A Dual Gold-Iron Catalysis for a One-Pot Synthesis of 2,3-Dihydroisoxazoles
FULL PAPERS
Benzyl 5-butyl-3-(4-methoxyphenyl)isoxazole-2(3H)-car-
boxylate (4eb): According to the general procedure, com-
pound 4eb is obtained in 45% yield as a pale yellow oil.
1H NMR (DMSO, 400 MHz): d=0.88 (t, J=7.2 Hz, 3H),
1.30–1.38 (m, 2H), 1.45–1.54 (m, 2H), 2.26 (t, J=7.4 Hz,
2H), 3.74 (s, 3H), 5.04 (s, 1H), 5.18 (s, 2H), 5.86 (s, 1H),
6.91 (d, J=8.5 Hz, 1H), 7.21 (d, J=8.6 Hz, 1H), 7.32–7.39
(m, 5H); 13C NM;R (DMSO, 100 MHz): d=13.74, 22.25,
25.29, 28.65, 55.30, 67.95, 68.03, 96.52, 113.91 (2C), 128.08
(2C,), 128.20, 128.22 (2C), 128.45 (2C), 133.06, 135.04,
155.38, 159.40; IR-FT (film): n=3028, 2966, 2928, 2870,
1738, 1713, 1682, 1609, 1511, 1456, 1380, 1336, 1303, 1248,
1173, 1107, 1032, 930, 842, 750, 697 cmꢀ1; MS (EI): m/z=367
(15), 281 (7), 232 (63), 207 (13), 188 (28), 160 (5), 148 (22),
135 (21), 121 (20), 91 (100), 77 (15) , 57 (10), 44 (40); HR-
MS (ES+): m/z=368.1862, calcd. for C22H25NO4 +H+:
368.1860.
Benzyl
5-butyl-3,3-diethylisoxazole-2(3H)-carboxylate
(4ib): According to the general procedure, compound 4gb is
obtained in 38% yield as a pale yellow oil. 1H NMR
(CDCl3, 400 MHz): d=0.85–0.90 (m, 9H), 1.28–1.38 (m,
2H), 1.46–1.59 (m, 4H), 1.63–1.72 (m, 2H), 2.51 (t, J=
7.6 Hz, 2H), 4.68 (s, 1H), 5.23 (s, 2H), 7.29–7.40 (m, 5H);
13C NMR (CDCl3, 100 MHz): d=8.02 (2C), 13.83, 22.18,
27.56, 29.71, 31.35 (2C), 67.38, 93.08, 107.61, 128.09 (2C),
128.13, 128.43 (2C), 136.04, 140.64, 152.4; IR-FT (film): n=
3065, 2963, 2932, 2874, 1738, 1707, 1455, 1411, 1350, 1264,
1099, 944, 916, 745, 697 cmꢀ1; MS (EI): m/z=317 (2), 288
(6), 244 (29), 91 (100), 70 (6), 57 (5), 41 (3); HR-MS
(ES+): m/z=318.2046, calcd. for C19H27NO3 +H+: 318.2069.
N-[5-Butyl-3-phenyl-2-(phenylsulfonyl)isoxazolidin-5-
yloxy]benzenesulfonamide (5aa): According to the general
procedure, compound 5aa is obtained in 67% yield as a pale
yellow oil. 1H NMR (CDCl3, 400 MHz): d=0.87 (t, J=
7.13 Hz, 3H), 1.14–1.36 (m, 3H), 1.49–1.59 (m, 1H), 1.79
(ddd, J=4.6 Hz and J=12.6 Hz and J=14.2 Hz, 1H), 2.19
(ddd, J=4.4 Hz and J=12.2 Hz and J=14.4 Hz, 1H), 2.28
(dd, J=11 Hz, J=13.4 Hz, 1H), 2.68 (dd, J=7.1 Hz and J=
13.4 Hz, 1H), 5.19 (dd, J=7.0 Hz and J=11 Hz, 1H), 7.27–
7.36 (m, 5H), 7,54 (t, J=7.8 Hz, 2H), 7.63 (t, J=7.6 Hz,
2H), 7.64 (dd, J=7.6 Hz and J=15.3 Hz, 1H), 7.70 (dd, J=
7.6 Hz and J=14.8 Hz, 1H) , 7.87 (d, J=7.5 Hz, 2H), 7.97
(d, J=7.4 Hz, 2H), 8.05 (s, 1H); 13C NMR (CDCl3,
100 MHz): d=13.85, 22.62, 26.35, 30.83, 46.61, 61.83, 115.48,
126.38 (2C), 128.1, 128.28 (2C), 128.58 (2C), 128.74 (2C),
129.09 (2C), 129.14 (2C), 133.68, 134.02, 136.86, 137.01,
139.18; IR-FT (film): n=3233, 2960, 2856, 1448, 1388, 1343,
1324, 1170, 1092, 1023, 964, 857, 754, 698, 600, 573,
554 cmꢀ1; MS (ES+): m/z=517 (50), 391 (27), 344 (100),
204 (6); HR-MS (ES+): m/z=517.1455, calcd. for
C25H28N2O6S2 +H+: 517.1467.
Benzyl 5-butyl-3-(thiophen-2-yl) isoxazole-2(3H)-carbox-
ylate (4fb): According to the general procedure, compound
1
4fb is obtained in 72% yield as a pale yellow oil. H NMR
(CDCl3, 400 MHz): d=0.92 (t, J=7.2 Hz, 3H), 1.35–1.43
(m, 2H), 1.54–1.62 (m, 2H), 2.29 (t, J=7.5 Hz, 2H), 4,87 (s,
1H), 5.25 (s, 2H), 6.20 (s, 1H), 6.95 (dd, J=3.52 Hz and J=
4.8 Hz, 1H), 7.03 (d, J=3.39 Hz, 1H), 7.26 (d, J=5.1 Hz,
1H), 7.25–7.32 (m, 5H); 13C NMR (CDCl3, 100 MHz): d=
13.73, 22.17, 25.29, 28.55, 63.64, 68.20, 95.56, 125.40, 125.79,
126.84, 128.17 (2C), 128.30, 128.49 (2C), 135.52, 145.10,
156.68; IR-FT: n=3114, 3033, 2957, 2931, 2871, 1739, 1716,
1682, 1497, 1455, 1393, 1320, 1242, 1115, 1064, 968, 718,
698 cmꢀ1; MS (EI): m/z=343 (16), 208 (79), 164 (3), 124
(14), 111 (6), 91 (100), 70 (3), 57 (8), 41 (4); HR-ESI-MS:
m/z=343.1302, calcd. for C19H21NSO3: 343.1320.
Benzyl 5-tert-butyl-3-phenylisoxazole-2(3H)-carboxylate
(4gb): According to the general procedure, compound 4gb is
obtained in 36% yield as a pale yellow oil. 1H NMR
(CDCl3, 400 MHz): d=1.23 (s, 9H), 4.77 (s, 1H), 5.19 (ab,
Jab =12.41 Hz, 1H), 5.25 (ab, Jab =12.41 Hz, 1H), 7.28–7.34
(m, 5H); 13C NMR (CDCl3, 100 MHz): d=27.97 (3C),
31.47, 67.90, 68.54, 94.25, 126.71 (2C), 127.85, 127.96 (2C),
128.12, 128.43 (2C), 128.59 (2C), 135.75, 141.03, 163.32; IR-
FT (film): n=3033, 2968, 2932, 2872, 1749, 1719, 1669, 1588,
1496, 1456, 1393, 1321, 1230, 1203, 1093, 1029, 926, 734,
696 cmꢀ1; MS (EI): m/z=337 (17), 278 (2), 202 (54), 186 (7),
160 (24), 117 (12), 105 (6), 91 (100), 77 (3), 57 (19), 41 (5);
HR-MS (ES+)MS: m/z=338.1779, calcd. for C21H23NO3 +
H+: 338.1756.
Benzyl 5-(benzyloxycarbonylaminooxy)-5-butyl-3-phenyl-
AHCTUNGTREGiNNUN soxazolidine-2-carboxylate (5ab): According to the general
procedure, compound 5ab is obtained in 76% yield, as a
pale yellow oil. H NMR (CDCl3, 400 MHz): d=0.83 (t, J=
1
7.2 Hz, 3H), 1.22–1.30 (m, 3H), 1.49–1.55 (m, 1H), 1.74
(ddd, J=4.3 Hz and J=12.4 Hz and J=14.3 Hz, 1H), 2.14
(ddd, J=4.1 Hz and J=11.6 Hz and J=14.4 Hz, 1H), 2.28
(dd, J=6.4 Hz and J=13.4 Hz, 1H), 2.92 (dd, J=9.1 Hz and
J=13.4 Hz, 1H), 5.11–5.22 (m, 4H), 5.34 (dd, J=6.6 Hz and
J=8.8 Hz, 1H), 7.26–7.37 (m, 15H), 8.07 (b, 1H); 13C NMR
(CDCl3, 100 MHz): d=13.72, 22.63, 26.13, 29.78, 45.32,
63.10, 67.38, 68.64, 115.47, 125.68 (2C), 127.59, 128.04,
128.31 (2C), 128.38 (2C), 128.47, 128.51 (2C), 128.63 (2C),
128.77 (2C), 135.12, 135.68, 141.34, 156.57, 159.60; IR-FT
(film): n=3306, 3072, 3033, 2959, 2927, 2871, 1758, 1718,
1497, 1455, 1387, 1310, 1252, 1227, 1102, 1028, 980, 866, 755,
698 cmꢀ1; MS (ES+): m/z=1010 (5), 505 (90), 338 (27), 289
(24), 271 (100), 217 (5), 204 (11), 189 (50), 168 (11), 124 (6),
83 (78); HR-MS (ES+): m/z=505.2322, calcd. for
C29H32N2O6 +H+: 505.2339.
Benzyl 5-phenethyl-3-phenylisoxazole-2(3H)-carboxylate
(4hb): According to the general procedure, compound 4hb
is obtained in 49% yield as a pale yellow oil. 1H NMR
(CDCl3, 400 MHz): d=2.63 (t, J=7.7 Hz, 2H), 2.92 (t, J=
7.8 Hz, 2H), 4.77 (dd, J=1.0 Hz and J=2.1 Hz), 5.22 (ab,
J=12.4 Hz, 1H), 5.24 (ab, J=12.4 Hz, 1H), 5.88 (s, 1H),
7.19–7.34 (m, 15H); 13C NMR (CDCl3, 100 MHz): d=27.41,
32.53, 68.10, 68.49, 97.45, 126.26 (2C), 126.88 (2C), 128.02,
128.15, 128.27, 128.40 (2C), 128.46 (2C), 128.49 (2C), 128.54
(2C), 135.59, 140.25, 140.59, 154.15; IR-FT (film): n=3063,
3030, 2929, 2875, 1745, 1714, 1683, 1603, 1496, 1455, 1392,
Benzyl 5-(benzyloxycarbonylaminooxy)-5-butyl-3-(4-chlor-
ophenyl) isoxazolidine-2-carboxylate (5bb): According to
the general procedure, compound 5bb is obtained in 79%
1324, 1233, 1110, 1076, 1029, 937, 910, 818, 751, 697 cmꢀ1
;
yield, as a white solid. H NMR (CDCl3, 400 MHz): d=0.83
1
MS (EI): m/z=385 (14), 294 (4), 250 (32), 208 (2), 194 (3),
158 (12), 145 (13), 117 (22), 105 (12), 91 (100), 77 (5), 65 (6),
44 (3); HR-MS (ES+): m/z=386.1726, calcd. for
C25H23NO3 +H+: 386.1756.
(t, J=7.13 Hz, 3H), 1.19–1.31 (m, 3H), 1.46–1.55 (m, 1H),
1.73 (ddd, J=4.3 Hz and J=12.6 Hz and J=14.2 Hz, 1H),
2.13 (ddd, J=4.4 Hz and J=11.8 Hz and J=14.4 Hz, 1H),
2.22 (dd, J=6.3 Hz, J=13.4 Hz, 1H), 2.91 (dd, J=9.1 Hz
Adv. Synth. Catal. 2009, 351, 1991 – 1998
ꢀ 2009 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1997