complex catalyzed transformation of
thiols and thioethers has been relatively well developed: (a) Okamura, H.;
Miura, M.; Takei, H. Tetrahedron Lett. 1979, 43. (b) Kuniyasu, H.; Ogawa,
A.; Sato, K.-I.; Ryu, I.; Kambe, N.; Sonoda, N. J. Am. Chem. Soc. 1992, 114,
5902. (c) Goux, C.; Lhoste, P.; Sinou, D. Tetrahedron Lett. 1992, 33, 8099.
(d) Ba¨ckvall, J.-E.; Ericsson, A. J. Org. Chem. 1994, 59, 5850. (e) Ogawa,
A.; Kawakami, J.; Mihara, M.; Ikeda, T.; Sonoda, N.; Hirao, T. J. Am. Chem.
Soc. 1997, 119, 12380 and references therein. (f) Xiao, W.-J.; Vasapollo, G.;
Alper, H. J. Org. Chem. 1998, 63, 2609 and references therein.
(5) (a) Kuniyasu, H.; Ogawa, A.; Miyazaki, S.-I.; Ryu, I.; Kambe, N.;
Sonoda, N. J. Am. Chem. Soc. 1991, 113, 9796. (b) Ogawa, A.; Sonoda, N.
J. Synth. Org. Chem. Jpn. 1996, 54, 894. (c) Ogawa, A.; Kuniyasu, H.; Sonoda,
N.; Hirao, T. J. Org. Chem. 1997, 62, 8361.
(11) Koelle, U.; Tjoe, C. R.; Wagner, T.; Englert, U. Organometallics 1995,
14, 703.
(6) Kuniyasu, H.; Sugoh, K.; Su, M. S.; Kurosawa, H. J. Am. Chem. Soc.
1997, 119, 4669.
(7) Antebi, S.; Alper, H. Tetrahedron Lett. 1985, 26, 2609.
(12) For carbonylation, see: (a) Kondo, T.; Suzuki, N.; Okada, T.; Mitsudo,
T. J. Am. Chem. Soc. 1997, 119, 6187. For C-C bond formation, see: (b)
Kondo, T.; Hiraishi, N.; Morisaki, Y.; Wada, K.; Watanabe, Y.; Mitsudo, T.
Organometallics 1998, 17, 2131 and references therein. For C-C bond
activation, see: (c) Kondo, T.; Kodoi, K.; Nishinaga, E.; Okada, T.; Morisaki,
Y.; Watanabe, Y.; Mitsudo, T. J. Am. Chem. Soc. 1998, 120, 5587.
(13) Excess alkene substrates used in the present reaction can be recovered
from the product mixture. For example, 3.3 mmol of 2-norbornene (44%)
was recovered after the addition reaction of (PhS)2 (1a) to 2-norbornene (2a).
In addition, the reaction of (PhS)2 (1a) with an equimolar amount of
2-norbornene (2a) reduced both the conversion of (1a) and the yield of adduct
(3a) to 82% and 78%, respectively.
(8) The thioselenation of alkenes under radical conditions has been
reported: (a) Toru, A.; Seko, T.; Maekawa, E. Tetrahedron Lett. 1985, 26,
3263. (b) Ogawa, A.; Tanaka, H.; Yokoyama, H.; Obayashi, R.; Yokoyama,
K.; Sonoda, N. J. Org. Chem. 1992, 57, 111.
(9) (a) Bennett, M. A.; Khan, K.; Wenger, E. In ComprehensiVe Organo-
metallic Chemistry II; Abel, E. W., Stone, F. G. A., Wilkinson, G., Eds.;
Pergamon: Oxford, U.K. 1995; Vol. 7, p 522. (b) Hidai, M.; Mizobe, Y.;
Matsuzaka, H. J. Organomet. Chem. 1994, 473, 1 and references therein.
(10) Fujita, K.; Ikeda, M.; Kondo, T.; Mitsudo, T. Chem. Lett. 1997, 57.
10.1021/ja983497+ CCC: $18.00 © 1999 American Chemical Society
Published on Web 01/05/1999

Communications to the Editor
J. Am. Chem. Soc., Vol. 121, No. 2, 1999 483
Table 2. Cp*RuCl(cod)-Catalyzed Addition of 1a to Terminal
Alkenesa
Figure 1. ORTEP diagram of [Cp*RuCl(µ-SPh)]2 (4). Selected bond
lengths [Å]: Ru1-Ru1* ) 2.860(1), Ru1-S1 ) 2.315(2), Ru1-S1* )
2.323(2), Ru1-Cl1 ) 2.470(2). Selected bond angles (deg): Ru1-S1-
Ru1* ) 76.15(5), S1-Ru1-S1* ) 103.85(5).
a 1a (2.5 mmol), 2 (25 mmol), Cp*RuCl(cod) (0.10 mmol), and
toluene (5.0 mL) at 100 °C for 8 h under an argon atmosphere.
b CH2dCH2 (15 atm) for 20 h. c For 48 h. d At 180 °C for 20 h.
and no reaction occurred with Pd(PPh3)4,4f,5 Pd(OAc)2,4b,d RhCl-
(PPh3)3,4b and Pt(PPh3)4 complexes, which are highly active
4b,e
catalysts for the transformation and carbonylation of sulfur-
containing compounds.
97% yield (exo 100%). Although complex 4 is considered to be
catalytically active, further mechanistic study involving a kinetic
study is required to determine whether the reaction proceeds on
the multimetallic ruthenium center. In any case, the high stereo-
selectivity in the reaction of 2-norbornene is due to the invariable
exo-coordination of 2-norbornene to an active ruthenium species16
because the π-electron density of the exo face of 2-norbornene is
higher than that of the endo face.17 Stereoselective cis-thioruth-
enation and reductive elimination with a retention of stereochem-
istry gives Vicinal-dithioether 3 exclusively in exo form.18
In conclusion, we have found the first practically useful
catalytic system for the formation of Vicinal-dithioethers from
organic disulfides and alkenes. This reaction will open up new
opportunities in transition-metal complex catalyzed sulfur chem-
istry, since organosulfur compounds are quite useful intermediates
in organic synthesis.19 The development of an enantioselective
version of this reaction as well as its mechanistic aspects is the
subject of current investigation.
The addition of diphenyl disulfide (1a) to ethylene (2b) and
several terminal alkenes (2c-g) also proceeded smoothly with a
Cp*RuCl(cod) catalyst, and the results are listed in Table 2. In
all cases, 1a was completely consumed, and the corresponding
adducts were obtained in high yields. No byproduct could be
detected by GLC. Some functional groups, such as trimethylsilyl
(2c), methoxycarbonyl (2d), and hydroxy groups (2e), did not
affect the reaction. On the other hand, the reaction of 1a with
simple terminal alkenes such as 1-octene (2g) required severe
reaction conditions. Under the usual reaction conditions (100 °C
for 8 h), 3i was obtained in only 15% yield. On the other hand,
3i was obtained in 62% yield by the reaction at 180 °C for 20 h.
Unfortunately, except for 2-norbornene, attempts to obtain Vicinal-
dithioethers with less strained internal alkenes, e.g., cyclohexene,
cis-4-octene, and dimethyl maleate, were not successful.
The stoichiometric reaction of 1a with Cp*RuCl(cod) gave a
novel thiolate-bridged diruthenium complex, [Cp*RuCl(µ-SPh)]2
(4), in 70% yield (eq 2, and Figure 1).14,15 To clarify the
Acknowledgment. This work was supported in part by a Grant-in-
Aid for Scientific Research from the Ministry of Education, Science,
Sports and Culture, Japan.
Supporting Information Available: Complete experimental proce-
dures, lists of spectral data and elemental analyses for all of the new
compounds, and crystallographic data for 4 (30 pages, print/PDF). An
X-ray crystallographic file, in CIF format, is available through the Web
only. See any current masthead page for ordering information and Web
access instructions.
intermediacy of complex 4 in the present reaction, complex 4
was reacted with an excess of 2a at 100 °C for 6 h, which gave
3a in an isolated yield of 12% (exo 100%) together with the
deposition of ruthenium metal (eq 3). Complex 4 also showed
high catalytic activity for the addition of 1a to 2a to give 3a in
JA983497+
(14) Crystallographic data for 4: C32H40Cl2S2Ru2, fw)761.83, monoclinic,
space group P21/n [No. 14], dark green prism, a ) 11.873(4) Å, b ) 9.556(4)
Å, c ) 14.089(3) Å, â ) 92.13(2)o, V ) 1597.3(8) Å3, Z ) 2, Dcalc ) 1.584
g/cm3, µ(Mo KR) ) 12.64 cm-1, Rigaku AFC7R diffractometer, 3667
reflections (unique), R ) 0.043, wR ) 0.046, GOF ) 1.04.
(15) A similar oxidative addition of diferrocenyl dichalcogenides to
[Cp*Ru(µ3-Cl)]4 has already been reported: Matsuzaka, H.; Qu, J.-P.; Ogino,
T.; Nishio, M.; Nishibayashi, Y.; Ishii, Y.; Uemura, S.; Hidai, M. J. Chem.
Soc., Dalton 1996, 4307.
(16) Mitsudo, T.; Naruse, H.; Kondo, T.; Ozaki, Y.; Watanabe, Y. Angew.
Chem., Int. Ed. Engl. 1994, 33, 580.
(17) Inagaki, S.; Fujimoto, H.; Fukui, K. J. Am. Chem. Soc. 1976, 98, 4054.
(18) The thioselenation of 2-norbornene under radical conditions gave a
mixture of exo- and endo-adducts (ref 8). Therefore, the radical mechanism
can be completely ruled out.
(19) Metzner, P.; Thuillier, A. In Sulfur Reagents in Organic Synthesis;
Academic Press: London, U.K., 1994; p. 75.