6454
X. Xie et al. / Tetrahedron Letters 42 (2001) 6451–6454
13C NMR (125 MHz, CDCl3, rt) l 9.0, 22.1, 29.7, 46.4,
1456 cm−1; HRMS (ES) calcd for C8H11N2 (MH+)
135.0922, found 135.0927. 9b: oil; 1H NMR (500 MHz,
CDCl3) l 2.08 (m, 2H), 2.27 (s, 3H), 2.99 (t, 6.8 Hz, 2H),
3.79 (t, 5.9 Hz, 2H), 7.13 (dd, 8.2 Hz, 4.7 Hz, 1H), 8.3 (d,
4.1 Hz, 1H); 1H NMR (360 MHz, DMSO-d6, rt) l
1.92–1.99 (m, 2H), 2.20 (s, 3H), 2.86 (t, 6.7 Hz, 2H), 3.71
(t, 6.1 Hz, 2H), 7.17 (dd, 8.2 Hz, 4.7 Hz, 1H), 8.00 (brs,
54.7, 57.3; 13C NMR (125 MHz, CDCl3, 250 K) N-in:
7.0, 20.5, 21.1, 27.2, 30.6, 45.8, 46.8, 51.8, 54.3, 55.7;
N-out: 12.6, 14.6, 23.2, 25.8, 29.7, 39.7, 45.5, 47.2, 53.0,
56.7; IR (film) 3281, 2931 cm−1; HRMS (ES) calcd for
C10H21N2 (MH+) 169.1705, found 169.1706. 2c: oil, 1H
NMR (500 MHz, CDCl3) l 1.22–1.25 (m, 1H), 1.41–1.46
(m, 3H), 1.58–1.73 (m, 3H), 2.03 (br., 1H), 2.23–2.34 (m,
3H), 2.50–2.55 (m, 1H), 2.61–2.66 (m, 1H), 2.77–2.84 (m,
3H), 2.99–3.01 (m, 1H), 3.31 (s, 3H), 3.41–3.50 (m, 2H);
13C NMR (125 MHz, CDCl3, rt) l 22.2, 26.5, 29.1, 29.6,
46.4, 52.2, 54.6, 58.8, 70.1; 13C NMR (125 MHz, CDCl3,
250 K) N-in: 20.2, 21.0, 27.7, 30.6, 46.7, 51.3, 53.4, 54.5,
57.8, 58.9, 68.7; N-out: 15.4, 23.0, 24.2, 26.1, 29.6, 39.6,
1
1H), 8.21 (dd, 4.3 Hz, 1.1 Hz, 1H); H NMR (360 MHz,
DMSO-d6, 60°C) l 1.93–2.02 (m, 2H), 2.20 (s, 3H), 2.87
(t, 6.7 Hz, 2H), 3.72 (t, 6.1 Hz, 2H), 7.17 (dd, 8.2 Hz, 4.7
Hz, 1H), 8.00 (d, 8.2 Hz, 1H), 8.21 (dd, 4.3 Hz, 1.1 Hz,
1H); 13C NMR (125 MHz, CDCl3) l 23.2, 30.3, 121.0,
131.6, 145.2, 169.9; 13C NMR (125 MHz, DMSO-d6) l
23.5, 23.6, 30.7, 45.1, 121.8, 132.2, 135.6, 145.3, 151.3,
170.6; IR (film) 2931, 1661 cm−1; HRMS (ES) calcd for
C10H13N2O (MH+) 177.1028, found 177.1030. 11b·BH3:
mp 102–104°C; 1H NMR (200 MHz, CDCl3) l 1.10 (t,
7.1 Hz, 3H), 1.98 (tt, 6.6 Hz, 6.6 Hz, 2H), 3.17–3.38 (m,
6H), 6.93–7.04 (m, 2H), 7.93–7.96 (m, 1H); 13C NMR (90
MHz, CDCl3) l 10.2, 20.4, 27.4, 45.4, 47.2, 118.4, 122.3,
135.2; IR (film) 2959, 2324, 1185 cm−1; anal. calcd for
C10H17BN2: C, 68.22; H, 9.73; N, 15.91; found C, 68.17;
45.6, 52.5, 53.2, 58.5, 70.2; IR (film) 2946, 1357 cm−1
;
HRMS (ES) calcd for C11H23N2O (MH+) 199.1810,
1
found 199.1809. 2d: oil, H NMR (500 MHz, CDCl3) l
0.81 (s, 9H), 1.19–1.40 (m, 2H), 1.49–1.56 (m, 3H),
1.70–1.87 (m, 3H), 2.08–2.15 (m, 2H), 2.28–2.31 (m, 1H),
2.39 (br., 1H), 2.57–2.66 (m, 3H), 2.77 (m, 1H), 3.01 (m,
1H); 13C NMR (125 MHz, CDCl3, rt) l 19.3, 23.1, 24.9,
27.7, 33.5, 41.2, 49.0, 53.4, 61.3, 65.9; 13C NMR (125
MHz, CDCl3, 250 K) 17.1, 22.6, 24.7, 26.1, 27.2, 33.6,
1
H, 10.24; N, 15.98. 11b: oil; H NMR (200 MHz, CDCl3)
39.5, 47.1, 52.6, 60.7, 65.4; IR (film) 2931, 1118 cm−1
;
l 1.06 (t, 7.1 Hz, 3H), 1.92–2.04 (m, 2H), 2.86 (t, 6.6 Hz,
2H), 3.08–3.31 (m, 4H), 6.75 (d, 8.3 Hz, 1H), 6.89 (dd,
8.3 Hz, 4.6 Hz, 1H), 7.72 (d, 4.6 Hz, 1H); 13C NMR (90
MHz, CDCl3) l 10.4, 18.4, 31.1, 44.6, 47.8, 116.1, 121.9,
HRMS (ES) calcd for C13H27N2 (MH+) 211.2174, found
211.2179.
6. Sanders, J. K.; Hunter, B. K. Modern NMR Spec-
troscopy, 2nd ed.; New York: Oxford, 1993; pp. 216–220.
7. For examples of this phenomenon, see: Reference 6, p.
219 and: (a) Binsch, G.; Kessler, H. Angew. Chem., Int.
Ed. Engl. 1980, 19, 4511–428; (b) Drankenberg, T.;
Forsen, S. J. Phys. Chem. 1970, 74, 1–7.
135.7, 140.9, 141.3; IR (film) 2967, 1577, 1456 cm−1
;
HRMS (ES) calcd for C10H15N2 (MH+) 163.1235, found
163.1232. 2a: oil, 1H NMR (500 MHz, CDCl3) l 1.19–
1.23 (m, 1H), 1.37–1.49 (m, 3H), 1.56–1.63 (m, 1H),
1.67–1.76 (m, 2H), 1.89 (br., 1H), 1.98–2.11 (m, 2H), 2.17
(m, 4H), 2.61–2.69 (m, 2H), 2.74–2.76 (m, 1H), 3.05–3.07
(m, 1H); 13C NMR (125 MHz, CDCl3, rt) l 21.2, 21.6,
24.4, 29.1, 42.5, 46.9, 54.7, 56.8, 59.8, 61.7; 13C NMR
(125 MHz, CDCl3, 250 K) 20.3, 21.0, 27.7, 30.5, 42.5,
46.7, 54.0, 57.2, 61.3; IR (film) 2933 cm−1; HRMS (ES)
calcd for C9H19N2 (MH+) 155.1548, found 155.1547. 2b:
oil, 1H NMR (500 MHz, CDCl3) l 0.96 (t, J=7.1 Hz,
3H), 1.05–1.29 (m, 3H), 1.42–1.50 (m, 3H), 1.62–1.78 (m,
3H), 2.06 (br., 1H), 2.20–2.78 (m, 6H), 3.03–3.06 (m, 1H);
8. With the exception of slight broadening of the C2 signal
of 10 in the 13C NMR spectrum.
9. The 13C NMR shift of C8 was particularly diagnostic,
occurring at ꢀ21 ppm for the N-in form and at ꢀ16
ppm for the N-out form.
10. For 2a and 2d, peaks for the minor isomer were observed
but with low intensity corresponding to <10%.
11. Santos, A. G.; Klute, W.; Torode, J.; Bo¨hm, V. P. W.;
Cabrita, E.; Runsink, J.; Hoffmann, R. W. New J. Chem.
1998, 993–997.