Pd-Catalyzed Reactions of Allenylphosphonates
was quenched with water (5 mL), extracted with diethyl ether
(3ϫ20 mL), dried (Na2SO4), filtered, and concentrated under vac-
uum. The reaction mixture was checked by 31P/1H NMR spec-
troscopy at this stage. Other details are presented in Table 1.
m/z = 379 [M – H]+. C19H25O6P (380.4): calcd. C 60.00, H 6.62;
found C 59.97, H 6.70.
18: Yield (NMR; isolated): 63%; 0.26 g (57%). M.p. 126–130 °C.
IR (KBr): ν = 2973, 2880, 1807, 1690, 1605, 1487, 1329, 1256 cm–1.
˜
1H NMR (400 MHz, CDCl3, 25 °C, TMS): δ = 0.81–0.86 (m, 3 H,
CH3), 1.07 (s, 3 H, CH3), 1.19 (s, 3 H, CH3), 1.83 (s, 3 H, CH3),
2.15–2.20 (m, 1 H, CHAHB), 2.49–2.54 (m, 1 H, CHAHB) 3.90–
3.94 (m, 2 H, OCH2), 4.22–4.27 (m, 2 H, OCH2), 6.07 [d, J =
10.1 Hz, 1 H, =(CH)P], 7.00–8.02 (m, 3 H, Ar), 9.90 (s, 1 H, CHO)
ppm. 13C NMR (100 MHz, CDCl3, 25 °C, TMS): δ = 7.9, 21.4,
21.6, 24.9, 32.0, 32.6 (d, J = 6.0 Hz), 75.3 (d, J = 3.0 Hz), 75.4 (d,
J = 3.0 Hz), 96.7, 98.9 (d, J = 198.0 Hz), 111.6, 123.8, 126.4 (d, J
= 23.0 Hz), 130.2, 136.3, 163.2 (d, J = 9.0 Hz), 167.1, 190.2 ppm.
31P NMR (160 MHz, CDCl3, 25 °C, TMS): δ = 11.5 ppm. LC–MS:
m/z = 351 [M + H]+. C18H23O5P (350.4): calcd. C 61.71, H 6.62;
found C 61.69, H 6.58.
Synthesis of Benzofurans 9 and 15–25
Representative Procedure for 9: The residue, after removing the sol-
vents from the above reaction mixture, using allene 1c (1.39 mmol),
Pd(OAc)2 (0.016 g, 0.069 mmol), (o-tolyl)3P (0.095 g, 0.21 mmol),
5-iodovanillin (1.67 mmol), and K2CO3 (0.384 g, 2.78 mmol) in
PEG-400 (5 mL), was subjected to column chromatography (hex-
ane/EtOAc) to afford desired product 9. Yield (NMR; isolated):
81%; 0.28 g (70%). Gummy solid. IR (KBr): ν = 2973, 1688, 1595,
˜
1495, 1323, 1271, 1121, 1059, 1007 cm–1. 1H NMR (400 MHz,
CDCl3, 25 °C, TMS): δ = 0.69 (s, 3 H, CH3), 1.21 (s, 3 H, CH3),
1.93 (s, 6 H, 2 CH3), 3.87–3.94 (m, 2 H, OCH2), 4.00 (s, 3 H,
OCH3), 4.26–4.31 (m, 2 H, OCH2), 5.95 [d, J = 9.8 Hz, 1 H, =(CH)
P], 7.47 (s, 1 H, Ar), 7.62 (s, 1 H, Ar), 9.89 (s, 1 H, CHO) ppm.
13C NMR (100 MHz, CDCl3, 25 °C, TMS): δ = 21.4, 21.7, 26.1,
26.1, 32.6 (d, J = 5.0 Hz), 56.3, 75.3 (d, J = 6.0 Hz), 94.8 (d, J =
6.0 Hz), 98.4 (d, J = 199.0 Hz), 113.1, 118.9, 125.7 (d, J = 23.0 Hz),
131.2, 146.3, 156.4, 165.0 (d, J = 9.0 Hz), 190.2 ppm. 31P NMR
(160 MHz, CDCl3, 25 °C, TMS): δ = 11.8 ppm. LC–MS: m/z = 367
[M + H]+. C18H23O6P (366.4): calcd. C 59.01, H 6.33; found C
59.15, H 6.32.
19: Yield (NMR; isolated): 63%; 0.25 g (57%). M.p. 136–140 °C.
IR (KBr): ν = 2971, 1688, 1591, 1464, 1323, 1275, 1059, 1007,
˜
828 cm–1. 1H NMR (400 MHz, CDCl3, 25 °C, TMS): δ = 0.84–0.89
(m, 3 H, CH3), 1.08 (s, 3 H, CH3), 1.21 (s, 3 H, CH3), 1.88 (s, 3 H,
CH3), 2.21–2.27 (m, 1 H, CHAHB), 2.50–2.56 (m, 1 H, CHAHB),
3.88–3.95 (m, 2 H, OCH2), 4.24–4.29 (m, 2 H, OCH2), 6.05 [d, J
= 9.6 Hz, 1 H, =(CH)P], 7.97–8.27 (m, 2 H, Ar), 9.8 (s, 1 H, CHO)
ppm. 13C NMR (100 MHz, CDCl3, 25 °C, TMS): δ = 8.4, 21.9,
22.2, 25.5, 32.6, 33.1 (d, J = 5.0 Hz), 75.9 (d, J = 4.0 Hz), 97.9 (d,
J = 5.0 Hz), 101.2 (d, J = 198.0 Hz), 123.6, 126.4 (d, J = 23.0 Hz),
132.3, 144.9, 163.8, 163.9, 167.4, 189.4 ppm. 31P NMR (160 MHz,
CDCl3, 25 °C, TMS): δ = 10.6 ppm. LC–MS: m/z = 477 [M +
H]+. C18H22IO5P (476.3): calcd. C 45.40, H 4.66; found C 45.42,
H 4.67.
15: Yield (NMR; isolated): 76%; 0.27 g (65%). M.p. 142–146 °C.
IR (KBr): ν = 2975, 2812, 1688, 1605, 1487, 1294, 1260 cm–1. H
1
˜
NMR (400 MHz, CDCl3, 25 °C, TMS): δ = 1.09 (s, 3 H, CH3),
1.18 (s, 3 H, CH3), 1.86 (s, 6 H, 2 CH3), 3.90–3.96 (m, 2 H, OCH2),
4.21–4.26 (m, 2 H, OCH2) 6.04 [d, J = 10.0 Hz, 1 H, =(CH)P] 7.00–
8.03 (m, 3 H, Ar) 9.91 (s, 1 H, CHO) ppm. 13C NMR (100 MHz,
CDCl3, 25 °C, TMS): δ = 21.4, 21.6, 26.1, 26.1, 32.5 (d, J = 5.0 Hz),
75.4 (d, J = 6.0 Hz), 93.7 (d, J = 5.0 Hz), 98.7 (d, J = 198.0 Hz),
111.9, 124.1, 125.7 (d, J = 23.0 Hz), 130.3, 136.2, 164.2 (d, J =
9.0 Hz), 166.3, 190.1 ppm. 31P NMR (160 MHz, CDCl3, 25 °C,
TMS): δ = 11.4 ppm. LC–MS: m/z = 337 [M + H]+. C17H21O5P
(336.3): calcd. C 60.71, H 6.29; found C 60.75, H 6.28. X-ray struc-
ture was done on this sample.
20: Yield: 0.29 g (68%). M.p. 102–104 °C. IR (KBr): ν = 2820,
˜
1682, 1593, 1233, 1140, 1051 cm–1. 1H NMR (400 MHz, CDCl3,
25 °C, TMS): δ = 2.54 (s, 3 H, CH3), 4.12 (s, 3 H, OCH3), 7.41–
7.87 (m, 7 H, Ar), 10.06 (s, 1 H, CHO) ppm. 13C NMR (100 MHz,
CDCl3, 25 °C, TMS): δ = 9.6, 56.3, 105.1, 112.1, 117.6, 126.9,
128.5, 128.7, 130.5, 132.9, 133.0, 146.0, 146.7, 152.7, 191.8 ppm.
LC–MS: m/z = 267 [M + H]+. C17H14O3 (266.3): calcd. C 76.68, H
5.30; found C 76.60, H 5.31.
16: Yield (NMR; isolated): 65%; 0.16 g (59%). M.p. 162–166 °C.
IR (KBr): ν = 2932, 2884, 1692, 1595, 1273, 1053, 997, 831 cm–1.
21: Yield: 0.38 g (69%). Gummy solid. IR (KBr): ν = 2832, 1688,
˜
˜
1
1593, 1454, 1263, 1173 cm–1. H NMR (400 MHz, CDCl3, 25 °C,
1H NMR (400 MHz, CDCl3, 25 °C, TMS): δ = 1.08 (s, 3 H, CH3),
1.20 (s, 3 H, CH3), 1.92 (s, 6 H, 2 CH3), 3.88–3.95 (m, 2 H, OCH2),
4.25–4.30 (m, 2 H, OCH2), 6.00 [d, J = 9.6 Hz, 1 H, =(CH)P], 7.97
(s, 1 H, Ar), 8.27 (s, 1 H, Ar), 9.85 (s, 1 H, CHO) ppm. 13C NMR
(100 MHz, CDCl3, 25 °C, TMS): δ = 20.4, 20.7, 25.2, 31.6 (d, J =
6.0 Hz), 77.4 (d, J = 6.0 Hz), 93.5, 99.5 (d, J = 198.0 Hz), 122.4,
124.2 (d, J = 23.0 Hz), 130.9, 143.5, 163.3, 163.4, 165.2, 187.8 ppm.
31P NMR (160 MHz, CDCl3, 25 °C, TMS): δ = 10.6 ppm. LC–MS:
m/z = 463 [M + H]+. C17H20IO5P (462.2): calcd. C 44.18, H 4.36;
found C 44.12, H 4.38.
TMS): δ = 2.53 (s, 3 H, CH3), 7.41–8.10 (m, 8 H, Ar), 10.10 (s, 1
H, CHO) ppm. 13C NMR (100 MHz, CDCl3, 25 °C, TMS): δ =
9.4, 111.6, 111.7, 122.2, 126.4, 126.8, 128.5, 128.8, 130.6, 131.9,
152.7, 157.3, 191.8 ppm. LC–MS: m/z = 237 [M + H]+. C16H12O2
(236.3): Calcd. C. 81.34, H 5.12; found C 81.32, H 5.11.
22: Yield: 0.15 g (51%). M.p. 80–84 °C. IR (KBr): ν = 1690, 1566,
˜
1445, 1422, 1262, 1165, 1071, 801 cm–1. 1H NMR (400 MHz,
CDCl3, 25 °C, TMS): δ = 2.54 (s, 3 H, CH3), 7.28–8.23 (m, 7 H,
Ar), 10.03 (s, 1 H, CHO) ppm. 13C NMR (100 MHz, CDCl3, 25 °C,
TMS): δ = 9.7, 75.6, 112.7, 122.0, 127.0, 128.5, 128.9, 128.9, 130.1,
131.5, 133.5, 134.7, 190.4 ppm. LC–MS: m/z = 363 [M + H]+.
C16H11IO2 (362.2): calcd. C 53.06, H 3.06; found C 53.08, H 3.03.
X-ray structure was done on this sample.
17: Yield (NMR; isolated): 64%; 0.25 g (55%). M.p. 118–122 °C.
IR (KBr): ν = 2963, 1682, 1593, 1495, 1462, 1318, 1254, 1146, 1125,
˜
1057, 1011 cm–1. 1H NMR (400 MHz, CDCl3, 25 °C, TMS): δ =
0.83–0.87 (m, 3 H, CH3), 1.06 (s, 3 H, CH3), 1.21 (s, 3 H, CH3),
1.88 (s, 3 H, CH3), 2.19–2.25 (m, 1 H, CHAHB), 2.56–2.60 (m, 1 23: Yield: 0.28 g (66%). M.p 128–132 °C. IR (KBr): ν = 2714, 1688,
˜
1
H, CHAHB), 3.87–3.93 (m, 2 H, OCH2), 4.00 (s, 3 H, OCH3), 4.25– 1584, 1485, 1356, 1298 cm–1. H NMR (400 MHz, CDCl3, 25 °C,
4.30 (m, 2 H, OCH2), 6.01 [d, J = 9.8 Hz, 1 H, =(CH)P], 7.46 (s,
TMS): δ = 1.68 (s, 6 H, 2 CH3), 3.97 (s, 3 H, OCH3), 6.43 [s, 1 H,
1 H, Ar), 7.61 (s, 1 H, Ar), 9.88 (s, 1 H, CHO) ppm. 13C NMR =(CH)Ph], 7.28–7.44 (m, 7 H, Ar), 9.56 (s, 1 H, CHO) ppm. 13C
(100 MHz, CDCl3, 25 °C, TMS): δ = 7.9, 21.4, 21.8, 25.2, 32.0, NMR (100 MHz, CDCl3, 25 °C, TMS): δ = 28.8, 56.1, 92.4, 110.3,
32.6 (d, J = 5.0 Hz), 56.3, 75.3 (d, J = 2.0 Hz), 75.31 (d, J = 2.0 Hz),
97.8 (d, J = 5.0 Hz), 98.5 (d, J = 199.0 Hz), 113.2, 118.6, 126.6 (d,
120.5, 122.5, 124.9, 127.8, 128.5, 128.7, 130.4, 136.3, 144.1, 146.0,
155.8, 190.7 ppm. LC–MS: m/z = 295 [M + H]+. C19H18O3 (294.4):
J = 23.0 Hz), 131.0, 146.0, 157.1, 163.8 (d, J = 9.0 Hz), 190.1 ppm. calcd. C 77.53, H 6.16; found C 77.52, H 6.14. X-ray structure was
31P NMR (160 MHz, CDCl3, 25 °C, TMS): δ = 11.8 ppm. LC–MS:
done on this sample.
Eur. J. Org. Chem. 2009, 5927–5940
© 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjoc.org
5935