Synthesis and reactivity of ferrocenecarboxylate ruthenium(II) complexes. Catalytic synthesis of a ferrocenecarboxylic enol ester

Article abstract of DOI:10.1021/om9804069

New ferrocenecarboxylate ruthenium(II) complexes were obtained from the reaction of [RuClH(CO)(PPh₃)₃] with ferrocenecarboxylic acid or its sodium salt. The reaction of alkenyl complexes [Ru(O₂C(C₅H₄)Fe(C₅H ₅))(CR′=CRH)(CO)(PPh₃)₂] with CO and catalytic synthesis of the phenylethyleneferrocenecarboxylic ester have been studied.

Full text of DOI:10.1021/om9804069

Organometallics 1998, 17, 4551-4555
4551
Syn th esis a n d Rea ctivity of F er r ocen eca r boxyla te
Ru th en iu m (II) Com p lexes. Ca ta lytic Syn th esis of a
F er r ocen eca r boxylic En ol Ester
Llu¨ısa Matas,1a Isabel Moldes,1a J osep Soler,1a and J osep Ros*,1a
Departament de Quı´mica, Universitat Auto`noma de Barcelona, 08193-Bellaterra, Spain
AÄ ngel Alvarez-Larena1b and J oan F. Piniella1b
Unitat de Cristal‚lografia, Universitat Auto`noma de Barcelona, 08193-Bellaterra, Spain
Received May 20, 1998
Summary: New ferrocenecarboxylate ruthenium(II) complexes were obtained from the
reaction of [RuClH(CO)(PPh3)3] with ferrocenecarboxylic acid or its sodium salt. The reaction
of alkenyl complexes [Ru(O2C(C5H4)Fe(C5H5))(CR′dCRH)(CO)(PPh3)2] with CO and catalytic
synthesis of the phenylethyleneferrocenecarboxylic ester have been studied.
In tr od u ction
dinating ligands as carboxylates,8 dithiocarboxylates, or
xanthates.9 The reaction of [Ru(η1-CR′dCRH)Cl(CO)-
(PPh3)2] complexes (R ) Me or Ph) with CO led to the
formation of hexacoordinated complexes containing an
η2-alkeneacyl ligand, whereas when R ) R′ ) CO2Me,
a simple CO coordination to the metal occurred. A η2
f η1 conversion was also observed when a carboxylate
ligand was added to the acyl compound.5 These results
suggested that both steric and electronic effects might
play a significant role in the CO-alkenyl coupling. To
examine the effects of the coordination of carboxylates
to the coordinatively unsaturated [RuCl(η1-CR′dCRH)-
(CO)(PPh3)2] complexes, we synthesized complexes with
carboxylates.8 Here we present a study of the coordina-
tion ability of the ferrocenecarboxylate anion coordi-
nated to mononuclear ruthenium(II) complexes and the
reactivity of this complex with CO. The catalytic
addition of ferrocenecarboxylic acid to phenylacetylene
using ruthenium(I) and ruthenium(II) complexes as
catalyst precursors was also undertaken. We chose this
particular acid because of its size and the strong
inductive effect of the ferrocene unit.10 Various ex-
amples of the coordination of the ferrocenecarboxylate
ligand have been reported, but they were restricted by
the low solubility of compounds.11 Examples of both η2
Insertion reactions into metal-hydrogen bonds are
very important steps in catalytic reactions such as
hydrogenation and isomerization of alkenes and alkynes.2
The hydride-ruthenium bond is highly reactive toward
alkynes and usually leads to η1-alkenyl compounds in
mild conditions via insertion reactions.3 The reaction
of the ruthenium hydride [RuClH(CO)(PPh3)2L] (L )
PPh3 or Py) with alkynes results in the formation of
alkenyl complexes. If L ) PPh3, the alkenyl compounds
[RuCl(η1-CR′dCRH)(CO)(PPh3)2] are coordinatively un-
saturated 4 and highly reactive toward small molecules
such as alkynes, CO,5 CO2,6 CS2,7 and bidentate coor-
* To whom correspondence should be addressed. E-mail: ros@
cc.uab.es.
(1) Departament de Qu´ımica, Universitat Auto`noma de Barcelona,
08193-Bellaterra (Barcelona), Spain. (b) Unitat de Cristal‚lografia,
Universitat Auto`noma de Barcelona, 08193-Bellaterra (Barcelona),
Spain.
(2) Comprehensive Organometallic Chemistry II; Abel, E. W., Stone,
F. G. A., Wilkinson, G., Eds.; Pergamon: New York, 1995; Vol. 12,
Chapter 2.
(3) Blackmore, T.; Bruce, M. I.; Stone, F. G. A.; Davis, R. E.; Garza,
A. J . Chem. Soc. D 1971, 852. (b) Blackmore, T.; Bruce, M. I.; Stone,
F. G. A. J . Chem. Soc., Dalton Trans. 1974, 106. (c) Davidson, J . L.;
Green, M.; Stone, F. G. A.; Welch, A. J . J . Chem. Soc., Dalton Trans.
1976, 2044. (d) Yamazaki, H.; Aoki, K. J . Organomet. Chem. 1976,
122, C54. (e) Sanchez-Delgado, R. A.¸Wilkinson, G. J . Chem. Soc.,
Dalton Trans. 1977, 804. (f) Bruce, M. I.; Gardner, R. C. F.; Stone, F.
G. A. J . Chem. Soc., Dalton Trans. 1979, 906. (g) Stosenberg, A. M.;
Muetterties, E. L. Organometallics 1985, 4, 1739. (h) Werner, W.;
Esteruelas, M. A.; Otto, H. Organometallics 1986, 5, 2295. (i) Bray, J .
M.; Mawby, R. J . J . Chem. Soc., Dalton Trans. 1989, 589.
(4) Torres, M. R.; Vegas, A.; Santos, A.; Ros, J . J . Organomet. Chem.
1986, 309, 169. (b) Torres, M. R.; Vegas, A.; Santos, A.; Ros, J . J .
Organomet. Chem. 1987, 326, 413. (c) Torres, M. R.; Santos, A.; Ros,
J .; Solans, X. Organometallics 1987, 6, 1091. (d) Santos, A.; Lo´pez, J .;
Matas, Ll.; Ros. J .; Galan, A.; Echavarren, A. M. Organometallics 1993,
12, 4215. (e) Echavarren, A. M.; Lo´pez, J .; Santos, A.; Romero, A.;
Hermoso, J . A.; Vegas, A. Organometallics 1991, 10, 2371. (f) Santos,
A.; Lo´pez, J .; Montoya, J .; Noheda, P.; Romero, A.; Echavarren, A. M.
Organometallics 1994, 13, 3605.
(7) Torres, M. R.; Perales, A.; Ros, J . Organometallics 1988, 7, 1233.
(8) Torres, M. R.; Perales, A.; Loumrhari, H.; Ros, J . J . Organomet.
Chem. 1990, 385, 379. (b) Loumrhari, H.; Matas, Ll.; Ros, J .; Torres,
M. R.; Perales, A. J . Organomet. Chem. 1991, 403, 373. (c) Loumrhari,
H.; Ros, J .; Torres, M. R.; Ros, J . Polyhedron 1990, 7, 907. (d) El
Guaouzi, M.; Ros, J .; Solans, X.; Font-Bardia, M. Inorg. Chim. Acta
1995, 231, 181.
(9) Loumrhari, M.; Ros, J .; Torres, M. R. Polyhedron 1991, 10, 421.
(10) Slocum, D. W.; Ernst, C. R. Adv. Organomet. Chem. 1972, 10,
106.
(11) Vigato, P. A.; Casellato, U.; Clemente, D. A.; Bandoli, G.; Vidali,
M. J . Inorg. Nucl. Chem. 1973, 35, 4131. (b) Bereman, R. D.;
Nalewajek, D. P. J . Inorg. Nucl. Chem. 1981, 43, 519. (c) Churchill,
M. R.; Li, Y. J .; Nalewajek, D.; Schaber, P. M.; Dorfman, J . Inorg.
Chem. 1985, 24, 2684. (d) Abuhijleh, A. L.; Woods, C. J . Chem. Soc.,
Dalton Trans. 1992, 1249. (e) Abuhijleh, A. L.; Pollitte, J .; Woods, C.
Inorg. Chim. Acta 1994, 215, 131. (f) Lee, S. M.; Kung-Kai, C.; Wing-
Tak, W. J . Organomet. Chem. 1996, 506, 77. (g) Collison, D.; Mabbs,
F. E.; Turner, S. S.; Powell, A. K.; McInnes, E. J . L.; Yellowless, L. J .
J . Chem. Soc., Dalton Trans. 1997, 1201. (h) Prokopuk, N.; Shriver,
D. F. Inorg. Chem. 1997, 36, 5609.
(5) Torres, M. R.; Perales, A.; Loumrhari, H.; Ros, J . J . Organomet.
Chem. 1990, 384, C61. (b) Montoya, J .; Santos, A.; Echavarren, A. M.;
Ros, J . J . Organomet. Chem. 1990, 390, C57. (c) Loumrhari, H.; Ros,
J .; Torres, M. R.; Santos, A.; Echavarren, A. M. J . Organomet. Chem.
1991, 411, 255.
(6) Loumrhari, H.; Ros, J .; Ya´n˜ez, R.; Torres, M. R. J . Organomet.
Chem. 1991, 408, 233.
S0276-7333(98)00406-3 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 09/19/1998

4552 Organometallics, Vol. 17, No. 21, 1998
Matas et al.
Sch em e 1
and η1 coordination of the ferrocenecarboxylate ligand
have been found in mononuclear and dinuclear cop-
per(II) complexes.11d-e
H)12 was observed at 1995 cm -1, and two C-O stretch-
ing frequencies at 1496 and 1397 cm-1 are consistent
with the structure proposed.13
The coordinatively unsaturated complex [RuCl(CR′d
CRH)(CO)(PPh3)2] (II) is also highly reactive toward the
ferrocenecarboxylate ligand. Complexes of type II
reacted with the sodium salt of ferrocenecarboxylic acid
dissolved in methanol to give hexacoordinated com-
plexes [Ru(O2C(C5H4)Fe(C5H5))(CR′dCRH)(CO)(PPh3)2],
where R ) R′ ) H (3a ); R ) CMe3, R′ ) H (3b); R )
R′) Ph (3c); R ) CO2Me, R′ ) H (3d ); and R ) R′ )
CO2Me (3e). IR spectra of complexes 3a -3e show ∆ )
ν(OCO)asym - ν(OCO)sym values of ca. 100 cm-1, which
confirms the η2-coordination of the carboxylate ligand.13
The chemical shifts of the vinyl protons are similar to
those of unsaturated complexes of type II and to other
carboxylate complexes, indicating a trans arrangement
of hydrogens in monosubstituted alkenyl groups (R′ )
H). The 31P{1H} spectra of complexes 3a -3e show a
singlet at 33-36 ppm and are consistent with two
mutually trans PPh3 ligands.4,12 Hexacoordinated al-
kenyl ferrocenecarboxylate complexes 3a -3e were also
prepared from the reaction of the hydride compound
[Ru(O2C(C5H4)Fe(C5H5))H(CO)(PPh3)2] (2) with the cor-
responding alkyne in refluxing dichloromethane.
Resu lts a n d Discu ssion
Syn th esis of Com p lexes. The summary of reac-
tions performed is shown in Scheme 1. A mixture of
products (1a and 1b ) was prepared by reaction of
[RuClH(CO)(PPh ) ] (I) with a solution of ferrocenecar-
3 3
boxylic acid in methanol at room temperature. Both
complexes 1a and 1b have the same formula [Ru(O2C-
(C5H4)Fe(C5H5))Cl(CO)(PPh3)2] and have the carbox-
ylate ligand η2-coordinated to ruthenium. The 31P{1H}
NMR spectrum of 1a indicates a trans arrangement of
2
phosphines, whereas two doublets with J PP ) 22.9 Hz
in the spectrum of 1b suggest a cis arrangement of PPh3
ligands.12 It is interesting to note that the 1H NMR
spectrum of 1b shows a doubling of the signals of the
ferrocenyl group. A possible reason for this pattern is
the presence of two different arrangements of the bulky
ferrocenyl group, which cannot rotate around the O2C-
C5H4 bond. The same complex [RuClH(CO)(PPh ) ] (I)
3 3
reacted with the sodium salt of the ferrocenecarboxylic
acid dissolved in methanol to give the complex 2, of
formula [Ru(O2C(C5H4)Fe(C5H5))H(CO)(PPh3)2]. A trip-
When complexes 3a and 3b were reacted with CO at
room temperature in dichloromethane solution, the
compounds of formula [Ru(O2C(C5H4)Fe(C5H5))(CR′d
2
let resonance at δ -16.2 ppm with J HP ) 21.6 Hz in
1
the H NMR spectrum and a singlet at δ 43.9 ppm in
the 31P{1H} NMR of 2 indicate that the hydride ligand
is in a cis position with respect to the PPh3 ligands,
which are mutually trans.4,12 A strong IR band of ν(Ru-
(13) Robinson, S. D.; Uttey, M. F. J . Chem. Soc., Dalton Trans. 1973,
1912. (b) Dobson, A.; Moore, D. S.; Robinson, S. D. J . Organomet. Chem.
1979, 177, C8. (c) Tocher, D. A.; Gould, R. D.; Stephenson, T. A.;
Bennet, M. A.; Ennet, J . P.; Matheson, T. W.; Sawyer, L.; Shah, V. K.
J . Chem. Soc., Dalton Trans. 1983, 1571.
(12) Esteruelas, M. A.; Werner, H. J . Organomet. Chem. 1986, 303,
221.

Ferrocenecarboxylate Ruthenium(II) Complexes
Organometallics, Vol. 17, No. 21, 1998 4553
Sch em e 2
Z
CRH)(CO)2(PPh3)2] (R ) R′ ) H (4a ); R ) CMe3, R′ )
H (4b)) were formed. Two IR bands of ν(C(O) together
with ∆ ) ν(OCO)asym - ν(OCO)sym values of 222 and 237
cm-1, respectively, indicated the coordination of two
mutually cis CO ligands5 and an η1-ferrocenecarboxylate
ligand.14 The remaining coordination sites of the ru-
thenium atom in complexes 4a and 4b are completed
by an alkenyl ligand and two PPh3 ligands in a trans
arrangement. The vinyl protons of these complexes
show chemical shifts and coupling similar to those in
complexes 3a and 3b. The 31P{1H} NMR spectra of
compounds 3a and 3b display singlets at 32.1 and 29.7
ppm, respectively.
Ca ta lytic Syn th esis of F er r ocen eca r boxyla te
En ol Ester s. Enol esters can be obtained from the
addition of carboxylic acids to alkynes in the presence
of a ruthenium complex.15 Enol esters are also inter-
mediates for the conversion of amino acids into amides
and peptides.16 The synthesis of ferrocenoyl amino acids
has recently been reported.17 We have found that the
addition of ferrocenecarboxylic acid to phenylacetylene
in the presence of a ruthenium catalyst gives stereo-
isomers of phenylethyleneferrocenecarboxylic ester 5
(Scheme 2). The reaction of ferrocenecarboxylic acid (1
equiv) with a small excess of phenylacetylene in reflux-
ing toluene for 20 h with [Ru2(HCO2)2(CO)4(PPh3)2]
(0.005 equiv) as a catalyst led to the Z isomer of 5
(100%) in 80% yield. When we used the mononuclear
Ru(II) complex 1a [Ru(O2C(C5H4)Fe(C5H5))Cl(CO)-
(PPh3)2] as a catalyst, the same reaction afforded a
mixture of gem (1%) and Z (99%) isomers in 83% yield.
Dinuclear [Ru2(RCO2)2(CO)4(PPh3)2] complexes18 and
arene [RuCl2(arene)(PR3)] complexes19 have been shown
to be active catalysts in the addition of carboxylic acids
to terminal alkynes. Phosphine-containing dinuclear
ruthenium(I) complexes are generally more regioselec-
tive than mononuclear compounds, and Markovnikov
addition (isomer GEM) is more common than the
formation of Z and E isomers. An opposite isomeric
relationship was observed when Ru3(CO)12 was used as
catalyst,15b which suggests that coordinated PPh3 ligands
are essential for the regioselectivity of this reaction. In
our case ferrocenecarboxylic acid seems to induce the
formation of the Z isomer as the major product in both
reactions.
Descr ip tion of th e Molecu la r Str u ctu r e of Com -
p lex 3a . The structure of 3a (Figure 1) consists of
[Ru(O2C(C5H4)Fe(C5H5))(CHdCH2)(CO)(PPh3)2] mol-
ecules separated by van der Waals distances. Selected
bond lengths and angles are collected in Table 1. The
Ru atom has a distorted octahedral coordination with
two PPh3 ligands occupying trans positions (P1-Ru-
P2 ) 175.9 (5)°). The rest of the ligands, η2-ferrocene-
carboxylate, η1-vinyl, and CO, complete the coordination
to the metal. The ferrocenecarboxylate ligand is un-
symmetrically η2-bonded to metal with Ru-O77 and
Ru-O78 distances of 2.192(3) and 2.269(3) Å, respec-
tively. These distances are shorter than others found
in acetate and formate mononuclear complexes of
Ru(II).8 The CdC bond length of 1.159(11) Å and the
CtO bond length of 1.088(6) Å are short, whereas the
Ru-alkenyl and Ru-CO bond lengths are longer than
those in related complexes.8 These significant differ-
ences may arise from the particular nature of this
carboxylate ligand. The ferrocenyl system is a strong
donor group, which makes the ferrocenecarboxylic acid
weaker than benzoic acid and aminoferrocene more
basic than aniline.10 The strong inductive quality of this
ligand explains why the Ru-carboxylate and O2-
C(C5H4) bonds are short, but this property is not
reflected in the structural parameters of CtO or vinyl
ligands. The Ru-CO and Ru-vinyl distances are long
(14) Nakamoto, K. Infrared and Raman Spectra of Inorganic and
Coordination Compounds, 4th ed.; Wiley: New York, 1986.
(15) Mitsudo, T.; Hori, Y.; Yamakawa, Y.; Watanabe, Y. J . Org.
Chem. 1987, 52, 2230. (b) Rotem, M.; Shvo, Y. J . Organomet. Chem.
1993, 448, 189. (c) Seiller, B.; Heins, D.; Bruneau, C.; Dixneuf, P. H.
Tetrahedron 1995, 51, 1091. (d) Bruneau, C.; Dixneuf, P. H. Chem.
Commun. 1997, 507, and references therein.
(16) Kabouche, Z.; Bruneau, C.; Dixneuf, P. H. Tetrahedron Lett.
1991, 32, 5359.
(17) Kraatz, H. B.; Lusztyk, J .; Enright, G. D. Inorg. Chem. 1997,
36, 2400.
(18) Neveux, M.; Seiller, M. P.; Hagedorn, F.; Bruneau, C.; Dixneuf,
P. H. J . Organomet. Chem. 1993, 451, 133.
(19) Rupin, C.; Dixneuf, P. H. Tetrahedron Lett. 1986, 27, 6323.
F igu r e 1. Molecular structure of [Ru(O2C(C5H4)Fe(C5H5))-
(CHdCH2)(CO)(PPh3)2] (3a ).

4554 Organometallics, Vol. 17, No. 21, 1998
Matas et al.
Ta ble 1. Selected Bon d Len gth s (Å) a n d Bon d
An gles (d eg) for Com p lex 3a
1479 (OCO)asym, 1401 (OCO)sym
.
31P{1H} NMR(CDCl3) δ: 29.18
(s) ppm. 1H NMR (CDCl3): δ 7.60-7.20 (m, 30 H), 3.83 (br s,
2 H), 3.79 (br s, 2 H), 3.46 (s, 5 H) ppm. (1b) IR (cm-1): 1950
Ru-C(3)
1.850(6)
2.192(3)
2.377(2)
2.009(5)
2.013(5)
2.026(5)
2.034(6)
2.032(5)
1.283(6)
1.463(7)
1.088(6)
Ru-C(1)
2.073(7)
2.269(3)
2.3845(14)
2.012(6)
2.017(5)
2.030(6)
2.039(6)
2.041(5)
1.263(6)
1.159(11)
(CtO), 1476 (OCO)asym, 1415 (OCO)sym
.
31P{1H} NMR-
Ru-O(77)
Ru-P(2)
Ru-O(78)
Ru-P(1)
(CDCl3): δ 44.17 (d, 2J PP ) 22.9 Hz), 42.04 (d, 2J PP ) 22.9 Hz)
ppm. 1H NMR (CDCl3): δ 7.60-7.20 (m, 60 H), 4.39 (br s, 2
H), 4.26 (s, 5 H), 4.19 (s, 5 H), 4.14 (br s, 2 H), 4.05 (br s, 2 H),
3.99 (br s, 2 H) ppm.
Fe-C(81)
Fe-C(82)
Fe-C(85)
Fe-C(72)
Fe-C(83)
C(76)-O(77)
C(71)-C(76)
C(3)-O(4)
Fe-C(75)
Fe-C(71)
Fe-C(74)
Fe-C(73)
Fe-C(84)
C(76)-O(78)
C(1)-C(2)
[Ru (O2C(C5H4)F e(C5H5))H(CO)(P P h 3)2] (2). Sodium fer-
rocenecarboxylate (500 mg, 20 mmol) dissolved in methanol
(5 mL) was added to a solution of [RuClH(CO)(PPh3)3] (200
mg, 20 mmol) in dichloromethane (15 mL). After 2 h of
stirring, the solvent was evaporated, and the resulting residue
was extracted with dichloromethane (10 mL). The orange
complex 2 was precipitated with hexane and filtered off (65%
yield).
C(3)-Ru-C(1)
C(3)-Ru-O(77)
C(1)-Ru-O(77)
C(3)-Ru-O(78)
C(1)-Ru-O(78)
O(77)-Ru-O(78)
C(3)-Ru-P(2)
C(1)-Ru-P(2)
91.5(2)
169.5(2)
98.8(2)
110.9(2)
157.1(2)
58.65(13) O(78)-Ru-P(1)
88.4(2)
89.8(2)
O(77)-Ru-P(2)
O(78)-Ru-P(2)
C(3)-Ru-P(1)
C(1)-Ru-P(1)
O(77)-Ru-P(1)
93.53(9)
95.05(10)
87.8(2)
91.8(2)
(2) Analysis: Found (calc) for C48H40O3P2FeRu: C, 65.35
(65.30); H, 4.52 (4.46)%. IR (cm-1): 1995 (Ru-H), 1924 (CtO),
89.96(9)
84.93(10)
175.90(5)
P(2)-Ru-P(1)
O(78)-C(76)-O(77) 118.3(4)
1496 (OCO)asym, 1397 (OCO)sym
.
31P{1H} NMR (CO(CD3)): δ
43.9 (s) ppm. 1H NMR (CDCl3): δ 7.80-7.20 (m, 30 H), 4.07
2
(br s, 2 H), 3.94 (br s, 2 H), 3.55 (s, 5 H), -16.2 (t, J PH ) 21.6
Hz, 1 H) ppm.
and CtO and CdC are short compared with other
related ruthenium(II) carboxylate complexes.8 The C76
atom lies on the C5H4 plane, and the planar O2C group
forms an angle of 5.20° with this plane. The RuO2C
plane forms a dihedral angle of 13.1° with the C5H4 ring.
These angles indicate that ligands coordinating to
ruthenium have moved the ferrocenyl group away, thus
minimizing steric repulsions, although the PPh3 ligands
remain in trans positions. The Fe-C5H4 distances
range from 2.012(6) through 2.039(6) Å, while Fe-C5H5
distances are between 2.009(7) and 2.041(7) Å. The
ferrocenyl group adopts a staggered conformation that
deviates from the eclipsed conformation by 19.0°. Both
staggered and eclipsed conformations have been re-
ported in other complexes.11
[Ru (O2C(C5H4)F e(C5H5))(CR′dCRH)(CO)(P P h 3)2] (R )
R′ ) H (3a ); R ) CMe3, R′ ) H (3b); R ) R′) P h (3c); R )
CO2Me, R′ ) H (3d ); a n d R ) R′ ) CO2Me (3e)). (a )
Syn th esis fr om Alk en yl Com p lexes [Ru (CR′dCRH)Cl-
(CO)(P P h 3)2]. Sodium ferrocenecarboxylate (1.1 equiv) dis-
solved in methanol was added to a solution of the alkenyl
complex in dichloromethane, and the mixture was stirred for
3 h. The solvent was evaporated, and the residue was
extracted with dichloromethane. Orange-yellow complexes
(3a -3e) were precipitated with hexane, filtered off, and dried.
Yields were 3a , 97%; 3b, 95%; 3c, 98%; 3d , 80%, and 3e, 70%.
(b ) Syn t h esis fr om [R u (O2C(C5H 4)F e(C5H 5))H (CO)-
(P P h 3)2] (2). To a solution of 2 in dichloromethane was added
the corresponding alkyne (1.2 equiv), and the resulting mixture
was refluxed for 2 h. After cooling to room temperature,
mixtures of complexes (3a -3e) and the hydride complex (2)
were precipitated with hexane, filtered off, and dried. Yields
were 3a , 42%; 3b, 60%; 3c, 60%; 3d , 70%; and 3e, 60%.
Exp er im en ta l Section
All reactions were performed under an N2 atmosphere. All
the solvents were distilled and dried before use. NMR spectra
were recorded on a Bruker AC-250 (1H, 250 MHz; 13C, 62 MHz;
31P, 102 MHz) spectrometer in CDCl3 or CD3CO solutions. IR
spectra were recorded on a Perkin-Elmer FT 1710 spectro-
photometer in KBr disks or with CH2Cl2 solutions. Elemental
analyses were obtained by the staff of the Chemical Analysis
Service of the University Autonoma of Barcelona. The [Ru-
ClH(CO)(PPh3)3]20 and [Ru(CR′dCRH)Cl(CO)(PPh3)2]4 com-
plexes were prepared by using previously published proce-
dures. Ferrocenecarboxylic acid was purchased commercially.
Sodium ferrocenecarboxylate was prepared by reacting ferro-
cenecarboxylic acid with sodium methoxide in methanol.
[Ru (O2C(C5H4)F e(C5H5))Cl(CO)(P P h 3)2] (1). Ferrocene-
carboxylic acid (330 mg, 14 mmol) dissolved in methanol (5
mL) was added to a solution of [RuClH(CO)(PPh3)3] (100 mg,
11 mmol) in dichloromethane (15 mL), and the resulting
mixture was stirred for 6 h. The solvent was evaporated, the
residue was extracted with dichloromethane (10 mL) and
chromatographed on a silica column. Complex 1a was eluted
with dichloromethane and 1b with a 4:1 dichloromethane-
ethyl acetate mixture. Both fractions were separately evapo-
rated to dryness and crystallized in dichloromethane-
methanol mixtures, and the resulting orange solids were
filtered off. Yields were 27% and 41% for 1a and 1b,
respectively.
(3a ) Analysis: Found (calc) for
CH2Cl2: C, 62.61 (62.83); H, 4.78 (4.48). IR (cm-1): 1897
(CtO), 1541 (CdC), 1498 (OCO)asym, 1401 (OCO)sym
31P{1H}
NMR(CDCl3): δ 35.7 (s) ppm. 1H NMR (CDCl3): δ 7.80-7.20
C50H42O3P2FeRu‚0.7
.
3
4
(m, 31 H), 5.00 (dd, J HH ) 9.2 Hz, J PH ) 2.1 Hz, 1 H), 4.52
3
4
(dd, J HH ) 16.5 Hz, J PH ) 1.8 Hz, 1 H), 4.01 (br s, 2 H), 3.83
(br s, 2 H), 3.40 (s, 5 H) ppm. 13C{1H} NMR (CDCl3): δ 206.0
(t, 3J CP ) 15.6 Hz, CO), 185.3 (CdO), 156.7 (t, 2J CP ) 10.8 Hz,
2
CHd), 134.9-127.3 (Ph), 119 (t, J CP ) 3.32 Hz, dCH2), 68.7,
68.6, 68.4 (C5H4), 68.3 (C5H5) ppm.
(3b) Analysis: Found (calc) for C54H50O3P2FeRu‚0.5
CH2Cl2: C, 64.14 (64.92); H, 5.39 (5.10). IR (cm-1): 1917 (C(O),
1512 (CdC), 1492 (OCO)asym, 1392 (OCO)sym
.
31P{1H} NMR-
(CDCl3): δ 35.6 (s) ppm. 1H NMR (CDCl3): δ 7.80-7.20 (m,
3
3
30 H), 6.22 (dd, J HH ) 16.0 Hz, J PH ) 2.1 Hz, 1 H), 4.87 (dd,
4
3J HH ) 16.0 Hz, J PH ) 1.8 Hz, 1 H), 4.01 (br s, 2 H), 3.83 (br
s, 2 H), 3.40 (s, 5 H), 0.85 (s, 9 H) ppm.
(3c) Analysis: Found (calc) for C62H50O3P2FeRu‚CH2Cl2: C,
65.83 (65.98); H, 4.92 (4.57). IR (cm-1): 1928 (C(O), 1516
(CdC), 1496 (OCO)asym, 1396 (OCO)sym
.
31P{1H} NMR-
(CDCl3): δ 35.7 (s) ppm. 1H NMR (CDCl3): δ 7.80-7.00 (m,
40 H), 5.30 (s, 1 H), 3.93 (br s, 2 H), 3.76 (br s, 2 H), 3.40 (s,
5 H) ppm.
(3d ) Analysis: Found (calc) for C52H44O5P2FeRu‚2CH2Cl2:
C, 57.23 (57.01); H, 4.39 (4.22). IR (cm-1): 1924 (C(O), 1699
(CdO),1556 (CdC), 1496 (OCO)asym, 1396 (OCO)sym
.
31P{1H}
(1) Analysis: Found (calc) for C48H39O3ClP2FeRu‚CH2Cl2:
NMR(CDCl3): δ 35.7 (s) ppm. 1H NMR (CDCl3): δ 9.56 (d,
C, 58.93 (58.67); H, 4.25 (4.12). (1a ) IR (cm-1): 1946 (CtO),
3J HH ) 14.4 Hz, 1 H,), 7.80-7.00 (m, 30 H), 5.26 (d, J HH
)
3
14.4 Hz, 1 H), 3.93 (br s, 2 H), 3.76 (br s, 2 H), 3.40 (s, 5 H),
3.37 (s, 3 H) ppm.
(20) Ahmad, N.; Levison, J . J .; Robinson, S. D.; Uttey, M. F. Inorg.
Synth. 1974, 15, 48.

Ferrocenecarboxylate Ruthenium(II) Complexes
Organometallics, Vol. 17, No. 21, 1998 4555
1
(3e) Analysis: Found (calc) for C54H46O7P2FeRu: C, 63.72
(63.25); H, 4.39 (4.22). IR (cm-1): 930 (CtO), 1713 (CdO),
monitored by H NMR spectroscopy. After 20 h the mixture
was cooled to room temperature and the solvent was evapo-
rated. The ratio of isomers was determined by 1H NMR in
CDCl3 of the crude of reaction. The resulting orange oil
contained the Z isomer (Ru2(HCO2)2(CO)4(PPh3)2 catalyst) or
a mixture of Z (99%) + GEM (1%) isomers of the phenyl-
ethyleneferrocenecarboxylic ester 5.
1561 (CdC), 1503 (OCO)asym, 1395 (OCO)sym
.
31P{1H} NMR-
(CDCl3): δ 33.3 (s) ppm. 1H NMR (CDCl3): δ 7.80-7.00 (m,
30 H), 4.32 (s, 1 H), 3.93 (br s, 2 H), 3.76 (br s, 2 H), 3.51 (s,
3 H), 3.40 (s, 5 H), 3.36 (s, 3 H) ppm.
[Ru (O2C(C5H4)F e(C5H5))(CR′dCR H)(CO)2(P P h 3)2] (R )
R′ ) H (4a ); R ) CMe3, R′ ) H (4b)). CO was bubbled into
a solution of [Ru(O2C(C5H4)Fe(C5H5))(CR′dCRH)(CO)(PPh3)2]
complexes in dichloromethane at room temperature, and the
progress of the reaction was monitored by IR spectroscopy. The
reaction was complete in 4 h. Yellow complexes 4a and 4b
were precipitated with hexane, filtered off, and dried. Yields
were 70% for both complexes.
(5) E + GEM isomers: IR (cm-1): 1727 (CdO), 1658 (Cd
C). 1H NMR (CDCl3): Z δ 7.30 (m, 5 H), 5.70 (d, J HH ) 7.3
3
3
Hz, 1 H), 4.87 (m, 2 H), 4.45 (m, 2 H), 4.19 (d, J HH ) 7.3 Hz,
1 H), 4.17 (s, 5 H) ppm; GEM: δ 7.30 (m, 5 H), 5.46 (d, 2J HH
)
2
1.5 Hz, 1 H), 5.04 (d, J HH ) 1.5 Hz, 1 H), 4.85 (m, 2 H), 4.41
(m, 2 H), 4.17 (s, 5 H) ppm.
X-r a y Diffr a ction Stu d y of 3a . 3a : C50H42O3P2RuFe‚
0.7CH2Cl2, Mr ) 969.14, monoclinic, space group P21/n (No.
14), a ) 10.069(1) Å, b ) 21.610(2) Å, c ) 20.822(2) Å, â )
99.34(1), V ) 4470.6 Å3, Z ) 4, Dc ) 1.440 g cm-3, µ ) 8.60
cm-1; measurements, Enraf-Nonius CAD4; radiation, graphite
monochromated Mo KR (λ ) 0.710 69 Å), T ) 293 K, data
collection range 2° < 2θ < 50°, ω-2θ scan, absorption
correction based on ψ-scan measurements; solution, SHELXS-
86 program; refinement on F2 for all reflections, SHELXL-93
program; 7851 unique reflections, 4010 observed [I > 2σ(I)];
number of variables 460, hydrogen atoms in calculated posi-
tions with isotropic temperature factors fixed at 1.2 times Ueq
of the corresponding carbon atoms. R(F) ) 0.050, Rw(F2) )
0.108 for the observed reflections.
(4a ) Analysis: Found (calc) For C51H42O4P2FeRu: C, 65.06
(65.32); H, 4.45 (4.51). IR (cm-1): 1944, 1917 (CtO), 1577 (Cd
C), 1618, 1396 (OCO). 31P{1H} (CDCl3): δ 32.1 (s) ppm. 1H
3
NMR (CDCl3): δ 7.8-7.2 (m, 31 H), 5.68 (d, J HH ) 8.0 Hz, 1
3
H), 4.80 (d, J HH ) 15 Hz, 1 H), 3.94 (br s, 2 H), 3.75 (br s, 2
H), 3.37 (s, 5 H) ppm.
(4b) Analysis: Found (calc) For C55H50O4P2FeRu: C, 66.00
(66.47); H, 5.03 (5.07). IR (cm-1): 1945, 1912 (CtO), 1565 (Cd
C), 1631, 1394 (OCO). 31P{1H} NMR (CDCl3): δ 29.7 (s) ppm.
3
1H NMR (CDCl3): δ 7.66-7.13 (m, 30 H), 6.36 (d, J HH ) 15.0
3
Hz, 1 H), 4.96 (d, J HH ) 15.0 Hz, 1 H), 3.94 (br s, 2 H), 3.75
(br s, 2 H), 3.73 (s, 5 H), 0.56 (s, 9 H) ppm. 13C{1H} NMR
2
2
(CDCl3): δ 244.1 (t, J CP ) 9.9 Hz, CO), 204.4 (t, J CP ) 14.4
2
Hz, CO), 196.2 (t, J CP ) 10.3 Hz, CHd), 180.1 (CdO), 139.6
(t, 2J CP ) 2.11 Hz, dCHtBu), 134.9-126.7 (Ph), 78.4, 69.1, 68.7
(C5H4), 68.12 (C5H5), 32 (CMe3), 29.0 (CMe3) ppm.
Ack n ow led gm en t. We thank the Direccio´n General
de Investigacio´n Cient´ıfica y Te´cnica for the financial
support (Projects PB92-0628 and PB96-1146).
Ca ta lytic Ad d ition of P h en yla cetylen e to F er r ocen e-
ca r boxylic Acid . The catalytic reaction was carried out
under an atmosphere of nitrogen. Phenylacetylene (0.05 mL,
44 mmol), ferrocenecarboxylic acid (0.1 g, 44 mmol), a ruthe-
nium catalyst (0.005 equiv of [Ru2(HCO2)2(CO)4(PPh3)2] or [Ru-
(O2C(C5H4)Fe(C5H5))Cl(CO)(PPh3)2]), and 15 mL of toluene
were placed in a 50 mL round-bottomed flask fitted with a
condenser coupled to a nitrogen line, and this mixture was
stirred for 20 h at 111 °C. The progress of the reaction was
Su p p or tin g In for m a tion Ava ila ble: Crystallographic
data including complete tables of atomic coordinates, bond
lengths and bond angles, and equivalent isotropic parameters
for 3a (11 pages). Ordering information is given on any
current masthead page.
OM9804069