7
082
M. Abrantes et al. / Tetrahedron Letters 52 (2011) 7079–7082
6
.
Kühn, F. E.; Groarke, M.; Bencze, É.; Herdtweck, E.; Prazeres, A.; Santos, A. M.; A. Synthesis 2007, 485–504; (b) Thiel, W. R. Coord. Chem. Rev. 2003, 245, 95–
Calhorda, M. J.; Romão, C. C.; Gonçalves, I. S.; Lopes, A. D.; Pillinger, M. Chem.
Eur. J. 2002, 8, 2370–2383.
(a) Hagrman, P. J.; Hagrman, D.; Zubieta, J. Angew. Chem., Int. Ed. 1999, 38,
106.
12. (a) Tollari, S.; Bruni, S.; Bianchi, C. L.; Rainoni, M.; Porta, F. J. Mol. Catal. 1993, 83,
311–322; (b) Ballistreri, F. P.; Barbuzzi, E. G. M.; Tomaselli, G. A.; Toscano, R. M.
J. Org. Chem. 1996, 61, 6381–6387; (c) Ballistreri, F. P.; Barbuzzi, E. G. M.;
Tomaselli, G. A.; Toscano, R. M. J. Mol. Catal. A: Chem. 1996, 114, 229–236.
13. General procedures for the oxidation of amines.
7
.
2
639–2684. and references therein; (b) Zapf, P. J.; LaDuca, R. L., Jr.; Rarig, R. S.,
Jr.; Johnson, K. M.; Zubieta, J. Inorg. Chem. 1998, 37, 3411–3414; (c) Xu, Y.; Lu, J.;
Goh, N. K. J. Mater. Chem. 1999, 9, 1599–1602; (d) Hagrman, P. J.; LaDuca, R. L.,
Jr.; Koo, H.-J.; Rarig, R., Jr.; Haushalter, R. C.; Whangbo, M.-H.; Zubieta, J. Inorg.
Chem. 2000, 39, 4311–4317; (e) Zhou, Y.; Zhang, L.; Fun, H.-K.; You, X. Inorg.
Chem. Commun. 2000, 3, 114–116; (f) Cui, C.-P.; Dai, J.-C.; Du, W.-X.; Fu, Z.-Y.;
Hu, S.-M.; Wu, L.-M.; Wu, X.-T. Polyhedron 2002, 21, 175–179; (g) Lu, Y.; Wang,
E.; Yuan, M.; Li, Y.; Hu, C. J. Mol. Struct. 2003, 649, 191–195; (h) Zhao, B.; Chen,
X.-Y.; Cheng, P.; Ding, B.; Liao, D.-Z.; Yan, S.-P.; Jiang, Z.-H. J. Coord. Chem. 2005,
Procedure A. To a stirred solution of amine (0.3–0.8 mmol) in dichloromethane
(0.5 M) were added, at 0 °C, TBHP (3-4 mol equiv, in one or two portions) and
catalyst 1 (2 mol %). The mixture was stirred at 40 °C for the necessary time
(see Table 2), then the mixture was filtered through Celite and the solvent was
removed under reduced pressure. The crude residue was purified by flash
column chromatography.
5
8, 467–472; (i) Zhou, D.-P.; Bi, D.-Q. Z. Kristallogr. NCS 2006, 221, 503–504; (j)
Procedure B. To a stirred solution of amine (0.3–0.8 mmol) in methanol (0.5 M)
was added at 0 °C UHP (3 mol equiv) and catalyst 1 (2 mol %). The mixture was
stirred at room temperature for the necessary time (see Table 2). The reaction
mixture developed a red-orange colour that disappeared at different times
depending on the amine type. The reaction mixture, then, remained yellow and
in some cases a white precipitate formed. After removal of the solvent under
reduced pressure, dichloromethane was added and the slurry formed was
filtered through Celite. The solvent was evaporated and the crude residue
purified by flash column chromatography.
Kim, J.; Lim, W. T.; Koo, B. K. Inorg. Chim. Acta 2007, 360, 2187–2191; (k)
Chuang, J.; Ouellette, W.; Zubieta, J. Inorg. Chim. Acta 2008, 361, 2357–2364; (l)
Lysenko, A. B.; Senchyk, G. A.; Lincke, J.; Lässig, D.; Fokin, A. A.; Butova, E. D.;
Schreiner, P. R.; Krautscheid, H.; Domasevitch, K. V. Dalton Trans. 2010, 39,
4
223–4231.
8
.
(a) Merino, P.; Tejero, T. Synlett 2011, 1965–1977; (b) Brandi, A.; Cardona, F.;
Cicchi, S.; Cordero, F. M.; Goti, A. Chem. Eur. J. 2009, 15, 7808–7821; (c)
Grigor’ev, I. A. In Nitrile Oxides, Nitrones Nitronates in Organic Synthesis; Feuer,
H., Ed., second ed.; John Wiley & Sons: New Jersey, 2008. pp. 144-161; (d) Rück-
Braun, K.; Freysoldt, H. E.; Wierschem, F. Chem. Soc. Rev. 2005, 34, 507–516; (e)
Martin, J. N.; Jones, R. C. F. In Synthetic Applications of 1,3-Dipolar Cycloaddition
Chemistry toward Heterocycles and Natural Products; Padwa, A., Pearson, W. H.,
Eds.; Wiley: Chichester, United Kingdom, 2002; Vol. 59, pp 1–8; (f) Gothelf, K.
V.; Jørgensen, K. A. Chem. Commun. 2000, 1449–1458; (g) Merino, P.; Franco, S.;
Merchan, F.; Tejero, T. Synlett 2000, 442–454; (h) Frederickson, M. Tetrahedron
All the nitrones synthesized were known compounds and gave analytical and
spectral data identical with the reported ones (see Ref.1
4a,16–18
). Spectroscopic
data of nitrone 12, that proved to be unstable even if stored at low
temperature, are reported here since no literature data are available.
2,6-Dimethyl-3,4,5,6-tetrahydropyridine-N-oxide (12):
R
f
0.36 (CH
6-H), 2.45-2.36 (m, 2H, 3-H), 2.06 (br s, 3H, C
1.83–1.60 (m, 3H, 5-H + 4-H), 1.47 (d, J = 6.8, 3H, C
50 MHz) d = 145.3 (s, C-2), 62.3 (d, C-6), 31.0 (t, C-3), 30.0 (t, C-5), 19.3 (q, C-2-
CH ), 19.0 (q, C-6-CH ), 15.6 (t, C-4); IR (CD Cl) = 2953, 2874, 2833, 1612,
2
Cl
2
/MeOH = 10:1); 1H NMR (CDCl
3
, 400 MHz) d = 3.92-3.80 (m, 1H,
2
–CH3), 2.05–1.97 (m, 1H, 5-H),
13
1
997, 53, 403–425.
6 3 3
–CH ); C NMR (CDCl ,
9
.
(a) Janzen, E. G. Acc. Chem. Res. 1971, 4, 31–40; (b) Janzen, E. G.; Wang, Y. Y.;
Shetty, R. V. J. Am. Chem. Soc. 1978, 100, 2923–2925; (c) Pou, S.; Halpern, H. J.;
Tsai, P.; Rosen, G. M. Acc. Chem. Res. 1999, 32, 155–161; (d) Tuccio, B.;
Lauricella, R.; Fréjaville, C.; Bouteiller, J.-C.; Tordo, P. J. Chem. Soc., Perkin Trans.
3
3
3
m
ꢁ
1
1457, 1449, 1426, 1374, 1176, 1089 cm ; MS (EI) m/z % = 127 (46), 112 (47),
73 (24), 55 (99), 41 (100).
2
1995, 295–298; (e) Allouch, A.; Roubaud, V.; Lauricella, R.; Bouteiller, J.-C.;
14. (a) Yamazaki, S. Bull. Chem. Soc. Jpn. 1997, 70, 877–884; (b) Ohtake, H.; Imada,
Y.; Murahashi, S.-I. Bull. Chem. Soc. Jpn. 1999, 72, 2737–2754; (c) Colonna, S.;
Pironti, V.; Carrea, G.; Pasta, P.; Zambianchi, F. Tetrahedron 2004, 60, 569–576.
15. (a) Hassan, A.; Wazeer, M. I. M.; Saeed, M. T.; Siddiqui, M. N.; Ali, Sk. A. J. Phys.
Org. Chem. 2000, 13, 443–451; (b) Hassan, A.; Wazeer, M. I. M.; Ali, Sk. A. J.
Chem. Soc. Perkin Trans. 2 1998, 393–399.
16. Murahashi, S. I.; Mitsui, H.; Shiota, T.; Tsuda, T.; Watanabe, S. J. Org. Chem.
1990, 55, 1736–1744.
17. Cicchi, S.; Hold, I.; Brandi, A. J. Org. Chem. 1993, 58, 5274–5275.
18. Goti, A.; Cardona, F.; Brandi, A.; Picasso, S.; Vogel, P. Tetrahedron: Asymmetry
1996, 7, 1659–1674.
Tuccio, B. Org. Biomol. Chem 2005, 3, 2458–2462.
0. (a) Murahashi, S.-I. Angew. Chem. Int. Ed. Engl. 1995, 34, 2443–2465; (b)
Marcantoni, E.; Petrini, M.; Polimanti, O. Tetrahedron Lett. 1995, 36, 3561–
1
3
562; (c) Murray, R. W.; Iyanar, K. J. Org. Chem. 1996, 61, 8099–8102; (d) Goti,
A.; Nannelli, L. Tetrahedron Lett. 1996, 37, 6025–6028; (e) Di Furia, F.; Licini, G.;
Modena, G.; Motterle, R.; Nugent, W. A. J. Org. Chem. 1996, 61, 5175–5177.
1. For reviews see: Merino, P. In Science of Synthesis Knowldedge Updates;
Schaumann, E., Ed.; George Thieme: Stuttgart, 2011; pp 325–403. Vol. 4;
Merino, P. In Science of Synthesis; Bellus, D., Padwa, A., Eds.; George Thieme:
Stuttgart, 2004; pp 511–580. Vol. 27; (a) Revuelta, J.; Cicchi, S.; Goti, A.; Brandi,
1