114
J.-T. Lai et al.
LETTER
(3) (a) Wong, Y.-L.; Ma, J.-F.; Law, W.-F.; Yan, Y.; Wong,
W.-T.; Zhang, Z.-Y.; Mak, T. C. W.; Nag, D. K. P. Eur. J.
Inorg. Chem. 1999, 2, 313. (b) Bergonzi, R.; Fabbrizzi, L.;
Licchelli, M.; Mangano, C. Coord. Chem. Rev. 1998, 170,
31.
r.t., the reaction was quenched with H2O, and the product
was extracted twice with CH2Cl2. The combined organic
extracts were dried over MgSO4, filtered, and concentrated.
The resulting crude product was purified by column
chromatography (1:9, EtOAc–hexanes) to give a white solid
in a 67% yield; mp 287–288 °C. 1H NMR (300 MHz,
CDCl3): d = 7.90 (d, J = 8.1 Hz, 2 H, ArH), 7.73 (d, J = 8.1
Hz, 2 H, ArH), 7.59 (d, J = 9.0 Hz, 1 H, ArH), 7.09 (d,
J = 3.0 Hz, 1 H, ArH), 6.63 (dd, J = 8.4, 3.0 Hz, 1 H, ArH),
6.58 (dd, J = 8.7, 2.4 Hz, 1 H, ArH), 6.54 (d, J = 8.4 Hz, 1 H,
ArH), 6.47 (d, J = 2.4 Hz, 1 H, ArH), 4.91 (s, 1 H, NH), 3.80
(s, 1 H, CH), 3.78 (s, 3 H, OCH3), 3.03 [s, 6 H, N(CH3)2],
0.99 (s, 3 H, CH3), 0.94 (s, 3 H, CH3). 13C NMR (75 MHz,
CDCl3): d = 163.0, 159.9, 154.3, 153.1, 152.9, 142.7, 132.7,
131.0 (q, JCF = 32.0 Hz), 129.4, 129.2, 126.1, 124.8 (q,
JCF = 3.5 Hz), 123.9 (q, JCF = 270.0 Hz), 113.8, 113.5, 113.4,
108.6, 104.2, 101.2, 97.9, 95.4, 55.7, 41.8, 40.1, 33.2, 22.9,
22.1. IR (KBr): n = 3280, 2935, 1685, 1616, 1326, 1125 cm–
1. HRMS (EI): m/z calcd for C30H27F3N2O4: 536.1923;
found: 536.1922 [M+].
(4) Impey, G. A.; Stynes, D. V. J. Am. Chem. Soc. 1993, 115,
7868.
(5) (a) Sutovsky, Y.; Linkhtenshtein, G. I.; Bittner, S.
Tetrahedron 2003, 59, 2939. (b) Shie, T.-L.; Lin, C.-H.;
Lin, S.-L.; Yang, D.-Y. Eur. J. Org. Chem. 2007, 29, 4831.
(6) (a) Mizobe, Y.; Ito, H.; Hisaki, I.; Miyata, M.; Hasegawa,
Y.; Tohnai, N. Chem. Commun. 2006, 2126. (b) Yang, J.-
S.; Liau, K.-L.; Tu, C.-W.; Hwang, C.-Y. J. Phys. Chem. A
2005, 109, 6450.
(7) Preisler, J.; Yeung, E. S. Anal. Chem. 1996, 68, 2885.
(8) Tablet, C.; Hillebrand, M. J. Photochem. Photobiol., A 2007,
189, 73.
(9) Annunziata, R.; Cinquini, M.; Cozzi, F.; Molteni, V.;
Schupp, O. Tetrahedron 1997, 53, 9715.
(10) Wang, J.-F.; Liao, Y.-X.; Kuo, P.-Y.; Gau, Y.-H.; Yang,
D.-Y. Synlett 2006, 2791.
(13) Crystallographic data (excluding structure factors) for 4 has
been deposited with the Cambridge Crystallographic Data
Centre as supplementary publication number CCDC-
744666. These data can be obtained free of charge via
data_request@ccdc.cam.ac.uk, or by contacting the
Cambridge Crystallographic Data Centre, 12 Union Road,
Cambridge CB2 1EZ, UK; fax: +44(1223)336033.
(11) Dömling, A. Chem. Rev. 2006, 106, 17.
(12) Procedure for the Preparation of 4
To a solution of p-anisidine (1.0 mmol), 4-(trifluoromethyl)-
benzaldehyde (1.0 mmol), isobutyraldehyde (1.0 mmol), and
a catalytic amount of Yb(OTf)3 (0.4 mmol) in DCE (10 mL)
was stirred at r.t. for 12 h. 4-Hydroxy-7-dimethylamino-
coumarin (1.0 mmol) was added to the mixture, and the
resulting solution was refluxed for 3 h. After being cooled to
Synlett 2010, No. 1, 111–114 © Thieme Stuttgart · New York