Catalytic addition of ferrocenyl ketones to olefins with the aid of Ru(H)2(CO)(PPh3)3

Article abstract of DOI:10.1016/S0022-328X(01)00716-1

The catalytic addition reactions of ferrocenyl ketones with terminal olefins in the presence of Ru(H)₂(CO)(PPh₃)₃ as catalyst have been studied. Benzoylferrocene reacts with triethoxyvinylsilane, styrene and vinylferrocene, respectively, to give 1:1 coupling products I-III in high yields. C-H bond cleavage takes place at the carbon atom of the benzene ring at the ortho position of the carbonyl group and C-C bond formation takes place at the terminal carbon atom of the olefins. 2-Furoylferrocene reacts with vinylferrocene to give a 1:1 coupling product IV and the C-H bond cleavage takes place at the carbon atom of the furan ring at the ortho position of the carbonyl group and the C-C bond formation takes place at the terminal carbon atom of vinylferrocene. The new products I-IV have been characterized by elemental analysis, ¹H-NMR and MS. The X-ray crystal structure of IV has been determined.

Full text of DOI:10.1016/S0022-328X(01)00716-1

Journal of Organometallic Chemistry 627 (2001) 127–131
www.elsevier.nl/locate/jorganchem
Note
Catalytic addition of ferrocenyl ketones to olefins with the aid of
Ru(H)2(CO)(PPh3)3
Hongguang Du a,*, Qun Liu b, Shujian Shi a, Shiwei Zhang b
a Department of Applied Chemistry, Beijing Uni6ersity of Chemical Technology, Beijing 100029, People’s Republic of China
b Institute of Physical Chemistry, Department of Chemistry, Beijing Uni6ersity, Beijing 100871, People’s Republic of China
Received 14 July 2000; received in revised form 19 January 2001
Abstract
The catalytic addition reactions of ferrocenyl ketones with terminal olefins in the presence of Ru(H)2(CO)(PPh3)3 as catalyst
have been studied. Benzoylferrocene reacts with triethoxyvinylsilane, styrene and vinylferrocene, respectively, to give 1:1 coupling
products I–III in high yields. CꢀH bond cleavage takes place at the carbon atom of the benzene ring at the ortho position of the
carbonyl group and CꢀC bond formation takes place at the terminal carbon atom of the olefins. 2-Furoylferrocene reacts with
vinylferrocene to give a 1:1 coupling product IV and the CꢀH bond cleavage takes place at the carbon atom of the furan ring at
the ortho position of the carbonyl group and the CꢀC bond formation takes place at the terminal carbon atom of vinylferrocene.
1
The new products I–IV have been characterized by elemental analysis, H-NMR and MS. The X-ray crystal structure of IV has
been determined. © 2001 Elsevier Science B.V. All rights reserved.
Keywords: Ferrocene; Ru(H)2CO(PPh3)3; CꢀH bond cleavage; Crystal structures; Catalysis; Catalytic CꢀH/olefin coupling
1. Introduction
(1)
Carbonꢀhydrogen bonds are ubiquitous in organic
chemistry. The activation of the CꢀH bond using tran-
The new reaction is unique because it is characterized
sition metals is a very interesting area in organometallic
by very high efficiency, high regioselectivity and wide
chemistry. Although extensive studies have been per-
applicability [7].
In this paper we report our studies of the catalytic
addition of ferrocenyl ketones to olefins with the aid of
Ru(H)2(CO)(PPh3)3 for the synthesis of new ferrocene
derivatives and the characterization of the new
products.
formed and there have already appeared a number of
reviews and papers, the ability to react sp2- and sp3-hy-
bridized CꢀH bonds is limited. A few years ago, Murai
and co-workers [1–6] found a very efficient catalytic
addition of a CꢀH bond in aromatic ketones to olefins
with the aid of ruthenium complexes. The new catalytic
reaction permits the one-step addition of CꢀH bonds in
aromatic ketones to terminal olefins and a new CꢀC
bond is formed between the carbon atom at the ortho
position of the carbonyl group and the terminal carbon
atom of the olefin (Eq. (1)).
2. Results and discussion
2.1. Reaction of ferrocenyl ketones with olefins
The results of the coupling reactions are listed in
Table 1.
Acetylferrocene, 1,1%-diacetylferrocene and formylfer-
rocene did not react with triethoxyvinylsilane using
* Corresponding author. Fax: +86-10-64435312.
E-mail address: dhg@buct.edu.cn (H. Du).
0022-328X/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(01)00716-1

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H. Du et al. / Journal of Organometallic Chemistry 627 (2001) 127–131
Ru(H)2(CO)(PPh3)3 as a catalyst even when an excess
of catalyst and a longer reaction time were used.
In the work of Murai and co-workers [4] 1-indanone,
a five-membered ketone, did not undergo a coupling
reaction at all while a-tetralone (a six-membered ke-
tone) and a seven-membered ketone did undergo the
coupling reaction. We think that the relative site of the
oxygen atom of the carbonyl group and the ortho CꢀH
bond may affect the reaction; therefore, we studied the
action of ferrocenyl cyclic ketones such as 1,2-(a-oxote-
tramethylene)ferrocene and 2,3-ferrocoindenone with
olefins such as triethoxyvinylsilane and vinylferrocene.
We found that they did not react at all, even when the
amounts of olefin and Ru(H)2(CO)(PPh3)3 were in-
creased and the reaction time extended.
Benzoylferrocene does react with terminal olefins
such as triethoxyvinylsilane, styrene and vinylferrocene
in the presence of Ru(H)2(CO)(PPh3)3 to give the 1:1
coupling products I–III in high yields (Runs 1–3). The
CꢀH bond cleavage takes place at the carbon atom of
the benzene ring at the ortho position of the carbonyl
group and the CꢀC bond formation takes place at the
terminal carbon atom of the olefins. 2-Furoylferrocene
reacts with vinylferrocene to give the 1:1 coupling
product IV. The CꢀH bond cleavage takes place at the
carbon atom of the furan ring at the ortho position of
the carbonyl group and the CꢀC bond formation takes
place at the terminal carbon atom of vinylferrocene
(Run 4). The structural formulas for compounds I–IV
are shown in Fig. 1.
All the results show no evidence for the CꢀH bond in
the cyclopentadienyl ring at the ortho position of the
carbonyl group in ferrocenyl ketones for coupling with
olefins by Ru(H)2(CO)(PPh3)3.
Murai and co-workers believe [1–4] that the reaction
mechanism may involve coordination of the ruthenium
complex with the ketone group on the aromatic ring.
Accordingly, we examined the reactions of N,N-
dimethylaminomethylferrocene with styrene, ferrocenyl-
methanol and a-hydroxyethylferrocene with triethoxy-
vinylsilane using Ru(H)2(CO)(PPh3)3 as catalyst. In all
cases, no reactions were observed.
2.2. Characterization of products I–IV
Products I–IV are new derivatives of ferrocene. They
are all air-stable compounds, and are characterized by
1
elemental analysis, H-NMR spectra and MS spectra.
Table 1
Catalytic addition reaction of ferrocenyl ketones with olefins
Run
Ketone
Olefin
Ket./Ole./Cat.
(mmol)
Time (h)
Product and Yield
(%)
Fig. 1. The structural formulas for compounds I–IV.

H. Du et al. / Journal of Organometallic Chemistry 627 (2001) 127–131
129
a singlet at l 3.80 ppm for compound I, a singlet at l
3.03 ppm for compound II, two symmetrical multiplets
between l 2.45 and 3.05 ppm for compound III and
two symmetrical multiplets between l 2.57 and 3.25
ppm for compound IV. It is obvious that the CꢀC bond
formation takes place at the terminal carbon atom of
the olefins.
2.3. X-ray crystal structure of compound IV
The structure of compound IV has been confirmed
by an X-ray crystal diffraction study. An ORTEP dia-
gram of the structure of IV is shown in Fig. 2, selected
bond lengths and bond angles are listed in Table 2.
The dihedral angle of C(12)ꢀC(13)ꢀC(16)ꢀC(17) is
100.7°. The ferrocene connected with C(17) has an
antiprismatic conformation with a torsion angle C(20)–
center–center–C(27) of 11.2°.
The furan ring is at an angle of 4.5° to the
C(12)ꢀC(11)ꢀC(5)ꢀO(1) mean plane, which shows that
the two planes are almost coplanar. This contributes to
the conjugative effect. The dihedral angle of
C(12)ꢀC(11)ꢀC(5)ꢀC(4) is 14.8°, which results from the
cooperation of the conjugative effect and the steric
effect. The ferrocene connected with C(5) has a pris-
matic conformation with a torsion angle C(6)–center–
center–C(5) of 1.1°, which is unusual. This may be due
to the result of packing of molecule IV in the crystal.
Fig. 2. Molecular structure of product IV.
Table 2
,
Selected bond lengths (A) and bond angles (°) for compound IV
Bond lengths
C(1)ꢀC(2)
C(2)ꢀC(3)
C(3)ꢀC(4)
C(4)ꢀC(5)
C(5)ꢀC(1)
C(5)ꢀC(11)
C(11)ꢀO(1)
C(11)ꢀC(12)
C(12)ꢀC(13)
C(12)ꢀO(2)
C(13)ꢀC(14)
C(13)ꢀC(16)
C(14)ꢀC(15)
C(15)ꢀO(2)
C(16)ꢀC(17)
C(17)ꢀC(18)
C(18)ꢀC(22)
C(18)ꢀC(19)
1.417(4)
1.393(5)
1.410(5)
1.437(4)
1.434(4)
1.469(4)
1.232(3)
1.453(4)
1.367(4)
1.389(3)
1.417(4)
1.500(4)
1.334(4)
1.354(4)
1.530(4)
1.503(4)
1.425(4)
1.424(4)
C(19)ꢀC(20)
C(20)ꢀC(21)
C(21)ꢀC(22)
Fe(1)ꢀC(1)
Fe(1)ꢀC(2)
Fe(1)ꢀC(3)
Fe(1)ꢀC(4)
Fe(1)ꢀC(5)
Fe(1)ꢀC(6)
Fe(1)ꢀC(7)
Fe(1)ꢀC(8)
Fe(1)ꢀC(9)
Fe(1)ꢀC(10)
Fe(2)ꢀC(18)
Fe(2)ꢀC(19)
Fe(2)ꢀC(20)
Fe(2)ꢀC(21)
Fe(2)ꢀC(22)
1.417(4)
1.415(5)
1.422(4)
2.026(3)
2.049(3)
2.048(3)
2.035(3)
2.029(3)
2.016(3)
2.020(3)
2.016(3)
2.041(4)
2.026(4)
2.051(3)
2.045(3)
2.041(3)
2.036(3)
2.039(3)
3. Experimental
3.1. Instruments and materials
Bond angles
C(2)ꢀC(1)ꢀC(5)
C(4)ꢀC(5)ꢀC(11)
C(1)ꢀC(5)ꢀC(11)
C(1)ꢀC(5)ꢀC(4)
O(1)ꢀC(11)ꢀC(5)
O(1)ꢀC(11)ꢀC(12)
C(5)ꢀC(11)ꢀC(12)
C(11)ꢀC(12)ꢀC(13) 131.5(3)
O(2)ꢀC(12)ꢀC(11)
C(13)ꢀC(12)ꢀO(2)
108.0(3)
131.2(3)
121.9(3)
106.7(3)
120.2(3)
118.1(3)
121.7(2)
C(12)ꢀC(13)ꢀC(16)
C(14)ꢀC(13)ꢀC(16)
C(13)ꢀC(14)ꢀC(15)
C(14)ꢀC(15)ꢀO(2)
C(15)ꢀ0(2)ꢀC(12)
C(13)ꢀC(16)ꢀC(17)
C(16)ꢀC(17)ꢀC(18)
C(17)ꢀC(18)ꢀC(19)
C(17)ꢀC(18)ꢀC(22)
C(22)ꢀC(18)ꢀC(19)
C(18)ꢀC(19)ꢀC(20)
127.4(3)
126.7(3)
107.5(3)
111.0(3)
106.2(2)
112.6(3)
113.5(3)
126.0(3)
126.5(3)
107.3(3)
108.3(3)
Melting points were determined on a microscopic
apparatus and were uncorrected. Elemental analyses
were performed with a Carlo Erba 1106 elemental
1
analyzer. H-NMR spectra were recorded on a Bruker
AC 80 Spectrometer, using CHCI3-d as solvent and
TMS as an internal standard. The MS analyses were
measured on a VG70 SE GC/MS gas chromatography
mass spectrometer.
Toluene and triethoxyvinylsilane were distilled under
nitrogen from CaH2. Styrene was distilled under re-
duced pressure. Vinylferrocene [8], benzoylferrocene [9],
2-furoylferrocene [10], acetylferrocene [11], 1,1%-di-
acetylferrocene[12], formylferrocene [13], 1,2-(a-oxote-
tramethylene)ferrocene [14], 2,3-ferrocoindenone [15],
N,N-dimethylaminomethylferrocene [16], ferrocenyl-
methanol [16] and a-hydroxyethylferrocene [17] were
prepared according to the literature procedures.
119.0(2)
109.3(2)
C(12)ꢀC(13)ꢀC(14) 105.9(3)
The results show that the catalytic reaction of benzoyl-
ferrocene and 2-furoylferrocene with terminal olefins
yield 1:1 coupling products.
The 1H-NMR spectra of compounds I–IV display
two symmetrical singlets of two protons for each be-
tween 4.50 and 5.30 ppm, which indicate the presence
of a single-substituted cyclopentadienyl ring. This is
consistent with the CꢀH bond cleavage at the carbon
atom of the benzene ring and the furan ring, but not at
the ortho position of the carbonyl group on the cy-
3.2. Preparation of Ru(H)2(CO) (PPh3)3
Ru(H)2(CO)(PPh3)3 was prepared by a modified
method from the literature [18]. The reaction was per-
1
clopentadienyl ring. The H-NMR spectra also display

130
H. Du et al. / Journal of Organometallic Chemistry 627 (2001) 127–131
formed under oxygen-free nitrogen. Hydrated ruthe-
nium trichloride (0.52 g, 2 mmol) in ethanol (20 ml),
aqueous formaldehyde (22 ml, 37% w/v solution) and
potassium hydroxide (82% content, 0.74 g, 10 mmol) in
ethanol (20 ml) were added quickly and successively to
a stirred solution of triphenylphosphine (3.14 g, 12
mmol) in boiling ethanol (140 ml). The mixture was
heated under reflux for 30 min, and then cooled. The
resultant gray precipitate was filtered off, and washed
with ethanol, deionized water, ethanol and petroleum
ether (b.p. 40–60°C). The crude product was recrystal-
lized from benzene–methanol twice. The precipitate
was filtered off, washed with methanol and petroleum
ether, and dried in vacuo. The colorless solids were
used for the catalytic reaction.
Ph). MS m/z (% relative intensity): 394 (100), 311 (37),
236 (12), 178 (7), 153 (12), 121 (13).
3.3.4. [2-(2-ferrocenylethyl) benzoyl]ferrocene (III)
Product III was isolated by neutral alumina column
chromatography with petroleum ether–ethyl acetate (v/
v 5:1) as eluent. Red liquid. Yield 93%. Anal. Found:
C, 69.59; H, 5.39. Calc. for C29H26OFe2: C, 69.36; H,
1
5.22%. H-NMR (l ppm): 2.45–3.05 (two symmetrical
multiplets, 4H, CH2), 4.03–4.77 (m, 18H, Cp), 7.20–
7.60 (m, 4H, Ph).
3.3.5. 3-(2-Ferrocenylethyl)-2-ferrocenoylfuran (IV)
The product was isolated by neutral alumina column
chromatography with petroleum ether–ethyl acetate (v/
v 10:1) as eluent. Red plates. Yield 80%. m.p. 118–
120°C. Anal. Found: C, 65.78; H, 5.01. Calc. for
3.3. Preparation of the products I–IV
1
C27H24O2Fe2: C, 65.89; H, 4.92%. H-NMR (l ppm):
2.57–3.25 (two symmetrical multiplets, 4H, CH2), 4.14
(s, 5H, unsubstituted Cp), 4.55 (s, 2H, substituted Cp),
5.21 (s, 2H, substituted Cp), 6.40 (s, 1H, b-H of oxygen
in furan ring), 7.45 (s, 1H, a-H of oxygen in furan ring).
MS m/z (% relative intensity): 492 (100), 427 (62), 362
(37), 297 (13), 246 (11), 199 (39), 121 (28).
3.3.1. General procedure for the synthesis
A 25-ml two-necked round-bottom flask, equipped
with a reflux condenser, a nitrogen inlet, a magnetic
stirring bar and a tube sealed with a rubber septum,
was flushed with dry nitrogen, and then the apparatus
was flame dried under a flow of dry nitrogen. In the
flask was placed Ru(H)2(CO)(PPh3)3, ferrocenyl ketone,
olefin and toluene under a flow of nitrogen. The mix-
ture was heated under vigorous reflux (at 135°C, oil
bath temperature) with stirring for an appropriate reac-
tion period under nitrogen atmosphere. The mixture
was allowed to cool to room temperature, and then was
passed through a short neutral alumina or silica gel
column with petroleum ether–ethyl acetate as eluent.
The effluent was concentrated on a rotary evaporator
and followed by an evaporation of the solvent in vacuo.
The products were characterized as follows.
Table 3
Crystal data and structure refinement for compound IV
Chemical formula
Formula weight
Crystal size (mm)
Crystal system
Space group
C27H24Fe2O2
492.16
0.2×0.4×0.6
Monoclinic
P21/c
,
a (A)
17.166(3)
9.462(2)
14.801(3)
90
115.44(3)
90
2170.9(7)
4
1.506
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
3
,
3.3.2. [2-(2-Triethoxysilylethyl)benzoyl] ferrocene (I)
The product was isolated by silica gel column chro-
matography with petroleum ether–ethyl acetate(v/v
4:1) as eluent. Brownish red liquid. Yield 91%. Anal.
Found: C, 62.31; H, 6.92. Calc. for C25H32O4SiFe: C,
V (A )
Z
Dcalc (g cm−3
)
v (mm−1
F(000)
)
1.358
1016
Temperature (K)
293(2)
1
,
62.50; H, 6.71%. H-NMR (l ppm): 1.20 (s, 9H, CH3),
Wavelength (A)
Theta range for data collection
0.71073
2.52–26.00
2.72 (s, 6H, OCH2), 3.80 (s, 4H, CH2CH2), 4.20–4.66
(m, 9H, Fc), 7.30 (s, 4H, Ph). MS m/z (% relative
intensity): 480 (100), 446 (56), 415 (15), 318 (17), 149
(19), 57 (32).
(°)
Index ranges
−185h521, −115k50,
−185l50
Reflections measured
Unique reflections
4308
4229
Rint
0.0121
92.9
4229/0/281
R1=0.0364, wR2=0.0911
R1=0.0650, wR2=0.1016
1.040
0.0027(3)
0.345, −0.419
3.3.3. [2-(2-Phenylethyl) benzoyl]ferrocene (II)
Completeness to 2q=26.00 (%)
Data/restraints/parameters
Final R indices [I\2|(I)]
R indices(all data)
Goodness-of-fit
Extinction coefficient
Highest peak and deepest hole
Product II was isolated by neutral alumina column
chromatography with petroleum ether–ethyl acetate (v/
v 20:1) as eluent. Brownish red liquid. Yield 98%. Anal.
Found: C, 75.92; H, 5.77. Calc. for C25H22OFe: C,
1
76.15; H, 5.62%. H-NMR (l ppm): 3.03 (s, 4H, CH2),
4.27 (s, 5H, unsubstituted Cp), 4.56 (s, 2H, substituted
Cp), 4.79 (s, 2H, substituted Cp), 7.30–7.70 (m, 9H,
−3
,
(e A
)

H. Du et al. / Journal of Organometallic Chemistry 627 (2001) 127–131
131
Acknowledgements
3.4. Crystallography
We are grateful to the National Natural Science
Foundation of China for financial support of this work.
The crystal used for X-ray diffraction was grown in
ethanol. The red plate crystal of IV was mounted on a
Rigaku AFC6S diffractometer. Unit cell parameters
were determined with q angles in the range of 2.52–
26.00° and refined with the full-matrix least-squares
method. Intensities were collected with graphite
monochromated Mo–Ka radiation by using the ꢀ-scan
technique. A total of 4308 reflections were measured
and 4229 reflections were considered as observed apply-
ing the condition I\2|(I). Data were corrected for the
Lorentz and polarization effects. All calculations were
performed using the SHELXL-93 program. The non-hy-
drogen atoms were refined anisotropically and the hy-
drogen atoms were included but not refined. Crystal
data and structure refinement are summarized in Table
3.
References
[1] S. Murai, F. Kakiuchi, S. Sekine, Y. Tanaka, A. Kamatani, M.
Sonoda, N. Chatani, Nature 366 (1993) 529.
[2] S. Murai, F. Kakiuchi, S. Sekine, Y. Tanaka, A. Kamatani, M.
Sonoda, N. Chatani, Pure Appl. Chem. 66 (1994) 1527.
[3] S. Murai, J. Synth. Org. Chem. Soc. Jpn 52 (1994) 992.
[4] F. Kakiuchi, S. Sekine, Y. Tanaka, A. Kamatani, M. Sonoda, N.
Chatani, S. Murai, Bull. Chem. Soc. Jpn 68 (1995) 62.
[5] M. Sonoda, F. Kakiuchi, N. Chatani, S. Murai, J. Organomet.
Chem. 504 (1995) 151.
[6] M. Sonoda, F. Kakiuchi, N. Chatani, S. Murai, Bull. Chem. Soc.
Jpn 70 (1997) 3117.
[7] S. Borman, Chem. Engng News 71 (50) (1993) 6.
[8] C.L. Sterzo, G. Ortaggi, J. Chem. Soc. Perkin Trans. 2 (1984) 345.
[9] M. Rausch, M. Vogel, H. Rosenberg, J. Org. Chem. 22 (1957) 903.
[10] R. Dabard, B. Gautheron, Comptes Rendus Hebdomadaires des
Se´ances de l’Acade´mie des Sciences 254 (1962) 2014.
[11] P.J. Graham, R.V. Lindsey, G.W. Parshall, M.L. Peterson, G.M.
Whitman, J. Am. Chem. Soc. 79 (1957) 3416.
4. Supplementary material
[12] M. Vogel, M. Rausch, H. Rosenberg, J. Org. Chem. 22 (1957) 1016.
[13] M. Rosenblum, A.K. Banerjee, N. Daniell, R.W. Fish, V. Schlatter,
J. Am. Chem. Soc. 85 (1963) 316.
[14] K.L. Rinehart Jr., R.J. Curby Jr., D.H. Gustafson, K.G. Harrison,
R.E. Bozak, D.E. Bublitz, J. Am. Chem. Soc. 84 (1962) 3263.
[15] D.E. Bublitz, W.E. McEwen, J. Kleinberg, J. Am. Chem. Soc. 84
(1962) 1845.
[16] J.K. Lindsay, C.R. Hauser, J. Org. Chem. 22 (1957) 355.
[17] F.S. Arimoto, A.C. Haven Jr., J. Am. Chem. Soc. 77 (1955) 6295.
[18] J.J. Levison, S.D. Robinson, J. Chem. Soc. A (1970) 2947.
.
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Data Center, CCDC no. 150793. Copies of this infor-
mation may be obtained free of charge from The
Director, CCDC, 12 Union Road, Cambridge, CB2
1EZ, UK (Fax: +44-1223-336033; e-mail: deposit@
ccdc.cam.ac.uk or www: http://www.ccdc.cam.ac.uk).