The Journal of Organic Chemistry
Article
using (S)-tert-butyl 4-phenylselenylhex-2-(E)-enoate and p-anisidine
with 1.1 equiv of NCS (silica gel, 20:1 n-hexane:EtOAc): orange oil
1 H), 7.12 (td, J 7.6 and 1.2, 1 H), 6.14−5.93 (m includes (br s, 1 H)
and (dtd, J 15.5, 6.4 and 1.5, 1 H)) 5.56 (ddt, J 15.5, 5.9 and 1.6, 1 H),
4.91 (d, J 5.9, 1 H), 2.18−2.05 (m, 2 H), 1.51 (s, 9 H), 1.01 (t, J 7.4, 3
H); δC (100 MHz, CDCl3) 169.9, 165.4, 152.1, 136.7, 130.8, 125.8,
123.1, 121.8, 120.8, 119.2, 82.6, 59.5, 28.0, 25.3, 13.2; m/z (ES+) 319
(100%, [MH]+), 263 (54%, [MH − CH3CH2CHCH2]+); HRMS
(ES+/TOF) m/z calculated for C17H23N2O2S+ [MH]+ 319.1480,
found 319.1495; enantiomeric ratio was determined as 97:3 by HPLC,
Chiralpak IA-3 column, 99:1 n-hexane:IPA, flow 1 mL min−1, UV
detection at 254 nm 21.1 min (minor), 34.7 min (major).
18
(31.8 mg, 54%); [α]D +41.3° (c = 0.93, CHCl3); IR 3384, 2966,
2932, 1728, 1513, 1459, 1369, 1239, 1150 cm−1; δH (400 MHz,
CDCl3) 6.76 (d, J 8.9, 2H), 6.58 (d, J 8.9, 2H), 5.89 (dtd, J 15.5, 6.5
and 1.4, 1H), 5.49 (ddt, J 15.4, 6.0 and 1.6, 1H), 4.34 (br t, J 5.9, 1H),
4.15 (br d, J 6.3, 1H), 2.13−2.01 (m, 2H), 1.44 (s, 9H), 0.98 (t, J 7.4,
3H); δC (100 MHz, CDCl3) 171.9, 152.6, 141.0, 136.1, 125.2, 115.1,
114.9, 81.9, 60.3, 55.9, 28.1, 25.2, 13.5; m/z (ES+) 292 (100%
+
[MH]+); HRMS (ES+/TOF) calculated for C17H26NO3 292.1913,
tert-Butyl (2S,3E)-2-[(4-Methoxy-1,3-benzothiazol-2-yl)-
amino]hex-3-enoate (8i). The title compound was prepared
according to the general procedure using (S)-tert-butyl 4-phenyl-
selenylhex-2-(E)-enoate and 2-aminobenzothiazole (silica gel, 9:1 n-
found 292.1925; enantiomeric ratio was determined as 96.5:3.5 using
HPLC, Chiralpak IA-3 column, 90:10 n-hexane:IPA, flow 1 mL min−1,
UV detection at 254 nm 5.9 min (minor), 7.6 min (major).
tert-Butyl (2S,3E)-2-[(4-Nitrophenyl)amino]hex-3-enoate
(8e). The title compound was prepared according to the general
procedure using (S)-tert-butyl 4-phenylselenylhex-2-(E)-enoate and 4-
nitroaniline (silica gel, 19:1 n-hexane:EtOAc): yellow oil (52.2 mg,
17
hexane:EtOAc): pale yellow oil/foam (57.1 mg, 82%); [α]D +37.7°
(c = 1.06, CHCl3); IR 3396, 2971, 2937, 2906, 1729, 1589, 1546, 1479,
1369, 1327, 1254, 1154, 1048 cm−1; δH (400 MHz, CDCl3) 7.19 (dd, J
7.9 and 1.0, 1 H), 7.03 (t, J 8.0, 1 H), 6.79 (dd, J 8.0 and 1.0, 1 H),
6.13 (br s, 1 H), 5.94 (dtd, J 15.4, 6.4 and 1.5, 1 H), 5.49 (ddt, J 15.5,
6.0 and 1.6, 1 H), 4.75 (br s, 1 H), 3.20 (s, 3 H), 2.10−2.03 (m, 2 H),
1.47 (s, 9 H), 0.97 (t, J 7.4, 3 H); δC (100 MHz, CDCl3) 169.5, 164.9,
150.7, 141.5, 136.8, 131.8, 123.1, 122.2, 113.1, 107.2, 82.6, 59.9, 55.8,
27.9, 25.2, 13.1; m/z (ES+) 349 (100%, [MH]+), 293 (47%, [MH −
CH3CH2CHCH2]+); HRMS (ES+/TOF) m/z calculated for
C18H25N2O3S+ 349.1586, found 349.1592; enantiomeric ratio was
determined as 96.5:3.5 by HPLC, Chiralpak IA-3 column, 90:10 n-
hexane:IPA, flow 1 mL min−1, UV detection at 236 nm 7.8 min
(minor), 10.3 min (major).
15
85%); [α]D +119.7° (c = 1.38, CHCl3); IR 3377, 2972, 2933, 1726,
1597, 1504, 1475, 1313, 1148, 1110 cm−1; δH (400 MHz, CDCl3) 8.07
(d, J 9.2, 2H), 6.53 (d, J 9.2, 2H), 5.86 (dtd, J 15.6, 6.5 and 1.4, 1H),
5.48 (ddt, J 15.5, 5.9 and 1.6, 1H), 5.36 (br s, 1H), 4.47 (dd, J 5.9 and
1.4, 1H), 2.15−2.04 (m, 2H), 1.48 (s, 9H), 0.98 (t, J 7.4, 3H); δC (100
MHz, CDCl3) 170.0, 151.5, 138.5, 137.0, 126.2, 111.9, 83.0, 58.0, 27.9,
25.2, 13.3; m/z (ES+) 307 (100%, [MH]+), 251 (49%, [M −
CH3CH2CHCH]+); HRMS (ES+/TOF) calculated for
+
C16H23N2O4 307.1658, found 307.1665; enantiomeric ratio was
determined as 96.5:3.5 using HPLC, Chiralpak IA-3 column, 95:5 n-
hexane:IPA, flow 1 mL min−1, UV detection at 224 nm 6.3 min
(minor), 6.8 min (major).
tert-Butyl (2S,3E)-2-[(pyridin-2-yl)amino]hex-3-enoate (8j).
The title compound was prepared according to the general procedure
using (S)-tert-butyl 4-phenylselenylhex-2-(E)-enoate and 2-amino-
pyridine (silica gel, 19:1 n-hexane:EtOAc): pale yellow oil (38.4 mg,
tert-Butyl (2S,3E)-2-{[3-(Hydroxymethyl)phenyl]amino}-
hexenoate (8f). The title compound was prepared according to the
general procedure using (S)-tert-butyl 4-phenylselenylhex-2-(E)-
enoate and 3-aminobenzyl alcohol (silica gel, 4:1 n-hexane:EtOAc):
pale yellow oil (27.3 mg, 62%); [α]D23 +20.7° (c = 0.86, CH3OH); IR
3391, 2968, 2932, 2874, 1726, 1608, 1488, 1369, 1323, 1256, 1148
cm−1; δH (400 MHz, CDCl3) 7,14 (t, J 7.9, 1H), 6.70 (ddd, J 7.6, 1.6
and 0.8, 1H), 6.61 (t, J 2.0, 1H), 6.53 (ddd, J 8.1, 2.4 and 0.9, 1H),
5.89 (dtd, J 15.4, 6.4 and 1.4, 1H), 5.49 (ddt, J 15.4, 5.7 and 1.6, 1H),
4.58 (s, 2H), 4.51 (br s, 1H), 4.42 (br s, 1H), 2.14−2.01 (m, 2H), 1.73
(br s, 1H), 1.46 (s, 9H), 0.98 (t, J 7.4, 3H); δC (100 MHz, CDCl3)
171.4, 146.9, 142.0, 136.0, 129.4, 124.5, 116.3, 112.7, 111.9, 82.0, 65.5,
58.9, 28.0, 25.3, 13.4; m/z (ES+) 292 (100%, [MH]+), 236 (16%,
[MH − CH3CH2CHCH]+); HRMS (ES+/TOF) m/z calculated for
21
73%); [α]D +23.6° (c = 1.27, CHCl3); IR 3363, 2967, 2933, 2874,
1724, 1600, 1482, 1368, 1328, 1254, 1146, 967 cm−1; δH (400 MHz,
CDCl3) 8.07 (ddd, J 5.2, 2.0 and 0.9, 1 H), 7.38 (ddd, J 8.2, 7.2 and
1.9, 1 H), 6.57 (ddd, J 7.2, 5.1 and 1.0, 1 H), 6.40 (dt, J 8.4 and 1.0, 1
H), 5.87 (dtd, J 15.6, 6.4 and 1.5, 1 H), 5.55 (1 H, ddt, J 15.5, 6.4 and
1.5, 1 H), 5.07 (br d, J 7.5, 1 H), 4.85 (ddd, J 7.5, 5.8 and 1.4, 1 H),
2.12−2.00 (m, 2 H), 1.45 (s, 9 H), 0.97 (t, J 7.4, 3 H); δC (100 MHz,
CDCl3) 171.3, 157.4, 147.9, 137.2, 135.5, 124.3, 113.4, 108.1, 81.7,
56.9, 28.0, 25.3, 13.3; m/z (ES+) 263 (19%, [MH]+), 207 (100%,
[MH − CH3CH2CHCH2]+); HRMS (ES+/TOF) m/z calculated
+
for C15H23N2O2 263.1760, found 263.1765; enantiomeric ratio was
+
C17H26NO3 292.1913, found 292.1920; enantiomeric ratio was
determined 94.5:5.5 by HPLC, Chiralpak IA-3 column, 96:4 n-
hexane:IPA, flow 1 mL min−1, UV detection at 268 nm 10.9 min
(minor), 22.1 min (major).
determined as 96.5:3.5 using HPLC, Chiralpak IA-3 column, 90:10
n-hexane:IPA, flow 1 mL min−1, UV detection at 212 nm 10.6 min
(minor), 13.4 min (major).
tert-Butyl (2S,3E)-2-[(6-Bromopyridin-2-yl)amino]hex-3-
enoate (8k). The title compound was prepared according to the
general procedure using (S)-tert-butyl 4-phenylselenylhex-2-(E)-
enoate and 2-amino-6-bromopyridine (silica gel, 20:1 n-hexane:E-
tert-Butyl (2S,3E)-2-[(1,3-Thiazol-2-yl)amino]hex-3-enoate
(8g). The title compound was prepared according to the general
procedure using (S)-tert-butyl 4-phenylselenylhex-2-(E)-enoate and 2-
aminothiazole (silica gel, 8:1 to 4:1 n-hexane:EtOAc): colorless oil
19
tOAc): pale yellow oil (52.0 mg, 76%); [α]D +23.6° (c = 1.19,
24
(39.4 mg, 73%); [α]D +93.2° (c = 1.11, CHCl3); IR 3326, 3198,
CHCl3); IR 3353, 2971, 2934, 2876, 1722, 1594, 1557, 1491, 1150
cm−1; δH (400 MHz, CDCl3) 7.20 (t, J 7.8, 1 H), 6.73 (d, J 7.5, 1 H),
6.28 (d, J 8.1, 1 H), 5.86 (dtd, J 15.4, 6.4 and 1.5, 1 H), 5.48 (ddt, J
15.4, 6.1 and 1.61, 1 H), 5.26 (br d, J 7.4, 1 H), 4.74 (ddd, J 7.3, 6.1
and 1.2, 1 H), 2.12−2.09 (m, 2 H), 1.46 (s, 9 H), 0.97 (t, J 7.5, 3 H);
δC (100 MHz, CDCl3) 170.7, 157.3, 140.1, 139.2, 136.2, 123.7, 116.4,
105.9, 82.0, 57.0, 27.9, 25.3, 13.3; m/z (ES+) 343 (88%, [MH + 2]+).
341 (82% [MH]+); HRMS (ES+/TOF) m/z calculated for
C15H22N2O279Br+ 341.0865, found 341.0850; enantiomeric ratio was
determined as 96.5:3.5 by HPLC, Chiralpak IA-3 column, 95:5 n-
hexane:IPA, flow 1 mL min−1, UV detection at 236 nm 8.6 min
(minor), 12.3 min (major).
2969, 2933, 1726, 1619, 1523, 1368, 1255, 1148 cm−1; δH (400 MHz,
CDCl3) 7.12 (d, J 3.6, 1 H), 6.50 (d, J 3.6, 1H), 5.91 (dtd, J 15.6, 6.4
and 1.4, 1 H), 5.72 (br s, 1 H), 5.48 (ddt, J 15.4, 6.1 and 1.6, 1 H),
4.67 (ddd, J 7.3, 5.9 and 1.2, 1 H), 2.10 (ddt, J 7.6, 6.3 and 1.4, 2 H),
1.47 (s, C(CH3)3, 9 H), 0.99 (t, J 7.4, 3 H); δC (100 MHz, CDCl3)
170.1, 168.2, 138.9, 136.7, 123.2, 107.3, 82.4, 60.1, 27.9, 25.3, 13.2; m/
z (ES+) 269 (100%, [MH]+), 214 (61%, [MH−C(CH3)3]+); HRMS
(ES+/TOF) m/z calculated for C13H20N2O2S+ [MH]+ 269.1324,
found 269.1334; enantiomeric ratio was determined as 94.5:5.5 by
HPLC, Chiralpak IA-3 column, 98:2 n-hexane:IPA, flow 1 mL min−1,
UV detection at 254 nm 30.3 min (minor), 70.8 min (major).
tert-Butyl (2S,3E)-2-[(1,3-Benzothiazol-2-yl)amino]hex-3-
enoate (8h). The title compound was prepared according to the
general procedure using (S)-tert-butyl 4-phenylselenylhex-2-(E)-
enoate and 2-aminobenzothiazole (silica gel, 14:1 n-hexane:EtOAc):
orange oil (46.8 mg, 74%); [α]D23 +54.8° (c = 0.99, CHCl3); IR 3314,
2973, 2932, 2875, 1725, 1599, 1540, 1456, 1445, 1368, 1153 cm−1; δH
(400 MHz, CDCl3) 7.59−7.54 (m, 2 H), 7.31 (ddd, J 7.7, 7.4 and 1.3,
tert-Butyl (2S,3E)-2-[(5-Iodopyridin-2-yl)amino]hex-3-enoate
(8l). The title compound was prepared according to the general
procedure using (S)-tert-butyl 4-phenylselenylhex-2-(E)-enoate and 2-
amino-5-iodopyridine (silica gel, 9:1 n-hexane:EtOAc): clear oil (60.2
27
mg, 78%); [α]D +34.9° (c = 0.97, CHCl3); IR 3359, 2967, 2933,
2873, 1722, 1586, 1476, 1368, 1256, 1149, 966 cm−1; δH (400 MHz,
CDCl3) 8.22 (dd, J 2.3 and 0.7, 1H), 7.58 (dd, J 8.7 and 2.3, 1H), 6.27
3905
dx.doi.org/10.1021/jo500341e | J. Org. Chem. 2014, 79, 3895−3907