Communication
0.5 mmol), p-tolualdehyde (3a; 121 mg, 1.0 mmol), 18-crown-6
(86 mg, 0.34 mmol), and CsF (258 mg, 1.7 mmol) in THF (3 mL).
After heating at reflux for 15 h, the mixture was washed with water
(10 mL) and extracted with dichloromethane (3 × 5 mL). The com-
bined extract was dried with sodium sulfate, filtered, and evapo-
rated to give a pale yellow oil, which was purified by chromatogra-
phy (silica gel; hexane/dichloromethane, 2:1) to afford di-
benzo[c,h][5,1]oxazecine (7a) as a pale yellow oil (65 mg, 0.28 mmol,
55 %). 1H NMR (400 MHz, CDCl3): δ = 2.29 (dt, J = 2.8, 6.0 Hz,
13.6 Hz, 1 H, CH2), 2.42 (s, 3 H, CH3), 2.64 (s, 3 H, NCH3), 2.69 (td,
J = 2.8, 13.6 Hz, 1 H, CH2), 2.98 (td, J = 2.8, 11.2 Hz, 1 H, CH2), 3.33
(dt, J = 3.2, 6.8 Hz, 11.2 Hz, 1 H, CH2), 6.43 (s, 1 H, CH), 6.85 (dd, J =
1.6, 8.0 Hz, 1 H, ArH), 6.94–6.96 (m, 1 H, ArH), 7.06–7.12 (m, 3 H,
ArH), 7.22–7.24 (m, 3 H, ArH), 7.34 (td, J = 1.6, 7.6 Hz, 1 H, ArH),
7.43–7.49 (m, 3 H, ArH) ppm. 13C NMR (101 MHz, CDCl3): δ = 21.33,
29.70, 46.75, 62.90, 82.23, 121.37, 123.94, 124.35, 126.13, 127.13,
127.42, 128.31, 128.97, 129.21, 130.14, 135.84, 136.59, 139.27,
142.07, 152.32, 160.73 ppm. HRMS (GC): calcd. for C23H23NO [M]+
329.1780; found 329.1771.
Table 3. Reaction of triflate 1a with amine 6b and aldehydes 3.
Entry
Aldehyde 3 Ar
Product
Yield [%]
10
11
1
2
3
4
3a
3b
3c
3e
p-MeC6H4
Ph
p-BrC6H4
p-MeOC6H4
10a
10b
10c
10d
51
36
59
36
25
34
15
32
Keywords: Multicomponent reactions · Aldehydes ·
Amines · Arynes · Nitrogen heterocycles
[1] A. W. Robertson, C. F. Martinez-Farina, D. A. Smithen, H. Yin, S. Monro, A.
Thompson, S. A. McFarland, R. T. Syvitski, D. L. Jakeman, J. Am. Chem.
Soc. 2015, 137, 3271–3275; Y. Wang, Z.-X. Yu, Acc. Chem. Res. 2015, 48,
2288–2296.
[2] R. Shintani, K. Ikeda, T. Hayashi, J. Org. Chem. 2011, 76, 4776–4780.
[3] L. Liu, S. Xu, H. Zhou, Tetrahedron 2013, 69, 8386–8391.
[4] D. J. Bergmann, E. M. Campi, W. Roy Jackson, A. F. Patti, D. Saylik, Aust.
J. Chem. 2000, 53, 835–844.
[5] D. J. Edmonds, D. Johnson, D. J. Procter, Chem. Rev. 2004, 104, 3371–
3403.
[6] G. Wittig, W. Merkle, Ber. Dtsch. Chem. Ges. 1943, 76, 109–120.
[7] T. Kametani, K. Kigasawa, M. Hiiragi, T. Aoyama, J. Org. Chem. 1972, 37,
1450–1453.
[8] F. Yong, Z. Zheng, Z. Wang, Eur. J. Org. Chem. 2012, 1495–1498.
[9] S. B. Sachin, T. Kalcharla, A. T. Biju, Org. Lett. 2013, 15, 5452–5455.
[10] H. Yoshida, T. Morishima, H. Fukushima, J. Ohshita, A. Kunai, Org. Lett.
2007, 9, 3367–3370.
[11] K. Okuma, A. Nojima, Y. Nakamura, N. Matsunaga, N. Nagahora, K. Shioji,
Bull. Chem. Soc. Jpn. 2011, 84, 328–332.
Figure 3. ORTEP drawing of compound 10c (50 % probability for thermal
[12] For recent reviews, see A. Bhunia, A. T. Biju, Synlett 2014, 25, 608–614;
P. M. Tadross, B. M. Stoltz, Chem. Rev. 2012, 112, 3550–3577; K. Okuma,
Heterocycles 2012, 85, 514–544; H. Yoshida, K. Takaki, Heterocycles 2012,
85, 1333–1349.
ellipsoids).
[13] S. S. Bhojgude, D. R. Baviskar, R. G. Gonnade, A. Biju, Org. Lett. 2015, 17,
6270–6273.
Conclusions
[14] A. A. Cant, G. H. V. Bertrand, J. L. Henderson, L. Roberts, M. F. Greaney,
Angew. Chem. Int. Ed. 2009, 48, 5199–5202; Angew. Chem. 2009, 121,
5301–5304.
[15] T. Aoki, S. Koya, R. Yamasaki, S. Saito, Org. Lett. 2012, 14, 4506–4509.
[16] H. Yoshida, E. Shirakawa, Y. Honda, T. Hiyama, Angew. Chem. Int. Ed. 2002,
41, 3247–3249; Angew. Chem. 2002, 114, 3381–3383.
We synthesized 9- and 10-membered N,O-containing heterocy-
cles starting from triflates, aldehydes, and substituted indolines
and tetrahydroquinolines. This method is suitable for the gen-
eral synthesis of 9- and 10-membered N,O-containing heterocy-
cles, because almost all indolines, tetrahydroquinolines, and al-
dehydes can serve as substrates.
[17] X-ray data for compound 10c: triclinic, P1, a = 9.079(5) Å, b = 9.604(5) Å,
¯
1.452 Mg m–3, Z = 2, R1 = 0.0381, wR2 = 0.1035. GOF = 1.121. CCDC
1456809 (for 10c) contains the supplementary crystallographic data for
Experimental Section
Reaction of Triflate 1a with N-methylindoline (6a) and p-tolual-
dehyde (3a): A solution of triflate 1a (254 mg, 0.85 mmol) in THF
(2 mL) was added to a solution of N-methylindoline (6a; 66 mg,
Received: March 2, 2016
Published Online: April 13, 2016
Eur. J. Org. Chem. 2016, 2264–2267
2267
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