T. Nguyen Van, N. De Kimpe / Tetrahedron 56 (2000) 7299–7304
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d, J8.0 Hz, vCH, A2B2 system), 8.27 (1H, s, CHvN); 13
C
overl.); 13C NMR (CDCl3): 12.8 (CH3), 41.6 (C-2), 46.1
(C-3), 55.0 (OCH3), 63.8 (C-4), 113.6 (2× vCH), 126.3
(vCH), 127.7 (2× vCH), 127.8 (2× vCH), 128.8 (2×
vCH), 131.5 (vCquat), 137.5 (vCquat), 158.5 (vCquat);
IR (NaCl): 1608, 1508, 1245, 1035, 739 cmϪ1; MS m/z: 253
(Mϩ, 1), 133 (11), 132 (100), 121 (19), 105 (27), 86 (19), 84
(31), 49 (63). Anal. C17H19NO, calcd C 80.60%, H 7.56%, N
5.53%; Found C 80.69%, H 7.50%, N 5.39%.
NMR (CDCl3): 20.2 (CH3), 67.9 (C-2), 72.3 (C-1), 127.2
(2× vCH), 128.4 (vCH), 128.5 (2× vCH), 128.8 (2×
vCH), 129.5 (2× vCH), 134.4 (vCquat), 136.7
(vCquat), 139.3 (vCquat), 160.10 (CvN); IR (KBr):
1640 (CvN), 1590, 1482, 1379, 1088, 1013, 974, 825,
723, 725 cmϪ1; MS m/z: 291/293/295 (Mϩ, 1), 261 (3),
221 (7), 168 (26), 166 (100). Anal. C16H15Cl2N, calcd C
65.77%, H 5.17%, N 4.79%; Found C 65.87%, H 5.30%,
N 4.63%.
(2S,3R)-(Ϫ)-2-Methyl-1-(4-methylbenzyl)-3-phenylaziri-
dine 4d. The synthesis of aziridine 4d was carried out
according to the general procedure to give the pure aziridine
Chiral 1,2,3-trisubstituted aziridines 4 and 9. To a solu-
tion of 330 mg (1.28 mmol) of benzaldimine 3 or 13 in
20 ml of absolute methanol was added 145 mg
(3.85 mmol) of sodium borohydride. The reaction mixture
was refluxed for 1 h, then MeOH was evaporated in vacuo.
The residue was treated with water, then extracted with
CH2Cl2. The combined extracts were washed with water,
dried (K2CO3) and evaporated in vacuo to give the crude
product, which was purified by flash chromatography on
silica gel column with ethyl acetate/hexane (10/90) to afford
the pure aziridines 4 and 9.
1
4d in 96% yield. [a]2D0Ϫ89 (c1.27; MeOH); H NMR
(CDCl3): 0.95 (3H, d, J5.7 Hz, CH3), 1.88–1.93 (1H, m,
H-2), 2.32 (3H, s, Ar–CH3), 2.65 (1H, d, J6.5 Hz, H-3),
3.51 (1H, d, J13.8 Hz, H-4), 3.75 (1H, d, J13.8 Hz, H-
4), 7.22–7.32 (9H, m, vCH); 13C NMR (CDCl3): 12.8
(CH3), 21.0 (Ar–CH3), 41.7 (C-2), 46.1 (C-3), 64.2 (C-4),
126.3 (vCH), 127.7 (3× vCH), 127.8 (3× vCH), 128.9
(2× vCH), 136.3 (2× vCquat), 137.5 (vCquat); IR
(NaCl): 1601, 1448, 1346, 1117, 795 cmϪ1; MS m/z: 237
(Mϩ, 2), 133 (10), 132 (100). Anal. C17H19N, calcd C
86.03%, H 8.07%, N 5.90%; Found C 86.19%, H 8.15%,
N 5.78%.
(2S,3R)-(Ϫ)-1-Benzyl-2-methyl-3-phenylaziridine 4a. The
synthesis of aziridine 4a was carried out according to the
general procedure to give the pure aziridine 4a in 99% yield.
(2R,3S)-(ϩ)-1-Benzyl-2-methyl-3-phenylaziridine 9a. The
synthesis of aziridine 9a was carried out according to the
general procedure to give the pure aziridine 9a in 97% yield.
[a]2D2ϩ116 (c1.2; MeOH); 1H NMR (CDCl3): 0.95 (3H,
d, J5.7 Hz, CH3), 1.80–1.85 (1H, m, H-2), 2.59 (1H, d,
J6.9 Hz, H-3), 3.50 (1H, d, J13.8 Hz, H-4), 3.69 (1H, d,
J13.8 Hz, H-4), 7.15–7.37 (10H, m, vCH); 13C NMR
(CDCl3): 12.8 (CH3), 41.7 (C-2), 46.2 (C-3), 64.4 (C-4),
126.4 (vCH), 127.7 (vCH), 127.6 (2× vCH), 127.8 (4×
vCH), 128.2 (2× vCH), 137.4 (vCquat), 139.4
(vCquat); IR (NaCl): 1601, 1492, 1449, 1348, 1027, 733,
698 cmϪ1; MS m/z: 223 (Mϩ, 2), 133 (12), 132 (100), 99
(23), 91 (17).
1
[a]2D2Ϫ60 (c0.9; MeOH); H NMR (CDCl3): 0.95 (3H,
d, J5.7 Hz, CH3), 1.80–1.85 (1H, m, H-2), 2.59 (1H, d,
J6.9 Hz, H-3), 3.50 (1H, d, J13.8 Hz, H-4), 3.70 (1H, d,
J13.8 Hz, H-4), 7.15–7.37 (10H, m, vCH); 13C NMR
(CDCl3): 12.8 (CH3), 41.8 (C-2), 46.3 (C-3), 64.5 (C-4),
126.4 (vCH), 126.7 (vCH), 127.7 (2× vCH), 127.8 (4×
vCH), 128.3 (2× vCH), 137.5 (vCquat), 139.4
(vCquat); IR (NaCl): 1599, 1491, 1374, 1119, 732,
698 cmϪ1; MS m/z: 223 (Mϩ, 2), 222 (1), 133 (10), 132
(100). Anal. C16H17N, calcd C 86.05%, H 7.67%, N
6.27%; Found C 85.94%, H 7.80%, N 6.23%.
(2S,3R)-(Ϫ)-1-(4-Chlorobenzyl)-2-methyl-3-phenylaziri-
dine 4b. The synthesis of aziridine 4b was carried out
according to the general procedure to give the pure aziridine
(2R,3S)-(ϩ)-1-(4-Chlorobenzyl)-2-methyl-3-phenylaziri-
dine 9b. The synthesis of aziridine 9b was carried out
according to the general procedure to give the pure aziridine
9b in 92% yield. [a]D22ϩ92.8 (c0.98; MeOH); 1H NMR
(CDCl3): 0.94 (3H, d, J5.7 Hz, CH3), 1.84–1.89 (1H, m,
H-2), 2.61 (1H, d, J6.5 Hz, H-3), 3.47 (1H, d, J14.0 Hz,
H-4), 3.69 (1H, d, J14.0 Hz, H-4), 7.23–7.35 (10H, m,
vCH); 13C NMR (CDCl3): 12.8 (CH3), 41.9 (C-2), 46.4
(C-3), 63.8 (C-4), 126.5 (vCH), 127.8 (2× vCH), 127.9
(2× vCH), 128.4 (2× vCH), 129.1 (2× vCH), 132.5
(vCquat), 137.2 (vCquat), 137.9 (vCquat); IR (NaCl):
1601, 1487, 1404, 1088, 1014, 813, 738, 700 cmϪ1; MS
m/z: 257/259 (Mϩ, 1), 179 (1), 164 (1), 133 (9), 132 (100).
1
4b in 96% yield. [a]2D0Ϫ76 (c0.54; MeOH); H NMR
(CDCl3): 0.94 (3H, d, J5.7 Hz, CH3), 1.84–1.89 (1H, m,
H-2), 2.61 (1H, d, J6.5 Hz, H-3), 3.47 (1H, d, J14.0 Hz,
H-4), 3.69 (1H, d, J14.0 Hz, H-4), 7.23–7.35 (9H, m,
vCH); 13C NMR (CDCl3), 12.7 (CH3), 41.8 (C-2); 46.3
(C3), 63.6 (C-4); 126.5 (vCH), 126.7 (2× vCH), 127.8
(2× vCH), 128.3 (2× vCH), 128.9 (2× vCH), 132.4
(vCquat), 137.2 (vCquat), 137.9 (vCquat); IR (NaCl):
1601, 1486, 1347, 1121, 733, 699 cmϪ1; MS m/z: 257/259
(Mϩ, 1), 133 (10), 132 (100). Anal. C16H16ClN, calcd C
74.55%, H 6.26%, N 5.43%; Found C 74.63%, H 6.14%,
N 5.37%.
1-Chloro-1-phenyl-2-propanone 7. To solution of 10.0 g
(7.46 mmol) of ketone 6 in 20 ml of carbon tetrachloride
was added 11.0 g (8.2 mmol) of sulfuryl chloride over a
period of 1 h at 0ЊC, after which the reaction mixture was
refluxed for 24 h. Then, the reaction mixture was poured in
the same amount of cold water, and was extracted with
dichloromethane. The extracts were washed with saturated
NaHCO3 solution and dried (MgSO4). The solvent was
removed in vacuo to give a residue, which was distilled to
give 10.68 g of pure a-chloroketone 7 in 85% yield; b.p.
(2S,3R)-(Ϫ)-2-Methyl-1-(4-methoxybenzyl)-3-phenyla-
ziridine 4c. The synthesis of aziridine 4c was carried out
according to the general procedure to give the pure aziridine
1
4c in 97% yield. [a]2D0Ϫ91 (c0.99; MeOH); H NMR
(CDCl3): 0.94 (3H, d, J5.7 Hz, CH3), 1.87–1.91 (1H, m,
H-2), 2.63 (1H, d, J6.7 Hz, H-3), 3.45 (1H, d, J13.5 Hz,
H-4), 3.72 (1H, d, J13.5 Hz, H-4), 3.75 (3H, s, OCH3),
6.84 (2H, d, J8.9 Hz, vCH, A2B2 system), 7.20–7.28
(5H, m, C6H5), 7.3 (2 H, d, J8.9 Hz, vCH, A2B2 system,