J.-M. Sotiropoulos, F.-X. Felpin et al.
Figure 6. Comparison of four reaction pathways.
with KBr pellets. Yields are of the isolated products that were deter-
mined to be pure by NMR spectroscopy and by thin layer chromatogra-
phy (TLC) unless otherwise stated.
d=51.9, 122.7, 124.8, 129.0, 130.3, 130.4, 133.5, 140.0, 148.2, 166.1 ppm;
IR (KBr): n˜ =1637, 1719, 2953, 3024 cmꢀ1; MS (EI): m/z: 207 [M], 176
[MꢀOCH3].
General procedure for the Heck cross-coupling reaction: To a solution of
aniline (2 mmol) in MeOH (10 mL) at 08C was added tBuONO (0.3 mL,
2.5 mmol). The mixture was stirred for 30 min at 08C before a solution of
(E)-Methyl-4-methoxycarbonylcinnamate (7c): This compound was pre-
pared according to the general procedure. Purification by column chro-
matography on silica gel (EtOAc/petroleum ether, 15%) gave the prod-
uct as a white solid. M.p.: 1248C (lit. 122–1238C);[17] 1H NMR (CDCl3,
250 MHz) d=3.81 (s, 3H), 3.92 (s, 3H), 6.51 (d, J=15.9 Hz, 1H), 7.57
(d, J=8.5 Hz, 2H), 7.70 (d, J=16.1 Hz, 1H), 8.04 ppm (d, J=8.2 Hz,
1H); 13C NMR (CDCl3, 75 MHz): d=51.8, 52.2, 120.1, 127.9, 130.0,
methyl acrylate (0.4 mL, 4.4 mmol) in MeOH (8 mL), PdACTHUNRGTNEUNG(OAc)2 (10 mg,
2.2 mol%), and a solution of MeSO3H (26 mL, 20 mol%) in MeOH
(4 mL) were added sequentially at 08C. Finally, anisole (1 mmol) was
added dropwise. The crude product was purified by column chromatogra-
phy on silica gel to give the corresponding cross-coupled product.
131.3, 138.5, 143.4, 166.4, 166.9 ppm; IR (KBr): n˜ =1641, 1720, 2958 cmꢀ1
MS (EI): m/z: 220 [M], 189 [MꢀOCH3].
;
(E)-Methyl-4-nitrocinnamate (7a): This compound was prepared accord-
ing to the general procedure. Purification by column chromatography on
silica gel (CH2Cl2/petroleum ether, 60%) gave the product as a white
solid. M.p.: 1618C (lit. 1618C);[15] 1H NMR (CDCl3, 300 MHz): d=3.84
(s, 3H), 6.56 (d, J=16.2 Hz, 1H), 7.67 (d, J=8.7 Hz, 2H), 7.72 (s, J=
15.8 Hz, 1H), 8.25 ppm (d, J=8.7 Hz, 2H); 13C NMR (CDCl3,
62.5 MHz): d=52.1, 122.0, 124.2, 128.6, 140.4, 141.9, 166.5 ppm; IR
(KBr): n˜ =1638, 1721, 2958, 3041 cmꢀ1; MS (EI): m/z: 207 [M], 176
[MꢀOCH3].
(E)-Methyl-2-nitrocinnamate (7b): This compound was prepared accord-
ing to the general procedure. Purification by column chromatography on
silica gel (CH2Cl2/petroleum ether, 70%) gave the product as a yellow
solid. M.p.: 71–728C (lit. 71–728C);[16] 1H NMR (CDCl3, 250 MHz): d=
3.80 (s, 3H), 6.34 (d, J=15.9 Hz, 1H), 7.49–7.68 (m, 4H), 8.01 (d, J=
7.9 Hz, 1H), 8.08 ppm (d, J=15.9 Hz, 1H); 13C NMR (CDCl3, 50 MHz):
E)-Methyl-2-methoxycarbonylcinnamate (7d): This compound was pre-
pared according to the general procedure. Purification by column chro-
matography on silica gel (EtOAc/petroleum ether, 15%) gave the prod-
uct as a colorless oil. 1H NMR (CDCl3, 300 MHz): d=3.80 (s, 3H), 3.92
(s, 3H), 6.29 (d, J=15.9 Hz, 1H), 7.39–7.45 (m, 1H), 7.49–7.60 (m, 2H),
7.95 (dm, J=7.7 Hz, 1H), 8.44 ppm (d, J=16.0 Hz, 1H); 13C NMR
(CDCl3, 75 MHz): d=51.6, 52.2, 120.6, 127.8, 129.3, 129.7, 130.6, 132.2,
136.2, 143.8, 166.8, 167.0; IR (KBr): n˜ =1597, 1635, 1715, 2953, 2998,
3068 cmꢀ1 HRMS (ES): calcd for C12H12O4Na: 243.0627 [M+Na+];
;
found: 243.0639.
Computational details: Calculations were performed with the Gaussi-
an 03 suite of programs[18] by using the hybrid functional B3LYP.[19,20]
B3LYP is a three-parameter functional, developed by Becke, which com-
bines the Becke gradient-corrected exchange functional and the Lee–
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