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LETTER
M.; Hartwig, J. F. Angew. Chem. Int. Ed. 2009, 48, 7841.
(d) Stanley, L. M.; Hartwig, J. F. J. Am. Chem. Soc. 2009,
131, 8971. (e) Uria, U.; Vicario, J. L.; Badía, D.; Carrillo, L.
Chem. Commun. 2007, 2509. (f) Lin, Q.; Meloni, D.; Pan,
Y.; Xia, M.; Rodgers, J.; Shepard, S.; Li, M.; Galya, L.;
Metcalf, B.; Yue, T.-Y.; Liu, P. L.; Zhou, J. Org. Lett. 2009,
9, 1999. (g) Gogoi, S.; Zhao, C.-G.; Ding, D. Org. Lett.
2009, 11, 2249.
(10) For previous examples using this series of primary amine
thiourea catalyst, see (a) Li, P.; Wang, Y.; Liang, X.; Ye, J.
Chem. Commun. 2008, 28, 3302. (b) Li, P.; Wen, S.; Yu, F.;
Liu, Q.; Li, W.; Wang, Y.; Liang, X.; Ye, J. Org. Lett. 2009,
11, 753.
(11) General Procedure for the Asymmetric Michael
Addition of 1,2,4-Triazole to Cyclic Enones Catalyzed by
1
(8) For reviews, see: (a) Dalko, P. I.; Moisan, L. Angew. Chem.
Int. Ed. 2001, 40, 3726. (b) Schreiner, P. R. Chem. Soc. Rev.
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Catal. 2004, 346, 1035. (d) Dalko, P. I.; Moisan, L. Angew.
Chem. Int. Ed. 2004, 43, 5138. (e) Seayad, J.; List, B. Org.
Biomol. Chem. 2005, 3, 719. (f) Guillena, G.; Ramón, D. J.
Tetrahedron: Asymmetry 2006, 17, 1465. (g) Marcelli, T.;
Maarseveen, J. H.; Hiemstra, H. Angew. Chem. Int. Ed.
2006, 45, 7496. (h) Gaunt, M. J.; Johansson, C. C. C.;
McNally, A.; Vo, N. T. Drug Discovery Today 2007, 12, 8.
(i) Enders, D.; Grondal, C.; Hüttl, M. R. M. Angew. Chem.
Int. Ed. 2007, 46, 1570. (j) Pellissier, H. Tetrahedron 2007,
63, 9267. (k) Yu, X.; Wang, W. Chem. Asian J. 2008, 3,
516. (l) Ouellet, S. G.; Walji, A. M.; Macmillan, D. W. C.
Acc. Chem. Res. 2007, 40, 1327. (m) Yu, X.; Wang, W.
Chem. Asian J. 2008, 3, 516. (n) Peng, F.; Shao, Z. J. Mol.
Catal. A: Chem. 2008, 285, 1. (o) Dondoni, A.; Massi, A.
Angew. Chem. Int. Ed. 2008, 47, 4638. (p) Melchiorre, P.;
Marigo, M.; Carlone, A.; Bartoli, G. Angew. Chem. Int. Ed.
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To a solution of cyclic enones (0.3 mmol) in toluene (2.0
mL) was added catalyst (19.2 mg, 0.04 mmol), 2-methoxy-
benzoic acid (4.5 mg, 0.03 mmol), and 1,2,4-triazole (13.8
mg, 0.2 mmol). The reaction mixture was stirred at 15 °C for
the time indicated in Table 2, and then the solvent was
removed under vacuum. The residue was purified by silica
gel chromatography to yield the desired addition product.
(12) General Procedure for the Asymmetric Michael
Addition of 1,2,4-Triazole to Open-Chain Enones
Catalyzed by 1
To a solution of benzalacetone derivates (0.3 mmol) in
CH2Cl2 (0.5 mL) was added catalyst (19.2 mg, 0.04 mmol),
4-nitrobenzoic acid (5.0 mg, 0.03 mmol), and 1,2,4-triazole
(13.8 mg, 0.2 mmol). The reaction mixture was stirred at 15
°C for the time indicated in Table 2, and then the solvent was
removed under vacuum. The residue was purified by silica
gel chromatography to yield the desired addition product.
(13) Crystal Structure Determination of Compound 9k
C12H12BrN3O, M = 294.16; a block crystal (0.410 × 0.337 ×
0.251 mm), T = 293 (2), l(MoKa) = 0.71073 Å,
orthorhombic, space group: P212121, a = 7.9498 (12) Å,
b = 12.4724 (17) Å, c = 25.479 (4) Å, V = 2526.3 (6) Å3,
15229 total reflections, 5718 unique, Rint = 0.0851,
R1 = 0.0437 (I > 2s), wR2 = 0.0827, Flack parameter: 0.023
(11). Please see CCDC 782894.
(9) For reviews, see: (a) Connon, S. J. Chem. Commun. 2008,
2499. (b) Miyabe, H.; Takemoto, Y. Bull. Chem. Soc. Jpn.
2008, 81, 785. (c) Lattanzi, A. Chem. Commun. 2009, 1452.
(d) Liu, X.; Lin, L.; Feng, X. Chem. Commun. 2009, 6145.
(e) Zhang, Z.; Schreiner, P. R. Chem. Soc. Rev. 2009, 38,
1187.
(14) Crystal Structure Determination of Compound 10
C12H19N3S2, M = 269.42; a block crystal (0.425 × 0.396 ×
0.350 mm), T = 293 (2), l(MoKa) = 0.71073 Å, monoclinic,
space group: P21, a = 6.8332 (12) Å, b = 10.5576 (18) Å,
c = 10.0377 (17) Å, V = 689.2 (2) Å3, 3825 total reflections,
2766 unique, Rint = 0.0380, R1 = 0.0497 (I > 2s),
wR2 = 0.1301, Flack parameter: 0.06 (10). Please see CCDC
782895.
Synlett 2010, No. 15, 2357–2360 © Thieme Stuttgart · New York