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dron Lett. 1997, 38, 7597–7598; (d) Moody, C. J.; Norton,
C. L. J. Chem. Soc., Perkin Trans. 1 1997, 2639–2643; (e)
Caddick, S.; Shering, C. L.; Wadman, S. N. Tetrahedron
2000, 56, 465–473; See also: (f) Hilton, S. T.; Ho, T. C. T.;
Pljevaljcic, G.; Schulte, M.; Jones, K. Chem. Commun.
2001, 209–210.
Bu3SnOO
or SRN1
F
14
O
N
Me
E
8. For the isolation of dihydro derivatives of indole, see: (a)
Ziegler, F. E.; Jeroncic, L. O. J. Org. Chem. 1991, 56,
3479–3486; (b) Gribble, G. W.; Fraser, H. L.; Badenock, J.
C. Chem. Commun. 2001, 805–806; (c) Flanagan, S. R.;
Harrowven, D. C.; Bradley, M. Tetrahedron Lett. 2003,
44, 1795–1798.
9. For reviews on acyl radical chemistry, see: (a) Ryu, I.;
Sonoda, N.; Curran, D. P. Chem. Rev. 1996, 96, 177–194;
(b) Chatgilialoglu, C.; Crich, D.; Komatsu, M.; Ryu, I.
Chem. Rev. 1999, 99, 1991–2069.
PhSeH
15
– H2O
OH
N
Me
G
Scheme 6. Proposed mechanism for the formation of tetracycles 14
and 15 under n-Bu6Sn2–hm conditions.
ꢁ
10. Upon arenes: (a) Motherwell, W. B.; Vazquez, S. Tetra-
hedron Lett. 2000, 41, 9667–9671, and references cited
therein; Upon pyridines: (b) Fontana, F.; Minisci, F.;
Barbosa, M. C. N.; Vismara, E. J. Org. Chem. 1991, 56,
2866–2869; Upon indoles and pyrroles: (c) Miranda, L.
ketones 6 and 14, which deserve interest due to their
potential pharmacological activities.26 Further extension
of this reaction to heterocyclic systems is currently
underway in our laboratory.
ꢁ
D.; Cruz-Almanza, R.; Pavon, M.; Alva, E.; Muchowski,
J. M. Tetrahedron Lett. 1999, 40, 7153–7157; (d) Allin, S.
M.; Barton, W. R. S.; Bowman, W. R.; McInally, T.
Tetrahedron Lett. 2001, 42, 7887–7890; Upon pyridines:
(e) Doll, M. K.-H. J. Org. Chem. 1999, 64, 1372–1374.
11. (a) Bennasar, M.-L.; Roca, T.; Griera, R.; Bosch, J. Org.
Lett. 2001, 3, 1697–1700; (b) Bennasar, M.-L.; Roca, T.;
Griera, R.; Bassa, M.; Bosch, J. J. Org. Chem. 2002, 67,
6268–6271; (c) Bennasar, M.-L.; Roca, T.; Ferrando, F.
Org. Lett. 2004, 6, 759–762.
Acknowledgements
Financial support from the ‘Ministerio de Ciencia y
ꢁ
Tecnologıa’, Spain, and the ‘Fondo Europeo de De-
sarrollo Regional’ (FEDER) through project BQU2003-
04967-C02-02 is gratefully acknowledged. We also
thank the DURSI (Generalitat de Catalunya) for Grant
2001SGR00084. F.F. thanks the University of Barce-
lona for a grant.
12. Batty, D.; Crich, D. Synthesis 1990, 273–275.
13. Olgen, S.; Akaho, E.; Nebioglu, D. Eur. J. Med. Chem.
2001, 36, 747–770.
14. Crich, D.; Hwang, J.-T. J. Org. Chem. 1998, 63, 2765–
2770.
References and notes
15. Chatgilialoglu, C. Acc. Chem. Res. 1992, 25, 188–194.
16. (a) Josien, H.; Ko, S.-B.; Bom, D.; Curran, D. P. Chem.
Eur. J. 1998, 4, 67–83; (b) Miranda, L. D.; Cruz-Almanza,
1. Studer, A.; Bossart, M. In Radicals in Organic Synthesis;
Renaud, P., Sibi, M. P., Eds.; Wiley-VCH: Weinheim,
2001; Vol. 2, pp 62–80.
2. For a recentdiscussion, see: Beckwith, A. L. J.; Bowry, V.
W.; Bowman, W. R.; Mann, E.; Parr, J.; Storey, J. M. D.
Angew. Chem., Int. Ed. 2004, 43, 95–98, and references
cited therein.
3. For recentleading references, see: (a) Fiumana, A.; Jones,
K. Tetrahedron Lett. 2000, 41, 4209–4211; (b) Kaoudi, T.;
Quiclet-Sire, B.; Seguin, S.; Zard, S. Z. Angew. Chem., Int.
Ed. 2000, 39, 731–733; (c) Harrowven, D. C.; L’Helias, N.;
Moseley, J. D.; Blumire, N. J.; Flanagan, S. R. Chem.
Commun. 2003, 2658–2659.
4. For instance, see: (a) Minisci, F.; Vismara, E.; Fontana, F.
Heterocycles 1989, 28, 489–519; (b) Murphy, J. A.;
Sherburn, M. S. Tetrahedron 1991, 47, 4077–4088; (c)
Harrowven, D. C.; Nunn, M. I. T.; Blumire, N. J.;
Fenwick, D. R. Tetrahedron 2001, 57, 4447–4454; (d)
Harrowven, D. C.; Sutton, B. J.; Coulton, S. Tetrahedron
Lett. 2001, 42, 9061–9064.
ꢁ
R.; Pavon, M.; Romero, Y.; Muchowski, J. M. Tetrahe-
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Bridge, C. F.; Cloonan, M. O.; Leach, D. C. Synlett 2001,
765–768; (d) Bennasar, M.-L.; Roca, T.; Griera, R.;
Bosch, J. J. Org. Chem. 2001, 66, 7547–7551.
17. Compound 6: 1H NMR (200 MHz, CDCl3) d 5.46 (s, 2H),
7.23 (m, 1H), 7.40–7.55 (m, 4H), 7.51 (s, 1H), 7.66 (ddd,
J ¼ 1:6, 7.6, 7.8 Hz, 1H), 7.80 (d, J ¼ 8:2 Hz, 1H), 8.38
(dd, J ¼ 1:6, 7.8 Hz, 1H); 13C NMR (50.3 MHz, CDCl3) d
44.4 (CH2), 105.9 (CH), 110.1 (CH), 121.5 (CH), 123.4
(CH), 125.6 (CH), 126.3 (CH), 127.2 (C), 127.3 (CH),
128.0 (CH), 130.6 (C), 132.6 (C), 133.2 (CH), 136.3 (C),
137.4 (C), 177.3 (CO); HRMS calcd for C16H11NO
233.0841, found 233.0834.
18. An electrophilic substitution mechanism can be excluded
as no cyclisation was observed after heating 2a under
300 W sunlamp irradiation without n-Bu6Sn2.
19. Bowman, W. R.; Heaney, H.; Jordan, B. M. Tetrahedron
1991, 47, 10119–10128, See also Ref. 6a.
5. Harrowven, D. C.; Sutton, B. J.; Coulton, S. Tetrahedron
2002, 58, 3387–3400.
20. Compound 7: 1H NMR (300 MHz, CDCl3) d 0.93 (t,
J ¼ 7:2 Hz, 9H), 1.39 (m, 12H), 1.68 (m, 6H), 3.05 (t,
J ¼ 7:8 Hz, 2H), 4.81 (t, J ¼ 7:8 Hz, 2H), 7.13 (m, 1H),
7.35–7.55 (m, 8H), 7.65 (d, J ¼ 7:8 Hz, 1H); 13C NMR
(75.4 MHz, CDCl3) d 13.7 (CH3), 16.8 (CH2), 27.1 (CH2),
27.9 (CH2), 37.1 (CH2), 46.1 (CH2), 110.2 (CH), 110.6
(CH), 120.1 (CH), 122.3 (CH), 124.2 (CH), 126.1 (C),
126.3 (CH), 128.4 (CH), 128.8 (CH), 129.4 (C), 138.6 (C),
139.2 (C), 166.2 (CO); CI-MS m=z 556 (MHþ).
6. (a) Aldabbagh, F.; Bowman, W. R.; Mann, E.; Slawin, A.
M. Z. Tetrahedron 1999, 55, 8111–8128; (b) Escolano, C.;
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7. For instance, see: (a) Kraus, G. A.; Kim, H. Synth.
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59, 2456–2466; (c) Wang, S.-F.; Chuang, C.-P. Tetrahe-
21. Kosugi, M.; Naka, H.; Sano, H.; Migita, T. Bull. Chem.
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