3724 Organometallics, Vol. 17, No. 17, 1998
Wang et al.
1H, C6H8), 3.52 (m, 1H, C6H8), 3.35 (m, 1H, OCH2CH3), 2.61
(m, 1H, OCH2CH3), 2.49 (m, 1H, C6H8), 2.20 (m, 1H, C6H8),
unusual reactions and the structural characterizations
of the reaction products.
1.54 (m, 2H, C6H8), 1.01 (t, 3H, OCH2CH3); MS m/e 340 (M+
-
CO), 312 (M+ - 2CO), 284 (M+ - 3CO), 239 (M+ - 3CO -
OC2H5), 228 (M+ - Fe(CO)3). Anal. Calcd for C19H20O4Fe: C,
61.97; H, 5.47. Found: C, 62.15; H, 5.49. [2-4-η-C6H8-
(CO)3F eC(OC2H5)C6H4CF 3-p] (8): yellow crystals (40% yield);
mp 76-78 °C (dec); IR (νCO) (n-hexane) 2060 (s), 1998 (vs),
1988 (vs) cm-1; 1H NMR (CD3COCD3) δ 7.67 (d, 4H, C6H4CF3),
5.05 (t, 1H, C6H8), 4.86 (t, 1H, C6H8), 4.53 (t, 1H, C6H8), 3.57
(m, 1H, C6H8), 3.36 (m, 1H, OCH2CH3), 2.73 (m, 1H, OCH2-
CH3), 2.56 (m, 1H, C6H8), 2.27 (m, 1H, C6H8), 1.58 (m, 2H,
C6H8), 1.04 (t, 3H, OCH2CH3); MS m/e 394 (M+ - CO), 366
Exp er im en ta l Section
All reactions were performed under a dry, oxygen-free N2
atmosphere by using standard Schlenk techniques. All sol-
vents employed were reagent grade and dried by refluxing over
the appropriate drying agents and stored over 4 Å molecular
sieves under a N2 atmosphere. The ethyl alcohol (EtOH) was
distilled from Mg(OEt)2, diethyl ether (Et2O) from sodium
benzophenone ketyl, and benzene from sodium metal, while
petroleum ether (30-60 °C) was distilled from CaH2 and CH2-
Cl2 from P2O5. The neutral alumina (Al2O3) used for chroma-
tography was deoxygenated at room temperature under high
vacuum for 16 h, deactivated with 5% w/w N2-saturated water,
and stored under N2. [(NH4)2Ce(NO3)6], P(n-Bu)3, PPh3,
P(OMe)3, P(OPh)3, and AsPh3 were purchased from either
Strem Chemical Co. or Aldrich Chemical Co. The compounds
[C6H8(CO)2FeC(OC2H5)Ar] (1, Ar ) C6H5; 2, Ar ) m-CH3C6H4;
3, Ar ) p-CH3C6H4; 4, Ar ) p-CF3C6H4) were prepared as
previously described.7
(M+ - 2CO), 338 (M+ - 3CO), 282 (M+ - Fe(CO)3), 258 (M+
-
3CO - C6H8). Anal. Calcd for C19H17O4F3Fe: C, 54.05; H,
4.06. Found: C, 54.26; H, 4.26.
Rea ction of 1 w ith CO To Give 5. Carbon monoxide gas
was bubbled though a solution of 0.10 g (0.31 mmol) of 1 in 30
mL of EtOH at -35 to -30 °C over a period of 0.5 h, during
which time the orange-red solution gradually turned light
yellow. After removal of the solvent at -20 °C in vacuo, the
residue was chromatographed on Al2O3 (neutral) at -10 °C
with petroleum ether as the eluant. The yellow band was
eluted and collected. Further treatment, as described in the
reaction of 1 with (NH4)2Ce(NO3)6, gave 0.10 g (90%, based on
1) of yellow crystalline 5, which was idetified by its mp and
IR and 1H NMR spectra.
The IR spectra were measured on a Shimadzu-IR-440
spectrophotometer. All 1H NMR spectra were recorded at
ambient temperature in acetone-d6 solution with TMS as the
internal reference, using a Bruker AM-300 spectrometer.
Electron ionization mass spectra (EIMS) were run on
Hewlett Packard 5989A spectrometer. Melting points obtained
on samples in sealed capillaries are uncorrected.
a
Similar reactions gave the following complexes: 6 (80%
yield), 7 (75% yield), and 8 (95% yield), which were identified
by their mp and IR and 1H NMR spectra.
Rea ction of [2-4-η-C6H8(CO)2F eC(OC2H5)C6H5] (1) w ith
(NH4)2Ce(NO3)6 To Give [2-4-η-C6H8(CO)3F eC(OC2H5)-
C6H5] (5). To a solution of 1 (0.50 g, 1.53 mmol) in 60 mL of
EtOH was added dropwise 0.84 g (1.53 mmol) of (NH4)2Ce-
(NO3)6 in 20 mL of EtOH at -35 °C within 20 min. The red
solution turned brown-yellow. After it was stirred at -35 to
-30 °C for 30 min, the solution was evaporated under vacuum
to dryness. The red oil residue was dissolved in 30 mL of N2-
saturated water. The aqueous solution was extracted with
ether. The extract was washed with 50 mL of water and then
dried over anhydrous Na2SO4. After removal of the solvent
in vacuo, the residue was chromatographed on an alumina
column (1.6 × 10-15 cm) at -10 °C with petroleum ether/
Et2O (15:1) as the eluant. The yellow band was collected.
Removal of solvent in vacuo and recrystallization of the crude
product from petroleum ether solution at -80 °C gave 0.17 g
(30%, based on 1) of yellow crystals of 5: mp 52-54 °C (dec);
Rea ction of 4 w ith P (n -Bu )3 To Give [2-4-η-C6H8(CO)2-
{P (n -Bu )3}F eC(OC2H5)C6H4CF 3-p] (9). Compound 4 (0.080
g, 0.20 mmol) was dissolved in 50 mL of petroleum ether (30-
60 °C) at -60 °C. To this solution was added dropwise 0.26
mmol of P(n-Bu)3 in 20 mL of petroleum ether. The reaction
mixture was stirred at -50 to -30 °C for 3 h. The resulting
yellow mixture was evaporated at -20 °C in vacuo to dryness.
The residue was chromatographed on Al2O3 at -15 °C with
petroleum ether as the eluant. The yellow band was collected.
After removal of the solvent, the crude product was recrystal-
lized from petroleum ether/CH2Cl2 at -80 °C to give 0.11 g
(78%, based on 4) of yellow crystals of 9: mp 22-23 °C (dec);
IR (νCO) (n-hexane) 1992 (vs), 1940 (vs) cm-1; 1H NMR (CD3-
COCD3) δ 7.58 (d, 4H, C6H4CF3), 4.32 (m, 1H, C6H8), 4.21 (t,
1H, C6H8), 3.99 (q, 1H, C6H8), 3.47 (m, 1H, C6H8), 3.32 (m, 1H,
OCH2CH3), 2.62 (m, 1H, OCH2CH3), 2.28 (m, 1H, C6H8), 2.13
(m, 1H, C6H8), 1.48-1.40 (m, 2H, C6H8), 1.37 (m, 18H, [CH3-
(CH2)3]3), 1.00 (t, 3H, OCH2CH3), 0.88 (m, 9H, [CH3(CH2)3]3);
MS m/e 596 (M+), 568 (M+ - CO), 540 (M+ - 2CO), 366 (M+
- CO - P(n-Bu)3). Anal. Calcd for C30H44O3F3PFe: C, 60.41;
H, 7.43. Found: C, 60.19; H, 7.58.
IR (νCO) (n-hexane) 2020 (w), 2000 (s), 1992 (vs) cm-1 1H
;
NMR (CD3COCD3) δ 7.58-7.32 (m, 4H, C6H5), 7.01 (t, 1H,
C6H5), 5.00 (m, 1H, C6H8), 4.76 (m, 1H, C6H8), 4.43 (t, 1H,
C6H8), 3.53 (m, 1H, C6H8), 3.34 (m, 1H, OCH2CH3), 2.63 (m,
1H, OCH2CH3), 2.51 (m, 1H, C6H8), 2.24 (m, 1H, C6H8), 1.55
(m, 2H, C6H8), 1.00 (t, 3H, OCH2CH3); MS m/e 326 (M+ - CO),
298 (M+ - 2CO), 270 (M+ - 3CO), 225 (M+ - 3CO - OC2H5),
214 (M+ - Fe(CO)3), 190 (M+ - 3CO - C6H8). Anal. Calcd
for C18H18O4Fe: C, 61.04; H, 5.12. Found: C, 61.20; H, 5.17.
The following complexes were prepared by similar reactions.
[2-4-η-C6H8(CO)2{P (OMe)3}F eC(OC2H5)C6H4CF 3-p ] (10):
yellow crystals (85% yield); mp 82 °C (dec); IR (νCO) (n-hexane)
2015 (vs), 1960 (vs) cm-1; 1H NMR (CD3COCD3) δ 7.61 (d, 3H,
C6H4CF3), 7.36 (s, 1H, C6H4CF3), 4.59 (m, 1H, C6H8), 4.38 (m,
1H, C6H8), 4.19 (q, 1H, C6H8), 3.53 (m, 1H, C6H8), 3.46-3.41
(s, s, 9H, P(OCH3)3), 3.33 (m, 1H, OCH2CH3), 2.67 (m, 1H,
OCH2CH3), 2.59 (m, 1H, C6H8), 2.16 (m, 1H, C6H8), 1.54-1.40
(m, 2H, C6H8), 1.02 (t, 3H, OCH2CH3); MS m/e 490 (M+ - CO),
462 (M+ - 2CO), 366 (M+ - CO - P(OMe)3). Anal. Calcd for
The following complexes were prepared by similar reactions.
[2-4-η-C6H8(CO)3F eC(OC2H5)C6H4CH3-m ] (6): orange-yellow
viscous oil (26% yield); IR (νCO) (n-hexane) 2040 (m), 1995
(s), 1983 (vs) cm-1; 1H NMR (CD3COCD3) δ 7.41-6.83 (m, 4H,
C6H4CH3), 2.34 (s, 3H, C6H4CH3), 4.98 (t, 1H, C6H8), 4.76 (t,
1H, C6H8), 4.42 (t, 1H, C6H8), 3.54 (m, 1H, C6H8), 3.36 (m, 1H,
OCH2CH3), 2.65 (m, 1H, OCH2CH3), 2.53 (m, 1H, C6H8), 2.19
(m, 1H, C6H8), 1.54 (m, 2H, C6H8), 0.96 (t, 3H, OCH2CH3); MS
m/e 340 (M+ - CO), 312 (M+ - 2CO), 284 (M+ - 3CO), 239
(M+ - 3CO - OC2H5), 228 (M+ - Fe(CO)3). Anal. Calcd for
C
21H26O6F3PFe: C, 48.67; H, 5.06. Found: C, 49.01; H, 5.19.
[2-4-η-C6H8(CO)2{P (OP h )3}FeC(OC2H5)C6H4CF3-p] (11): yel-
low crystals (80% yield); mp 68-70 °C (dec); IR (νCO)(n-
hexane) 2040 (m), 1972 (vs) cm-1 1H NMR (CD3COCD3) δ
;
7.58-7.38 (m, 10H, C6H5 + C6H4CF3), 7.23-7.12 (m, 9H, C6H5
+ C6H4CF3), 4.81 (q, 1H, C6H8), 4.30 (q, 1H, C6H8), 3.88 (t,
1H, C6H8), 3.49 (m, 1H, C6H8), 3.31 (m, 1H, OCH2CH3), 2.64
(m, 1H, OCH2CH3), 2.49 (m, 1H, C6H8), 1.50 (m, 1H, C6H8),
1.40-1.20 (m, 2H, C6H8), 0.97 (t, 3H, OCH2CH3); MS m/e 648
(M+ - 2CO), 366 (M+ - CO - P(OPh)3). Anal. Calcd for
C
19H20O4Fe: C, 61.97; H, 5.47. Found: C, 62.41; H, 5.77. [2-4-
η-C6H 8(CO)3F eC(OC2H 5)C6H 4CH 3-p ] (7): orange oil (31%
yield); IR (νCO) (n-hexane) 2050 (m), 2000 (s), 1990 (vs) cm-1
;
1H NMR (CD3COCD3) δ 7.48-7.14 (m, 4H, C6H4CH3), 2.27 (s,
3H, C6H4CH3), 4.97 (t, 1H, C6H8), 4.73 (t, 1H, C6H8), 4.42 (t,