Watson and Yudin
t r a n s-N -Be n zyl-N ′-p h e n yl-1,2-cycloh e xa n e d ia m in e
(2c): White solid, mp 72-73°C (lit.44 mp 68-70°C), 99% yield.
1H NMR (CDCl3, 400 MHz) δ 7.30-7.25 (m, 4H), 7.22-7.18
(m, 1H), 7.12 (t, J ) 7.9 Hz, 2H), 6.67 (t, J ) 7.9 Hz, 1H), 6.62
(d, J ) 7.9 Hz, 2H), 3.89 (d, J ) 13.4 Hz, 1H), 3.65 (d, J )
13.4 Hz, 1H), 3.42 (d, 1H), 3.10 (d, 1H), 2.31 (td, 1H), 2.17-
2.11 (m, 3H), 1.74-1.65 (m, 2H), 1.33-1.17 (m, 3H), 1.04-
0.94 (m, 1H); 13C NMR (CDCl3, 100 MHz) δ 148.3, 140.8, 129.3,
128.4, 128.1, 126.9, 117.7, 114.1, 60.9, 57.5, 50.8, 32.5, 31.5,
25.0, 24.7. ESI 281 (M+ + 1); EI-MS m/z (%) 280 (M+, 40), 188
(52), 172 (28), 146 (47), 132 (37), 106 (81), 91 (100); HR-MS
calcd for C19H24N2 280.193949, obsd 280.194107.
tr a n s-N-Ben zyl-N′-m eth yl-N′-ph en yl-1,2-cycloh exan edi-
1
a m in e (2d ): Clear oil, 84% yield. H NMR (CDCl3, 300 MHz)
δ 7.30-7.18 (m, 7H), 6.87 (d, J ) 8.0 Hz, 2H), 6.72 (t, J )
7.2 Hz, 1H), 3.90 (d, J ) 13.6 Hz, 1H), 3.67 (d, J ) 13.4
Hz, 1H), 3.51 (td, 1H), 2.60 (td, 1H), 2.53 (s, 3H), 2.26-2.21
(m, 2H), 1.74-1.62 (m, 3H), 1.43-1.14 (m, 4H); 13C NMR
(CDCl3, 75 MHz) δ 151.3, 140.8, 129.2, 128.5, 128.3, 126.9,
117.6, 114.8, 64.1, 56.8, 50.9, 31.8, 30.7, 27.0, 25.9, 24.7. ESI
295 (M+ + 1); EI-MS m/z (%) 294 (M+, 67), 187 (64), 146 (59),
F IGURE 6. X-ray structure of amino alcohol-(C6F5)3B(OH2)
complex (3) showing 30% probability displacement ellipsoids.
Selected bond lengths (Å) and angles (deg): B(1)-O(2) 1.498-
(5), B(1)-C(11A) 1.654(5), B(1)-C(21) 1.655(5), B(1)-C(31)
1.651(5); O(2)-B(1)-C(31) 106.2(3), O(2)-B(1)-C(11A) 107.5-
(3), O(2)-B(1)-C(21) 108.9(3).
120 (100), 107 (60), 91 (81); HR-MS calcd for
294.209599, obsd 294.209200.
C20H26N2
tr a n s-N-Ben zyl-N′-(1-(S)-p h en ylet h yl)-1,2-cycloh ex-
a n ed ia m in e (2e): Isolated as a 50:50 mix of diastereomers
1
as a clear oil, 98% yield. H NMR (CDCl3, 300 MHz) δ 7.35-
7.15 (m, 10H), 3.94 (d, 1H), 3.89 (m, 2H), 3.83 (m, 1H), 3.66
(d, J ) 1.8 Hz, 1H), 3.62 (d, J ) 1.9 Hz, 1H), 2.35 (td, 2H),
2.22 (td, 2H), 2.15-1.88 (m, 8H), 1.33 (d, J ) 6.7 Hz, 1H),
1.31 (d, J ) 6.6 Hz, 1H), 1.21-1.07 (m, 4H), 1.05-0.81 (m,
4H); 13C NMR (CDCl3, 75 MHz) δ 147.6, 146.0, 141.4, 141.3,
128.5, 128.5, 128.4, 128.1, 128.0, 126.9, 126.8, 126.8, 126.7,
61.5, 61.4, 59.7, 57.9, 55.8, 54.4, 51.1, 50.9, 32.7, 31.7, 31.6,
31.6, 25.8, 25.4, 25.2, 25.0, 24.9, 24.0. ESI 309 (M+ + 1);
EI-MS m/z (%) 308 (M+, 5), 217 (22), 203 (50), 189 (38), 120
(54), 105 (94), 91 (100); HR-MS calcd for C21H28N2 308.225249,
obsd 308.224048.
Exp er im en ta l Section
Rep r esen ta tive P r oced u r e for th e Rin g-Op en in g Re-
a ction of Azir id in es w ith Nu cleop h iles Ca ta lyzed w ith
B(C6F 5)3: tr a n s-N,N′-Diben zyl-1,2-cycloh exa n ed ia m in e
(2a ). In a 15 × 100 mm2 screw cap test tube, fitted with septum
and magnetic stir bar, was placed N-benzyl cyclohexene imine
(155 mg, 0.827 mmol), B(C6F5)3 (42 mg, 0.083 mmol, 10 mol
%), and 4 mL of degassed A.C.S. grade acetonitrile. No special
precautions were taken to exclude water from the reaction.
N-Benzylamine (108 µL, 1 mmol) was added via syringe and
the solution was stirred under a stream of argon at 65 °C for
16 h; when TLC showed no remaining starting material. The
solvent was removed in vacuo and to the residue was added
0.8 g of Amberlyst A-21 resin (1 g per mmol of product) and 5
mL of dichloromethane. The solution was stirred for 1 h then
the resin was removed by filtration through a cotton plug. The
solvent was removed in vacuo and the residue was purified
by flash chromatography (Rf )0.3, SiO2, 95:5 CH2Cl2/MeOH)
to yield 2a (238 mg, 0.808 mmol, 98%) as a clear oil that
solidified to a white solid after standing.
t r a n s-N -(2-(P h e n y lt h io )c y c lo h e x y l)b e n ze n e m e t h -
a n a m in e (2f):45 Clear oil, 98% yield. 1H NMR (CDCl3, 300
MHz) δ 7.35-7.20 (m, 10H), 3.91 (d, J ) 13.1 Hz, 1H), 3.70
(d, J ) 13.1 Hz, 1H), 2.94 (dd, 1H), 2.88 (s, 1H), 2.42 (td, J )
9.5, 4.0 Hz, 1H), 2.18 (m, 1H), 2.07 (d, 1H), 1.66 (m, 2H), 1.43-
1.11 (m, 4H); 13C NMR (CDCl3, 75 MHz) δ 140.3, 133.6, 133.3,
128.9, 128.6, 128.3, 127.4, 127.0, 59.0, 53.6, 50.9, 33.5, 32.0,
26.3, 24.4. ESI 298 (M+ + 1); EI-MS m/z (%) 297 (M+, 8), 188
(37), 146 (60), 106 (93), 91 (100); HR-MS calcd for C19H23NS
297.154428, obsd 297.155122.
tr a n s-3-(2-N-Ben zyla m in o-cycloh exyla m in o)p r op ion -
1
ic a cid m eth yl ester (2 g): Light brown oil, 54% yield. H
tr a n s-N,N′-Diben zyl-1,2-cycloh exan ediam in e (2a): White
NMR (CDCl3, 400 MHz) δ 7.33-7.20 (m, 5H), 3.90 (d, J ) 13.2
Hz, 1H), 3.63 (d, 1H), 3.62 (s, 3H), 3.00 (m, 1H), 2.71 (m, 1H),
2.47 (m, 2H), 2.19-2.07 (m, 4H), 1.82 (br s, 2H), 1.71 (m, 2H),
1.35-1.19 (m, 2H), 1.05-0.90 (m, 2H); 13C NMR (CDCl3, 100
MHz) δ 173.4, 141.2, 128.4, 128.3, 126.9, 61.6, 61.0, 51.6, 51.2,
42.4, 35.5, 31.8, 31.7, 25.2, 25.1. ESI 291 (M+ + 1); EI-MS m/z
(%) 291 (M+ + H+, 18), 290 (M+, 13), 217 (21), 199 (27), 185
(62), 142 (37), 104 (72), 96 (63), 91 (100); HR-MS calcd for
1
solid, mp 34-35 °C (lit.79 mp 36-37 °C), 98% yield. H NMR
(CDCl3, 400 MHz) δ 7.30-7.18 (m, 5H) 3.86 (d, J ) 13.2 Hz,
1H), 3.63 (d, J ) 13.1 Hz, 1H), 2.24 (m, 1H), 2.13 (d, 2H), 1.70
(m, 1H), 1.20 (m, 1H), 1.01 (m, 1H); 13C NMR (CDCl3, 100
MHz) δ 141.0, 128.3, 128.0, 126.8, 60.9, 50.9, 31.5, 25.0. ESI
295 (M+ + 1); EI-MS m/z (%) 294 (M+, 10), 203 (29), 189 (27),
106 (42), 91 (100); HR-MS calcd for C20H26N2 294.209599, obsd
294.209710.
C
17H26N2O2 290.199428, obsd 290.198649. The compound was
tr a n s-N-Ben zyl-N′-(4-m et h oxy-b en zyl)-1,2-cycloh ex-
a n ed ia m in e (2b): Clear oil, 99% yield. 1H NMR (CDCl3, 300
MHz) δ 7.31-7.29 (m, 4H), 7.24-7.21 (m, 3H), 6.33 (m, 2H),
3.89 (d, J ) 13.2 Hz, 1H), 3.83 (d, J ) 13.0 Hz, 1H), 3.78 (s,
3H), 3.65 (d, J ) 13.2 Hz, 1H), 3.59 (d, J ) 13.0 Hz, 1H), 2.25
(m, 2H), 2.17-2.13 (m, 2H), 1.95 (s, 2H), 1.71 (m, 2H), 1.22
(m, 2H), 1.08-1.02 (m, 2H); 13C NMR (CDCl3, 75 MHz) δ 158.7,
141.3, 133.4, 129.3, 128.5, 128.2, 126.9, 113.9, 61.1, 60.9, 55.4,
51.1, 50.4, 31.7, 31.7, 25.2, 25.2. ESI 325 (M+ + 1); EI-MS m/z
(%) 324 (M+, 5), 203 (34), 136 (37), 121 (100), 91 (68); HR-MS
calcd for C21H28N2O 324.220164, obsd 324.220302.
found to decompose when passed through either silica or
alumina. Therefore, the compound contains small amounts of
impurities.
tr a n s-3-(2-N-Ben zyla m in o-cycloh exyla m in o)p r op a n -1-
ol (2h ): Clear oil, 97% yield. 1H NMR (CDCl3, 400 MHz) δ
7.31-7.20 (m, 5H), 3.88 (d, J ) 12.8 Hz, 1H), 3.82 (s, 1H),
3.70 (t, 2H), 3.63 (d, J ) 13 Hz, 1H), 2.82-2.77 (m, 1H), 2.68-
2.63 (m, 1H), 2.19-2.06 (m, 4H), 1.69-1.64 (m, 4H), 1.23-
1.18 (t, 2H), 1.12-0.99 (m, 4H); 13C NMR (CDCl3, 100 MHz)
δ140.9, 128.4, 128.1, 126.8, 63.0, 62.1, 60.5, 50.9, 46.1, 32.2,
31.6, 31.4, 25.1, 24.8. ESI 263 (M+ + 1). The compound was
found to decompose when passed through either silica or
alumina and over time even when stored at -20 °C. Therefore,
the compound contains small amounts of impurities.
(79) Bennani, Y. L.; Hanessian, S. Tetrahedron 1996, 52, 13837-
13866.
5166 J . Org. Chem., Vol. 68, No. 13, 2003