consumed completely. Then the mixture was allowed to settle for
5 min, and the resulting mixture was found facile separated into
two phases. The upper layer comprises reactants and products,
and the lower layer ILs, catalyst, and water (generated during
reaction). After simple separation by decantation, the upper
phase was subject to column chromatography on silica gel (200–
300 meshes) (petroleum ether/ethyl acetate = 5/1, v/v). The
yield of 6a was 3.650 g (98% based on PhCHO). All the products
were characterized by comparison of 1H and 13C NMR spectral
data.15
work behaves the same way as that of Leng et al. (reference 8a). In this
paper, we adopt the term “facile separation catalyst system” rather
than “reaction-induced self-separation catalyst system” as requested
by one of the reviewers.
9 (a) Y. Yamamoto, X. Chen and K. Akiba, J. Am. Chem. Soc., 1992,
114, 7906; (b) Y. Yamamoto, X. Chen, S. Kojima, K. Ohdoi, M.
Kitano, Y. Doi and K. Y. Akiba, J. Am. Chem. Soc., 1995, 117, 3922;
(c) S. Shimada, O. Yamazaki, T. Tanaka, M. L. N. Rao, Y. Suzuki
and M. Tanaka, Angew. Chem., Int. Ed., 2003, 42, 1845; (d) S. Yin, J.
Maruyama, T. Yamashita and S. Shimada, Angew. Chem., Int. Ed.,
2008, 47, 6590; (e) S. Yin and S. Shimada, Chem. Commun., 2009,
1136; (f) R. Qiu, S. Yin, X. Zhang, J. Xia, X. Xu and S. Luo, Chem.
Commun., 2009, 4759; (g) R. Qiu, Y. Qiu, S. Yin, X. Xin, S. Luo,
C.-T. Au, W.-Y. Wong and S. Shimada, Adv. Synth. Catal., 2010, 352,
153.
10 (a) N. Abermil, G. Masson and J. Zhu, J. Am. Chem. Soc., 2008,
130, 12596; (b) C. J. Abraham, D. H. Paull, T. Bekele, M. T. Scerba,
T. Dudding and T. Lectka, J. Am. Chem. Soc., 2008, 130, 17085;
(c) D. H. Paull, C. J. Abraham, M. T. Scerba, E. Alden-Danforth
and T. Lectka, Acc. Chem. Res., 2008, 41, 655.
Acknowledgements
This work was financially supported by the NSFC (Grant
Nos. 20973056, 20873038 and E50725825), and the 863 project
(2009AA05Z319). Prof. C.-T. Au (adjunct professor of Hunan
University) and Prof. W.-Y. Wong thank the Hong Kong Baptist
University for a Faculty Research Grant (FRG/08-09/II-09).
Prof. Yin thanks Dr S. Shimada of AIST in Japan for helpful
advice.
11 (a) M. P. Jensen, J. A. Dzielawa, P. Rickert and M. L. Dietz, J. Am.
Chem. Soc., 2002, 124, 10664; (b) S.-G. Lee, Chem. Commun., 2006,
1049.
12 (a) A. Yanagisawa, R. Goudu and T. Arai, Org. Lett., 2004, 6, 4281;
(b) U. P. Kreher, A. E. Rosamilia, C. L. Raston, J. L. Scott and C. R.
Strauss, Org. Lett., 2003, 5, 3107.
13 (a) F. Chu, L. S. Flatt and E. V. Anslyn, J. Am. Chem. Soc., 1994,
116, 4194; (b) S.-J. Jeon and P. J. Walsh, J. Am. Chem. Soc., 2003,
125, 9544; (c) J. G. Kim, K. M. Waltz, I. F. Garcia, D. Kwiatkowski
and P. J. Walsh, J. Am. Chem. Soc., 2004, 126, 12580; (d) S. Wang and
L. Zhang, J. Am. Chem. Soc., 2006, 128, 14274; (e) X. Huang and L.
Zhang, J. Am. Chem. Soc., 2007, 129, 6398; (f) W.-J. Lu, Y.-W. Chen
and X.-L. Hou, Angew. Chem., Int. Ed., 2008, 47, 10133; (g) D. C.
Pryde, G. N. Maw, S. Planken, M. Y. Platts, V. Sanderson, M. Corless,
A. Stobie, C. G. Barber, R. Russell, L. Foster, L. Barker, C. Wayman,
P. V. D. Graaf, P. Stacey, D. Morren, C. Kohl, K. Beaumont, S.
Coggon and M. Tute, J. Med. Chem., 2006, 49, 4409.
14 (a) T. Kotani, D. Nagai, K. Asahi, H. Suzuki, F. Yamao, N. Kataoka
and T. Yagura, Antimicrob. Agents Chemother., 2005, 49, 2729; (b)
X.-W. Zhang, J. Xia, H.-W. Yan, S.-L. Luo, S.-F. Yin, C.-T. Au and
W.-Y. Wong, J. Organomet. Chem., 2009, 694, 3019.
15 (a) G. Bartoli, M. Bosco, A. Carlone, R. Dalpozzo, P. Galzerano, P.
Melchiorre and L. Sambri, Tetrahedron Lett., 2008, 49, 2555; (b) R.
Fan, W. Wang, D. Pu and J. Wu, J. Org. Chem., 2007, 72, 5905; (c) P.
Hauwert, G. Maestri, J. Sprengers, M. Catellani and C. J. Elsevier,
Angew. Chem., Int. Ed., 2008, 47, 3223; (d) G. R. Krishnan and K.
Sreekumar, Eur. J. Org. Chem., 2008, 4763; (e) Z. Li, H. Li, X. Guo,
L. Cao, R. Yu, H. Li and S. Pan, Org. Lett., 2008, 10, 803; (f) R.
Matsubara, F. Berthiol and S. Kobayashi, J. Am. Chem. Soc., 2008,
130, 1804; (g) Y. Wang, J. Ye and X. Liang, Adv. Synth. Catal., 2007,
349, 1033.
Notes and references
1 D. J. Cole-Hamilton, Science, 2003, 299, 1702.
2 (a) A. Corma and H. Garcıa, Chem. Rev., 2003, 103, 4307; (b) C.
Cope´ret, M. Chabanas, R. P. Saint-Arroman and J.-M. Basset,
Angew. Chem., Int. Ed., 2003, 42, 156; (c) C. Baleiza˜o and H. Garcia,
Chem. Rev., 2006, 106, 3987; (d) F. Shi, M. K. Tse, M.-M. Pohl, A.
Bruckner, S. Zhang and M. Beller, Angew. Chem., Int. Ed., 2007,
46, 8866; (e) R. J. Boyd, J. Am. Chem. Soc., 2008, 130, 10447; (f) A.
Motta, I. L. Fragal and T. J. Marks, J. Am. Chem. Soc., 2008, 130,
16533.
3 (a) Y. Motoyama, K. Mitsui, T. Ishida and H. Nagashima, J. Am.
Chem. Soc., 2005, 127, 13150; (b) W. Miao and T. H. Chan, Acc.
Chem. Res., 2006, 39, 897; (c) D. E. Bergbreiter, J. Tian and
C. Hongfa, Chem. Rev., 2009, 109, 530; (d) S. Ikegami and H.
Hamamoto, Chem. Rev., 2009, 109, 583.
4 R. Akiyama and S. Kobayashi, Chem. Rev., 2009, 109, 594.
5 P. Wasserscheid and T. Welton, ILs in Synthesis: Second, Completely
Revised and Enlarged Edition. Wiley-VCH, Weinheim, 2008.
6 H. Zhi, C. Lu, Q. Zhang and J. Luo, Chem. Commun., 2009, 2878.
7 B. Tan, J. Y. Jiang, Y. H. Wang, L. Wei, D. J. Chen and Z. L. Jin,
Appl. Organomet. Chem., 2008, 22, 620.
8 (a) Y. Leng, J. Wang, D. Zhu, X. Ren, H. Ge and L. Shen, Angew.
Chem., Int. Ed., 2009, 48, 168; (b) The catalyst system reported in this
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