K. Nienkemper et al. / Journal of Organometallic Chemistry 693 (2008) 3063–3073
3071
solid (0.65 g, 39%). Crystallization from a methanol/triethylamine
mixture gave crystals suitable for X-ray diffraction. MS-ESI (m/z,
ES+, in methanol): 291.0 [M+H]+, 313.0 [M+Na]+. Anal. Calc. for
tion (0.781 6 T 6 0.985), Z = 4, monoclinic, space group P21/n,
(No. 14), k = 1.54178 Å, T = 223 K, and / scans, 20993 reflections
collected ( h, k, l), [(sinh)/k] = 0.60 Åꢀ1
5794 independent
(I)], 398 refined
x
,
C12H7N2OF5: C, 49.67; H, 2.43; N, 9.65. Found: C, 49.56; H, 2.32;
(Rint = 0.054) and 4600 observed reflections [I P 2r
N, 9.57%. 1H NMR (600 MHz, C6D6, 298 K): d = 7.74 (ddd,
3J = 6.4 Hz, 4J = 1.2 Hz, 5J = 0.5 Hz, 1H, 6-HPy), 6.41 (dd, 3J = 7.7 Hz,
4J = 1.9 Hz, 1H, 3-HPy), 6.15 (td, 3J = 7.7 Hz, 4J = 1.2 Hz, 1H, 4-HPy),
6.06 (ddd, 3J = 7.7 Hz, 3J = 6.4 Hz, 4J = 1.9 Hz, 1H, 5-HPy), 5.60 (br s,
1H, NH), 4.21 (d, 3J = 7.3 Hz, 2H, CH2NH). 13C{1H} NMR (151 MHz,
C6D6, 298 K): d = 147.9 (C2Py), 139.4 (C6Py), 125.1 (C3Py), 124.7
(C5Py), 123.5 (C4Py), 46.4 (CH2NH), n.o. (C6F5). 19F NMR (564 MHz,
C6D6, 298 K): d = ꢀ159.3 (m, 2F, o-PhF), ꢀ164.9 (m, 2F, m-PhF),
ꢀ171.6 (m, 1F, p-PhF).
parameters, R = 0.098, wR2 = 0.260, max. residual electron density
0.37 (ꢀ0.24) e Åꢀ3, hydrogen atoms calculated and refined as rid-
ing atoms.
4.7. 2-[1-(2,6-Diisopropylphenylamino)methylethyl]pyridine-N-oxide
(15a)
Trimethylaluminum (1.97 mL, 1.44 g, 20.0 mmol) was added
carefully to a solution of 11a (3.00 g, 10.1 mmol) in toluene
(100 mL) at 0 °C and the reaction mixture was stirred over night
at room temperature. After adding aqueous NaOH solution, the or-
ganic phase was separated and the aqueous phase was extracted
with chloroform. The combined organic phases were dried over
MgSO4 and the solvent was removed in vacuo. Finally the product
was obtained after column chromatography (SiO2; pentane/trieth-
ylamine/chloroform/methanol 15:2:1:1) as a white solid (1.79 g,
57%). Crystallization from a chloroform/methanol/triethylamine
mixture gave crystals suitable for X-ray diffraction. M.p. 88 °C
(DSC). MS-ESI (m/z, ES+, in methanol): 313.2 [M+H]+, 335.2
[M+Na]+, 647.4 [2M+Na]+. Anal. Calc. for C20H28N2O: C, 76.88; H,
9.03; N, 8.97. Found: C, 76.89; H, 9.01; N, 8.88%. 1H NMR
(500 MHz, CDCl3, 298 K): d = 8.29 (dd, 3J = 6.4 Hz, 4J = 1.0 Hz, 1H,
6-HPy), 7.33 (br d, 1H, 3-HPy), 7.25 (br t, 1H, 4-HPy), 7.19 (br t,
1H, 5-HPy), 7.06 (m, 1H, 4-HAr), 7.02 (m, 2H, 3-HAr), 5.77 (br s,
1H, NH), 3.28 (sept, 3J = 6.8 Hz, 2H, CH(CH3)2), 1.54 (s, 6H,
NC(CH3)2), 1.02 (d, 3J = 6.8 Hz, 12H, CH(CH3)2). 13C{1H} NMR
(126 MHz, CDCl3, 298 K): d = 156.3 (C2Py), 148.4 (C2Ar), 141.4
(C6Py), 138.9 (C1Ar), 126.3 (C4Py), 125.1 (C4Ar), 124.0 (C5Py), 123.1
(C3Py), 122.8 (C3Ar), 58.0 (NC(CH3)2), 28.1 (CH(CH3)2), 26.1
(NC(CH3)2), 24.2 (CH(CH3)2).
X-ray crystal structure analysis for 6c: formula C12H7F5N2O ꢂ 1/2
H2O, M = 299.20, colorless crystal 0.40 ꢁ 0.25 ꢁ 0.15 mm,
a = 25.262(1),
b = 5.629(1),
q
c = 17.097(1) Å,
b = 103.22(1)°,
V = 2366.8(5) Å3,
calc = 1.679 g cmꢀ3 = 0.165 mmꢀ1, empirical
, l
absorption correction (0.937 6 T 6 0.976), Z = 8, monoclinic, space
group C2/c, (No. 15), k = 0.71073 Å, T = 198 K,
x and / scans,
7512 reflections collected ( h, k, l), [(sinh)/k] = 0.67 Åꢀ1, 2834
independent (Rint = 0.042) and 1978 observed reflections
[I P 2r
(I)], 195 refined parameters, R = 0.041, wR2 = 0.116, max.
residual electron density 0.20 (ꢀ0.25) e Åꢀ3, hydrogen atom at
N8 and water from difference fourier map, other calculated and re-
fined as riding atoms.
4.6. Reaction of 11a with methyllithium: formation of 12
Methyllithium (1.6 M in diethylether, 4.6 mL, 7.30 mmol) was
added to a solution of 11a (2.06 g, 6.95 mmol) in diethylether
(100 mL) at ꢀ78 °C. Subsequently, the reaction mixture was stirred
for 2 h at ꢀ78 °C then for 12 h at room temperature. After addition
of aqueous ammonium chloride solution, the phases were sepa-
rated and the aqueous phase was extracted with dichloromethane
(30 mL). The combined organic phases were dried over MgSO4, fil-
tered, and the solvent was removed in vacuo. The obtained yellow
oil was purified by column chromatography (SiO2; cyclohexane/
ethyl acetate/triethylamine 30:1:1) to yield the product as a yel-
low, crystalline solid (1.05 g, 53%). Crystallization from a pen-
tane/chloroform/methanol/triethylamine mixture gave crystals
suitable for X-ray diffraction. M.p. 189 °C (DSC). MS-ESI (m/z, ES+,
in methanol): 575.4 [M+H]+, 597.4 [M+Na]+. Anal. Calc. for
C38H46N4O: C, 79.40; H, 8.07; N, 9.75. Found: C, 78.73; H, 7.93;
N, 9.69%. 1H NMR (500 MHz, THF-d8, 298 K): d = 9.19 (dd,
3J = 7.9 Hz, 4J = 1.0 Hz, 1H, 30-HPy), 8.454 (dd, 3J = 7.9 Hz,
4J = 1.0 Hz, 1H, 50-HPy), 8.450 (dd, 3J = 7.8 Hz, 4J = 2.1 Hz, 1H, 3-
HPy), 8.01 (t, 3J = 7.9 Hz, 1H, 40-HPy), 7.63 (dd, 3J = 7.8 Hz,
4J = 2.1 Hz, 1H, 5-HPy), 7.49 (t, 3J = 7.8 Hz, 1H, 4-HPy), 7.16 (m, 2H,
3-HAr), 7.157 (m, 2H, 30-HAr), 7.05 (ps t, 1H, 4-HAr), 7.045 (ps t,
1H, 40-HAr), 3.03 (sept, 3J = 6.9 Hz, 2H, CH(CH3)2), 2.80 (sept,
3J = 6.9 Hz, 2H, CH(CH3)20 ), 2.29 (s, 3H, @CCH30 ), 2.18 (s, 3H, @CCH3),
1.26 (d, 3J = 6.9 Hz, 6H, CH(CH3ACH3B)), 1.171 (d, 3J = 6.9 Hz, 6H,
X-ray crystal structure analysis for 15a: formula C20H28N2O,
M = 312.44,
colorless
crystal
c = 36.415(1) Å,
0.35 ꢁ 0.30 ꢁ 0.15 mm,
a = 17.666(1),
b = 8.845(1),
b = 100.21(1)°,
V = 5599.9(7) Å3,
q
calc = 1.112 g cmꢀ3
,
l
= 0.529 mmꢀ1, empirical
absorption correction (0.837 6 T 6 0.925), Z = 12, monoclinic,
space group P21/c, (No. 14), k = 1.54178 Å, T = 293 K,
x and / scans,
50552 reflections collected ( h, k, l), [(sinh)/k] = 0.60 Åꢀ1, 9993
independent (Rint = 0.046) and 8034 observed reflections
[I P 2r
(I)], 652 refined parameters, R = 0.050, wR2 = 0.129, max.
residual electron density 0.18 (ꢀ0.19) e Åꢀ3, hydrogen atom at
N10 from difference fourier map, other calculated and refined as
riding atoms.
4.8. 2-[1-(2,6-Diisopropylphenylamino)methylethyl]-6-
isopropylpyridine-N-oxide (15b) (according to the procedure
described for the synthesis of 15a)
Trimethylaluminum (113 lL, 85.0 mg, 1.18 mmol) was reacted
CH(CH3ACH3 )0), 1.165 (d, 3J = 6.9 Hz, 6H, CH(CH3ACH3B)), 1.14 (d,
with a solution of 11b (0.20 g, 0.59 mmol) in toluene (15 mL).
The described workup was carried out, to yield the product after
column chromatography (SiO2; pentane/triethylamine/chloro-
form/methanol 60:1:1:1) as a white solid (0.13 g, 63%). Crystalliza-
tion from a n-heptane gave crystals suitable for X-ray diffraction.
MS-ESI (m/z, ES+, in methanol): 355.3 [M+H]+, 377.3 [M+Na]+,
731.5 [2M+Na]+. Anal. Calc. for C23H34N2O: C, 77.92; H, 9.67; N,
7.90. Found: C, 77.67; H, 9.66; N, 7.65%. 1H NMR (600 MHz, CDCl3,
298 K): d = 7.18 (m, 1H, 5-HPy), 7.16 (m, 1H, 4-HPy), 7.11 (dd,
3J = 7.3 Hz, 4J = 2.4 Hz, 1H, 3-HPy), 7.04 (m, 1H, 4-HAr), 6.97 (m,
2H, 3-HAr), 5.99 (br s, 1H, NH), 3.87 (sept, 3J = 6.9 Hz, 1H,
CH(CH3)2Py), 3.14 (br sept, 3J = 6.9 Hz, 2H, CH(CH3)2Ar), 1.54
(s, 6H, NC(CH3)2), 1.33 (d, 3J = 6.9 Hz, 6H, CH(CH3)2Py), 0.95 (d,
3J = 6.9 Hz, 12H, CH(CH3)2Ar). 13C{1H} NMR (151 MHz, CDCl3,
B
3J = 6.9 Hz, 6H, CH(CH3ACH3 )0). 13C{1H} NMR (126 MHz, THF-d8,
B
298 K): d = 167.4 (@CCH30 ), 165.6 (@CCH3), 156.5 (C60Py), 151.7
(C6Py), 149.5 (C20Py), 148.0 (C2Py), 147.4 (C10Ar), 146.0 (C1Ar),
137.3 (C40Py), 136.5 (C2Ar), 136.2 (C20Ar), 128.5 (C3Py), 127.4
(C30Py), 126.0 (C5Py), 125.0 (C4Py), 124.6, 124.3 (C4Ar C40Ar),
,
0
0
Py
123.59, 123.56 (C3Ar, C3 Ar), 122.1 (C5 ), 29.1 (CH(CH3)02), 28.7
(CH(CH3)2), 23.7 (CH(CH3ACH3B)), 23.5 (CH(CH3ACH3 )0), 23.0
B
(CH(CH3ACH3B)), 22.9 (CH(CH3ACH3 )0), 19.6 (@CCH3), 17.2
B
(@CCH03).
X-ray crystal structure analysis for 12: formula C38H46N4O,
M = 574.79, yellow crystal 0.50 ꢁ 0.30 ꢁ 0.03 mm, a = 11.2767(4),
b = 10.4211(3), c = 29.1668(9) Å, b = 96.249(2)°, V = 3407.19(19) Å3,
q
calc = 1.121 g cmꢀ3 = 0.522 mmꢀ1, empirical absorption correc-
, l