Selective reactions of functionalized ruthenium(II) σ-alkynyl complexes with dicobalt octacarbonyl and tetracobalt dodecacarbonyl: Synthesis of cyclopentenone derivatives via intermolecular pauson-khand reactions

Article abstract of DOI:10.1021/om970645g

Treatment of [Ru{C=CCPh₂(C=CH)}(η⁵-C₉H ₇)(PPh₃)₂] (1) with [Co₂(CO)₈] leads to the formation of the adduct [Ru{C=CCPh₂(μ₂-η²-C=CH)Co ₂(CO)₆}(η⁵-C₉H ₇)(PPh₃)₂] (3) through the selective coordination of the Co₂(CO)₆ fragment at the terminal alkyne group on 1. Similarly, the enynyl complex [Ru{C=CCH=CH(C=CPh)}(η⁵-C₉H₇)(PPh ₃)₂] ((E,Z)-2), prepared via a Wittig reaction from [Ru{C=CCH₂(PPh₃)}(η⁵-C₉H ₇)(PPh₃)₂][PF₆] (5) and phenylpropargyl aldehyde, also reacts with [Co₂(CO)₈] to yield selectively the adduct [Ru-{C=CCH=CH(μ₂-η²-C=CPh)Co₂(CO) ₆}(η⁵-C₉H₇)(PPh ₃)₂] ((E,Z)-6). Protonation of complexes 3 and (E,Z)-6 with HBF₄·Et₂O affords the cationic vinylidene derivatives [Ru{=C=C(H)-CPh₂(μ₂-η²-C=CH)Co ₂(CO)₆}(η⁵-C₉H ₇)(PPh₃)₂][BF₄] (4) and [Ru{=C=C(H)CH=CH(μ₂-η²-C=CPh)Co ₂(CO)₆}(η⁵-C₉H ₇)(PPh₃)₂][BF₄] ((E,Z)-7), respectively. Dicobalt adduct complexes 3 and (E,Z)-6 undergo Pauson-Khand cyclization processes with strained cyclic alkenes (norbornadiene and norbornene) to afford regioselectively the tricyclic cyclopentenone derivatives 8a,b, 9a,b, (E,Z)-10, and 11. (E,Z)-6 reacts with [Co₄(CO)₁₂] to give an unprecedented ruthenium(II) vinylidene complex containing a tetranuclear butterfly type cobalt cluster (12), which has been characterized by X-ray diffraction.

Full text of DOI:10.1021/om970645g

Organometallics 1998, 17, 697-706
697
Selective Rea ction s of F u n ction a lized Ru th en iu m (II)
σ-Alk yn yl Com p lexes w ith Dicoba lt Octa ca r bon yl a n d
Tetr a coba lt Dod eca ca r bon yl: Syn th esis of
Cyclop en ten on e Der iva tives via In ter m olecu la r
P a u son -Kh a n d Rea ction s
Victorio Cadierno, M. Pilar Gamasa, and J ose´ Gimeno*
Departamento de Quı´mica Orga´nica e Inorga´nica, Instituto Universitario de Quı´mica
Organometa´lica “Enrique Moles” (Unidad Asociada al CSIC), Facultad de Qu´ımica,
Universidad de Oviedo, 33071 Oviedo, Spain
J osep M. Moreto´* and Susagna Ricart
Departament de Quı´mica Orga`nica Biolo`gica, CID (CSIC), C/ J . Girona 18-26,
08034 Barcelona, Spain
Anna Roig and Elies Molins
Institut de Cie`ncia de Materials de Barcelona, Campus Universitari de Bellaterra,
08193 Cerdanyola, Barcelona, Spain
Received J uly 28, 1997
Treatment of [Ru{CtCCPh2(CtCH)}(η5-C9H7)(PPh3)2] (1) with [Co2(CO)8] leads to the
formation of the adduct [Ru{CtCCPh2(µ2-η2-CtCH)Co2(CO)6}(η5-C9H7)(PPh3)2] (3) through
the selective coordination of the Co2(CO)6 fragment at the terminal alkyne group on 1.
Similarly, the enynyl complex [Ru{CtCCHdCH(CtCPh)}(η5-C9H7)(PPh3)2] ((E,Z)-2), pre-
pared via a Wittig reaction from [Ru{CtCCH2(PPh3)}(η5-C9H7)(PPh3)2][PF6] (5) and phen-
ylpropargyl aldehyde, also reacts with [Co2(CO)8] to yield selectively the adduct [Ru-
{CtCCHdCH(µ2-η2-CtCPh)Co2(CO)6}(η5-C9H7)(PPh3)2] ((E,Z)-6). Protonation of complexes
3 and (E,Z)-6 with HBF4‚Et2O affords the cationic vinylidene derivatives [Ru{dCdC(H)-
CPh2(µ2-η2-CtCH)Co2(CO)6}(η5-C9H7)(PPh3)2][BF4] (4) and [Ru{dCdC(H)CHdCH(µ2-η2-
CtCPh)Co2(CO)6}(η5-C9H7)(PPh3)2][BF4] ((E,Z)-7), respectively. Dicobalt adduct complexes
3 and (E,Z)-6 undergo Pauson-Khand cyclization processes with strained cyclic alkenes
(norbornadiene and norbornene) to afford regioselectively the tricyclic cyclopentenone
derivatives 8a ,b, 9a ,b, (E,Z)-10, and 11. (E,Z)-6 reacts with [Co4(CO)12] to give an
unprecedented ruthenium(II) vinylidene complex containing a tetranuclear “butterfly” type
cobalt cluster (12), which has been characterized by X-ray diffraction.
In tr od u ction
carbonyl ligands of the dicobalt unit. The currently
accepted mechanistic pathway for this transformation,
initially proposed by Magnus,4 indicates the unambigu-
ous intermediacy of the [Co2(CO)6(µ2-η2-RCtCR′)] com-
plex.5
The scope of this cycloaddition reaction with respect
to the alkyne is considerable, and virtually all alkynes
participate in this process. Although the intramolecular
Metal-mediated cyclization reactions are becoming
increasingly popular as tools for selective organic syn-
thesis.1 Indeed, the Pauson-Khand reaction, which
affords cyclopentenones from the reaction of alkenes
with alkynes in the presence of dicobalt octacarbonyl,
represents one of the most expeditious ways to achieve
functionalized cyclopentane derivatives.2 Accordingly,
this procedure has been successfully applied to the
synthesis of a large variety of natural products.3 This
cyclopentenone formation reaction can be regarded as
a formal [2 + 2 + 1] cycloaddition where the alkyne and
alkene moieties serve as two-carbon components, whereas
the carbonyl functionality is supplied from one of the
(3) See for example: (a) Exon, C.; Magnus, P. J . Am. Chem. Soc.
1983, 105, 2477. (b) Hua, D. H. J . Am. Chem. Soc. 1986, 108, 3835. (c)
Hua, D. H.; Coulter, M. J .; Badejo, I. Tetrahedron Lett. 1987, 28, 5465.
(d) Billington, D. C.; Willison, D. Tetrahedron Lett. 1984, 25, 4041. (e)
Schore, N. E.; Rowley, E. G. J . Am. Chem. Soc. 1988, 110, 5224. (f)
Magnus, P.; Becker, D. P. J . Am. Chem. Soc. 1987, 109, 7945. (g)
J ohnstone, C.; Kerr, W. J .; Lange, U. J . Chem. Soc., Chem. Commun.
1995, 459.
(4) (a) Magnus, P.; Exon, C.; Albaugh-Robertson, P. Tetrahedron
1985, 41, 5861. (b) Magnus, P.; Principe, L. M. Tetrahedron Lett. 1985,
26, 4851.
(5) The interaction of alkynes with [Co2(CO)8] leading to [Co2(CO)6-
(µ2-η2-RCtCR′)] adducts has been recognized as one of the classical
reactions in the field of organometallic chemistry: Dickson, R. S.;
Fraser, P. J . Adv. Organomet. Chem. 1974, 12, 323.
(1) (a) Schore, N. E. Chem. Rev. 1988, 88, 1081. (b) Seebach, D.
Angew. Chem., Int. Ed. Engl. 1990, 29, 1320. (c) Lautens, M.; Klute,
W.; Tam, W. Chem. Rev. 1996, 96, 49. (d) Fru¨hauf, H. W. Chem. Rev.
1997, 97, 523.
(2) Schore, N. E. in Comprehensive Organic Synthesis; Trost, B. M.,
Ed.; Pergamon: Oxford, U.K., 1991; Vol. 5, pp 1037-1064.
S0276-7333(97)00645-6 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 01/30/1998

698 Organometallics, Vol. 17, No. 4, 1998
Cadierno et al.
Ch a r t 1
Sch em e 1
versions of this reaction give typically the best perfor-
mances, the intermolecular reaction with strained al-
kenes occurs under milder conditions in the absence of
any activator. Moreover, it has been observed that the
presence of a nearby metal carbene moiety, probably
activating the alkyne functionalization, may addition-
ally promote the reaction, which proceeds under the
lowest reported temperatures.6
As part of our current research work on the reactivity
of unsaturated carbene complexes containing the inden-
ylruthenium(II) moiety [Ru(η5-C9H7)(PPh3)2] as metal
auxiliary, we have described the synthesis of a large
variety of functionalized (σ-alkynyl)ruthenium(II) com-
plexes.7 Since we are especially interested in exploiting
the potential utility of these derivatives, we wondered
about the possible effect of this metallic auxiliary on the
Pauson-Khand type process. Thus, in this paper we
describe the reactions of the ruthenium(II) σ-alkynyl
derivatives 1 and 2 (Chart 1) with dicobalt octacarbonyl
and the construction of the cyclopentenone framework
resulting from the reaction of the ruthenium-alkyne-
cobalt complexes with strained cyclic alkenes. Recently,
related cyclopentenone derivatives have been also ob-
tained by starting from iron(II)8 and platinum(II)9
σ-alkynyl complexes.
quencies for a [Co2(CO)6(µ2-η2-RCtCR′)] adduct in the
range 2020-2086 cm-1 5
overlapping the expected
,
ν(CtC) absorption band. The 1H and 13C{1H} NMR
spectra exhibit resonances in accordance with the
proposed structure.10 Significantly, in the 1H NMR
spectra the low-field proton resonance from the C2H
group (δ 6.62 ppm), compared to that in the parent
compound 1 (δ 2.45 ppm),7g is characteristic of cobalt
η2-alkyne complexes.9,11 The 13C{1H} NMR spectra
exhibit the expected signals for the bridging C2H unit
as singlets in the range δ 80-120 ppm. The CR and Câ
resonances appear as a triplet due to the coupling with
the two equivalent phosphorus atoms (δ 99.97 ppm, 2J CP
) 21.8 Hz) and a singlet at lower field, respectively (see
Experimental Section).
Addition of electrophiles to Câ on σ-alkynyl complexes
[M]CtCR has been described as one of the most
versatile entries into vinylidene complexes for a wide
variety of systems.12 Thus, the treatment of a solution
of 3 in diethyl ether with an excess of HBF4‚Et2O, at
room temperature, leads to the formation of the mono-
substituted cationic vinylidene derivative 4 (Scheme 1),
which has been isolated from the reaction mixture as
an insoluble, air-stable tetrafluoroborate salt (75%
yield). Complex 4 has been characterized by elemental
analysis, conductance measurements, and NMR (31P-
{1H}, 1H, and 13C{1H}) spectroscopy (see Experimental
Section).
Resu lts a n d Discu ssion
In ter a ction of Ru th en iu m (II) σ-Alk yn yl Com -
p lexes w ith [Co2(CO)8]. Treatment of [Ru{CtCCPh2-
(CtCH)}(η5-C9H7)(PPh3)2]7g (1) with a slight excess of
[Co2(CO)8] in THF at room temperature generates the
red adduct 3 (Scheme 1), which has been isolated after
column chromatography in 76% yield.
As expected on the basis of steric effects, the spec-
troscopic data (IR and NMR) of complex 3 show that
the coordination of the Co2(CO)6 fragment has occurred
at the terminal alkyne group of the complex 1 (details
are given in the Experimental Section). The infrared
spectrum exhibits the typical carbonyl stretching fre-
We have previously reported that alkynyl-phospho-
nio complexes [Ru{CtCCH(R)(PR3)}(η5-C9H7)(PPh3)2]-
[PF6] (R ) H, Ph) are excellent substrates for Wittig
reactions, leading to the formation of new double
carbon-carbon bonds.7c,e Thus, treating a THF solution
(6) (a) Camps, F.; Moreto´, J . M.; Ricart, S.; Vin˜as, J . M. Angew.
Chem., Int. Ed. Engl. 1991, 30, 1470. (b) J ordi, L.; Ricart, S.; Vin˜as, J .
M.; Moreto´, J . M. Organometallics 1997, 16, 2808. (c) Kretschik, O.;
Nieger, M.; Do¨tz, K. H. Chem. Ber. 1997, 130, 507.
of the alkynyl-phosphonio complex 5 (R ) H, PR3
)
PPh3) with 1 equiv of LinBu at -20 °C, adding phenyl-
propargyl aldehyde, and warming the mixture to room
temperature resulted in the formation of the enynyl
complex 2 (Scheme 2). This compound was obtained as
(7) (a) Cadierno, V.; Gamasa, M. P.; Gimeno, J .; Lastra, E.; Borge,
J .; Garc´ıa-Granda, S. Organometallics 1994, 13, 745. (b) Cadierno, V.;
Gamasa, M. P.; Gimeno, J .; Lastra, E. J . Organomet. Chem. 1994, 474,
C27. (c) Cadierno, V.; Gamasa, M. P.; Gimeno, J .; Borge, J .; Garc´ıa-
Granda, S. J . Chem. Soc., Chem. Commun. 1994, 2495. (d) Cadierno,
V.; Gamasa, M. P.; Gimeno, J .; Gonza´lez-Cueva, M.; Lastra, E.; Borge,
J .; Garc´ıa-Granda, S. Organometallics 1996, 15, 2137. (e) Houbrechts,
S.; Clays, K.; Persoons, A.; Cadierno, V.; Gamasa, M. P.; Gimeno, J .
Organometallics 1996, 15, 5266. (f) Cadierno, V.; Gamasa, M. P.;
Gimeno, J .; Borge, J .; Garc´ıa-Granda, S. Organometallics 1997, 16,
3178. (g) Cadierno, V.; Gamasa, M. P.; Gimeno, J .; Lo´pez-Gonza´lez,
M. C.; Borge, J .; Garc´ıa-Granda, S. Organometallics 1977, 16, 4453.
(8) Akita, M.; Terada, M.; Ishii, N.; Hirakawa, H.; Moro-oka, Y. J .
Organomet. Chem. 1994, 473, 175.
(10) (a) Gamasa, M. P.; Gimeno, J .; Mart´ın-Vaca, B. M.; Borge, J .;
Garc´ıa-Granda, S.; Pe´rez-Carren˜o, E. Organometallics 1994, 13, 4045.
(b) Gamasa, M. P.; Gimeno, J .; Godefroy, I.; Lastra, E.; Mart´ın-Vaca,
B. M.; Garc´ıa-Granda, S.; Gutie´rrez-Rodr´ıguez, A. J . Chem. Soc.,
Dalton Trans. 1995, 1901.
(11) See for example: (a) Holmes, A. B.; J ennings-White, C. L. D.;
Schulthess, A. H.; Akinde, B.; Walton, D. R. M. J . Chem. Soc., Chem.
Commun. 1979, 840. (b) Holmes, A. B.; J ones, G. E. Tetrahedron Lett.
1980, 21, 3111.
(9) Lewis, J .; Lin, B.; Raithby, P. R. Transition Met. Chem. 1995,
20, 569.
(12) For a general review see: Bruce, M. I. Chem. Rev. 1991, 91,
197.

Reactions of Functionalized Ru(II) σ-Alkynyl Complexes
Sch em e 2
Organometallics, Vol. 17, No. 4, 1998 699
a nonseparable mixture of the E and Z stereoisomers
(ca. 1/2) in 79% yield.
(µ2-η2-1,3-enyne) complexes.13 Furthermore, these de-
rivatives now play a burgeoning role in organic synthe-
sis.14
The structure of the conjugated chain on 2 was
ascertained from the 1H and 13C{1H} NMR spectroscopic
data. Thus, the olefinic protons appear as doublets (J HH
) 15.3 (E) and 10.3 Hz (Z)) in the range δ 5.72-7.51
ppm. The coordinated triple bond shows a considerable
polarization. While CR in 13C{1H} NMR falls within the
aromatic region, the corresponding Câ appears at δ
116.23 ppm for both isomers. Singlet signals of the
noncoordinated CtC and the olefinic carbons have been
assigned using DEPT experiments in the range δ
91.61-110.56 ppm (see Experimental Section for de-
tails).
Syn t h esis of (σ-Alk yn yl)r u t h en iu m (II) Com -
p lexes Con ta in in g Cyclop en ten on e F r a gm en ts via
P a u son -Kh a n d Rea ction s. The reactions between
the dicobalt adducts 3 and 6 with strained cyclic alkenes
have been examined in order to explore their utility for
the construction of cyclopentenone frameworks. Thus,
the treatment of complex 3 with norbornadiene and
norbornene at 85 °C results in the formation of the
tricyclic cyclopentenone derivatives 8a (72%) and 8b
(69%), respectively (Scheme 3).
The proposed structures for compounds 8a ,b in which
the bulky [Ru(CtCCPh2)(η5-C9H7)(PPh3)2] fragment is
placed at the R-position of the cyclopentenone rings, are
usually observed in other Pauson-Khand cycloadditions
starting from analogous terminal alkyne dicobalt ad-
ducts.2 Complexes 8a ,b have been analytically and
spectroscopically characterized. 31P{1H} NMR spectra
display two doublet signals (AB system) (8a , 53.13 and
53.56 ppm (2J PP ) 33.9 Hz); 8b, 52.73 and 53.21 ppm
(2J PP ) 33.7 Hz)). The nonequivalence of the phospho-
rus nuclei is due to the presence of chiral carbon atoms
on the added cycloalkane.
Similarly to complex 1 coordination of the Co2(CO)6
fragment on 2 takes place selectively on the less
sterically hindered (and probably electronically richer)
CtC bond, leading to the formation of complex 6 (68%
yield), isolated as a green solid (Scheme 2). The E/Z
steroisomer ratio on 6 is the same as that found in the
parent enynyl compound 2 (ca. 1/2). Analytical and
spectroscopic data (IR and 31P{1H}, 1H, and 13C{1H}
NMR) are in accordance with the proposed formulation
(see Experimental Section for details).
Similarly to the case for complex 3 the protonation of
complex 6 with HBF4‚Et2O, in THF at -20 °C, takes
place selectively on the Câ of the enynyl chain, leading
to the formation of the cationic alkenyl-vinylidene
derivative 7 (68% yield; E/ Z ca. 1/2) (Scheme 2). The
presence of the vinylidene moiety was identified, as
usual, on the basis of the low-field triplet resonance in
13C{1H} NMR of the carbene carbon RudCR (E, 357.10
1H and 13C{1H} NMR spectra are in agreement with
the presence of the tricyclic cyclopentenone fragments
(details are given in the Experimental Section). The
1
most remarkable feature in the H NMR spectra is the
presence of doublet signals in the range δ 2.01-2.31
ppm, corresponding to the CH protons of the cyclopen-
tenone ring. The values of the chemical shift and
coupling constants (ca. J HH ) 5.0 Hz) for these new
bridgehead protons indicate that the cyclopentenone
ring is fused to the norbornadiene and norbornene
2
2
ppm, J CP ) 15.6 Hz; Z, 357.31 ppm; J CP ) 15.3 Hz;
assigned by taking into account the signal intensity).
The formation of 7 clearly indicates the higher nu-
cleophilic character of the Câ atom of the enynyl moiety
compared to that of the olefinic carbons. It is well-
known that [Co2(CO)6]-stabilized propargylium ions can
be easily obtained by electrophilic additions on Co2(CO)6-
(13) (a) Nicholas, K. M. Acc. Chem. Res. 1987, 20, 207. (b) Elamouri,
H.; Gruselle, M. Chem. Rev. 1996, 96, 1077 and references cited
therein.
(14) Mukai, C.; Hanaoka, M. Synlett 1996, 11 and references cited
therein.

700 Organometallics, Vol. 17, No. 4, 1998
Cadierno et al.
Sch em e 3
Sch em e 4
4. Thus, the treatment of 4 with norbornadiene or
norbornene led to the formation of the neutral σ-alkynyl
complexes 8a ,b probably due to a deprotonation of the
vinylidene complex 4 in the reaction media.
In order to find out to what extent the molecular
design of the (σ-alkynyl)ruthenium(II)-dicobalt starting
complexes may affect these cycloaddition reactions the
behavior of the enynyl complex 6 (E + Z) toward
norbornadiene and norbornene has been also explored.
Thus, the reaction of 6 with norbornadiene at 85 °C
affords, after column chromatographic purification, the
orange cyclopentenone complexes (E)-10 (16%) and (Z)-
10 (49%) (Scheme 4).
31P{1H} NMR spectra of complexes (E)-10 and (Z)-10
display, similarly to those of complexes 8a ,b, two
2
doublet resonances (ca. J PP ) 30 Hz) of the diastereo-
skeleton in an exo fashion. 13C{1H} NMR spectra
display characteristic triplet (2J CP ) 23.2 Hz) resonances
for the Ru-CR carbon nucleus at δ 97.17 (8a ) and 96.68
(8b) ppm. The Câ and Cγ nuclei resonate as two singlets
at ca. δ 114 and 54 ppm, respectively. The CH and CH2
carbon atoms of the tricyclic units appear as high-field
singlets (δ 28.64-55.82 ppm), while those of the olefinic
and CdO groups resonate at lower fields, in the ranges
δ 155.84-161.52 and 204.78-205.93 ppm, respectively.
As the stereochemistry of the fusion of the two rings
was found to follow the general trend, being in exo
fashion, the regiochemistry for the mutual arrangement
of the alkene and the alkyne turned out to be that
predicted: the ketone carbonyl in the final product binds
the most crowded end of the triple bond.2 This was
concluded from the low-field chemical shift for the
olefinic proton and also from that for the corresponding
topic phosphorus nuclei at ca. δ 51 ppm. Moreover, IR
spectra show the expected ν(CtC) and ν(CdO) absorp-
tion bands. An exo fusion between the norbornadiene
skeletons and the cyclopentenone rings is again found
as deduced from the coupling constants (J HH ) 5.6 (E)
and 5.8 Hz (Z)) displayed by the CH protons of the
fusion carbons of the cyclopentenone rings. In order to
elucidate the resulting regiochemistry, we carried out
some 1H NMR Eu(III) shifting experiments.15 Thus, the
addition of variable amounts of [Eu(tfn)3]16 to solutions
of complexes (E)-10 and (Z)-10 in CDCl3 was found
mainly to shift the phenyl proton resonances to lower
field. These results indicated that the phenyl group is,
in both cases, placed at the R-position of the cyclopen-
tenone ring. 13C{1H} NMR data are also in accordance
with the proposed structures (see Experimental Section
for details).
1
Câ atom in their H and 13C{1H} NMR spectra (ca. 7.50
The reaction of adduct 6 with norbornene proceeds,
however, in a different way (Scheme 5). Thus, the
treatment of 6 with norbornene at 85 °C yields the new
enynyl complex 11 (42%), identified by comparison of
its spectroscopic data to those shown by the analogous
complex (Z)-10 (see Experimental Section) along with
the E stereoisomer of 2 probably generated from the loss
of the Co2(CO)6 fragment in the parent complex 6.
and 161.50 ppm), respectively, in both 8a and 8b.
The corresponding vinylidene derivatives containing
the tricyclic cyclopentenone fragments have been syn-
thesized through the protonation in Et2O of the σ-al-
kynyl complexes 8a ,b with tetrafluoroboric acid at room
temperature. The treatment leads to the formation of
the desired tetrafluoroborate complexes 9a ,b isolated
as brown stable solids (71 and 69%, respectively)
(Scheme 3). The presence of the vinylidene moiety in
9a ,b is clearly confirmed by 1H and 13C{1H} NMR
spectroscopy (see Experimental Section for spectroscopic
data).
(15) It is well-known that when lanthanide complexes are added to
solutions of organic compounds containing heteroatoms they cause a
shift of the proton resonances: (a) Cotton, S. Lanthanides & Actinides;
MacMillan Physical Science Series; Oxford University Press: New
York, 1991. (b) Lanthanide Shift Reagents in Stereochemical Analysis;
Morrill, T. C., Ed.; VCH: Weinheim, Germany, 1986.
(16) tfn ) 1,1,1,2,2,3,3,7,7,8,8,9,9,9-tetradecafluoro-4,6-nonanedi-
onate.
It is worth mentioning that vinylidene complexes 9a ,b
can not be directly obtained by starting from complex

Reactions of Functionalized Ru(II) σ-Alkynyl Complexes
Organometallics, Vol. 17, No. 4, 1998 701
Ta ble 1. Selected Bon d Dista n ces (Å) a n d Bon d
An gles (d eg) for Com p lex 12
Distances
Ru-C*a
1.924
Co(1)-C(51)
Co(4)-C(51)
Co(2)-C(50)
Co(2)-Co(4)
Co(2)-Co(1)
Co(2)-Co(3)
Co(2)-C(47)
Co(3)-Co(4)
Co(3)-C(50)
Co(3)-C(51)
2.106(2)
2.014(2)
1.979(2)
2.6311(10)
2.4542(8)
2.4665(8)
2.076(2)
2.4204(7)
2.048(2)
2.118(2)
Ru-P(1)
2.3584(8)
2.3539(8)
1.884(2)
1.281(3)
1.451(3)
1.331(3)
1.457(3)
1.408(3)
2.4463(7)
2.098(2)
Ru-P(2)
Ru-C(46)
C(46)-C(47)
C(47)-C(48)
C(48)-C(49)
C(49)-C(50)
C(50)-C(51)
Co(1)-Co(4)
Co(1)-C(50)
Angles
C*-Ru-C(46)
C*-Ru-P(1)
C*-Ru-P(2)
122.88(7) C(50)-C(51)-C(52) 126.8(2)
118.31(2) C(46)-C(47)-Co(2) 121.2(3)
125.38(2) C(48)-C(47)-Co(2) 108.3(2)
P(1)-Ru-P(2)
C(46)-Ru-P(2)
C(46)-Ru-P(1)
Ru-C(46)-C(47)
C(46)-C(47)-C(48) 131.0(2)
C(47)-C(48)-C(49) 119.7(2)
C(48)-C(49)-C(50) 115.9(2)
C(49)-C(50)-C(51) 134.9(2)
102.90(3) Co(4)-Co(1)-Co(2)
88.62(7) Co(1)-Co(2)-Co(3)
90.44(7) Co(1)-Co(2)-Co(4)
64.95(2)
92.48(2)
57.38(2)
56.58(2)
65.14(2)
93.82(2)
58.27(2)
57.67(2)
F igu r e 1. ORTEP view of the structure of complex 12.
For clarity, aryl groups of the triphenylphosphine ligands
are omitted.
175.3(2)
Co(3)-Co(2)-Co(4)
Co(4)-Co(3)-Co(2)
Co(3)-Co(4)-Co(1)
Co(3)-Co(4)-Co(2)
Co(1)-Co(4)-Co(2)
Sch em e 5
a
C* ) centroid of C(37), C(38), C(39), C(40), and C(41).
those between the centroid C* and the legs show typical
values of a pseudooctahedron. The unsaturated chain
consisting of the carbon atoms C46-C47-C48-C49-C50-
C51 is linked to a tetranuclear “butterfly” type cobalt
cluster through the terminal triple bond C(50)-C(51)
in such a way that the C-C bond is nearly parallel to
the hinge of the butterfly (see Figure 1). A similar
arrangement is shown in the structures of the well-
known tetranuclear complexes [Co4(CO)10(µ4-η2-RCt
CR′)].17
The Co-Co distances are similar and are close (aver-
age 2.4837 Å) to those of the metal lattice (2.50 Å), the
hinge bond of the butterfly (Co(2)-Co(4) ) 2.6311(10)
Å) being longer (ca. 0.18 Å) than the rest (see Table 1).
The bonding of the alkyne to the tetranuclear cluster
can be formally described as consisting of two σ-bonds
(C(50)-Co(2) and C(51)-Co(4)) and a delocalized four-
center-two-electron π-bonding system between C(50),
C(51), Co(1), and Co(3). In accordance with this de-
scription, the former carbon-cobalt distances (1.979(2)
and 2.014(2) Å, respectively) are significantly shorter
than those implied in the π-bond (average 2.0925 Å).
The Co(2) atom is also bound to the Câ atom C(47) of
the vinylidene group with a bond length of 2.076(2) Å,
which is consistent with the presence of a single metal-
carbon bond. The vinylidene ligand is bound to ruthe-
nium in a nearly linear fashion, with an Ru-C(46)-
C(47) angle of 175.3(2)°. The Ru-C(46) and C(46)-
C(47) bond lengths of 1.884(2) and 1.281(3) Å, respec-
tively, are larger than those observed in analogous
indenylruthenium(II) vinylidene complexes.7a,f,10a These
distances seem to indicate an effective contribution of
an η2-alkyne canonical form (Chart 2). In fact, the Co-
(2) and C(46) atoms are located at a relatively short
distance (2.940 Å), and a bonding interaction between
In contrast, when this reaction is performed in re-
fluxing THF, the new complex 12 (10%), isolated as a
green air-stable solid, is formed along with 11 (33%) and
(E)-2 (21%). Complex 12 has been characterized by an
X-ray crystallographic study, and its molecular struc-
ture is shown in Figure 1. Selected bond distances and
angles are listed in Table 1.
Complex 12 consists of an unprecedented vinylideneru-
thenium(II) fragment, displaying the typical three-
legged piano-stool geometry, which is attached to the
tetranuclear cobalt cluster Co4(CO)9. The Ru atom is
bonded to the η5-indenyl group, the P(1) and P(2) atoms
of the phosphines, and a carbon atom (C(46)) of the
unsaturated vinylidene chain. The interligand angles
P(1)-Ru-P(2), C(46)-Ru-P(1) and C(46)-Ru-P(2) and
(17) See for example: (a) Dahl, L. F.; Smith, D. L. J . Am. Chem.
Soc. 1962, 84, 2450. (b) Gervasio, G.; Rossetti, R.; Stanghellini, P. L.
Organometallics 1985, 4, 1612. (c) Osella, D.; Ravera, M.; Nervi, C.;
Housecroft, C. E.; Raithby, P. R.; Zanello, P.; Laschi, F. Organometallics
1991, 10, 3253.

702 Organometallics, Vol. 17, No. 4, 1998
Cadierno et al.
Sch em e 6
Ch a r t 2
alkynyl moiety would be too far away to allow such an
interaction). Probably, this cisoid arrangement may
also favor the proton abstraction observed in the reac-
tion of the vinylidene complex 4 with norbornadiene and
norbornene (see above), affording the alkynyl complexes
8a ,b. Such an arrangement of the vinylidene group
would locate one of the unsaturated cobalt atoms
(generated during the Pauson-Khand cycloadition) in
the proximity of the hydrogen atom of the vinylidene
group.
The presence of the tetranuclear cobalt fragment in
the structure of complex 12 suggests that it could be
directly obtained from the reaction of the enynyl com-
plex 2 with [Co4(CO)12]. Accordingly, when a mixture
of 2 and [Co4(CO)12] was heated under reflux in THF
for 2 h, complex 12 was obtained, after column chro-
matography, in 44% yield (Scheme 6), also with the E
isomer of complex 6.19
It is worth mentioning that vinylidene complex 12 is
also active in Pauson-Khand reactions. Thus, treat-
ment of 12 with norbornadiene leads finally to the
formation of (Z)-10 in almost quantitative yield (Scheme
6). However, a longer reaction time (90 min) and a
higher temperature (90 °C) are required with respect
to the reaction starting from enynyl complex 6. This
seems to indicate that complex 12 is not an intermediate
in these cycloaddition processes, and only by loss of a
Co2(CO)4 unit (more forcing reaction conditions) may the
process be reconducted to the same intermediate in-
volved in the conventional Pausson-Khand reaction.
The behavior of adducts 3 and 6 with a large variety
of unstrained alkenes has been also studied. However,
the displacement of the coordinated alkyne by the
alkenes takes place instead to give the parent complexes
1 and 2, respectively, even in the presence of amine
N-oxides.20
these two atoms cannot be discarded. Moro-oka and co-
workers have recently reported a similar bonding
interaction in the binuclear vinylidene complex [(η5-
C5H4Me)MndCdCH(Fp)] (Fp ) Fe(CO)2(η5-C5H5)) with
a distance of 2.866(6) Å.18 The contribution of this
canonical form in the bonding to the cluster is consistent
with the chemical shifts observed for the CR and Câ
atoms in the 13C{1H} NMR spectrum (see Experimental
Section). The C(48)-C(49) bond length of 1.331(3) Å is
consistent with the presence of a double C-C bond.
The formation of complex 12 can be understood as the
result of the reaction of (Z)-6 with 1 equiv of the
fragment Co2(CO)6 or Co2(CO)5, which is eliminated in
the process of formation of complexes (E)-2 and 11,
respectively (Scheme 5). It is interesting to note that
the atypical interaction of the Câ atom C(47) with the
Co(2) atom arises from the Z configuration of the enynyl
chain, which probably also is promoting the formation
of complex 11 from (Z)-6 (for the E isomer the metal
(19) It has been previously reported that [Co2(CO)6(µ2-η2-RCtCR′)]
adducts can be obtained from the reactions of alkynes with Co4(CO)12
:
Dickson, R. S.; Tailby, G. R. Aust. J . Chem. 1970, 23, 229.
(20) Amine N-oxides have been shown to promote Pauson-Khand
reactions in a wide range of examples: (a) Billington, D. C.; Kerr, W.
J .; Pauson, P. L. J . Organomet. Chem. 1988, 341, 181. (b) Gordon, A.
R.; J ohnstone, C.; Kerr, W. J . Synlett 1995, 1083. (c) Kerr, W. J .; Kirk,
G. G.; Middlemiss, D. Synlett 1995, 1085 and references cited therein.
(18) Akita, M.; Ishii, N.; Takabuchi, A.; Tanaka, M.; Moro-oka, Y.
Organometallics 1994, 13, 258.

Reactions of Functionalized Ru(II) σ-Alkynyl Complexes
Organometallics, Vol. 17, No. 4, 1998 703
-11.45. Anal. Calcd for RuC68H49O6F4Co2P2B: C, 61.42; H,
3.71. Found: C, 60.93; H, 3.91.
Exp er im en ta l Section
Syn th esis of [Ru {CtCCHdCH(CtCP h )}(η5-C9H7)(P -
P h 3)2] [(E,Z)-2]. To a solution of [Ru{CtCCH2(PPh3)}(η5-
C9H7)(PPh3)2][PF6] (5; 1.186 g, 1 mmol) in 25 mL of THF, kept
at -20 °C, was added a solution of LinBu (1.6 M in hexane,
0.625 mL, 1 mmol). After the addition was complete, the color
of the solution had changed from yellow to violet. The reaction
mixture was stirred for 15 min; phenylpropargyl aldehyde
(0.366 mL, 3 mmol) was added, and after this mixture was
warmed to room temperature it was stirred for 30 min. The
solvent was then removed in vacuo and the orange solid
residue transferred to an Alox I chromatography column.
Elution with hexane/diethyl ether (1/1) gave complex 2 as a
mixture of stereoisomers E/Z (1/2). Yield: 79%. Anal. Calcd
for RuC57H44P2: C, 76.75; H, 4.97. Found: C, 76.13; H, 4.81.
IR (KBr; ν(CtC), cm-1), and NMR spectroscopic data are as
follows. E: 2038, 2140; 31P{1H} (C6D6) δ 51.57 (s) ppm; 1H
The manipulations were performed under dry nitrogen
using vacuum-line and standard Schlenk techniques. All
reagents were obtained from commercial suppliers and used
without further purification. Solvents were dried by standard
methods and distilled under nitrogen before use. The com-
plexes [Ru{CtCCPh2(CtCH)}(η5-C9H7)(PPh3)2],7g [Ru{CtCCH2-
(PPh3)}(η5-C9H7)(PPh3)2][PF6]7e and Co4(CO)1221 were prepared
by following the methods reported in the literature.
Infrared spectra were recorded on a Perkin-Elmer 1720-XFT
spectrometer. The conductivities were measured at room
temperature, in ca. 10-3 mol dm-3 acetone solutions, with a
J enway PCM3 conductimeter. The C and H analyses were
carried out with a Perkin-Elmer 240-B microanalyzer. NMR
spectra were recorded on a Bruker AC300 instrument at 300
MHz (1H), 121.5 MHz (31P), or 75.4 MHz (13C) using SiMe4 or
85% H3PO4 as standard. DEPT experiments were carried out
for all the complexes. 1H-1H COSY and 1H-13C HMQC
experiments were carried out for (E)-6, (Z)-6, and 9a .
Legend for indenyl skeleton:
(C6D6) δ 4.69 (d, 2H, J HH ) 2.2 Hz, H-1,3), 5.57 (t, 1H, J HH
)
2.2 Hz, H-2), 6.14 (d, 1H, J HH ) 15.3 Hz, dCH), 6.28 and 6.65
(m, 2H each, H-4,7 and H-5,6), 6.88-7.51 (m, 36H, Ph and
dCH) ppm; 13C{1H} (C6D6) δ 75.19 (s, C-1,3), 91.61 and 92.65
(s, CtC), 95.47 (s, C-2), 109.58 (s, C-3a,7a), 110.56 (s, dCH),
116.23 (s, Câ), 123.14-138.63 (m, Ph, C-4,7, C-5,6, dCH and
Ru-CR) ppm. ∆δ(C-3a,7a) ) -21.12. Z: 2038, 2182; 31P{1H}
(C6D6) δ 50.84 (s) ppm; 1H (C6D6) δ 4.78 (d, 2H, J HH ) 2.6 Hz,
The numbering system for the indenyl skeleton is as follows:
H-1,3), 5.72 (d, 1H, J HH ) 10.3 Hz, dCH), 6.02 (t, 1H, J HH
)
2.6 Hz, H-2), 6.28 and 6.65 (m, 2H each, H-4,7 and H-5,6),
6.88-7.51 (m, 34H, Ph and dCH), 7.67 (d, 2H, J HH ) 7.6 Hz,
Ph) ppm; 13C{1H} (C6D6) δ 75.19 (s, C-1,3), 92.46 and 92.52 (s,
CtC), 96.90 (s, C-2), 108.39 (s, dCH), 109.99 (s, C-3a,7a),
116.23 (s, Câ), 123.14-138.63 (m, Ph, C-4,7, C-5,6, dCH and
Ru-CR) ppm. ∆δ(C-3a,7a) ) -20.71.
Syn th esis of [Ru {CtCCP h 2(µ2-η2-CtCH)Co2(CO)6}(η5-
C9H7)(P P h 3)2] (3). [Co2(CO)8] (0.513 g, 1.5 mmol) was added
at room temperature to a solution of [Ru{CtCCPh2(CtCH)}-
(η5-C9H7)(PPh3)2] (1; (0.956 g, 1 mmol) in 30 mL of THF, and
the resulting solution was stirred for 1 h. The solvent was
then removed in vacuo and the red solid residue transferred
to an Alox I chromatography column. Elution with diethyl
ether gave a red band which was collected and evaporated to
give the desired compound. Yield (%), IR (THF; ν(CtO), cm-1),
and NMR spectroscopic data are as follows: 76; 2020, 2048,
2086; 31P{1H} (C6D6) δ 51.72 (s) ppm; 1H (C6D6) δ 4.68 (d, 2H,
J HH ) 1.6 Hz, H-1,3), 5.51 (t, 1H, J HH ) 1.6 Hz, H-2), 6.43 (m,
2H, H-4,7 or H-5,6), 6.62 (s, 1H, CH), 6.86-7.67 (m, 42H, Ph
and H-4,7 or H-5,6) ppm; 13C{1H} (C6D6) δ 55.77 (s, Cγ), 72.97
Syn th esis of [Ru {CtCCHdCH(µ2-η2-CtCP h )Co2(CO)6}-
(η5-C9H7)(P P h 3)2] [(E,Z)-6]. [Co2(CO)8] (0.513 g, 1.5 mmol)
was added at room temperature to a solution of [Ru-
{CtCCHdCH(CtCPh)}(η5-C9H7)(PPh3)2] ((E,Z)-2; 0.892 g, 1
mmol) in 30 mL of THF and the resulting solution stirred for
1 h. The solvent was then removed in vacuo and the green
solid residue transferred to an Alox I chromatography column.
Elution with diethyl ether gave a green band, which was
collected and evaporated to give complex 6 as a mixture of
stereoisomers E/Z (1/2). Yield: 68%. IR (THF; ν(CtO), cm-1):
2017, 2047, 2083. Anal. Calcd for RuC63H54O6Co2P2: C,
63.69; H, 4.58. Found: C, 63.39; H, 4.22. NMR spectroscopic
data are as follows. E: 31P{1H} (C6D6) δ 49.65 (s) ppm; 1H
(C6D6) δ 4.71 (m, 2H, H-1,3), 5.66 (m, 1H, H-2), 6.10 (m, 2H,
H-4,7 or H-5,6), 6.46-7.92 (m, 39H, Ph, CHdCH and H-4,7
or H-5,6) ppm; 13C{1H} (C6D6) δ 75.13 (s, C-1,3), 90.46 and
93.22 (s, C), 95.55 (s, C-2), 110.26 (s, C-3a,7a), 117.72 (s, Câ),
123.18 and 126.11 (s, C-4,7 and C-5,6), 124.70 (s, dCH),
2
(s, C-1,3), 80.37 (s, CH), 96.10 (s, C-2), 99.97 (t, J CP ) 21.8
Hz, Ru-CR), 110.89 (s, C-3a,7a), 115.89 and 117.07 (s, C and
Câ), 124.12 (s, C-4,7 or C-5,6), 125.95-148.71 (m, Ph and C-4,7
or C-5,6), 200.66 (s, CtO) ppm. ∆δ(C-3a,7a) ) -19.81. Anal.
Calcd for RuC68H48O6Co2P2: C, 65.76; H, 3.89. Found: C,
65.42; H, 3.77.
Syn th esis of [Ru {dCdC(H)CP h 2(µ2-η2-CtCH)Co2(CO)6}-
(η5-C9H7)(P P h 3)2][BF 4] (4). To a stirred solution of the
alkynyl complex 3 (1.24 g, 1 mmol) in 100 mL of diethyl ether,
at room temperature, was added a dilute solution of HBF4‚
Et2O in diethyl ether dropwise. Immediately, an insoluble
solid precipitated but the addition was continued until no
further solid was formed. The solution was then decanted and
the brown solid washed with diethyl ether (3 × 20mL) and
vacuum-dried. Yield (%), IR (THF; ν(CtO), cm-1), conductivity
(acetone, 20 °C, Ω-1 cm2 mol-1), and NMR spectroscopic data
are as follows: 75; 2026, 2052, 2090; 31P{1H} ((CD3)2CO) δ
2
127.48-139.95 (m, Ph and dCH), 143.74 (t, J CP ) 23.9 Hz,
Ru-CR), 200.39 (s, CtO) ppm. ∆δ(C-3a,7a) ) -20.44. Z: 31P-
1
{1H} (C6D6) δ 50.77 (s) ppm; H (C6D6) δ 4.76 (m, 2H, H-1,3),
5.91 (m, 1H, H-2), 6.25 (m, 2H, H-4,7 or H-5,6), 6.46-7.92 (m,
39H, Ph, CHdCH and H-4,7 or H-5,6) ppm; 13C{1H} (C6D6) δ
75.13 (s, C-1,3), 93.49 and 93.84 (s, C), 95.55 (s, C-2), 109.80
(s, C-3a,7a), 118.36 (s, Câ), 120.31 and 124.05 (s, dCH), 123.18
and 126.11 (s, C-4,7 and C-5,6), 127.48-139.95 (m, Ph and
Ru-CR), 201.16 (s, CtO) ppm. ∆δ(C-3a,7a) ) -20.90.
Syn th esis of [Ru {dCdC(H)CHdCH(µ2-η2-CtCP h )Co2-
(CO)6}(η5-C9H7)(P P h 3)2)][BF 4] (E,Z)-7. To a solution of the
enynyl complex (E,Z)-6 (1.188 g, 1 mmol) in 50 mL of THF, at
room temperature, was added dropwise an excess of a diluted
solution of HBF4‚Et2O in diethyl ether (ca. 3 mmol). The
resulting solution was stirred at room temperature for 30 min.
The solvent was then removed in vacuo and the black solid
obtained washed with diethyl ether (3 × 20 mL) and vacuum-
dried. Complex 7 was obtained as a mixture of stereoisomers
E/ Z (1/2). Yield (%), IR (THF; ν(CtO), cm-1), and conductivity
(acetone, 20 °C, Ω-1 cm2 mol-1) data are as follows: 68; 2086,
4
37.33 (s) ppm; 1H ((CD3)2CO) δ 4.69 (t, 1H, J HP ) 1.9 Hz,
RudCdCH), 5.43 and 7.24 (m, 2H each, H-4,7 and H-5,6), 5.52
(d, 2H, J HH ) 2.9 Hz, H-1,3), 6.46 (t, 1H, J HH ) 2.9 Hz, H-2),
6.69-7.59 (m, 41H, Ph and CH) ppm; 13C{1H} ((CD3)2CO) δ
56.75 (s, Cγ), 80.63 (s, CH), 81.82 (s, C-1,3), 100.37 (s, C-2),
115.73 (s, C), 119.25 (s, C-3a,7a), 124.60 and 128.67 (s, C-4,7
and C-5,6), 124.76 (s, Câ), 129.38-146.38 (m, Ph), 200.52 (s,
CtO), 342.52 (t, 2J CP ) 15.8 Hz, RudCR) ppm. ∆δ(C-3a,7a) )
(21) King, R. B. In Organometallic Syntheses; Eisch, J . J ., King, R.
B., Eds.; Academic Press: New York, 1965, Vol I, p 98.

704 Organometallics, Vol. 17, No. 4, 1998
Cadierno et al.
2051, 2021; 108. Anal. Calcd for RuC63H45O6F4Co2P2B: C,
59.78; H, 3.58. Found: C, 59.02; H, 3.72. NMR spectroscopic
data are as follows. E: 31P{1H} ((CD3)2CO) δ 41.98 (s) ppm;
1H ((CD3)2CO) δ 5.82-5.87 (m, 4H, H-1,3, H-2 and RudCdCH),
6.44 (m, 2H, H-4,7 or H-5,6), 6.67 (d, 1H, J HH ) 14.4 Hz, dCH),
6.98-7.76 (m, 38H, Ph, dCH and H-4,7 or H-5,6) ppm; 13C{1H}
((CD3)2CO) δ 86.88 (s, C-1,3), 93.19 and 93.46 (s, C), 99.34 (s,
C-2), 115.02 (s, C-3a,7a), 118.55, 121.36 and 122.37 (s, CHdCH
and Câ), 123.73-138.80 (m, Ph, H-4,7 and H-5,6), 200.37 (s,
CtO), 357.10 (t, 2J CP ) 15.6 Hz, RudCR) ppm. ∆δ(C-3a,7a) )
C-3a and C-7a), 114.65 (s, Câ), 123.94-147.38 (m, Ph, C-4, C-5,
C-6, and C-7), 155.84 (s, dC), 161.52 (s, dCHi), 205.93 (s, C)O)
ppm. ∆δ(C-3a,7a) ) -20.25. Anal. Calcd for RuC70H58P2O:
C, 77.97; H, 5.42. Found: C, 77.15; H, 5.63.
Syn th esis of Vin ylid en e Com p lexes 9a ,b. To a stirred
solution of the corresponding alkynyl complex 8a ,b (1 mmol)
in 100 mL of diethyl ether, at room temperature, was added
dropwise a dilute solution of HBF4‚Et2O in diethyl ether.
Immediately, an insoluble solid precipitated, but the addition
was continued until no further solid was formed. The solution
was then decanted and the brown solid washed with diethyl
ether (3 × 20 mL) and vacuum-dried. Yield (%), IR (KBr;
ν(BF4), ν(C)O). cm-1), conductivity (acetone, 20 °C; Ω-1 cm2
mol-1), and NMR spectroscopic data are as follows. Anal.
Calcd for RuC70H57F4P2BO: (9a ) C, 72.22; H, 4.93. Found: C,
71.98; H, 4.87. 9a : 71; 1060, 1694; 112; 31P{1H} (CDCl3) δ
35.87 (d, 2J PP ) 22.8 Hz, PPh3), 37.16 (d, 2J PP ) 22.8 Hz, PPh3)
1
-15.68. Z: 31P{1H} ((CD3)2CO) δ 40.81 (s) ppm; H ((CD3)2-
CO) δ 5.82-5.87 (m, 4H, H-1,3, H-2 and RudCdCH), 6.44 (m,
2H, H-4,7 or H-5,6), 6.57 (d, 1H, J HH ) 9.8 Hz, dCH), 6.98-
7.76 (m, 38H, Ph, dCH and H-4,7 or H-5,6) ppm; 13C{1H}
((CD3)2CO) δ 84.95 and 90.95 (s, C), 86.53 (s, C-1,3), 99.52 (s,
C-2), 115.42 (s, C-3a,7a), 116.35, 118.77 and 121.32 (s, CHdCH
and Câ), 123.73-138.80 (m, Ph, C-4,7 and C-5,6), 200.37 (s,
CtO), 357.31 (t, 2J CP ) 15.3 Hz, RudCR) ppm. ∆δ(C-3a,7a) )
-15.28.
1
ppm; H (CDCl3) δ 0.93 (d, 1H, J HH ) 9.0 Hz, He or Hf), 1.28
(d, 1H, J HH ) 9.0 Hz, He or Hf), 2.45 (d, 1H, J HH ) 4.7 Hz, Ha),
2.74 and 2.81 (m, 1H each, Hc and Hd), 2.90 (m, 1H, Hb), 5.30
(m, 2H, H-1 and H-3), 5.38 (m, 2H, H-4, H-5, H-6 or H7), 5.70
(s, 1H, RudCdCH), 6.23 (m, 2H, H-2 and Hg or Hh), 6.34 (m,
1H, Hg or Hh), 6.58-7.45 (m, 43H, Ph, Hi, and H-4, H-5, H-6
or H-7) ppm; 13C{1H} (CDCl3) δ 41.39 (s, CHeHf), 43.56 and
44.11 (s, CHc and CHd), 46.42 and 53.59 (s, CHa and CHb),
52.64 (s, Cγ), 79.95 and 80.04 (s, C-1 and C-3), 99.50 (s, C-2),
115.95 (s, Câ), 116.59 and 118.40 (s, C-3a and C-7a), 122.95,
123.70, 127.04 and 127.11 (s, C-4, C-5, C-6, and C-7), 127.85-
153.44 (m, Ph, dCHg, and dCHh), 153.44 (s, dC), 162.09 (s,
Rea ction of [Ru {CtCCP h 2(µ2-η2-CtCH)Co2(CO)6}(η5-
C9H7)(P P h 3)2] (3) w ith Nor bor n a d ien e. A solution of
complex 3 (1.242 g, 1 mmol) in 20 mL of norbornadiene was
heated at 85 °C for 30 min. The solvent was then removed in
vacuo and the orange solid residue transferred to an Alox I
chromatography column. Elution with CH2Cl2 gave complex
8a (orange band). The labeling scheme is as follows:
2
dCHi), 207.23 (s, CdO), 340.25 (t, J CP ) 15.8 Hz, RudCR)
ppm. ∆δ(C-3a,7a) ) -13.20. Anal. Calcd for RuC70H59F4P2-
BO (9b): C, 72.10; H, 5.09. Found: C, 72.30; H, 5.15; 119;
2
9b: 69; 1060, 1691; 31P{1H} (CDCl3) δ 36.03 (d, J PP ) 22.5
2
1
Hz, PPh3), 37.11 (d, J PP ) 22.5 Hz, PPh3) ppm; H (CDCl3) δ
0.73 (d, 1H, J HH ) 9.8 Hz, He or Hf), 0.88 (d, 1H, J HH ) 9.8
Hz, He or Hf), 1.34 (m, 2H, CH2), 1.60 (m, 2H, CH2), 2.20 and
2.29 (m, 1H each, Hc and Hd), 2.33 (d, 1H, J HH ) 4.7 Hz, Ha),
2.74 (m, 1H, Hb), 5.32 (m, 4H, H-1, H-3, and H-4, H-5, H-6, or
H-7), 5.68 (s, 1H, RudCdCH), 6.20 (m, 1H, H-2), 6.52-7.44
(m, 43H, Ph, dCHi, and H-4, H-5, H-6, or H-7) ppm; 13C{1H}
(CDCl3) δ 28.19, 29.18, and 31.53 (s, CH2), 38.55, 39.51, 47.00,
and 55.07 (s, CHa, CHb, CHc, and CHd), 52.52 (s, Cγ), 79.98
and 80.08 (s, C-1 and C-3), 99.50 (s, C-2), 116.07 (s, Câ), 116.67
and 118.30 (s, C-3a and C-7a), 123.01 and 123.69 (s, C-4, C-5,
C-6, or C-7), 127.02-143.90 (m, Ph and C-4, C-5, C-6, or C-7),
152.62 (s, dC), 162.65 (s, dCHi), 208.63 (s, CdO), 340.20 (t,
2J CP ) 15.8 Hz, RudCR) ppm. ∆δ(C-3a,7a) ) -13.21.
Yield (%), IR (KBr; ν(C)O), ν(CtC), cm-1), and NMR spec-
troscopic data are as follows: 72; 1700, 2075; 31P{1H} (C6D6)
2
2
δ 53.13 (d, J PP ) 33.9 Hz, PPh3), 53.56 (d, J PP ) 33.9 Hz,
1
PPh3) ppm; H (C6D6) δ 1.32 (d, 1H, J HH ) 8.8 Hz, He or Hf),
1.47 (d, 1H, J HH ) 8.8 Hz, He or Hf), 2.20 (d, 1H, J HH ) 5.0
Hz, Ha), 2.31 (m, 2H, Hb and Hc or Hd), 2.93 (m, 1H, Hc or Hd),
4.64 (m, 2H, H-1 and H-3), 5.40 (m, 1H, H-2), 5.90 (m, 2H, Hg
and Hh), 6.48 (m, 2H, H-4, H-5, H-6, or H-7), 6.79-7.82 (m,
43H, Ph, Hi and H-4, H-5, H-6, or H-7) ppm; 13C{1H} (C6D6) δ
42.03 (s, CHeHf), 43.97, 44.31, 46.53, and 54.24 (s, CHa, CHb,
CHc, and CHd), 54.16 (s, Cγ), 73.84 and 74.21 (s, C-1 and C-3),
Rea ction of [Ru {CtCCHdCH(µ2-η2-CtCP h )Co2(CO)6}-
(η5-C9H7)(P P h 3)2] ((E,Z)-6) w ith Nor bor n a d ien e. A solu-
tion of (E,Z)-6 (1.188 g, 1 mmol) in 20 mL of norbornadiene
was heated at 85 °C for 30 min. The solvent was then removed
in vacuo and the orange solid residue transferred to an Alox
I chromatography column. Initial elution with diethyl ether
gave an orange band, from which the enynyl complex (E)-10
was obtained by solvent removal. Further purification by
elution with a hexane/methanol (4/1) mixture gave an orange
solution, from which the enynyl complex (Z)-10 was obtained.
The labeling scheme is as follows:
2
96.08 (s, C-2), 97.17 (t, J CP ) 23.2 Hz, Ru-CR), 110.20 and
110.76 (s, C-3a and C-7a), 114.56 (s, Câ), 123.93-147.27 (m,
Ph, C-4, C-5, C-6 and C-7), 137.50 and 138.43 (s, dCHg and
dCHh), 156.90 (s, dC), 161.49 (s, dCHi), 204.78 (s, C)O) ppm.
∆δ(C-3a,7a) ) -20.22. Anal. Calcd for RuC70H56P2O: C,
78.12; H, 5.24. Found: C, 78.47; H, 5.44.
Rea ction of [Ru {CtCCP h 2(µ2-η2-CtCH)Co2(CO)6}(η5-
C9H7)(P P h 3)2] (3) w ith Nor bor n en e. A solution of complex
3 (1.242 g, 1 mmol) in 20 mL of norbornene was heated at 85
°C for 30 min. The solvent was then removed in vacuo and
the orange solid residue transferred to an Alox I chromatog-
raphy column. Elution with CH2Cl2 gave complex 8b (orange
band). Yield (%), IR (KBr; ν(C)O), ν(CtC), cm-1), and NMR
spectroscopic data are as follows: 69; 1706, 2071; 31P{1H}
2
2
(C6D6) δ 52.73 (d, J PP ) 33.7 Hz, PPh3), 53.21 (d, J PP ) 33.7
Hz, PPh3) ppm; 1H (C6D6) δ 0.74-1.31 (m, 6H, CH2), 1.84 (m,
1H, Hc or Hd), 2.01 (d, 1H, J HH ) 5.0 Hz, Ha), 2.12 (m, 1H,
Hb), 2.44 (m, 1H, Hc or Hd), 4.65 (m, 2H, H-1 and H-3), 5.41
(m, 1H, H-2), 6.50 (m, 2H, H-4, H-5, H-6, or H-7), 6.80-7.83
(m, 41H, Ph, Hi, and H-4, H-5, H-6, or H-7), 7.59 (d, 2H, J HH
) 7.5 Hz, Ph) ppm; 13C{1H} (C6D6) δ 28.64, 29.50, and 31.97
(s, CH2), 38.92, 39.48, 47.63, and 55.82 (s, CHa, CHb, CHc, and
CHd), 53.88 (s, Cγ), 73.86 and 74.26 (s, C-1 and C-3), 96.18 (s,
Anal. Calcd for RuC65H52P2O ((E)-10): C, 77.13; H, 5.18.
Found: C, 77.32; H, 5.23. Yield (%), IR (KBr; ν(C)O), ν(CtC),
cm-1), and NMR spectroscopic data are as follows: E: 16; 1692,
2
C-2), 96.68 (t, J CP ) 23.2 Hz, Ru-CR), 110.18 and 110.71 (s,

Reactions of Functionalized Ru(II) σ-Alkynyl Complexes
Organometallics, Vol. 17, No. 4, 1998 705
2
2041; 31P{1H} (C6D6) δ 51.63 (d, J PP ) 30.5 Hz, PPh3), 51.91
Ta ble 2. Cr ysta llogr a p h ic Da ta for Com p lex 12
(d, J PP ) 30.5 Hz, PPh3) ppm; 1H (C6D6) δ 1.24 (d, 1H, J HH
)
2
chem formula
a, Å
C66H44O9P2Co4Ru
11.107(2)
9.5 Hz, He or Hf), 1.38 (d, 1H, J HH ) 9.5 Hz, He or Hf), 2.29 (m,
1H, Hc), 2.35 and 2.79 (d, 1H each, J HH ) 5.6 Hz, Ha and Hb),
3.10 (m, 1H, Hd), 4.66 and 4.70 (m, 1H each, H-1 and H-3),
5.63 (m, 1H, H-2), 5.90 and 5.98 (m, 1H each, Hg and Hh), 6.30
(m, 2H, H-4, H-5, H-6, or H-7), 6.59-6.65 (m, 4H, Ph and Hi
or Hj), 6.81-7.48 (m, 34H, Ph, and H-4, H-5, H-6, or H-7), 8.38
(d, 1H, J HH ) 15.4 Hz, Hi or Hj) ppm; 13C{1H} (C6D6) δ 42.99
(s, CHeHf), 44.41 (s, CHc), 45.17 (s, CHd), 50.92 and 53.97 (s,
CHa and CHb), 75.85 (s, C-1 and C-3), 96.43 (s, C-2), 109.96
and 110.44 (s, C-3a and C-7a), 118.33 (s, Câ), 123.07 and 123.15
(s, CHi and CHj), 123.58, 123.91, 126.55 and 126.81 (s, C-4,
C-5, C-6 and C-7), 125.17 (t, 2J CP ) 24.6 Hz, Ru-CR), 128.21-
139.55 (m, Ph), 138.54 and 138.91 (s, CHg and CHh), 141.38
and 164.20 (s, CdC), 207.89 (s, C)O) ppm. ∆δ (C-3a,7a) )
-20.50. Anal. Calcd for RuC65H52P2O ((Z)-10): C, 77.13; H,
5.18. Found: C, 77.74; H, 5.14. Z: 49; 1674, 2027; 31P{1H}
b, Å
15.564(5)
c, Å
17.896(4)
R, deg
â, deg
γ, deg
mol wt
Z
97.55(2)
90.25(1)
109.69(2)
1379.74
2
V, Å3
2883.6(12)
1.589
D
calcd, g cm-3
F(000)
1388
radiation
monochromator
temp, K
Mo KR (λ ) 0.710 69 Å)
graphite
293(2)
space group
cryst syst
P1h
triclinic
cryst size, mm
0.22 × 0.32 × 0.43
µ, mm-1
1.50
2
2
(C6D6) δ 51.35 (d, J PP ) 30.0 Hz, PPh3), 51.69 (d, J PP ) 30.0
Hz, PPh3) ppm; H (C6D6) δ 1.37 (d, 1H, J HH ) 9.1 Hz, He or
Hf), 1.50 (d, 1H, J HH ) 9.1 Hz, He or Hf), 2.43 and 2.85 (d, 1H
each, J HH ) 5.8 Hz, Ha and Hb), 2.88 (m, 1H, Hc), 3.14 (m, 1H,
Hd), 4.70 (m, 2H, H-1 and H-3), 5.57 (m, 1H, H-2), 6.02 (m,
2H, Hg and Hh), 6.30 and 6.68 (m, 2H each, H4, H-5, H-6, and
θ range, deg
index ranges for data collecn
1.15-24.98
1
-13 e h e 13
-18 e k e 18
0 e l e 21
no. of rflns measd
no. of indep rflns
refinement method
no. of data/restraints/params
goodness of fit on F2
final R factors R(I > 2σ(I))
final R factors R(all data)
10 239
9882 (R(int)a ) 0.0134)
full-matrix least-squares on F2
9882/0/740
H-7), 6.85-7.38 (m, 35H, Ph, Hi and Hj), 7.57 (d, 2H, J HH
)
7.1 Hz, Ph) ppm; 13C{1H} (C6D6) δ 43.55 (s, CHeHf), 44.75 (s,
CHd), 46.20 (s, CHc), 47.16 and 53.71 (s, CHa and CHb), 76.14
(s, C-1 and C-3), 96.00 (s, C-2), 110.37 and 110.73 (s, C-3a and
C-7a), 120.70 (s, Câ), 123.77, 124.00, 126.96, and 127.16 (s, C-4,
C-5, C-6, and C-7), 125.88 and 127.28 (s, CHi and CHj),
127.47-139.14 (m, Ph), 138.50 and 139.01 (s, CHg and CHh),
1.040
R1 ) 0.0240, wR2 ) 0.0557
R1 ) 0.0376, wR2 ) 0.0607
a
Rint ) ∑(I - I )/∑I.
complex 12. Yield (%), IR (THF; ν(CtO), cm-1), and NMR
spectroscopic data are as follows: 44; 1845, 1958, 2000, 2031,
2049; 31P{1H} (CD2Cl2) δ 40.37 (s) ppm; 1H (CD2Cl2) δ 4.88 (d,
1H, J HH ) 5.7 Hz, dCH), 5.50 (m, 5H, H-2, H-1,3, and H-4,7
or H-5,6), 6.21 (d, 1H, J HH ) 5.7 Hz, dCH), 6.92-7.57 (m, 37H,
Ph and H-4,7 or H-5,6) ppm; 13C{1H} (CD2Cl2) δ 76.55 (s,
C-1,3), 95.46 (s, C-2), 116.29 (s, C-3a,7a), 121.34 (s, C), 123.79
(s, C-4,7 or C-5,6), 127.06 and 139.79 (s, CHdCH), 127.44-
2
140.35 and 167.32 (s, CdC), 141.26 (t, J CP ) 24.6 Hz, Ru-
CR), 204.73 (s, CdO) ppm. ∆δ(C-3a,7a) ) -20.15.
Rea ction of [Ru {CtCCHdCH(µ2-η2-CtCP h )Co2(CO)6}-
(η5-C9H7)(P P h 3)2] ((E,Z)-6) w ith Nor bor n en e. A solution
of (E,Z)-6 (1.188 g, 1 mmol) in 20 mL of norbornene was heated
at 85°C for 90 min. The solvent was then removed in vacuo
and the brown solid residue transferred to an Alox I chroma-
tography column. Initial elution with diethyl ether gave an
orange band, from which the precursor complex (E)-2 was
isolated. Further purification by elution with a hexane/
methanol (4/1) mixture gave an orange solution, from which
the enynyl complex 11 was obtained. Yield (%), IR (KBr;
ν(C)O), ν(CtC), cm-1), and NMR spectroscopic data are as
follows: 42; 1674, 2027; 31P{1H} (C6D6) δ 51.32 (d, 2J PP ) 30.5
3
152.74 (m, Ph and C-4,7 or C-5,6), 157.39 (t, J CP ) 8.8 Hz,
Câ), 169.46 (s, C), 209.66 and 213.67 (bs, CtO), 279.21 (t, 2J CP
) 18.1 Hz, RudCR) ppm. ∆δ(C-3a,7a) ) -14.41. Anal. Calcd
for RuC66H44O9Co4P2: C, 57.45; H, 3.21. Found: C, 56.95; H,
3.59.
X-r a y Diffr a ct ion St u d y. Data collection, crystal, and
refinement parameters are collected in Table 2. The unit cell
parameters were obtained from the least-squares fit of 25
reflections (with θ between 16 and 20°). Graphite-monochro-
mated Mo KR radiation was used. Data were collected on an
Enraf-Nonius CAD4 diffractometer with the ω-2θ scan tech-
nique and a variable scan rate, with a maximum scan time of
60 s per reflection. No decay of standards was observed.
Lorentz, polarization, and absorption (empirical ψ scan,
maximum and minimum transmission factors 0.9991 and
0.8491) corrections were applied, and the data were reduced
to |Fo| values.
2
1
Hz, PPh3), 51.60 (d, J PP ) 30.5 Hz, PPh3) ppm; H (C6D6) δ
0.81 (d, 1H, J HH ) 9.9 Hz, He or Hf), 1.10 (m, 2H, CH2), 1.29
(d, 1H, J HH ) 9.9 Hz, He or Hf), 1.36 (m, 2H, CH2), 2.27 and
2.63 (d, 1H each, J HH ) 5.8 Hz, Ha and Hb), 2.39 (m, 1H, Hc),
2.66 (m, 1H, Hd), 4.70 (m, 2H, H-1 and H-3), 5.59 (m, 1H, H-2),
6.30 and 6.66 (m, 2H each, H4, H-5, H-6, and H-7), 6.86-7.36
(m, 35H, Ph, Hi, and Hj), 7.59 (d, 2H, J HH ) 7.5 Hz, Ph) ppm;
13C{1H} (C6D6) δ 28.97 (s, CH2), 29.65 (s, CH2), 32.63 (s, CH2),
39.10 (s, CHd), 40.72 (s, CHc), 47.17 and 54.69 (s, CHa and
CHb), 75.46 (s, C-1 and C-3), 95.38 (s, C-2), 109.71 and 110.05
(s, C-3a and C-7a), 119.92 (s, Câ), 123.09, 123.30, 125.45,
126.32, 124.69, and 126.66 (s, C-4, C-5, C-6, C-7, CHi, and CHj),
127.11-138.82 (m, Ph and dC), 140.39 (t, 2J CP ) 24.3 Hz, Ru-
CR), 167.51 (s, dC), 205.58 (s, CdO) ppm. ∆δ(C-3a,7a) )
-20.82. Anal. Calcd for RuC65H54P2O; C, 76.98; H, 5.37.
Found C, 76.01; H, 5.31.
The structure was solved by SHELX-86.22 Isotropic full-
2
matrix least-squares refinement on |Fo| using SHELXL9323
converged to R ) 0.08. Finally, all hydrogen atoms were
geometrically placed. During the final stages of the refine-
ment, the positional parameters and the anisotropic thermal
parameters of the non-H atoms were refined. The geo-
metrically placed hydrogen atoms were isotropically refined
with a common thermal parameter, riding on their parent
Syn th esis of Com p lex 12. Co4(CO)12 (0.858 g, 1.5 mmol)
was added to a solution of [Ru{CtCCHdCH(CtCPh)}(η5-
C9H7)(PPh3)2] ((E,Z)-2; 0.892 g, 1 mmol) in 30 mL of THF and
the resulting solution refluxed for 2 h. The solvent was then
removed in vacuo and the green solid residue transferred to
an Alox I chromatography column. Elution with diethyl ether
gave a green band which from which (E)-6 was obtained.
Further purification by elution with a diethyl ether/dichlo-
romethane (3/1) mixture gave a new green band, which was
collected and evaporated to dryness to produce pure cluster
2
2
atoms. The function minimized was [∑w(Fo2 - Fc )2/∑w(Fo )2]1/2
;
(22) Sheldrick, G. M. SHELX86. In Crystallographic Computing 3;
Sheldrick, G. M., Kruger, C., Goddard, R., Eds.; Clarendon Press:
Oxford, U.K., 1985.
(23) Sheldrick, G. M. SHELXL93. In Crystallographic Computing
6; Flack, P., Parkanyi, P., Simon, K., Eds.; IUCr/Oxford University
Press: Oxford, U.K., 1993.

706 Organometallics, Vol. 17, No. 4, 1998
Cadierno et al.
w ) 1/[σ2(Fo2) + (0.0260P)2], where P ) (Max(Fo2,0) + 2Fc2)/3
with σ2(Fo2) from counting statistics. No constraint or restraint
was used during the refinement. The excellent final R values
obtained suggest the exceptional quality of the initial data set.
Ack n ow led gm en t. This work was supported by the
Direccio´n General de Investigacio´n Cient´ıfica y Te´cnica
(Project PB93-0325) and the EU (Human Capital Mobil-
ity program, Project ERBCHRXCT 940501). We thank
the Fundacio´n para la Investigacio´n Cient´ıfica y Te´cnica
de Asturias (FICYT) for a fellowship to V.C.
The maximum shift to esd ratio in the last full-matrix least-
squares cycle was 0.003. The final difference Fourier map
showed no peaks higher than 0.28 e Å-3 nor deeper than -0.40
e Å-3
. Atomic scattering factors were taken from ref 24.
Geometrical calculations were made with SHELXL93.23 The
crystallographic plots were made with ZORTEP. All calcula-
tions were made at the “Institut de Ciencia de Materials de
Barcelona” on a DEC-ALPHA computer and a VOBIS portable
PC.
Su p p or tin g In for m a tion Ava ila ble: Crystal structure
data for 12, including tables of atomic and thermal parameters,
bond distances, and bond angles (12 pages). Ordering infor-
mation is given on any current masthead page.
(24) International Tables for X-Ray Crystallography; Kynoch
Press: Birminghan, U.K. 1974; Vol. IV.
OM970645G