M.-F. Pouliot et al. / Tetrahedron Letters 53 (2012) 4121–4123
4123
Nukkla, M. A.; Zielinski, N. A.; Tahir, S. K.; Fitzgerald, M.; Kim, K. H.; Marsh, K.;
Frost, D.; Ng, S.-C.; Rosenberg, S.; Sham, H. L. Bioorg. Med. Chem. 2002, 12, 465–
469.
- Et
BF4
+ N SF2
Et
F
S
NEt2
F
2. Hargaden, G. C.; Giry, P. J. Chem. Rev. 2009, 109, 2505–2550.
3. Wong, G. S. K.; Wu, W. In Oxazoles: Synthesis, Reactions, and Spectroscopy, Part B;
Palmer, D. C., Ed.; John Wiley & Sons, Inc.: Hoboken, 2004; pp 331–528.
4. Riobé, F.; Avarvari, N. Coord. Chem. Rev. 2010, 254, 1523–1533.
5. 2-Thiazolines, see: Gaumont, A.-C.; Gulea, M.; Levillain, J. Chem. Rev. 2009, 109,
1371–1401 and references cited therein.
6. 2-Benzoxazoles, see for examples: (a) Wu, Y.; Peng, X.; Fan, J.; Gao, S.; Tian, M.;
Zhao, J.; Sun, S. J. Org. Chem. 2007, 72, 62–70; (b) Boyer, J.; Arnoult, E.;
Médebielle, M.; Guillemont, J.; Unge, J.; Jochmans, D. J. Med. Chem. 2011, 54,
7974–7985; (c) Massue, J.; Frath, D.; Ulrich, G.; Retailleau, P.; Ziessel, R. Org.
Lett. 2012, 14, 230–233.
7. For selected synthetic methods, see: (a) Lafargue, P.; Guenot, P.; Lellouche, J.-P.
Heterocycles 1995, 41, 947–958; (b) Wipf, P.; Venkatraman, S. Tetrahedron Lett.
1996, 37, 4659–4662; (c) Phillips, A. J.; Uto, Y.; Wipf, P.; Reno, M. J.; Williams, D.
R. Org. Lett. 2000, 2, 1165–1168; (d) Bunnage, M. E.; Davies, S. G.; Goodwin, C. J.
J. Chem. Soc., Perkin Trans. 1 1994, 17, 2385–2391; (e) Wuts, P. G. M.; Northuis, J.
M.; Kwan, T. A. J. Org. Chem. 2000, 65, 9223–9225; (f) Kangani, C. O.; Kelley, D.
E. Tetrahedron Lett. 2005, 46, 8917–8920; (g) Schwekendiek, K.; Glorius, F.
Synthesis 2006, 2996–3002; (h) Kangani, C. O.; Kelley, D. E.; Day, B. W.
Tetrahedron Lett. 2006, 47, 6497–6499; (i) Fan, L.; Lobkovsky, E.; Ganem, B. Org.
Lett. 2007, 9, 2015–2017; (j) Chaudhry, P.; Schoenen, F.; Neuenswander, B.;
Lushington, G. H.; Aubé, J. J. Comb. Chem. 2007, 9, 473–476; (k) Petersson, M. J.;
Jenkins, I. D.; Loughlin, W. A. Org. Biomol. Chem. 2009, 7, 739–746; (l) Kempe,
K.; Lobert, M.; Hoogenboom, R.; Schubert, U. S. J. Comb. Chem. 2009, 11, 274–
280.
O
OH
O
O
Ph
Ph
N
H
CO2Me
Ph
N
CO2Me
- HBF4
H
1h
3
- HF
O
-
S
F
NEt2
O
N
CO2Me
2h
Scheme 1. Mechanistic proposal for the cyclodehydration reaction.
Table 3
Preparation of N-containing heterocycles
OH
8. (a) Burrell, G.; Evans, J. M.; Jones, G. E.; Stemp, G. Tetrahedron Lett. 1990, 31,
3649–3652; (b) Lafargue, P.; Guenot, P.; Lellouche, J.-P. Heterocycles 1995, 41,
947–958; (c) Mahler, S. G.; Serra, G. L.; Antonow, D.; Manta, E. Tetrahedron Lett.
2001, 42, 8143–8146; (d) Nicolaou, K. C.; Nevalainen, M.; Zak, M.; Bulat, S.;
Bella, M.; Safina, B. S. Angew. Chem., Int. Ed. 2003, 42, 3418–3424.
9. The reagent [Et2SF2]BF4 is commercially available under the trademark
XtalFluor-E (2 equiv.)
X
X
R2
R1
R2
R1
N
H
4a-d
DCE (0.1 M), 90 °C, 18 h
N
n
n
5a-d
XtalFluor-EÒ
.
10. (a) Beaulieu, F.; Beauregard, L.-P.; Courchesne, G.; Couturier, M.; Laflamme, F.;
L’Heureux, A. Org. Lett. 2009, 11, 5050–5053; (b) L’Heureux, A.; Beaulieu, F.;
Bennet, C.; Bill, D. R.; Clayton, S.; Laflamme, F.; Mirmehrabi, M.; Tadayon, S.;
Tovell, D.; Couturier, M. J. Org. Chem. 2010, 75, 3401–3411.
11. Pouliot, M.-F.; Angers, L.; Hamel, J.-D.; Paquin, J.-F. Org. Biomol. Chem. 2012, 10,
988–993.
Entry
Substrate
Product
Yielda (%)
OH
CO2Me
S
N
S
Ph
CO2Me
1
76
Ph
N
H
5a
12. Aitken, R. A.; Armstrong, D. P.; Galt, R. H. B.; Mesher, S. T. E. J. Chem. Soc., Perkin
Trans. 1 1997, 935–943.
4a
13. De Jonghe, S.; Van Overmeire, I.; Gunst, J.; De Bruyn, A.; Hendrix, C.; Van
Calenbergh, S.; Busson, R.; De Keukeleire, D.; Philippe, J.; Herdewijn, P. Bioorg.
Med. Chem. Lett. 1999, 9, 3159–3164.
14. Compound 2f is prone to epimerization, see for example: Kuwano, R.;
Kameyama, N.; Ikeda, R. J. Am. Chem. Soc. 2011, 133, 7312–7315.
15. Ait-Haddou, H.; Hoarau, O.; Cramailere, D.; Pezet, F.; Dara, J.-C.; Balavoine, G. G.
A. Chem. Eur. J. 2004, 10, 699–707.
16. Sutherland, A.; Vederas, J. C. Chem. Commun. 1999, 1739–1740.
17. McKeever, B.; Pattenden, G. Tetrahedron 2003, 59, 2713–2727.
18. For selected synthetic methods, see: (a) Altenhoff, G.; Glorius, F. Adv. Synth.
Catal. 2004, 346, 1661–1664; (b) Chen, Y.-X.; Qian, L.-F.; Zhang, W.; Han, B.
Angew. Chem., Int. Ed. 2008, 47, 9330–9333; (c) Blacker, A. J.; Farah, M. M.; Hall,
M. I.; Marsden, S. P.; Saidi, O.; Williams, J. M. J. Org. Lett. 2009, 11, 2039–2042.
19. For selected synthetic methods, see: (a) Mitchell, M. A.; Benicewicz, B. C.
Synthesis 1994, 675–677; (b) Cwik, A.; Hell, Z.; Hegedüs, A.; Finta, Z.; Horváth,
Z. Tetrahedron Lett. 2002, 43, 3985–3987.
HO
PivHN
O
N
5b
2
3
4
70
81
55
4b
O
O
Ph
Ph
N
H
OH
Ph
Ph
N
5c
4c
O
O
OH
N
H
N
4d
5d
a
Isolated yield.
References and notes
1. For examples, see: Li, Q.; Wood, K. W.; Claireborne, A.; Gwanltey, S. L., II; Barr,
K. J.; Liu, G.; Gehke, L.; Credo, R. B.; Hua Hui, Y.; Lee, J.; Warner, R. B.; Kovar, P.;