Linear Amines from Internal Alkenes
FULL PAPER
230–400 mesh)from Merck was used for column chromatography. Infra-
red spectra were recorded on a Nicolet 510 FT-IR spectrophotometer.
High-pressure IR spectra were measured in a 50 mL home-made stainless
steel autoclave fitted with a mechanical stirrer and ZnS windows.[24] Syn-
thesis gas (CO/H2, 1:1, 99.9%)was purchased from Air Liquide. Gas
chromatographic analyses were run on a Hewlett–Packard HP 5890 chro-
matograph with FID detector and a HP5 column (cross-linked 5% PhMe
siloxane). GC/MS analyses were conducted on an Agilent-6890N instru-
ment with a HP5 column.
25.60, 21.60, 13.10 ppm; GC-MS (EI, 70 eV): m/z: 187 [M]+, 126, 116, 88,
70, 57, 42, 29; elemental analysis calcd (%)for C 10H21NS: C 64.22, H,
11.22, N 7.48, S 17.10; found: C 64.32, H 11.54, N 6.99, S 17.43.
N-Hexyl-N’-benzylpiperazine:[28] Yield: 94% (GC). 1H NMR (400 MHz,
CDCl3): d = 7.24–7.34 (m, 5H), 3.55 (s, 2H), 3.37–3.41 (m, 8H), 2.83 (t,
J = 5.2 Hz, 2H), 2.35–2.55 (m, 2H), 1.47–1.55 (m, 6H), 0.88–0.95 ppm (t,
J = 7.1 Hz, 3H); 13C NMR (100 MHz, CDCl3) d = 138.6, 129.5, 128.6,
127.4, 63.53, 59.36, 53.71, 53.54, 32.22, 27.88, 27.36, 23.01, 14.56 ppm; GC-
MS (EI, 70 eV): m/z: 260 [M]+, 189, 161, 146, 128, 114, 98, 91, 84, 70, 58,
42, 29; HRMS calcd for C17H28N2 [M]+: 260.22714; found: 260.22525.
Hydroaminomethylation: The hydroaminomethylation reactions were
carried out in a 200-mL home-made stainless steel autoclave or in a Parr
stainless steel autoclave (100 mL). In a typical experiment, the autoclave
N-(7-Hydroxyheptyl)piperidine:[29] Yield: 97% (GC). 1H NMR
(400 MHz, CDCl3): d = 3.66 (t, J = 5.6 Hz, 2H), 3.45 (t, J = 5.5 Hz,
2H), 3.02–3.07 (m, 4H), 2.40–2.66 (m, 2H), 1.80–1.95 (m, 2H), 1.42–1.76
was loaded with
a solution of [RhACHTREU(GN cod)2]BF4 (0.1 mol%), ligand
(m, 6H), 0.79–0.93 ppm (m, 6H); 13C NMR (100 MHz, CDCl3): d
=
(0.4 mol%), pent-2-ene (10.0 mmol), and piperidine (10.0 mmol) in a
methanol/toluene mixture (1:1, 30 mL). Subsequently, the autoclave was
pressurized with CO (7 bar)and hydrogen (33 bar)and heated to 125 8C.
After 12 h the autoclave was allowed to cool to room temperature and
the gases were vented. The reaction mixture was dried over MgSO4 and
analyzed by GC with bis(methoxyethyl)ether as an external standard,
and by GC/MS.
62.73, 59.95, 54.93, 33.14, 29.76, 28.10, 27.00, 26.14, 26.09, 24.75 ppm; GC-
MS (EI, 70 eV): m/z: 199 [M]+, 182, 169, 154, 140, 124, 110, 98, 84, 70,
55, 41, 31; HRMS calcd for C12H25NO [M]+: 199.19333; found:
199.19362.
N-Hexyl-2,3-dihydro-1H-indole: Yield: 86% (GC). 1H NMR (400 MHz,
CDCl3): d = 6.66–7.52 (m, 4H), 3.58 (t, J = 8.3 Hz, 2H), 3.39 (t, J =
7.3 Hz, 2H), 3.20 (t, J = 8.3 Hz, 2H), 1.75–1.81 (m, 2H), 1.57–1.67 (m,
6H), 1.16 ppm (t, J = 6.9 Hz, 3H); 13C NMR (100 MHz, CDCl3): d =
153.2, 130.5, 127.7, 124.8, 119.8, 107.3, 53.53, 49.87, 32.21, 29.04, 27.88,
23.16, 21.91, 14.66 ppm; GC-MS (EI, 70 eV): m/z: 203 [M]+, 188, 174,
158, 144, 132, 117, 91, 77, 65, 51, 41, 29; elemental analysis calcd (%)for
C14H21N: C 82.70, H 10.41, N 6.89; found: C 82.58, H 10.21, N 6.60.
N-(5-Cyanopentyl)piperidine: Yield: 45% (GC). 1H NMR (400 MHz,
CDCl3): d = 3.41 (t, J = 5.7 Hz, 2H), 3.24 (t, J = 5.7 Hz, 2H), 2.39–2.43
(m, 4H), 2.20–2.30 (m, 6H), 1.70–1.78 ppm (m, 6H); 13C NMR
(100 MHz, CDCl3): d = 119.6, 55.53, 49.99, 27.12, 27.01, 26.38, 25.76,
25.19, 20.55 ppm; GC-MS (EI, 70 eV): m/z: 180 [M]+, 165, 151, 140, 124,
110, 98, 84, 70, 55, 41, 28; HRMS calcd for C11H20N2 [M]+: 180.16271;
found: 180.17890.
N-(6,6-Dimethoxyhexyl)thiomorpholine: Yield: 80% (GC). 1H NMR
(400 MHz, CDCl3): d = 4.28 (t, J = 5.5 Hz, 1H), 3.23–3.33 (m, 4H),
2.26–2.30 (m, 4H), 2.61 (s, 6H), 2.32–2.39 (m, 2H), 1.51–1.54 (m, 2H),
1.26–1.42 ppm (m, 6H); 13C NMR (100 MHz, CDCl3): d = 104.7, 59.68,
55.42, 52.79, 32.80, 28.34, 27.77, 26.79, 24.87 ppm; GC-MS (EI, 70 eV):
m/z: 247 [M]+, 232, 216, 200, 186, 172, 154, 142, 116, 98, 88, 81, 75, 55,
42, 29; HRMS calcd for C12H25NO2S [M]+: 247.16060; found: 247.16057.
N-(6,6-Dimethoxyhexyl)dimethylamine: Yield: 84% (GC). 1H NMR
(400 MHz, CDCl3): d = 4.52 (t, J = 5.7 Hz, 1H), 3.47 (m, 6H), 2.33–2.38
(m, 2H), 2.40 (s, 6H), 2.34–2.38 (m, 2H), 1.59–1.64 ppm (m, 6H);
13C NMR (100 MHz, CDCl3): d = 104.7, 60.03, 52.84, 45.72, 32.72, 27.93,
27.62, 24.85 ppm; GC-MS (EI, 70 eV): m/z: 189 [M]+, 174, 158, 142, 114,
98, 81, 75, 58, 42, 29; HRMS calcd for C10H23NO2 [M]+: 189.17288;
found: 189.17282.
N-(5-Hydroxyoctyl)piperidine: Yield: 66% (GC). 1H NMR (400 MHz,
[D6]benzene): d = 3.53 (m, 1H), 2.26 (m, 4H), 2.23 (t, J = 6.8 Hz, 2H),
2.15–2.21 (m, 6H), 1.33–1.49 (m, 6H), 1.14–1.23 (m, 4H), 0.93 ppm (t, J
= 7.0 Hz, 3H); 13C NMR (100 MHz, CDCl3): d = 70.82, 59.35, 54.90,
40.46, 37.74, 27.09, 26.26, 24.94, 23.78, 19.40, 14.49 ppm; GC-MS (EI,
70 eV): m/z: 213 [M]+, 196, 170, 184, 156, 140, 124, 110, 98, 84, 70, 55, 41,
29; HRMS calcd for C13H27NO [M]+: 213.20962; found: 213.20982.
High-pressure FT-IR experiments: In a typical experiment the high-pres-
sure IR autoclave was charged with
a solution of [RhACHTRE(UNG cod)2]BF4
(0.1 mol%)and four equivalents of ligand in a methanol/toluene mixture
(1:1, 15 mL). The autoclave was purged three times with CO/H2 (1:1,
10 bar), pressurized with CO (7 bar) and H2 (28 bar), and heated to
1258C. Catalyst formation was monitored over time. Next, a mixture of
pent-2-ene and piperidine was introduced with an overpressure of hydro-
gen to a total pressure of 50 bar, the pressure that would be reached at T
= 1258C when the autoclave was pressurized with 7 bar CO and 33 bar
H2 at room temperature (as in the standard hydroaminomethylation
method). IR spectra were recorded every 15 min. After 12 h, the auto-
clave was cooled to room temperature and the gases were vented. The
reaction mixture was dried over MgSO4 and analyzed by GC with use of
bis(methoxyethyl)ether as an external standard and by GC/MS.
Physical data for amines
N-Hexylpiperidine:[20] Yield: 98% (GC). H NMR (400 MHz, CDCl3): d
1
= 2.26–2.33 (brm, 4H), 2.21 (t, J = 7.9 Hz, 2H), 1.51 (quint, J = 5.6 Hz,
4H), 1.41–1.45 (m, 2H), 1.38–1.43 (m, 2H), 1.21–1.28 (m, 6H), 0.81 ppm
(t, J
= = 60.05, 55.01,
7.1 Hz, 3H); 13C NMR (100 MHz, CDCl3): d
32.41, 27.85, 27.24, 26.31, 24.87, 22.99, 14.41 ppm; GC-MS (EI, 70 eV):
m/z: 169 [M]+, 154, 140, 124, 98, 84, 70, 55, 41, 29; HRMS calcd for
C11H23N [M]+: 169.18388; found: 169.18304.
N-Heptylpiperidine:[25] Yield: 98% (GC). 1H NMR (400 MHz, CDCl3): d
= 2.30–2.42 (brm, 4H), 2.25 (t, J = 7.8 Hz, 2H), 1.63 (quint, J = 5.6 Hz,
4H), 1.52–1.57 (m, 2H), 1.44–1.49 (m, 2H), 1.23–1.36 (m, 8H), 0.89 ppm
(t, J
= = 60.02, 55.05,
7.1 Hz, 3H); 13C NMR (100 MHz, CDCl3): d
32.46, 30.01, 28.53, 27.96, 26.35, 25.06, 23.17, 14.45 ppm; GC-MS (EI,
70 eV): m/z: 183 [M]+, 168, 154, 140, 124, 98, 84, 70, 55, 41, 29; HRMS
calcd for C12H25N [M]+: 183.19869; found: 183.19810.
1
N-Nonylpiperidine:[26] Yield: 99% (GC). H NMR (400 MHz, CDCl3): d
= 2.47–2.53 (brm, 4H), 2.40 (t, J = 7.6 Hz, 2H), 1.72 (quint, J = 5.6 Hz,
4H), 1.62–1.66 (m, 2H), 1.55–1.60 (m, 2H), 1.34–1.46 (m, 12H), 1.01 ppm
(t, J
= = 60.08, 55.02,
7.1 Hz, 3H); 13C NMR (100 MHz, CDCl3): d
32.27, 30.01, 29.95, 29.67, 28.17, 27.30, 26.32, 24.88, 23.05, 14.46 ppm; GC-
MS (EI, 70 eV): m/z: 211 [M]+, 196, 182, 168, 154, 140, 124, 110, 98, 84,
70, 55, 41, 29; HRMS calcd for C14H29N [M]+: 211.22819; found:
211.23000.
N-Hexylmorpholine:[27] Yield: 92% (GC). 1H NMR (400 MHz, CDCl3):
d = 3.63 (t, J = 4.8 Hz, 4H), 3.32–3.69 (m, 4H), 2.24 (t, J = 7.9 Hz,
2H), 1.40–1.43 (m, 2H), 1.19–1.26 (m, 6H), 0.81 ppm (t, J = 7.1 Hz,
3H); 13C NMR (100 MHz): d = 65.97, 58.25, 52.81, 30.79, 26.20, 25.53,
21.60, 13.04 ppm; GC-MS: m/z: 171 [M]+, 156, 142, 126, 100, 84, 70, 56,
42, 29; HRMS calcd for C10H21NO [M]+: 171.16258; found: 171.16231.
N-Hexylthiomorpholine: Yield: 92% (GC). 1H NMR (400 MHz, CDCl3):
d = 3.68–3.75 (m, 4H), 3.50 (t, J = 5.6 Hz, 4H), 2.80 (t, J = 5.6 Hz,
2H), 2.47–2.54 (m, 2H), 1.42–1.53 (m, 6H), 1.03 ppm (t, J = 7.1 Hz,
3H); 13C NMR (100 MHz, CDCl3): d = 58.50, 54.10, 30.80, 27.00, 26.20,
Acknowledgements
R.P.J.B. would like to thank Celanese Chemicals Europe GmbH for fi-
nancial support. S. Buchholz, H. Baudisch, K. Reincke, Dr. C. Fischer,
and Dr. W. Baumann (all Likat)are thanked for excellent analytic sup-
port. We thank Degussa AG (Oxeno Olefinchemie GmbH)for samples
of octene mixtures. Generous support from the state of Mecklenburg-
Vorpommern (Germany), the Fonds der Chemischen Industrie (Ger-
many), and the Bundesministerium für Bildung und Forschung (BMBF,
Germany)are gratefully acknowledged.
Chem. Eur. J. 2006, 12, 8979 – 8988
ꢁ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
8987