organic extracts were dried with anhydrous Na2SO4 and evaporated
under reduced pressure; the residue was then purified by column
chromatography over silica gel to afford the corresponding Henry
product with high purity. 1H NMR (CDCl3, 300 MHz, ppm): d 8.25
(d, J = 8.4 Hz, 2 H), 7.61 (d, J = 8.4 Hz, 2 H), 5.57–5.62 (m, 1 H),
4.57 (m, 2 H), 3.18 (br, 1 H).
4 (a) S. J. Miller, Nat. Biotechnol., 2004, 22, 1378; (b) Z. Tang and A.
Marx, Angew. Chem., Int. Ed., 2007, 46, 7297; (c) M. M.
Rozenman and D. R. Liu, ChemBioChem, 2006, 7, 253; (d) S. K.
Silverman, Org. Biomol. Chem., 2004, 2, 2701; (e) Z. J. Gartner and
D. R. Liu, J. Am. Chem. Soc., 2001, 123, 6961.
5 M. Chandra and S. K. Silverman, J. Am. Chem. Soc., 2008, 130,
2936.
1 T. M. Devlin, Textbook of Biochemistry with Clinical Correlations,
John Wiley & Sons, New York, 1997.
6 (a) G. Roelfes and B. L. Feringa, Angew. Chem., Int. Ed., 2005
44, 3230; (b) D. Coquire, B. L. Feringa and G. Roelfes, Angew.
Chem., Int. Ed., 2007, 46, 9308; (c) G. Roelfes, A. J.
Boersma and B. L. Feringa, Chem. Commun., 2006, 635; (d) A. J.
Boersma, B. L. Feringa and G. Roelfes, Org. Lett., 2007, 9, 3647;
(e) N. Shibata, H. Yasui, S. Nakamura and T. Toru, Synlett, 2007,
1153.
7 (a) F. A. Luzzio, Tetrahedron, 2001, 57, 915 and references therein;
(b) A. V. Davis, M. Driffield and D. K. Smith, Org. Lett., 2001, 3,
3075; (c) J. M. Concellon, H. R. Solla and C. Concellon, J. Org.
Chem., 2006, 71, 7919; (d) T. Jiang, H. X. Gao, B. X. Han, G. Y.
Zhao, Y. H. Chang, W. Z. Wu, L. Gao and G. Y. Yang,
Tetrahedron Lett., 2004, 45, 2699; (e) J. A. Weeden and J. D.
Chisholm, Tetrahedron Lett., 2006, 47, 9313.
2 For reviews see: (a) Y. Lu and J. W. Liu, Curr. Opin. Biotechnol.,
2006, 17, 580; (b) G. Roelfes, Mol. BioSyst., 2007, 3, 126; (c) L. J.
Scherer and J. J. Rossi, Nat. Biotechnol., 2003, 21, 1457; (d) J. W.
Liu and Y. Lu, J. Fluoresc., 2004, 14, 343; (e) Y. Lu and J. W. Liu,
Acc. Chem. Res., 2007, 40, 315; (f) J. P. May, R. Ting, L. Lermer, J.
M. Thomas, Y. Roupioz and D. M. Perrin, J. Am. Chem. Soc.,
2004, 126, 4145; (g) Y. Isaka, Curr. Opin. Mol. Ther., 2007, 9, 132.
3 (a) M. W. Kanan, M. M. Rozenman, K. Sakurai, T. M. Snyder and
D. R. Liu, Nature, 2004, 431, 545; (b) X. Y. Li and D. R. Liu,
Angew. Chem., Int. Ed., 2004, 43, 4848 and references therein;
(c) A. P. Silverman and E. T. Kool, Chem. Rev., 2006, 106, 3775;
(d) K. Sakurai, T. M. Snyder and D. R. Liu, J. Am. Chem. Soc.,
2005, 127, 1660; (e) S. Obika, M. Tomizu, Y. Negoro, A. Orita, O.
Nakagawa and T. Imanishi, ChemBioChem, 2007, 8, 1924; (f) M.
Oberhuber and G. F. Joyce, Angew. Chem., Int. Ed., 2005, 44, 7580.
8 (a) R. Ballini and G. Bosica, J. Org. Chem., 1997, 62, 425; (b) K. R.
Reddy, C. V. Rajasekhar and G. G. Krishna, Synth. Commun.,
2007, 37, 1971.
ꢁc
This journal is The Royal Society of Chemistry 2008
3794 | Chem. Commun., 2008, 3792–3794