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G. A. Molander, J. A. C. Romero / Tetrahedron 61 (2005) 2631–2643
flash chromatography to provide the title compound as a
clear, colorless oil in 92% yield; Rf 0.25 (10:90 MeOH/
CH2Cl2); 1H NMR (500 MHz, CDCl3) d 7.35 (d, JZ7.4 Hz,
2H), 7.25 (m, 2H), 7.17 (t, JZ7.3 Hz, 1H), 5.99 (dd, JZ
10.8, 17.6 Hz, 1H), 5.70–5.84 (m, 1H), 5.07 (d, JZ17.6 Hz,
1H), 5.01 (dd, JZ0.8, 10.8 Hz, 1H), 4.96 (dd, JZ1.6,
17.2 Hz, 1H), 4.87 (dd, JZ1.3, 10.1 Hz, 1H), 4.68 (s, 2H),
3.20 (d, JZ6.4 Hz, 2H), 4.19 (s, 6H); 13C NMR (125 MHz,
CDCl3) d 147.4, 142.7, 138.7, 128.1, 127.9, 126.2, 115.0,
111.7, 59.6, 53.0, 52.9, 24.5; IR (neat) 3051, 2963,
1435 cmK1; LRMS (CI) m/z 215 (100), 200 (67), 104
(83); Anal. Calcd for C15H21N: C, 83.67; H, 9.83; Found: C,
83.80; H, 9.70.
1.23–1.32 (m, 1H), 0.99–1.02 (m, 2H), 0.82–0.94 (m, 1H),
0.25–0.27 (m, 3H).
4.1.6. 3-(N-Allyl-N-a,a-dimethylallyl)amino-3-methyl-
phenylsilylpropane (12). The title compound was prepared
according to the general procedure for the preparation of 4
using 5 mol% of Cp*2LuMe$THF at 100 8C in a sealed
tube. The reaction was complete after 1.5 h as indicated by
1H NMR analysis. Workup and purification by flash
chromatography gave the title compound in 84% yield; Rf
0.25 (10:90 MeOH/CH2Cl2); 1H NMR (500 MHz, CDCl3) d
7.39–7.41 (m, 2H), 7.29–7.34 (m, 5H), 7.23–7.27 (m, 2H),
7.09–7.13 (m, 1H), 4.93–5.99 (m, 1H), 4.97–5.04 (m, 2H),
4.20–4.23 (m, 1H), 3.64 (s, 2H), 2.52 (dd, JZ6.1, 7.4 Hz,
2H), 1.25–1.28 (m, 2H), 0.99 (s, 6H), 0.61–0.64 (m, 2H),
1.17–1.19 (m, 3H); 13C NMR (125 MHz, CDCl3) d 147.6,
143.5, 136.7, 134.3, 129.2, 127.9, 127.8, 127.8, 126.1,
111.4, 59.6, 54.9, 54.5, 25.4, 24.2, 10.9, K5.8; IR (neat)
3032, 2967, 2119, 1461 cmK1; LRMS (CI) m/z 337 (42),
336 (100), 240 (73); Anal. Calcd for C22H31NSi: C, 78.27;
H, 9.26; Found: C, 78.14; H, 9.21.
4.1.4. 1-(N-Allyl-N-benzylamino)-2-methyl-2-propene
(10). N-Benzylallylamine was synthesized by a published
procedure. To N-benzylallylamine (1.87 g, 10.0 mmol) in
20.0 mL of MeCN was added K2CO3 (2.76 g, 20.0 mmol)
in one portion. The suspension stirred for 0.5 h before
adding 3-bromo-2-methyl-1-propene (1.74 g, 1.30 mL,
12.9 mmol). The suspension was stirred overnight at room
temperature. The solvent was removed in vacuo, and the
crude residue was dissolved in 10 mL of Et2O and washed
with 5 mL of H2O. The organic layer was separated, dried
with MgSO4, filtered, and reduced in vacuo. The diene was
purified by flash chromatography to provide the title
compound as a clear, colorless oil in 93% yield; Rf 0.25
(10:90 MeOH/CH2Cl2); 1H NMR (500 MHz, CDCl3) d
7.32–7.34 (m, 2H), 7.27–7.30 (m, 2H), 7.12–7.22 (m, 1H),
5.78–5.92 (m, 1H), 5.18 (dd, JZ1.6, 17.2 Hz, 1H), 5.11 (dd,
JZ1.3, 10.2 Hz, 1H), 4.92–4.93 (m, 1H), 4.83–4.84 (m,
1H), 3.51 (d, JZ4.5 Hz, 2H), 2.98–3.01 (m, 2H), 2.91–2.96
(m, 2H), 1.73–1.75 (m, 3H); 13C NMR (125 MHz, CDCl3) d
144.0, 139.2, 136.1, 128.7, 128.1, 126.7, 116.8, 112.5, 60.5,
37.7, 56.3, 20.7; IR (neat) 3042, 2946, 1454 cmK1; LRMS
(CI) m/z 201 (100), 160 (63), 104 (87); Anal. Calcd for
C14H19N: C, 83.53; H, 9.51; Found: C, 83.06; H, 9.06.
4.1.7. N-Benzylpiperidine-2,2-dimethyl-3-methylphenyl-
silylmethane (13). The title compound was prepared
according to the general procedure for the preparation of 4
using 5 mol% of [CpT2MSLuMe]2 at 100 8C in a sealed tube.
1
The reaction was complete after 12 h as indicated by H
NMR analysis. Workup and purification by flash chroma-
tography gave the title compound as a mixture of
diastereomers in 84% yield; Rf 0.25 (10:90 MeOH/
CH2Cl2); 1H NMR (500 MHz, CDCl3) d 7.54–7.56 (m,
2H), 7.27–7.36 (m, 6H), 7.23–7.27 (m, 1H), 7.13–7.20 (m,
1H), 4.40–4.43 (m, 1H), 3.82–3.89 (m, 1H), 3.08–3.13 (m,
1H), 2.39–2.48 (m, 1H), 2.24–2.32 (m, 1H), 1.50–1.72 (m,
2H), 1.32–1.48 (m, 4H), 1.18–1.31 (m, 2H), 1.03–1.17 (m,
1H), 0.93 (s, 3H), 0.58–0.71 (m, 1H), 0.35–0.37 (m, 3H);
13C NMR (125 MHz, CDCl3) d 142.0, 137.0, 134.3, 134.3,
129.2, 128.2, 128.0, 128.0, 127.9, 126.3, 57.9, 54.3, 54.2,
47.0, 47.0, 42.7, 42.6, 31.6, 29.1, 28.9, 26.9, 25.5, 25.4,
25.3, 22.6, 16.2, 16.1, K4.6, K5.5; IR (neat) 3047, 2954,
2119, 1435 cmK1; LRMS (CI) m/z 337 (100), 218 (73);
Anal. Calcd for C22H31NSi: C, 78.27; H, 9.26; Found: C,
78.43; H, 9.06.
4.1.5. trans-N-Benzylpiperidine-2-methyl-3-methylphe-
nylsilylmethane (11). The title compound was prepared
according to the general procedure for the preparation of 21
using 5 mol% of Cp*2LuMe$THF at room temperature in a
glovebox. The reaction was complete after 1 h as indicated
by GC analysis. Workup and purification by flash
chromatography gave the title compound as a mixture of
diastereomers in 84% yield; Rf 0.25 (10:90 MeOH/CH2Cl2);
1H NMR (500 MHz, CDCl3) d 7.53–7.60 (m, 2H), 7.20–
7.35 (m, 8H), 4.38–4.41 (m, 1H), 3.79–3.85 (m, 1H), 3.30–
3.34 (m, 1H), 2.59–2.66 (m, 1H), 2.24–2.29 (m, 1H), 2.09–
2.15 (m, 1H), 1.76–1.83 (m, 1H), 1.48–1.63 (m, 2H), 1.34–
1.48 (m, 1H), 1.19–1.32 (m, 1H), 1.08–1.15 (m, 4H), 0.78–
0.90 (m, 1H), 0.31–0.34 (m, 3H); 13C NMR (125–MHz,
CDCl3) d 140.0, 134.3, 129.1, 128.9, 128.1, 127.8, 126.6,
61.7, 61.7, 58.6, 50.3, 50.2, 38.1, 38.0, 30.6, 23.7, 23.6,
18.4, 18.2, 15.0, –4.7, –5.1; IR (neat) 3048, 2928, 2116,
1442 cmK1; LRMS (CI) m/z 322 (100), 218 (73); Anal.
Calcd for C21H29NSi: C, 77.96; H, 9.03; Found: C, 77.43; H,
4.1.8. 1-(N-Allyl-N-tert-butylamino)-2-methyl-2-propene
(16). N-(tert-Butylamino)-2-methyl-2-propene was synthe-
sized by a published procedure.6 To N-(tert-butylamino)-2-
methyl-2-propene (0.382 g, 3.00 mmol) in 6.00 mL of
MeCN was added K2CO3 (0.829 g, 6.00 mmol) in one
portion. The suspension was stirred for 0.5 h before adding
3-bromo-2-methyl-1-propene
(0.526 g,
0.393 mL,
3.90 mmol). The suspension was stirred overnight at room
temperature. The solvent was removed in vacuo, and the
crude residue was dissolved in 5 mL of Et2O and washed
with 3 mL of H2O. The organic layer was separated, dried
with MgSO4, filtered, and reduced in vacuo. The diene was
purified by flash chromatography to provide the title
compound as a clear, colorless oil in 82% yield; Rf 0.25
(10:90 MeOH/CH2Cl2); 1H NMR (500 MHz, CDCl3) d
5.84–5.92 (m, 1H), 5.01–5.07 (m, 1H), 4.92–4.95 (m, 2H),
4.75 (dd, JZ1.2, 2.5 Hz, 1H), 3.15 (d, JZ6.2 Hz, 1H), 3.00
(s, 3H), 1.70 (s, 3H), 1.07 (s, 9H); 13C NMR (125 MHz,
CDCl3) d 146.3, 139.5, 114.3, 110.8, 55.3, 54.8, 52.4, 27.5,
1
8.95. Minor diastereomer: H NMR (500 MHz, CDCl3) d
7.44–7.47 (m, 2H), 7.28–7.34 (m, 7H), 7.22–7.26 (m, 1H),
4.30–4.32 (m, 1H), 3.61–3.66 (m, 1H), 3.41–3.44 (m, 1H),
2.78–2.82 (m, 1H), 2.29–2.35 (m, 1H), 2.19–2.27 (m, 1H),
1.70–1.85 (m, 1H), 1.51–1.62 (m, 4H), 1.38–1.45 (m, 1H),