1254
J.-L. Zhu, Y.-H. Chan
LETTER
isomer) = 1.38 (td, J1 = 7.1 Hz, J2 = 0.7 Hz, 6 H), 2.32 (td,
J1 = 7.8 Hz, J2 = 6.4 Hz, 2 H), 2.95 (br t, J = 7.9 Hz, 2 H),
4.21–4.34 (m, 4 H), 5.00 (br d, J = 11.5 Hz, 1 H), 5.04 (br d,
J = 17.1 Hz, 1 H), 5.82 (dm, J = 17.1 Hz, 1 H), 7.37–7.45
(m, 3 H), 7.65 (br d, J = 7.8 Hz, 2 H). 13C NMR (100 MHz,
CDCl3): d (Z-isomer) = 16.1 (d, J = 6.1 Hz), 30.2, 34.7, 64.5
(d, J = 5.5 Hz), 115.8, 127.5, 128.3, 129.6, 132.1, 136.5,
166.9 (d, J = 13.0 Hz); d (E-isomer) = 16.2 (d, J = 6.3 Hz),
27.0, 30.5, 64.6 (d, J = 6.0 Hz), 115.8, 127.1, 128.7, 130.5,
133.6, 136.6, 166.7 (d, J = 13.4 Hz). HRMS–FAB: m/z calcd
for C15H23O4NP [M + H]+: 312.1365; found: 312.1357.
(13) The reactions were performed similarly as indicated in ref.
12 except for adding 4 Å MS (90 mg/1 mmol) to the solution
of oxime before Pd(PPh3)4 and DBU were introduced.
(14) The E/Z ratios were tentatively assigned based on 1H NMR
spectra.
(15) Stock, G.; Brizzolara, A.; Landesman, H.; Szmuszkovicz, J.;
Terrell, R. J. Am. Chem. Soc. 1963, 85, 207.
(16) Crotti, P.; Badalassi, F.; Di Bussolo, V.; Favero, L.;
Pineschi, M. Tetrahedron 2001, 57, 8559.
(17) Goto, M.; Akimoto, K.-i.; Aaoki, K.; Shindo, M.; Koga, K.
Tetrahedron Lett. 1999, 40, 8129.
(12) Typical Procedure of the Amino-Heck Reaction for 1a
Under a nitrogen atmosphere, Pd(PPh3)4 (89 mg, 0.08 mmol)
and DBU (356 mg, 2.34 mmol) were sequentially added to a
solution of 1a (120 mg, 0.39 mmol) in anhyd MeCN
(19.3ml) at r.t. The resulting yellow suspension was quickly
warmed to 80 °C and continued to stir for 3 h. The mixture
was then filtrated through a Celite pad, washed with EtOAc
and concentrated. The chromatographic purification of the
crude products on aluminum oxide (hexane–EtOAc = 30:1,
10:1, and 5:1) provided 2a in 90% yield (55 mg) and 9 in
10% yield (6 mg).
(18) For the characterizations of 2a and 2k, see: (a) Hironori, T.;
Mitsuru, K.; Koichi, K. Bull. Chem. Soc. Jpn. 2002, 75,
1451. (b) For 2b and 2h, see: Mitsuru, K.; Hideyuki, Y.;
Motoki, Y.; Koichi, N. Heterocycles 2005, 65, 273. (c) For
2c and 2d, see: Dana, C.; Convert, O.; Giranet, J.-P.;
Mulliez, E. Can. J. Chem. 1976, 54, 1827. (d) For 2e, see:
Jones, R. A.; Karatza, M.; Voro, T. N.; Civeir, P. U.; Franck,
A.; Ozturk, O.; Seaman, J. P.; Whitmore, A. P.; Williamson,
D. J. Tetrahedron 1996, 52, 8724. (e) For 2f, see:
Berthiaume, S. L.; Bray, B. L.; Hess, P.; Liu, Y.; Maddox,
M. L. Can. J. Chem. 1995, 73, 675. (f) For 2i, see: Arcadi,
A.; Rossi, E. Tetrahedron 1998, 54, 15253. (g) For 2j, see:
Hiroya, K.; Matsumoto, S.; Ashikawa, M.; Ogiwara, K.;
Sakamoto, T. Org. Lett. 2006, 23, 5349.
5-Methyl-2-phenyl-1H-pyrrole (2a): IR (neat): 3399, 774,
751 cm–1. 1H NMR (400 MHz, CDCl3): d = 2.36 (s, 3 H),
5.99 (m, 1 H), 6.44 (t, J = 3.0 Hz, 1 H), 7.19 (t, J = 7.3 Hz, 1
H), 7.36 (t, J = 7.8 Hz, 2 H), 7.45 (br d, J = 8.2 Hz, 2 H), 8.13
(br s, 1 H). 13C NMR (100 MHz, CDCl3): d = 13.2, 106.2,
108.0, 123.4, 125.7, 128.9, 129.1, 130.8, 133.0. LRMS
(MALDI): m/z calcd for C11H11N [M]+: 157.1; found: 157.0.
2-Phenylpyridine (9): IR (neat): 1735, 1266, 739 cm–1. 1H
NMR (400 MHz, CDCl3): d = 7.19–7.26 (m, 1 H), 7.40–7.52
(m, 3 H), 7.70–7.79 (m, 2 H), 8.00 (d, J = 7.3 Hz, 2 H), 8.70
(d, J = 4.7 Hz, 1 H). 13C NMR (100 MHz, CDCl3): d = 120.6,
122.1, 126.9, 128.8, 129.0, 136.7, 139.4, 149.7, 157.5.
LRMS (MALDI): m/z calcd. for C11H10N [M + H]+: 156.1;
found: 156.1.
(19) As an unknown compound, the spectral data of 2-(1-heptyl)-
5-methyl-1H-pyrrole (2g) are as follows: IR (neat): 3373,
2925, 2854, 765 cm–1. 1H NMR (400 MHz, CDCl3): d = 0.89
(t, J = 6.9 Hz, 3 H), 1.22–1.39 (m, 8 H), 1.54–1.66 (m, 2 H),
2.25 (s, 3 H), 2.55 (t, J = 7.7 Hz, 2 H), 5.76 (br s, 1 H), 5.77
(br s, 1 H), 7.56 (br s, 1 H). 13C NMR (100 MHz, CDCl3):
d = 13.0, 14.1, 22.6, 27.8, 29.1, 29.4, 29.8, 31.8, 104.8,
105.6, 125.8, 131.6. HRMS–FAB: m/z calcd for C12H20N
[M – H]+: 178.1596; found: 178.1600.
Synlett 2008, No. 8, 1250–1254 © Thieme Stuttgart · New York