508
M. Kaname et al. / Tetrahedron Letters 52 (2011) 505–508
Tetrahedron 2008, 64, 7741–7744; (f) Garin, J.; Melendez, E.; Merchan, F. L.;
Merino, P.; Orduna, J.; Tejero, T. Synth. Commun. 1990, 20, 2327–2334.
6. (a) Vera, M. D.; Pelletier, J. C. J. Comb. Chem. 2007, 9, 569–570; (b) Spatz, J. H.;
Bach, T.; Umkehrer, M.; Bardin, J.; Ross, G.; Burdack, C.; Kolb, J. Tetrahedron Lett.
2007, 48, 9030–9034; (c) Evindar, G.; Batey, R. A. J. Org. Chem. 2006, 71, 1802–
1808; (d) Joyce, L. L.; Evindar, G.; Batey, R. A. Chem. Commun. 2004, 446–447;
(e) Feng, E.; Huang, H.; Zhou, Y.; Ye, D.; Jiang, H.; Liu, H. J. Comb. Chem. 2010, 12,
422–429; (f) Bendí, C.; Bravo, F.; Uriz, P.; Fernández, E.; Claver, C.; Castillón, S.
Tetrahedron Lett. 2003, 44, 6073–6077.
7. (a) Ding, Q.; He, X.; Wu, J. J. Comb. Chem. 2009, 11, 587–591; (b) Guo, Y.-J.; Tang,
R.-Y.; Zhong, P.; Li, J.-H. Tetrahedron Lett. 2010, 51, 649–652.
8. (a) Xie, Y.; Zhang, F.; Li, J.; Shi, X. Synlett 2010, 901–904; (b) Xie, Y.; Zhang, F.;
Chen, X.; Li, J. Heterocycles 2010, 81, 2087–2096.
9. (a) Bogert, M. T.; Stull, A. J. Am. Chem. Soc. 1927, 49, 2011–2016; (b) Hasan, C.;
Hunter, R. F. J. Chem. Soc. 1935, 1762–1766; (c) Fujiwara, S.; Asanuma, Y.; Shin-
ike, T.; Kambe, N. J. Org. Chem. 2007, 72, 8087–8090.
Figure 1. ORTEP drawing of 3Aa with thermal ellipsoid plot (50% probability).
Selected bond lengths (Å) and angles (°); Se1–C1 1.918(2), Se1–C7 1.887(2), C1–N1
1.301(3), N1–C2 1.398(3), C2–C7 1.406(3), C1–Se1–C7 84.05(9), N1–C1–Se1
116.0(2), C1–N1–C2 112.4(2), N1–C2–C7 117.7(2), C2–C7–Se1 109.8(2).
10. (a) Atanassov, P. K.; Linden, A.; Heimgartner, H. Heterocycles 2003, 61, 569–
579; (b) Atanassov, P. K.; Linden, A.; Heimgartner, H. Helv. Chim. Acta 2003, 86,
3235–3243.
11. (a) Garud, D. R.; Koketsu, M.; Ishihara, H. Molecules 2007, 12, 504–535; (b)
Heimgartner, H.; Zhou, Y.; Atanassov, P. K.; Sommen, G. L. Phosphorus Sulfur
Silicon Relat. Elem. 2008, 183, 840–855; (c) Ninomiya, M.; Garud, D. R.; Koketsu,
M. Heterocycles 2010, 81, 2027–2055.
12. Sashida, H.; Pan, C.; Kaname, M.; Minoura, M. Synthesis 2010, 3091–3096.
13. Reviews: (a) Sashida, H. Rev. Heteroatom Chem. 2000, 22, 59–78; (b) Sashida, H.
J. Syn. Org. Chem. Jpn. 2001, 59, 355–362; (c) Sashida, H. Mini-Rev. Org. Chem.
2007, 4, 105–114; (d) Sashida, H.; Minoura, M. J. Syn. Org. Chem. Jpn. 2009, 67,
714–723.
14. Recent works: (a) Sashida, H.; Nakayama, A.; Kaname, M. Synthesis 2008,
3229–3236; (b) Sashida, H.; Nakabayashi, S.; Kaname, M.; Minoura, M.
Heterocycles 2010, 80, 1339–1352; (c) Sashida, H.; Satoh, H.; Ohyanagi,
K.; Kaname, M. Molecules 2010, 15, 1466–1472; Sashida, H.; Kaname, M.;
Sashida, H.; Kaname, M.; Nakayama, A.; Suzuki, H.; Minoura, M.
Tetrahedron 2010, 66, 5149–5157.
reas, which were not converted into the desired selenazoles under
the optimized conditions. Therefore, not only products but also
starting anilines were not obtained by the reaction of 2-bromoan-
iline and 2-chloroaniline with isoselenocyanate .
The structures of these 2-aminobenzoselenazoles
3 were
determined by their MS, 1H, and 13C NMR spectra and elemental
analyses, and finally established by single-crystal X-ray studies
using cyclohexyl derivative 3Aa (Fig. 1).16
In summary, the one-pot copper-catalyzed ligand-free tandem
addition–cyclization of the 2-iodoanilines with the isoselenocya-
nates for the practical synthesis of the 2-aminobenzoselenazoles
via the C–Se bond formation of the 2-iodophenyl selenoureas
smoothly occurred; the intermediates, selenoureas, could be iso-
lated. A variety of 2-aminobenzoselenazoles were easily obtained
in moderate to high yields.
15.
A
typical experimental procedure for tandem addition–cyclization of 2-
iodoaniline 1a with isoselenocyanate 2A is as follow: mixture of 2-
A
iodoaniline 1a (219 mg, 1 mmol), cyclohexyl isoselenocyanate (208 mg,
1.1 mmol), Cu(OTf)2 (0.1 mmol), and CsCO3 (1.25 mmol) in dry xylene
(2.5 mL) was heated at 130 °C for 30–48 h under argon atmosphere. The
mixture was diluted with benzene (30 mL), and the organic layer was washed
with water (20 mL ꢀ 2), dried over anhydrous Na2SO4, and evaporated in
vacuo. The obtained residue was purified by silica gel chromatography using
Acknowledgments
CHCl3–MeOH
(100:3)
as
eluent
to
give
pure
2-
cyclohexylaminobenzoselenazole 3Aa. Yield: 272 mg (97%). Colorless
needles, mp 141–142 °C (CHCl3–hexane). IR (KBr-tab): 3178 (NH), 1591
This work was supported in part by a Grant-in Aid for Scientific
Research from the Ministry of Education, Science and Culture, Ja-
pan (19590022). Thanks are due to Mr. Koki Fujii (Hokuriku Uni-
versity) for his technical assistance.
(C@N) cmꢁ1 1H NMR (CDCl3) d: 1.14–1.44, 1.57–1.66, 1.71–1.78, 2.07–2.14,
.
3.37–3.45 (5H, m, 1H, 2H, m, 2H, m, 1H, m, cyclohexyl-H), 6.11 (1H, br s, NH),
6.98, 7.26, 7.51, 7.60 (1H, dd, J = 7.8, 7.3 Hz, 1H, dd, J = 8.1, 7.3 Hz, 1H, d,
J = 8.1 Hz, 1H, d, J = 7.8 Hz, Ph-H). 13C NMR (CDCl3) d: 24.8 (t), 25.4 (t), 33.3 (t),
56.0 (d), 119.8 (d), 121.4 (d), 124.1 (d), 126.1 (d), 132.8 (s), 154.1 (s), 167.2 (s).
EI-MS: m/z (%) = 280 (M+, 52), 223 (8), 198 (100), 171 (13). EI-HRMS: m/z calcd
for C13H16N280Se [M+]: 280.0479; found: 280.0481.
References and notes
16. Single crystals of 3Aa were obtained from solutions of methanol/
1. This paper constitutes Part 33 in the series ‘Studies on Tellurium-Containing
Heterocycles’, For Part 32: Sashida, H.; Nakabayashi, S.; Suzuki, H.; Kaname, M.;
Minoura, M. Tetrahedron Lett. 2010, 51, 5395–5398.
2. (a) Horton, D. A.; Bourne, G. T.; Smythe, M. L. Chem. Rev. 2003, 103, 893–930;
(b) Deng, X.; Manji, N. S. Eur. J. Org. Chem. 2010, 680–686.
3. (a) Easmon, J.; Puerstinger, G.; Thies, K.-S.; Heinisch, G.; Hofmann, J. J. Med.
Chem. 2006, 49, 6343–6350; (b) Kumar, D.; Jacob, M. R.; Reynolds, M. B.;
Kerwin, S. M. Bioorg. Med. Chem. 2002, 10, 3997–4004; (c) Kantam, M. L.;
Venkanna, G. T.; Kumar, K. B. S.; Balasubrahmanyam, V.; Bhargava, S. Synlett
2009, 1753–1756. and references cited therein; (d) Naidu, A. B.; Sekar, G.
Synthesis 2010, 579–586.
4. (a) Hyvl, J.; Srogl, J. Eur. J. Org. Chem. 2010, 15, 2849–2851; (b) Mike, J. F.;
Inteman, J. J.; Ellern, A.; Jeffries-EL, M. J. Org. Chem. 2010, 75, 495–497; (c) Zhu,
C.; Akiyama, T. Synlett 2010, 2457–2460.
dichloromethane after slow evaporation of the solvent at room temperature.
Diffraction data were collected on
equipped with graphite monochromated MoK
(k = 0.71073 Å). The structures were solved by direct methods (SHELXS-97),17
a
Bruker Apex-II CCD diffractometer
a
a
radiation source
and refined by full-matrix least-square methods on F2 for all reflections (SHELXL
-
97)18 with all non-hydrogen atoms anisotropic and all hydrogen atoms
isotropic. For 3Aa, the structure analysis is based on 2926 observed
reflections with I > 2.00
196 K, trigonal, space group R3, a = 23.670(4) Å, b = 23.670(4) Å,
c = 11.9466(18) Å, Z = 18, R = 0.0268, Rw = 0.0681,
V = 5796.5(2) Å3,
r(I) and 150 variable parameters; purple needles,
ꢀ
GOF = 1.118. CCDC 793875 for 3Aa contains the supplementary
crystallographic data for this Letter. These data can be obtained free of
charge from the Cambridge Crystallographic Data Centre via
5. (a) Jaseer, E. A.; Prasad, D. J. C.; Dandapat, A.; Sekar, G. Tetrahedron Lett. 2010,
51, 5009–5012; (b) Bose, D. S.; Idrees, M. Tetrahedron Lett. 2007, 48, 669–672;
(c) Bose, D. S.; Idrees, M. J. Org. Chem. 2006, 71, 8261–8263; (d) Huang, X.; Tang,
J. Tetrahedron 2003, 59, 4851–4856; (e) Downer-Riley, N. K.; Jackson, Y. A.
17. Sheldrick, G. M. SHELXS-97, Program for Crystal Structure Solution; Universität
Göttingen, 1997.
18. Sheldrick, G. M. SHELXL-97, Program for Crystal Structure Refinement; Universität
Göttingen, 1997.