612
M. Gꢀomez et al. / Polyhedron 23 (2004) 611–616
terminal oxazoline unit introduces a new dimension to
this new type of complexes, since all of the ferrocene-
oxazoline compounds reported so far have the oxazoline
fragment directly bound to ferrocene, because of the
ortho directing behaviour of this functional group which
leads to the synthesis of planar chiral ferrocenes [7,13].
In this exploratory work, racemic amino alcohols have
been used. Preliminary attempts to coordinate these
compounds to Pd and Au failed.
2.3. 1-Ethenyl-(4-(40-isobutyl-30,40-dihydrooxazol-20-yl)-
phenyl)ferrocene, 6
Compound prepared following the methodology de-
scribed for 5. Starting materials: 0.100 g (0.227 mmol) of
1-(ethenyl-4-cianophenyl)ferrocene, 0.204 g (1.74 mmol)
of leucinol and a catalytic amount of zinc chloride.
1
Yield: 0.068 g (73%). H NMR (400 MHz, CDCl3) d
0.95 (m, 3H), 0.97 (m, 3H), 1.40 (m, 1H), 1.80 (m, 2H),
3.98 (t, 8.0 Hz, 1H), 4.13 (s, 5H), 4.29 (m, 2H), 4.47 (m,
2H), 6.69 (d, 16.0 Hz, 1H), 6.94 (d, 16.0 Hz, 1H), 7.42
(d, 8.0 Hz, 2H), 7.88 (d, 8.0 Hz, 2H) ppm. 13C NMR (50
MHz, CDCl3) d 21.62, 21.93, 24.46, 44.54, 64.06, 65.97,
68.17, 68.24, 71.93, 81.69, 124.13, 124.35, 127.43,
127.86, 163.0 ppm. IR (KBr) 1640 (C@N) cmꢀ1. Anal.
Calc. for C25H27NOFe: C, 72.65; H, 6.58; N, 3.39.
Found C, 71.90; H, 6.80; N, 3.10%. MS (FAB positive)
m=z 413 ([M]þ).
2. Experimental
2.1. General data
All compounds were prepared under a purified nitro-
gen atmosphere using standard Schlenk and vacuum-line
techniques. The solvents were purified by standard pro-
cedures [14] and distilled under nitrogen. Ethenyl-ferro-
cene derivatives 1 and 2 were prepared as previously
described [5a,5b]. 2-aminobutanol (Fluka) and leucinol
(Aldrich) were used without previous purification. NMR
spectra were recorded on JEOL Eclipse 400, Bruker DRX
500 (1H, standard SiMe4) and Varian Gemini 200 (13C, 50
MHz, standard SiMe4) in CDCl3. Chemical shifts were
reported downfield from standards. IR spectra were re-
corded on a Nicolet 520 FT-IR and FTIR Nicolet Impact
400 spectrometers. FAB mass chromatograms were ob-
tained on a Fisons V6-Quattro instrument. Optical rota-
tions were measured on a Perkin Elmer 241MC
spectropolarimeter. Elemental analyses were carried out
2.4. 1,10-Bis(ethenyl-(4-(40-ethyl-30,40-dihydrooxazol-20-
yl)phenyl))ferrocene, 7
0.200 g (0.454 mmol) of 1,10-bis(ethenyl-4-cianophe-
nyl)ferrocene, 0.624 g (7.0 mmol) of 2-aminobutanol
and a catalytic amount of zinc chloride. The mixture
was filtered off and the solvent was removed under re-
duced pressure, affording an oil, which was chroma-
tographied over SiO2 using dichloromethane/hexane (1/
1) as eluent. The product corresponded to the fractions
with Rf ¼ 0:4 on the TLC sheet. After removing the
solvent, 7 was obtained as a red solid. Yield (based on
2): 0.053 g (20%). 1H NMR (400 MHz, CDCl3) d 0.98 (t,
7.5 Hz, 6H), 1.63 (m, 2H), 1.77 (m, 2H), 4.05 (t, 8.0 Hz,
2H), 4.28 (m, 2H), 4.29 (m, 4H), 4.42 (m, 4H), 4.44 (dd,
11.8 Hz, 8.0 Hz, 2H), 6.61 (d, 16.5 Hz, 2H), 6.85 (d, 16.5
Hz, 2H), 7.31 (d, 8.4 Hz, 4H), 7.81 (d, 8.4 Hz, 4H) ppm.
ꢀ
ꢁ
by the Serveis Cientıfico-Tecnics de la Universitat de
Barcelona in an Eager 1108 microanalyzer.
2.2. 1-Ethenyl-(4-(40-ethyl-30,40-dihydrooxazol-20-yl)ph-
enyl)ferrocene, 5
IR (KBr) 1645 (C@N) cmꢀ1
.
Anal. Calc. for
C36H36N2O2Fe: C, 73.97; H, 6.21; N, 4.79. Found C,
74.30; H, 6.40; N, 4.55%. MS (FAB positive) m=z 585
([M]þ).
0.100 g (0.227 mmol) of 1-(ethenyl-4-cianophenyl)fer-
rocene, 0.155 g (1.74 mmol) of 2-aminobutanol and a
catalytic amount of zinc chloride were dissolved in 10 cm3
of toluene at room temperature. The mixture was refluxed
for 8 days (monitored by TLC). The mixture was filtered
off and the solvent was removed under reduced pressure,
affording an oil, which was chromatographied over SiO2
using ethyl acetate/hexane (1/1) as eluent. After removing
the solvent, 5 was obtained as a red solid. Yield: 0.045 g
(52%). 1H NMR (400 MHz, CDCl3) d 1.01 (t, 7.0 Hz, 3H),
1.72 (m, 2H), 4.05 (m, 2H), 4.28 (m, 1H), 4.32 (2, 5H), 4.46
(m, 4H), 6.65 (d, 16.0 Hz, 1H), 6.76 (d, 16.0 Hz, 1H), 7.69
(d, 8.0 Hz, 2H), 7.81 (d, 8.0 Hz, 2H) ppm. 13C NMR (50
MHz, CDCl3) d 12.00, 22.00, 25.20, 44.35, 64.00, 65.40,
68.00, 68.10, 71.50, 82.00, 123.90, 124.30, 127.40, 127.70,
164.00 ppm. IR (KBr) 1650 (C@N) cmꢀ1. Anal. Calc. for
C23H23NOFe: C, 71.70; H, 6.02; N, 3.64. Found C, 70.50;
H, 6.00; N, 3.50%. MS (FAB positive) m=z 385 ([M]þ).
2.5. 1,10-Bis(ethenyl-(4-(40-isobutyl-30,40-dihydrooxazol-
20-yl)phenyl))ferrocene, 8
0.200 g (0.454 mmol) of 1,10-bis(ethenyl-4-cianophe-
nyl)ferrocene, 0.820 g (7.0 mmol) of leucinol and a
catalytic amount of zinc chloride. The mixture was fil-
tered off and the solvent was removed under reduced
pressure, affording an oil, which was chromatographied
over SiO2 using dichloromethane/hexane (1/1) as eluent.
The product corresponded to the fractions with Rf ¼ 0:4
on the TLC sheet. After removing the solvent, 8 was
obtained as a red solid. Yield (based on 2): 0.047 g
1
(16%). H NMR (400 MHz, CDCl3) d 0.98 (m, 12H),
1.39 (m, 2H), 1.73 (m, 2H), 1.76 (m, 2H), 3.98 (t, 8.0 Hz,
2H), 4.14 (m, 8H), 4.29 (m, 4H), 4.46 (m, 4H), 6.52 (dd,