Preparation of ferrocenyl mono- and dienone derivatives through aldol condensation of 1,1′-diacetylferrocene with aromatic aldehydes in dry conditions

Article abstract of DOI:10.1016/S0022-328X(01)00927-5

1,1′-Diacetylferrocene was condensed with aromatic aldehydes without solvent in the presence of solid NaOH. Diacetylferrocene can give good yields of mono- or diene with either one or two molecules of a wide range of aldehydes depending only on the stoichiometry. Cyclization to ferrocenphane does not occur in this condition.

Full text of DOI:10.1016/S0022-328X(01)00927-5

Journal of Organometallic Chemistry 637–639 (2001) 782–785
www.elsevier.com/locate/jorganchem
Note
Preparation of ferrocenyl mono- and dienone derivatives through
aldol condensation of 1,1%-diacetylferrocene with aromatic
aldehydes in dry conditions
Wan-yi Liu a, Qi-hai Xu a, Bao-hua Chen a, Yong-min Liang a, Yong-xiang Ma a,*,
Wei-min Liu b
a National Laboratory of Applied Organic Chemistry, Lanzhou Uni6ersity, Lanzhou 730000, China
b Laboratory of Solid Lubrication, Lanzhou Institute of Chemical Physicals Chinese Academy of Science, Lanzhou 730000, China
Received 4 January 2001; received in revised form 14 March 2001; accepted 19 March 2001
Abstract
1,1%-Diacetylferrocene was condensed with aromatic aldehydes without solvent in the presence of solid NaOH. Diacetylferrocene
can give good yields of mono- or diene with either one or two molecules of a wide range of aldehydes depending only on the
stoichiometry. Cyclization to ferrocenphane does not occur in this condition. © 2001 Elsevier Science B.V. All rights reserved.
Keywords: 1,1%-Diacetylferrocene; 1-Acetyl-1%-enonylferrocenes; 1,1%-Dienonylferrocenes; Aldol condensation; Solid-state reaction
tions of acetylferrocene in dry conditions with mi-
crowave irradiation for synthesis of ferrocenylenones
were described [8]. The method has also some disavan-
tages, such as needing PTC and combustion in the
microwave oven. We have investigated the synthesis of
ferrocenylenones using solid NaOH to catalyze this
process under solvent-free conditions [9]. The main
advantages of this procedure are the following: shorter
reaction time, higher yields, and cleaner reaction with
easier work-ups.
Herein, we report a selective synthesis of 1-acetyl-1%-
enonylferrocenes (3) and 1,1%-dienonylferrocenes (4)
without the ferrocenphane (5) by using a powdered
NaOH catalyzed aldol condensation of diacetylfer-
rocene with aromatic aldehydes (2) and a varying mate-
rial ratio in a dry state. The operation has advantages,
such as reduced pollution, low costs, high yields and
simplicity in processing and handling.
1. Introduction
1,1%-Diacetylferrocenes are important compounds be-
cause of their photographic properties [1] and as pre-
cursors for semiconducting polymers [2]. Main
synthetic methods for such ferrocenylenones are acyla-
tion [3] and aldol condensations [2,4]. However, the
methods have serious disadvantages, such as use of
large amounts of solvents, unavailable acyl chlorides
[3], and low product yields [2,4]. Much attention has
been focused on the Claisen–Schmidt reactions of 1,1%-
diacetylferrocene with aromatic aldehydes in homoge-
neous solutions [5]. But, this reaction generally yields a
mixture of 1,1%-dienonylferrocenes and ferrocenphane.
In recent papers, the conditions to select the formation
of the dienone derivative or the corresponding ferrocen-
phane have been established [6,7]. But they bear some
of the following shortcomings: low yield, long reaction
time, and reagent wasting. Recently, some aldol reac-
* Correspondence author. Fax: +86-931-861-1688.
E-mail address: mayx@lzu.edu.cn (Y.-x. Ma).
0022-328X/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(01)00927-5

W.-y. Liu et al. / Journal of Organometallic Chemistry 637–639 (2001) 782–785
783
aqueous–ethanolic sodium hydroxide produces a red
product 4 and a yellow product 5 as it is shown in
Table 2, and 5 is the principal product. By increasing
the ratio of aldehyde, the amount of 4 was also in-
creased and it became the principal product. However,
under dry conditions, this condensation reaction gave 3
and another red product 4. The red product 3 decreased
and 4 increased as the molecular ratio of benzaldehyde
was increased. Ferrocenyl mono- and dienone deriva-
tives produced in this way have the E-configuration.
2. Results and discussion
The results are listed in Table 1 and in Section 3. All
of the products were characterized by H-NMR, MS
and IR spectroscopy.
1
From Table 1, we can see that the aldol condensation
can be carried out in mild conditions to give satisfac-
tory yields of compounds 3 and 4. When the ratio of
1/2 is 1:1, the principal product is 1 and the product 4
is also produced along with an increase of 2. The 1
reacts completely when adding more aromatic alde-
hydes and the yields of 4 are also increased. From entry
7 to 16, we can infer that enones bearing electron-draw-
ing groups on the aromatic ring are more reactive than
those with electron-donating groups.
3. Experimental
3.1. Preparation of the materials
1H-NMR spectra were performed on a DRX-200
spectrometer or a FC-80 spectrometer by using CDCl3
For reaction in presence of solvent, the condensation
of diacetylferrocene and benzaldehyde with 5%
Table 1
Preparation of compounds 3 and 4
Entry
Ratio
R
Time (min)
Temp. (°C)
Yield (%)
M.p. (lit) (°C)
(ketone/aldehyde)
Compd. 3
68 (3a)
Compd. 4
23 (4a)
Compd. 3
Compd. 4
1
1/1
Ph
20
40
131–132
181–183
(180–182) [4a]
181–183
2
3
4
5
6
7
8
9
10
11
1/3
1/1
1/3
1/1
1/3
1/1
1/2.5
1/1
1/2.5
1/1
Ph
2-Furyl
2-Furyl
PhCHꢀCH–
PhCHꢀCH–
4-Cl–C6H4
4-Cl–C6H4
3,4-OCH2OC6H3 50
3,4-OCH2OC6H3 50
20
15
15
15
15
20
20
40
40
40
40
40
70
70
75
75
70
Trace
74 (3b)
Trace
70 (3c)
Trace
56 (3d)
20
54 (3e)
8
65 (3f)
92
12 (4b)
87
15 (4c)
94
18 (4d)
70
10 (4e)
69
10 (4f)
(131–132) [4c]
110–112
160 (162) [2]
64–65
170–172
160–161
180
216
130–132
114–116
3-O2N–C6H4
40
201–203
(200–202) [4b]
12
13
14
15
16
1/2.5
1/1
1/2.5
1/1
3-O2N–C6H4
4-O2NC6H3
4-O2NC6H3
30
40
40
70
70
70
75
75
10
62 (3g)
11
66 (3h)
10
73
12 (4g)
75
8 (4h)
64
265 (265) [4b]
30–31
210
224
p-N(CH3)2C6H4 50
1/2.5
50
Table 2
Aldol condensation reaction of 1 and 2a in the dry state and in 5% NaOH aqueous EtOH [4a] with various equivalents of benzaldehyde
C6H5CHO equi. Reaction temp. (°C)
Reaction time (min)
Solvent
Red product yield
(%)
Yellow product yield (%)
3a
4a
5a
1:1
1:2
r.t.
15
r.t.
r.t.
40
r.t.
r.t.
r.t.
30
90
30
90
240
25
–
60–65
–
40–45
–
–
–
–
–
Trace
6–13 66–68
20–22
23
–
96
72
75
–
EtOH [4a]
–
EtOH [4a]
MeOH [4b]
–
–
60
68
–
22
5
1:4
1:6
90
360
EtOH [4a]
EtOH [4a]

784
W.-y. Liu et al. / Journal of Organometallic Chemistry 637–639 (2001) 782–785
as a solvent and Me4Si as an internal reference. Mass
spectra were obtained on a ZAB-HS mass spectrometer
by fast atom bombardment (FAB, MASPEC 11 date
base). IR spectra were recorded on a Nicolet AVATAR
360 FT-IR spectrophotometer as KBr discs in the
4000–200 cm−1 region. The elemental analysis was
carried out with an Elementary Vario EL analyzer. The
melting points reported here were uncorrected. Di-
acetylferrocene (1) was synthesized as reported [10].
Aromatic aldehydes were purchased and used as
received.
3.2.5. 1-Acetyl-1%-(i-phenyl6inyl) acryloylferrocene (3c)
Red solid, m.p. 170–172 °C. 1H-NMR (l, ppm):
7.85–7.24 (m, 5H, ph), 7.93, 7.04 (dd, 2H, J=15.1 Hz,
–C–CH=CH–), 6.74–6.54 (dd, 2H, J=15.2Hz,
–CH=CH–ph). 4.88, 4.59 (2m, 8H, Cp); MS m/z (%):
384.2 (50); Anal. Calc. for C23H20O2Fe: C, 71.92; H,
5.21. Found: C, 71.45; H, 4.85%. IR(KBr, cm−1) 1750
(CꢀO), 1670 (CꢀO), 1640 (CꢀC).
3.2.6. 1-1%-bis(i-Phenyl6inyl)acryloylferrocene (4c)
Red solid, m.p. 64–65 °C.1H-NMR (l, ppm): 7.90,
7.19 (dd, 4H, J=15.2 Hz, –CCH=CH–), 6.99, 6.44
(dd, 4H, J=15.2 Hz, –CHꢀCHph), 7.70–7.43 (m,
10H, ph), 4.96, 4.63 (2m, 8H, Cp); MS m/z (%): 498.3
(10), Anal. Calc. for C32H26O2Fe: C, 77.13; H, 5.22.
Found: C, 77.62; H, 5.69%. IR (KBr, cm−1): 1658
(CꢀO), 1598 (CꢀC).
3.2. General procedure for the preparation of 3 and 4
A mixture of 1 (1 mmol), 2 (1 mmol) and 0.2 g
NaOH (5mmol) were ground with an agate mortar and
a pestle, and allowed to stand at 40 °C (entry 1–6) or
70–75 °C (entry 7–16) for a specific time as shown in
Table 1. The final products were extracted with CH2Cl2
and the solution was dried with MgSO4. After filtra-
tion, the solvent was removed and the enones were
separated from the residue by column chromatography
(silica gel CH2Cl2–50% EtOAc as eluant).
3.2.7. 1-Acetyl-1%-(p-chlorocinnamoyl)ferrocene (3d)
Red solid, m.p. 160–161 °C. 1H-NMR (l, ppm):
7.89, 7.14 (dd, 2H, vinyl, J=15 Hz), 7.70–7.48 (m, 4H,
ph), 4.92, 4.80, 4.63, 4.55 (4t, 8H, Cp), 2.38 (s, 3H,
CH3); MS m/z (%): 392.7 (41), Anal. Calc. for
C21H17ClO2Fe: C, 64.22; H, 4.33. Found: C, 64.67; H,
4.68%. IR(KBr, cm−1):1730 (CꢀO), 1665 (CꢀO), 1630
(CꢀC).
3.2.1. 1-Acetyl-1%-cinnamoylferrocene (3a)
Red solid, m.p. 131–132 °C. 1H-NMR (l, ppm):
7.87, 7.02 (dd, 2H, vinyl protons, J=15.5 Hz), 7.9–7.2
(m, 5H, ph), 4.81, 4.79, 4.59, 4.52 (4t, 8H, Cp), 2.34 (s,
3H, CH3); MS m/z (%): 358.2 (60), Anal. Calc. for
C21H18O2Fe: 358.2; IR (KBr, cm−1): 1744 (CꢀO), 1668
(CꢀO), 1645 (CꢀC).
3.2.8. 1,1%-bis[(p-Chlorocinnamoyl)]ferrocene (4d)
Red solid, m.p. 216 °C. 1H-NMR (l, ppm): 7.92,
7.04 (dd, vinyl, 4H, J=14.3 Hz), 7.78–7.58 (m, 8H,
ph), 4.95, 4.80, 4.67, 4.56 (4t, 8H, Cp); MS m/z (%):
515.3 (3), Anal. Calc. for C28H20Cl2O2Fe: C, 65.26; H,
3.88; Found: C, 65.67, H, 3.68%. IR (KBr, cm−1): 1659
(CꢀO), 1588 (CꢀC).
3.2.2. 1,1%-Dicinnamoylferrocene (4a)
Red solid, m.p. 181–183 °C. 1H-NMR (l, ppm):
7.41, 7.02 (dd, 4H, vinyl protons, J=15.3 Hz), 7.8–7.2
(m, 10H, ph), 4.93, 4.62, 4.26 (3m, 8H, Cp); MS m/z
(%): 446.3 (90), Anal. Calc. for C28H22O2Fe; 446.3; IR,
(KBr, cm−1): 1654 (CꢀO), 1572 (CꢀC).
3.2.9. 1-Acetyl-1%-piperonyloylferrocene (3e)
Red solid, m.p. 180 °C. 1H-NMR (l, ppm): 7.64,
7.03 (dd, 2H vinyl, J=14.4 Hz), 7.46–6.83 (m, 3H,
ph), 6.50 (s, 2H, OCH2O), 4.93, 4.52 (2m, 8H, Cp), 2.36
(s, 3H, CH3); MS m/z (%) 402.3 (30), Anal. Calc. for
C22H18O4Fe: C, 68.66; H, 4.97; Found: C, 69.13; H,
4.57%. IR (KBr, cm−1): 1740 (CꢀO), 1666 (CꢀO), 1635
(CꢀC).
3.2.3. 1-Acetyl-1%-(2-furyl)acryloylferrocene (3b)
Red solid, m.p. 110–112 °C. 1H-NMR (l, ppm):
7.43 (s, 1H, furyl), 6.65 (s, 1H, furyl), 6.45 (s, 1H,
furyl), 7.57, 6.93 (dd, 2H, vinyl, J=15.8 Hz), 4.91,
4.79, 4.57, 4.54 (4t, 8H, Cp), 2.36 (s, 3H, CH3); MS m/z
(%): 347.2 (33), Anal. Calc. for C19H15O3Fe: C,
65.75;H, 4.32. Found: C, 66.23; H, 4.81 IR (KBr,
cm−1): 1748 (CꢀO), 1667 (CꢀC), 1630 (CꢀC)..
3.2.10. 1,1%–bis-Piperonyloylferrocene (4e)
Red solid, m.p. 130–132 °C. 1H-NMR (l, ppm):
7.79, 7.28 (dd, 4H, J=14.3 Hz), 7.60–6.82 (m, 6H, ph),
6.01 (br, 4H, OCH2O), 4.89, 4.60 (2m, 8H,Cp); MS m/z
(%): 534.2(1.3), Anal. Calc. for C30H22FeO6: C, 67.45;
H, 4.12. Found: C, 67.48; H, 4.61%. IR (KBr, cm−1):
1654 (CꢀO), 1593 (CꢀC).
3.2.4. 1,1%-bis[i-(2-Furyl)acryloyl]ferrocene (4b)
1
Red solid. m.p. 160 °C. H-NMR (l, ppm): 7.46 (s,
2H, furyl), 6.67 (s, 2H, furyl), 6.48 (s, 2H, furyl), 7.56,
6.92 (dd, 4H, vinyl, J=15.2 Hz), 4.93, 4,57 (2m, 8H,
Cp); MS m/z (%): 426.2 (64), Anal. Calc. for
C24H18O4Fe:426.2; IR (KBr, cm−1): 1650 (CꢀO), 1590
(CꢀC).
3.2.11. 1-Acetyl-1%-(m-nitrocinnamoyl)ferrocene (3f).
Red solid, m.p.. 201–201 °C. 1H-NMR (l, ppm):
8.22, 7.08 (dd, 2H, J=15 Hz), 7.80–7.55 (m,4H, ph),
4.96, 4.90, 4.69, 4.62 (4t, 8H, Cp), 2.54 (s, 3H, CH3);

W.-y. Liu et al. / Journal of Organometallic Chemistry 637–639 (2001) 782–785
785
MS m/z (%): 403.2(10), Anal. Calc. for C21H17O4NFe:
3.2.16. 1,1%-bis-(p-N,N-Dimethylcinnamoyl)ferrocene
(4h)
C, 62.55; H, 4.22; N, 3.47. Found: C, 62.98; H, 4.67; N,
3.78%. IR (KBr, cm−1): 1720 (CꢀO), 1678 (CꢀO), 1600
(CꢀC).
Red solid, m.p. 224 °C 1H-NMR (l, ppm): 7.80, 6.90
(dd, 4H, vinyl, J=15.8 Hz), 7.71–6.68 (m, 8H, ph),
4.95, 4.77, 4.55, 4.23 (4t, 8H, Cp), 2.98 (br, 12H,
N(CH3)2); MS m/z (%): 533.4 (3), Anal. Calc. for
C32H33N2O2Fe: C, 72.05; H, 6.19; N, 5.25. Found: C,
72.47; H, 6.63; N, 5.73%. IR (KBr, cm−1): 1658 (CꢀO),
1572 (CꢀC).
3.2.12. 1,1%-bis(m-Nitrocinnamoyl)ferrocene (4f)
Red solid, m.p. 108–109 °C, 1H-NMR (l, ppm):
8.26, 7.26, (dd, 4H, J=15 Hz), 7.77–7.56 (m, 8H, ph),
4.94, 4.87, 4.65, 4.61 (4t, 8H, Cp); MS m/z (%): 536.7
(10), Anal. Calc. for C28H20N2O6Fe: C,62.65; H, 3.73;
N, 5.38. Found: C, 62.89; H, 4.02; N, 4.98%. IR (KBr,
cm−1) 1658 (CꢀO), 1597 (CꢀC).
Acknowledgements
The authors are grateful to the NSF (QT program)
and the foundation of the key teacher from the Min-
istry of Education of PRC for its financial support.
3.2.13. 1-Acetyl-1%-(p-nitrocinnamoyl)ferrocene (3g)
Red solid, m.p. 265 °C, 1H-NMR (l, ppm): 8.37,
7.12 (dd, 2H, J=15 Hz), 7.92–7.68 (m, 4H, ph), 4.97,
4.85, 4.68, 4.62 (4t, 8H, Cp), 2.60 (s, 3H, CH3); MS
m/z (%): 403.2 (15), Anal. Calc. for C21H17O4NFe: C,
62.55; H, 4.22; N, 3.47. Found: C, 62.90; H, 4.71; N,
3.25%. IR (KBr, cm−1): 1720 (CꢀO), 1640 (CꢀO), 1612
(CꢀC).
References
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Organometal. Chem. 214 (1981) 107.
3.2.14. 1,1%-bis(p-Nitrocinnamoyl)ferrocene (4g)
Red solid, m.p. 210 °C, 1H-NMR (l, ppm): 8.49,
7.26 (2dd, 4H, J=15.1 Hz), 8.27–7.71 (m, 8H, ph),
4.98, 4.86, 4.68, 4.63 (4t, 8H, Cp); MS m/z (%): 536.7
(1), Anal. Calc. for C28H20N2O6Fe: C, 62.65; H, 3.73;
N,5.38. Found: C, 62.18; H, 4.04; N, 4.96%. IR (KBr,
cm−1): 1660 (CꢀO), 1600 (CꢀC).
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5443.
3.2.15. 1-Acetyl-1%-(p-N,N-dimethylcinnamoyl)ferrocene
(3h)
1
Red solid, m.p. 30–31 °C H-NMR (l, ppm): 7.68,
6.71 (dd, 2H, vinyl, J=15.6 Hz), 7.48, 6.63 (m, 4H,
ph), 4.89, 4.61, 4.30 (2m, 8H, Cp), 2.97 (s, 6H,
N(CH3)2), 2.44 (s, 3H, CH3); MS m/z (%): 401.2 (15),
Anal. Calc. for C23H23O2NFe: C, 68.85; H, 5.73; N,
3.49. Found: C, 69.15; H, 5.34; N, 3.87%. IR (KBr,
cm−1): 1730 (CꢀO), 1660 (CꢀO), 1630 (CꢀC).