LETTER
TAPC-Catalyzed Synthesis of Thioethers from Thiols and Alcohols
2209
ther studies to establish the mechanistic pathway for the
present reaction are currently in progress.
References and Notes
(1) Cremlyn, R. J. An Introduction to Organosulfur Chemistry;
Wiley: Chichester, 1996.
(2) (a) Madesclaire, M. Tetrahedron 1988, 44, 6537.
(b) Firouzabadi, H.; Iranpoor, N.; Jafarpour, M. J. Sulfur
Chem. 2005, 26, 313.
In conclusion, we have described a new application of
TAPC for the easy and efficient synthesis of different
thioethers by the reaction of aliphatic and aromatic thiols
with cinnamyl alcohol and electronically diverse benzyl
alcohols under solvent-free conditions. The method is not
suitable for the preparation of thioethers from aliphatic al-
cohols. We believe that the use of TAPC as a catalyst for
the present reaction is advantageous in many ways and
will open up several new possibilities for its further use in
developing many metal-free environmentally friendly and
cost-effective methodologies in organic synthesis.
(3) Nicolaou, K. C.; Koumbis, A. E.; Snyder, S. A.; Simonsen,
K. B. Angew. Chem. Int. Ed. 2000, 39, 2529.
(4) Procter, D. J.; Archer, N. J.; Needham, R. A.; Bell, D.;
Marchington, A. P.; Rayner, C. M. Tetrahedron 1999, 55,
9611.
(5) Kumar, P.; Pandey, P. K.; Hegde, V. R. Synlett 1999, 1921.
(6) Chelucci, G.; Culeddu, N.; Saba, A.; Valenti, R.
Tetrahedron: Asymmetry 1999, 10, 3537.
(7) Falck, J. R.; Lai, J.-Y.; Cho, S.-D.; Yu, J. Tetrahedron Lett.
1999, 40, 2903.
(8) Garofalo, A.; Campiani, G.; Fiorini, I.; Nacci, V.
Tetrahedron 1999, 55, 1479.
(9) Shibata, K.; Yamaga, H.; Mitsunobu, O. Heterocycles 1999,
Alcohols and thiols are commercial products (Merck chemical com-
pany) and were used without further purification. TAPC was pre-
pared according to reported procedure.28
50, 947.
Melting points were determined in a capillary tube and are not cor-
(10) Palomo, C.; Oiarbide, M.; Lopez, R.; Gomez-Bengoa, E.
Tetrahedron Lett. 2000, 41, 1283.
(11) Zaragoza, F. Tetrahedron 2001, 57, 5451.
(12) (a) Herradura, P. S.; Pendola, K. A.; Guy, R. K. Org. Lett.
2000, 2, 2019. (b) Firouzabadi, H.; Iranpoor Gholinejad, M.
Adv. Synth. Catal. 2010, 352, 119.
(13) Wendeborn, S.; De Mesmaeker, A.; Brill, W. K.-D.;
Berteina, S. Acc. Chem. Res. 2000, 33, 215.
(14) Savarin, C.; Srogl, J.; Liebeskind, L. S. Org. Lett. 2002, 4,
1
rected. H NMR spectra were recorded on a Bruker-200 spectro-
meter using TMS as internal standard.
General Procedure for the Preparation of Thioethers
To the mixture of alcohol (1 mmol) and TAPC (0.1 mmol, 0.035 g),
thiol (1 mmol) was added at 50 °C with continuous stirring for the
appropriate reaction time as indicated in Table 2. The progress of
the reaction was monitored by TLC. After the completion of the re-
action, H2O (10 mL) was added to the reaction mixture. The residue
was then extracted with EtOAc (4 × 5 mL), and the combined ex-
tracts were dried (MgSO4). The filtrate was evaporated, and the cor-
responding thioether was obtained as the only product. The identity
of the products was confirmed by comparing their physical and
spectral data with the known compounds. Spectral and physical data
for selected compounds follow.
4309.
(15) Ogawa, A.; Ikeda, T.; Kimura, K.; Hirao, T. J. Am. Chem.
Soc. 1999, 121, 5108.
(16) (a) Firouzabadi, H.; Iranpoor, N.; Abbasi, M. Adv. Synth.
Catal. 2009, 351, 755. (b) Firouzabadi, H.; Iranpoor, N.;
Jafarpour, M.; Ghaderi, A. J. Mol. Catal. A: Chem. 2006,
249, 98.
(17) Firouzabadi, H.; Iranpoor, N.; Jafarpour, M. Tetrahedron
Lett. 2006, 47, 93.
(18) (a) Patai, S. The Chemistry of the Functional Groups – The
Chemistry of the Thiol Group; Wiley: London, 1974, 669.
(b) Parham, W. E.; Wynberg, H. Org. Synth., Coll. Vol. IV
1963, 295. (c) Boscato, J. F.; Catala, J. M.; Franta, E.;
Brossas, J. Tetrahedron Lett. 1980, 21, 1519.
Benzyl(4-methoxyphenyl)sulfane (Table 2, Entry 3)
Mp 47–49 °C (lit.23 mp 48–49 °C).
1H NMR (200 MHz, CDCl3): d = 3.83 (s, 3 H), 4.12 (s, 2 H), 6.84–
6.88 (m, 2 H), 7.21–7.36 (m, 6 H).
2-[(Phenylmethyl)thio]naphthalene (Table 2, Entry 5)
Mp 89–90 °C (lit.25 mp 90–90.5 °C).
(d) Hundscheid, F. J. A.; Tandon, V. K.; Rouwette, P. H. A.
M.; van Leusen, A. M. Tetrahedron 1987, 43, 5073.
(e) Malmstrom, J.; Gupta, V.; Engman, L. J. Org. Chem.
1998, 63, 3318. (f) Blanchard, P.; Jousselme, B.; Frere, P.;
Roncali, J. J. Org. Chem. 2002, 67, 3961.
1H NMR (200 MHz, CDCl3): d = 4.31 (s, 2 H), 7.24–7.56 (m, 7 H),
7.79–8.08 (m, 5 H).
2-[(Benzylthio)-1H-benzo[d]imidazole (Table 2, Entry 6)
(19) Tundo, P.; Selva, M. Acc. Chem. Res. 2002, 35, 706.
(20) Ono, Y. Pure Appl. Chem. 1996, 68, 367.
(21) (a) Schenk, R.; Römer, G. Ber. Dtsch. Chem. Ges. B 1924,
57, 1343. (b) Allcock, H. R. J. Am. Chem. Soc. 1964, 86,
2591. (c) Graham, J. C.; Marr, D. H. Can. J. Chem. 1972, 50,
3857. (d) Hashimoto, M.; Obora, Y.; Sakaguchi, S.; Ishii, Y.
J. Org. Chem. 2008, 73, 2894. (e) Voznicova, R. K.;
Taraba, J.; Prihoda, J.; Alberti, M. Polyhedron 2008, 27,
2077. (f) Allcock, H. R.; Desorcie, J. L.; Harris, P. J. J. Am.
Chem. Soc. 1983, 105, 2814. (g) Rolland, O.; Griffe, L.;
Poupot, M.; Maraval, A.; Ouali, A.; Coppel, Y.; Fournie, J.
J.; Bacquet, G.; Turrin, C. O.; Caminade, A. M.; Majoral, J.
P.; Poupot, R. Chem. Eur. J. 2008, 14, 4836.
(22) (a) Bahrami, K.; Khodaei, M. M.; Kavianinia, I. Synthesis
2007, 547. (b) Bahrami, K.; Khodaei, M. M.; Naali, F. J.
Org. Chem. 2008, 73, 6835. (c) Bahrami, K.; Khodaei, M.
M.; Tirandaz, Y. Synthesis 2009, 369. (d) Khodaei, M. M.;
Bahrami, K.; Tirandaz, Y. J. Sulfur Chem. 2009, 30, 581.
(e) Bahrami, K.; Khodaei, M. M.; Farrokhi, A. Tetrahedron
Mp 184–185 °C (lit.22r mp 184–185 °C).
1H NMR (200 MHz, DMSO): d = 4.59 (s, 2 H), 7.10–7.16 (m, 2 H),
7.25–7.36 (m, 3 H), 7.45–7.49 (m, 4 H).
2-[(Benzylthio)methyl]furan (Table 2, Entry 7)
Oil (lit.22r oil).
1H NMR (200 MHz, CDCl3): d = 3.70 (s, 2 H), 3.80 (s, 2 H), 6.27
(d, J = 3.2 Hz, 1 H), 6.43 (d, J = 3.2 Hz, 1 H), 7.37–7.50 (m, 6 H).
Acknowledgment
We are thankful to the Razi University Research Council for partial
support of this work.
Synlett 2011, No. 15, 2206–2210 © Thieme Stuttgart · New York