K.H. Kang et al. / Tetrahedron 69 (2013) 2542e2549
2547
2.96 (q, J¼7.2 Hz, 1H), 1.61e1.25 (m, 8H), 1.38 (s, 9H), 1.22 (d,
J¼7.2 Hz, 3H), 0.87 (t, J¼6.8 Hz, 3H); 13C NMR (CDCl3, 100 MHz)
176.5 (quat.), 143.0 (quat.), 136.4 (quat.), 127.4 (CH), 124.2 (CH),
123.9 (CH), 119.3 (CH), 67.9 (CH), 41.0 (CH), 40.8 (quat.), 36.2 (CH2),
31.7 (CH2), 28.4 (CH3), 25.4 (CH2), 22.5 (CH2), 21.1 (CH3), 13.9 (CH3);
IR (neat, cmꢀ1) 2958, 2923, 2853, 1652, 1562, 1473, 1391, 668, 647;
CSP-HPLC (Chiralpak AD-H column; 5% 2-propanol in hexane;
0.5 mL/min) 96:4 er, 15.0 min (major enantiomer), 20.3 min (mi-
nor enantiomer).
4.2.20. N-Pivaloyl-(R)-2-(4-chlorophenyl)-(R)-3-(5-methyl-2-
thienyl) indoline (3s). A yellow oil (149 mg, 73% overall yield). 1H
NMR (CDCl3, 400 MHz) 8.31 (d, J¼8.4 Hz, 1H), 7.37e7.05 (m, 7H),
6.53 (m, 1H), 6.49 (d, J¼3.2 Hz, 1H), 5.68 (s, 1H), 4.34 (s, 1H), 2.41 (s,
3H), 1.08 (s, 9H); 13C NMR (CDCl3, 100 MHz) 177.4 (quat.), 144.6
(quat.), 143.3 (quat.), 141.3 (quat.), 139.3 (quat.), 133.3 (quat.), 131.2
(quat.), 129.2 (CH), 128.8 (CH), 126.7 (CH), 125.6 (CH), 124.9 (CH),
124.8 (CH), 124.4 (CH), 119.3 (CH), 71.9 (CH), 53.0 (CH), 40.6 (quat.),
28.4 (CH3), 15.4 (CH3); IR (neat, cmꢀ1) 2970, 2928, 1652, 1475, 1355,
HRMS (FAB) calcd for C19H30NO (Mþþ1): 288.2327. Found
20
288.2328; [
a]
ꢀ20.8 (c 0.018, CHCl3); CSP-HPLC (Chiralpak AD-H
D
column; 2% 2-propanol in hexane; 0.5 mL/min) 90:10 er, 61.6 min
(major enantiomer), 13.0 min (minor enantiomer).
4.2.16. N-Pivaloyl-(R)-2-(4-chlorophenyl)-(S)-3-methylindoline
(3o). A colorless oil (105 mg, 64% overall yield). 1H NMR (CDCl3,
400 MHz) 8.25 (d, J¼8.4 Hz, 1H), 7.29e7.04 (m, 7H), 5.39 (s, 1H),
3.08 (q, J¼7.2 Hz, 1H), 1.42 (d, J¼7.2 Hz, 3H), 1.22 (s, 9H); 13C NMR
(CDCl3, 100 MHz) 177.4 (quat.), 143.7 (quat.), 142.0 (quat.), 134.4
(quat.), 132.9 (quat.), 128.9 (CH), 127.9 (CH), 126.4 (CH), 124.5 (CH),
124.3 (CH), 118.8 (CH), 69.9 (CH), 47.3 (CH), 40.7 (quat.), 28.5 (CH3),
22.1 (CH3); IR (neat, cmꢀ1) 3423, 2964, 2924, 2854, 1643, 1475,
1400, 1355, 1322, 1190, 1088, 1013, 811, 758, 669. Anal. Calcd for
1188, 1092, 1013, 754, 737. Anal. Calcd for C24H24ClNOS: C, 70.31; H,
20
5.90; N, 3.42; S, 7.82. Found: C, 70.38; H, 5.81; N, 3.32; S, 7.67; [a]
D
ꢀ38.4 (c 0.055, CHCl3); CSP-HPLC (Chiralpak AD-H column; 5% 2-
propanol in hexane; 0.5 mL/min) 99:1 er, 11.0 min (major enan-
tiomer), 19.2 min (minor enantiomer).
4.2.21. N-Pivaloyl-(R)-3-(2-benzothienyl)-(S)-2-ethylindoline (3t). A
colorless oil (134 mg, 74% overall yield). 1H NMR (CDCl3, 400 MHz)
8.18 (d, J¼8.4 Hz, 1H), 7.73e7.10 (m, 7H), 6.68 (s, 1H), 4.52 (dd,
J¼10.8 and 2.4 Hz, 1H), 4.37 (s, 1H), 1.84e1.63 (m, 2H), 1.17 (s, 9H),
1.13 (t, J¼7.6 Hz, 3H); 13C NMR (CDCl3, 100 MHz) 176.6 (quat.),
146.7 (quat.), 144.0 (quat.), 140.0 (quat.), 139.4 (quat.), 132.1
(quat.), 128.6 (CH), 125.7 (CH), 124.4 (CH), 124.3 (CH), 124.0 (CH),
123.4 (CH), 122.3 (CH), 121.3 (CH), 119.8 (CH), 70.4 (CH), 47.1 (CH),
C20H22ClNO: C, 73.27; H, 6.76; N, 4.27. Found: C, 73.28; H, 6.74; N,
20
4.25; [
a
]
þ49.4 (c 0.038, CHCl3); CSP-HPLC (Chiralpak AD-H col-
D
umn; 2% 2-propanol in hexane; 0.5 mL/min) 92:8 er, 15.0 min
(major enantiomer), 13.3 min (minor enantiomer).
4.2.17. N-Pivaloyl-(R)-2-(4-methoxyphenyl)-(S)-3-methylindoline
(3p). A colorless oil (94 mg, 58% overall yield). 1H NMR (CDCl3,
400 MHz) 8.27 (d, J¼8.4 Hz, 1H), 7.28e6.75 (m, 7H), 5.38 (s, 1H),
3.73 (s, 3H), 3.09 (q, J¼7.2 Hz,1H), 1.40 (d, J¼7.2 Hz, 3H),1.23 (s, 9H);
13C NMR (CDCl3, 100 MHz) 177.6 (quat.), 158.6 (quat.), 144.0 (quat.),
135.6 (quat.), 134.9 (quat.), 127.7 (CH), 126.1 (CH), 124.3 (CH), 118.8
(CH), 114.0 (CH), 70.0 (CH), 55.2 (CH3), 47.4 (CH), 40.7 (quat.), 28.5
(CH3), 22.1 (CH3); IR (neat, cmꢀ1) 3447, 2963, 2924, 2863, 1639,
1511, 1475, 1357, 1247, 1177, 1030, 820, 765, 669. Anal. Calcd for
40.7 (quat.), 28.3 (CH3), 28.2 (CH2), 10.0 (CH3); IR (neat, cmꢀ1
)
2961, 2923, 2869, 1644, 1473, 1457, 1356, 1185, 1077, 723. Anal.
Calcd for C23H25NOS: C, 75.99; H, 6.93; N, 3.85; S, 8.82. Found: C,
20
75.81; H, 6.99; N, 3.91; S, 8.82; [
a
]
þ10.1 (c 0.011, CHCl3); CSP-
D
HPLC (Chiralpak AD-H column; 1% 2-propanol in hexane;
0.5 mL/min) 97:3 er, 38.4 min (major enantiomer), 49.4 min (mi-
nor enantiomer).
C21H25NO2: C, 77.98; H, 7.79; N, 4.33. Found: C, 77.89; H, 7.65; N,
20
4.17; [
a]
þ52.0 (c 0.015, CHCl3); CSP-HPLC (Chiralpak AD-H col-
4.2.22. N-Pivaloyl-(R)-3-(2-benzothienyl)-(S)-2-styrylindoline
(3u). A colorless oil (151 mg, 69% overall yield). 1H NMR (CDCl3,
400 MHz) 8.30 (d, J¼8.0 Hz, 1H), 7.75e7.10 (m, 13H), 6.78 (s, 1H),
6.51 (d, J¼16.0 Hz, 1H), 6.34 (dd, J¼16.0 and 5.2 Hz, 1H), 5.43 (d,
J¼5.2 Hz, 1H), 4.48 (s, 1H), 1.19 (s, 9H); 13C NMR (CDCl3, 100 MHz)
177.3 (quat.), 145.8 (quat.), 144.2 (quat.), 139.5 (quat.), 139.4
(quat.), 136.0 (quat.), 131.6 (quat.), 131.0 (CH), 129.0 (CH), 128.8
(CH), 128.6 (CH), 128.0 (CH), 126.5 (CH), 125.6 (CH), 124.6 (CH),
124.5 (CH), 124.2 (CH), 123.5 (CH), 122.3 (CH), 121.6 (CH), 119.9
D
umn; 2% 2-propanol in hexane; 0.5 mL/min) 91:9 er, 27.4 min
(major enantiomer), 32.2 min (minor enantiomer).
4.2.18. N-Pivaloyl-(R)-3-(5-methyl-2-thienyl)-(S)-2-phenethylindoline
(3q). A colorless oil (151 mg, 75% overall yield). 1H NMR (CDCl3,
400 MHz) 8.09 (d, J¼8.0 Hz, 1H), 7.30e7.06 (m, 8H), 6.47 (dd, J¼2.8
and 0.8 Hz, 1H), 6.28 (d, J¼3.2 Hz, 1H), 4.53 (dd, J¼10.4 and 2.8 Hz,
1H), 4.32 (s, 1H), 2.88e2.72 (m, 2H), 2.38 (s, 3H), 2.03e1.94 (m, 2H),
1.11 (s, 9H); 13C NMR (CDCl3, 100 MHz) 176.6 (quat.), 143.8 (quat.),
143.3 (quat.), 140.5 (quat.), 138.8 (quat.), 132.9 (quat.), 128.6 (CH),
128.5 (CH), 128.3 (CH), 126.3 (CH), 125.5 (CH), 124.8 (CH), 124.4 (CH),
124.2 (CH), 119.5 (CH), 68.9 (CH), 47.0 (CH), 40.5 (quat.), 36.6 (CH2),
32.1 (CH2), 28.1 (CH3), 15.3 (CH3); IR (neat, cmꢀ1) 3059, 2920, 2853,
1645, 1475, 1403, 1357, 1189, 1083, 795, 700; HRMS (FAB) calcd for
(CH), 69.7 (CH), 50.8 (CH), 40.7 (quat.), 28.5 (CH3); IR (neat, cmꢀ1
)
3442, 3026, 2973, 2930, 2360, 2341, 1641, 1476, 1401, 1356, 1186,
739, 691. Anal. Calcd for C29H27NOS: C, 79.60; H, 6.22; N, 3.20; S,
7.33. Found: C, 79.72; H, 6.28; N, 3.31; S, 7.42; [
a
]
20 ꢀ39.2 (c 0.013,
D
CHCl3); CSP-HPLC (Chiralpak AD-H column; 2% 2-propanol in
hexane; 0.5 mL/min) 97:3 er, 41.0 min (major enantiomer),
34.2 min (minor enantiomer).
C26H30NOS (Mþþ1): 404.2048. Found 404.2047; [
a]
D
20 þ18.0 (c 0.012,
CHCl3); CSP-HPLC (Chiralpak AD-H column; 5% 2-propanol in hex-
ane; 0.5 mL/min) 97:3 er, 18.4 min (major enantiomer), 36.9 min
(minor enantiomer).
4.2.23. N-Pivaloyl-(R)-3-(2-benzothienyl)-(R)-2-phenylindoline
(3v). A colorless oil (144 mg, 70% overall yield). 1H NMR (CDCl3,
400 MHz) 8.39 (d, J¼8.0 Hz, 1H), 7.78e7.09 (m, 13H), 6.83(s, 1H),
5.86(s, 1H), 4.53 (s, 1H), 1.06 (s, 9H); 13C NMR (CDCl3, 100 MHz)
177.6 (quat.), 146.6 (quat.), 145.0 (quat.), 142.7 (quat.), 139.6 (quat.),
139.5 (quat.), 130.7 (quat.), 129.0 (CH), 128.9 (CH), 127.6 (CH), 125.8
(CH), 125.2 (CH), 124.7 (CH), 124.5 (CH), 124.2 (CH), 123.5 (CH),
122.4 (CH), 121.4 (CH), 119.3 (CH), 71.6 (CH), 53.6 (CH), 40.7 (quat.),
28.4 (CH3); IR (neat, cmꢀ1) 3056, 2971, 2920, 1641, 1473, 1356, 1185,
748, 694. Anal. Calcd for C27H25NOS: C, 78.80; H, 6.12; N, 3.40; S,
4.2.19. N-Pivaloyl-(R)-3-(5-methyl-2-thienyl)-(S)-2-styrylindoline
(3r). A colorless oil (140 mg, 70% overall yield). 1H NMR (CDCl3,
400 MHz) 8.25 (d, J¼8.0 Hz, 1H), 7.34e7.06 (m, 8H), 6.51e6.26 (m,
4H), 5.29 (d, J¼5.2 Hz, 1H), 4.35 (s, 1H),2.39 (s, 3H), 1.21 (s, 9H); 13C
NMR (CDCl3, 100 MHz) 177.3 (quat.), 144.0 (quat.), 143.0 (quat.),
139.1 (quat.), 136.1(quat.), 132.4 (quat.), 130.7 (CH), 129.2 (CH),
128.6 (CH), 128.5 (CH), 127.9 (CH), 126.5 (CH), 125.4 (CH), 124.8
(CH), 124.5 (CH), 119.7 (CH), 70.3 (CH), 50.2 (CH), 40.6 (quat.), 28.5
(CH3), 15.4 (CH3); IR (neat, cmꢀ1) 2961, 2922, 1646, 1474, 1401,
7.79. Found: C, 78.97; H, 6.20; N, 3.41; S, 7.81; [
a
]
20 ꢀ20.4 (c 0.010,
D
CHCl3); CSP-HPLC (Chiralcel OD column; 1% 2-propanol in hexane;
0.5 mL/min) 97:3 er, 15.9 min (major enantiomer), 23.8 min (minor
enantiomer).
1356, 1186, 967, 799, 737, 693; HRMS (FAB) calcd for C26H28NOS
20
(Mþþ1): 402.1892. Found 402.1891; [
a
]
ꢀ49.7 (c 0.018, CHCl3);
D