CD2Cl2): 221.6 (s, CS2), 46.2 (t, CH2), 12.1 (q, CH3); IR (cm21, KBr): n
1518 [s, (CN)], 957 (MoIVO); DCI-MS (isobutane), m/z (isotopic
abundance): 410 (59). trans-9-Thiabicyclo[6.1.0]nonane (trans-5a)11: yield
69%; mp 58–59 °C, colorless needles; 1H NMR (200 MHz, CDCl3):
0.95–1.20 (m, 4 H), 1.60 (m, 2 H), 1.85–2.10 (m, 4 H), 2.45 (m, 2 H), 2.68
(m, 2 H, CHS); 13C NMR (50 MHz, CDCl3): 26.3 (t), 29.3 (t), 29.5 (t), 41.2
(d). trans-10-Thiabicyclo[7.1.0]decane (trans-5b): yield 87%; mp 62.5–63
°C, colorless needles; 1H NMR (200 MHz, CDCl3): 0.77–1.06 (m, 2 H),
1.23–1.60 (m, 6 H), 1.62–1.82 (m, 2 H), 1.87–2.07 (m, 2 H), 2.35–2.50 (m,
2 H), 2.64–2.77 (m, 2 H); 13C NMR (50 MHz, CDCl3): 22.6 (t), 25.9 (t),
30.2 (t), 35.9 (t), 44.4 (d); IR (cm21, KBr): n 2933 (s), 2849 (s), 1459(s),
1444 (s), 637 (s). Anal. calcd. for C9H16S: C 69.17; H 10.32; S 20.51.
Found: C 69.09; H 10.38; S 20.26%. cis-9-Thiabicyclo[6.1.0]nonane (cis-
5a)12: yield 20%; colorless oil; 1H NMR (200 MHz, CDCl3): 1.20–1.80 (m,
10 H), 2.34 (m, 2 H), 2.93 (m, 2 H); 13C NMR (200 MHz, CDCl3): 26.3 (t),
29.3 (t), 29.5 (t), 41.2 (d). exo-3-Thiatricyclo[3.2.1.02,4]octane (5c)12: yield
50%; mp 31–32 °C, colorless waxy solid; 1H NMR (200 MHz, CDCl3): 0.65
(d, J = 10.0 Hz, 1 H), 1.24 (m, 2 H), 1.45–1.70 (m, 3 H), 2.45 (s, 2 H), 2.74
(s, 2 H); 13C NMR (50 MHz, CDCl3): 27.5 (3 3 t), 37.5 (2 3 d), 37.6 (2 3
d). exo-1a,2a,3,5a,6,6a-Hexahydro-2,6-methano-2H-indeno[5,6-b]thiirene
(5d): yield 28%; colorless oil; 1H NMR (200 MHz, CDCl3): 0.81–0.92 (m,
1H), 1.62–1.75 (m, 1 H), 2.19–2.81 (m, 5 H), 2.87–2.93 (d, J = 4.16 Hz, 2
H), 3.22–3.33 (m, 1 H), 5.56–5.72 (m, 2H); 13C NMR (200 MHz, CDCl3):
30.9 (d), 31.0 (t), 34.5 (d), 37.5 (d), 39.6 (d), 41.2 (d), 42.5 (d), 54.3 (d),
130.1 (d), 132.2 (d); EI-HRMS, m/z: calcd. for C10H12S: 164.0662. Found:
1
164.0662. 6-Thiabicyclo[3.1.0]hexane (5e)12: yield 16%; colorless oil; H
Scheme 4 Catalytic cycle for the generation of the disulfur complex 3 and
the sulfuration of (E)-cyclooctene [(E)-4a) and (E)-cyclononene [(E)-4b].
NMR (200 MHz, CDCl3): 1.42–2.15 (m, 6 H), 3.30 (m, 2 H); 13C NMR (200
MHz, CDCl3): 18.0 (t), 28.9 (t), 41.7 (d).
1 D. V. Deubel, J. Sundermeyer and G. Frenking, Org. Lett., 2001, 3, 329;
S. Ozaki, T. Takahashi and I. Sudo, Japan Patent Kokai 133309, 1974;
[Chem. Abstr., 1975, 82, 156973y]
2 M. M. T. Khan and M. R. H. Siddiqui, Inorg. Chem., 1991, 30, 1157. All
our efforts to repeat this work failed under the reported catalytic
conditions with the poorly reactive cyclohexene and even the highly
reactive (E)-cyclooctene as sulfur acceptors. Our failure to realize this
claim, motivated us to develop an authentic metal-catalyzed episulfida-
tion method with elemental sulfur.
3 J. D. Kendall and N. S. Simpkins, Synlett, 1998, 391; A. J. Blake, P. A.
Cooke, J. D. Kendall, N. S. Simpkins and S. M. Westaway, J. Chem.
Soc., Perkin Trans. 1, 2000, 153.
4 K. R. Prabhu, P. S. Sivanand and S. Chandrasekaran, Angew. Chem., Int.
Ed., 2000, 39, 4316.
disulfur complex 3 by PPh3, the intermediary sulfido complex A
was suggested.10
In view of the difficulties with the previous report,2 presently
the first catalytic episulfidation of (E)-cycloalkenes with
elemental sulfur has been developed, in which the molybdenum
oxo complex 2 functions as catalyst and the disulfur complex 3
as sulfur-transfer agent. These encouraging results should
stimulate an intense search for more reactive molybdenum
disulfur complexes to effect in a general manner the direct
episulfidation of olefins with elemental sulfur.
We thank the Deutsche Forschungsgemeinschaft and the
Fonds der Chemischen Industrie for generous financial sup-
port.
5 K. Leonard, K. Plute, R. C. Haltiwanger and M. Rakowski Dubois,
Inorg. Chem., 1979, 18, 3246.
6 S. Xiaoqing, Y. Huixing and H. Degang, Int. J. Chem. Kinet., 1989, 21,
737.
Notes and references
§ General episulfidation procedure: in an NMR tube were placed under
argon gas 64.2 mg (2.00 mmol) of elemental sulfur and 28.6 mg (70.0 mmol)
of molybdenum oxo complex 2 in 0.7 ml of oxygen-free acetone, and 130
ml (1.00 mmol) of (E)-cyclooctene [(E)-4] were added. The tube was sealed
with a rubber septum and Parafilm®, then heated for 15 h in an oil bath to
56 °C. After cooling to room temperature, the tube was opened, the
suspension transferred to a flask and the solvent evaporated (40 °C/500
mbar). The residue was subjected to silica-gel flash chromatography and
98.0 mg (69%) of trans-9-thiabicyclo[6.1.0]nonane (trans-5a) was
isolated, Rf (silica gel, petroleum ether) = 0.33. Bis(diethylcarbamodi-
thioato-S,SA)oxomolybdenum 2:7 1H NMR (200 MHz, CD2Cl2): 1.36 (t, 3J
= 7.18 Hz, 12 H, 4 3 CH3), 3.92 (m, 8 H, 4 3 CH2); 13C NMR (50 MHz,
7 C. G. Young, J. Chem. Educ., 1995, 72, 751.
8 J. W. McDonald and W. E. Newton, Inorg. Chim. Acta, 1980, 44,
L81.
9 C. G. Young, L. J. Laughlin, S. Colmanet and S. D. B. Scrofani, Inorg.
Chem., 1996, 35, 5368; P. D. Smith, D. A. Slizys, G. N. George and C.
G. Young, J. Am. Chem. Soc., 2000, 122, 2946.
10 S. Xiaoqing, Y. Huixing and H. Degang, Int. J. Chem. Kinet., 1989, 21,
749.
11 W. Adam, B. Fröhling, K. Peters and S. Weinkötz, J. Am. Chem. Soc.,
1998, 120, 8914.
12 M. U. Bombala and S. V. Ley, J. Chem. Soc., Perkin Trans. 1, 1979,
3013.
Chem. Commun., 2001, 1910–1911
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