2 For selected papers, see: (a) H. Guo, Q. Xu and O. Kwon, J. Am.
Chem. Soc., 2009, 131, 6318; (b) B. S. Santos, A. L. Cardoso,
A. Matos Beja, M. Ramos Silva, J. A. Paixao, F. Palacios and
T. M. V. D. Pinho e Melo, Eur. J. Org. Chem., 2010, 3249;
(c) B. Baskar, P.-Y. Dakas and K. Kumar, Org. Lett., 2011,
13, 1988; (d) X.-Y. Chen, M.-W. Wen, S. Ye and Z.-X. Wang,
Org. Lett., 2011, 13, 1138; (e) N. Pinto, P. Retailleau, A. Voituriez
and A. Marinetti, Chem. Commun., 2011, 47, 1015; (f) Y. S. Tran,
T. J. Martin and O. Kwon, Chem.–Asian. J., 2011, 6, 2101;
(g) T. Wang and S. Ye, Org. Biomol. Chem., 2011, 9, 5260;
(h) X.-C. Zhang, S.-H. Cao, Y. Wei and M. Shi, Chem. Commun.,
2011, 47, 1548; (i) B. J. Cowen and S. J. Miller, J. Am. Chem. Soc.,
2007, 129, 10988; (j) Y. Du, J. Feng and X. Lu, Org. Lett., 2005,
7, 1987; (k) Z. R. He, X. F. Tang, Y. M. Chen and Z. J. He, Adv.
Synth. Catal., 2006, 348, 413; (l) J. A. Marshall and Y. Tang,
J. Org. Chem., 1993, 58, 3233; (m) N. Pinto, M. Neel,
A. Panossian, P. Retailleau, G. Frison, A. Voituriez and
A. Marinetti, Chem.–Eur. J., 2010, 16, 1033; (n) Y.-L. Shi and
M. Shi, Org. Lett., 2005, 7, 3057.
3 For reviews, see: (a) V. V. R. M. Krishna Reddy, D. Udaykiran,
U. S. Chintamani, E. Mahesh Reddy, C. Kameswararao and
G. Madhusudhan, Org. Process Res. Dev., 2011, 15, 462;
(b) M. A. P. Martins, C. P. Frizzo, D. N. Moreira, L. Buriol and
P. Machado, Chem. Rev., 2009, 109, 4140.
4 For selected papers on Lewis bases-catalyzed cycloaddition of
allenoates with aldimines, see: (a) B. Zhang, Z. He, S. Xu,
G. Wu and Z. He, Tetrahedron, 2008, 64, 9471; (b) Y. S. Tran
and O. Kwon, Org. Lett., 2005, 7, 4289; (c) N. Pinto, N. Fleury-
Bregeot and A. Marinetti, Eur. J. Org. Chem., 2009, 146;
´
(d) R. P. Wurz and G. C. Fu, J. Am. Chem. Soc., 2005,
127, 12234; (e) B. J. Cowen and S. J. Miller, J. Am. Chem. Soc.,
2007, 129, 10988; (f) Y.-Q. Fang and E. N. Jacobsen, J. Am. Chem.
Soc., 2008, 130, 5660.
Fig. 1 Possible catalytic cycles.
5 (a) Z. Xu and X. Lu, J. Org. Chem., 1998, 63, 5031; (b) C. Zhang
and X. Lu, J. Org. Chem., 1995, 60, 2906.
6 For recent development and application of Lu’s reaction, see:
(a) Y. Du and X. Lu, J. Org. Chem., 2003, 68, 6463;
(b) C. E. Henry and O. Kwon, Org. Lett., 2007, 9, 3069; (c) J. Lee,
Y.-I. Lee, M. J. Kang, Y.-J. Lee, B.-S. Jeong, J.-H. Lee, M.-J. Kim,
J.-y. Choi, J.-M. Ku, H.-g. Park and S.-S. Jew, J. Org. Chem., 2005,
70, 4158; (d) S. G. Pyne, K. Schafer, B. W. Skelton and A. H. White,
Chem. Commun., 1997, 2267; (e) J.-C. Wang and M. J. Krische,
Angew. Chem., Int. Ed., 2003, 42, 5855.
7 (a) X. F. Zhu, J. Lan and O. Kwon, J. Am. Chem. Soc., 2003,
125, 4716; (b) Y. S. Tran and O. Kwon, J. Am. Chem. Soc., 2007,
129, 12632.
8 (a) G.-L. Zhao, J.-W. Huang and M. Shi, Org. Lett., 2003, 5, 4737;
(b) G.-L. Zhao and M. Shi, J. Org. Chem., 2005, 70, 9975;
(c) J.-B. Denis, G. Masson, P. Retailleau and J. Zhu, Angew.
Chem., Int. Ed., 2011, 50, 5356.
Fig. 2 Possible resonance structure of B and B0.
or gamma-position (intermediate B0), and thus favors the
5-endo cyclization (Fig. 2). In contrast, there is no such
contribution in a DABCO-derived intermediate, and thus
favors the 4-exo cyclization to give the [2+2] cycloadduct.
In conclusion, the Lewis bases-catalyzed cycloadditions of
allenoates and cyclic ketimines were developed. The [2+2] and
[3+2] formal cycloadditions were found when DABCO and
PPh3 were used as the catalyst, respectively, giving the corres-
ponding sultam-fused azetidines and dihydropyrroles in good
yields with high regioselectivities. Further investigation of the
reaction mechanism and other cycloaddition reactions of
cyclic ketimines are underway in our laboratory.
9 S. M. Weinreb, Top. Curr. Chem., 1997, 190, 131.
10 (a) M. Rommel, T. Fukuzumi and J. W. Bode, J. Am. Chem. Soc.,
2008, 130, 17266; (b) X. F. Xiong, H. Zhang, J. Peng and
Y. C. Chen, Chem.–Eur. J., 2011, 17, 2358.
11 (a) F. A. Davis, J. C. Towson, D. B. Vashi, R. ThimmaReddy,
J. P. McCauley, M. E. Harakal and D. J. Gosciniak, J. Org. Chem.,
1990, 55, 1254; (b) K. H. Ahn, C. Ham, S.-K. Kim and C.-W. Cho,
J. Org. Chem., 1997, 62, 7047.
12 (a) Z. Liu, N. Shibata and Y. Takeuchi, J. Org. Chem., 2000,
65, 7583; (b) S. Nakamura, M. Hayashi, Y. Hiramatsu, N. Shibata,
Y. Funahashi and T. Toru, J. Am. Chem. Soc., 2009, 131, 18240;
(c) M. Penso, D. Albanese, D. Landini, V. Lupi and A. Tagliabue,
J. Org. Chem., 2008, 73, 6686; (d) C. B. Yu, D. W. Wang and
Y. G. Zhou, J. Org. Chem., 2009, 74, 5633; (e) F. Clerici,
M. Gelmi, S. Pellegrino and D. Pocar, Top. Heterocycl. Chem.,
2007, 9, 179.
Financial support from National Science Foundation of
China (20932008), the Ministry of Science and Technology
of China (2011CB808600) and the Chinese Academy of
Sciences are greatly acknowledged.
13 For mechanism study, see: (a) Y. Xia, Y. Liang, Y. Chen,
M. Wang, L. Jiao, F. Huang, S. Liu, Y. Li and Z.-X. Yu, J. Am.
Chem. Soc., 2007, 129, 3470; (b) E. Meicier, B. Fonovic, C. Henry,
O. Kwon and T. Dudding, Tetrahedron Lett., 2007, 48, 3617;
(c) Y. Liang, S. Liu, Y. Xia, Y. Li and Z.-X. Yu, Chem.–Eur. J.,
2008, 14, 4361; (d) T. Dudding, O. Kwon and E. Mercier, Org.
Lett., 2006, 8, 3643.
Notes and references
1 For reviews, see: (a) B. J. Cowen and S. J. Miller, Chem. Soc. Rev.,
2009, 38, 3102; (b) X. Lu, C. Zhang and Z. Xu, Acc. Chem. Res., 2001,
34, 535; (c) J. A. Marshall, Chem. Rev., 2000, 100, 3163;
(d) J. L. Methot and W. R. Roush, Adv. Synth. Catal., 2004,
346, 1035; (e) Y. Wei and M. Shi, Acc. Chem. Res., 2010, 43, 1005;
(f) L.-W. Ye, J. Zhou and Y. Tang, Chem. Soc. Rev., 2008, 37, 1140.
14 No ring expansion of cycloadduct 3j to 4j/5j was observed with
extended reaction time in the presence of DABCO or PPh3.
c
This journal is The Royal Society of Chemistry 2012
Chem. Commun., 2012, 48, 1317–1319 1319