Ruthenium-acetylide-mediated catalytic dimerization of RC≡CH (R = Ph, CO2Me) and the formation of the new ruthenium η3-butadienyl complex C5Me5Ru(PPh3)[η 3-PhCHCHC=C(Ph)C≡CCPh]

Article abstract of DOI:10.1021/om970366t

The in-situ-generated ruthenium-acetylide species C₅Me₅Ru(PPh₃)C≡CPh (1) was found to catalyze the dimerization of RC≡CH to give predominantly the head-to-head dimers trans-RCH=CHC≡CR (R = Ph (3), TON = 607 h^-1; R = CO₂Me (4), TON = 975 h^-1). A new ruthenium η³-butadienyl complex C₅Me₅Ru(PPh₃)(η ³-PhCHCHC=C(Ph)C≡CPh) (5) was isolated at the end of the catalytic dimerization of PhC≡CH (81% based on Ru). The structure of the 1.5 benzene-solvated complex 5·1.5C₆H₆ was established by X-ray crystallography. Complex 5 was independently prepared from the stoichiometric reaction of C₅Me₅Ru(PPh₃)-(Cl)=C=CHPh (2) with the dimer 3 in the presence of NEt₃. The formation of an intermediate η²-alkyne complex C₅Me₅Ru(PPh₃)(η ²-PhCH=CHC=CPh)(C=CPh) (6) was observed during the reaction.

Full text of DOI:10.1021/om970366t

3910
Organometallics 1997, 16, 3910-3913
Ru th en iu m -Acetylid e-Med ia ted Ca ta lytic Dim er iza tion
of RCtCH (R ) P h , CO2Me) a n d th e F or m a tion of th e
New Ru th en iu m η3-Bu ta d ien yl Com p lex
C5Me5Ru (P P h 3)[η3-P h CHCHCdC(P h )CtCCP h ]
Chae S. Yi* and Nianhong Liu
Department of Chemistry, Marquette University, Milwaukee, Wisconsin 53201-1881
Arnold L. Rheingold and Louise M. Liable-Sands
Department of Chemistry, The University of Delaware, Newark, Delaware 19716
Received May 1, 1997X
The in-situ-generated ruthenium-acetylide species C5Me5Ru(PPh3)CtCPh (1) was found
to catalyze the dimerization of RCtCH to give predominantly the head-to-head dimers trans-
RCHdCHCtCR (R ) Ph (3), TON ) 607 h-1; R ) CO2Me (4), TON ) 975 h-1). A new
ruthenium η3-butadienyl complex C5Me5Ru(PPh3)(η3-PhCHCHCdC(Ph)CtCPh) (5) was
isolated at the end of the catalytic dimerization of PhCtCH (81% based on Ru). The structure
of the 1.5 benzene-solvated complex 5‚1.5C6H6 was established by X-ray crystallography.
Complex 5 was independently prepared from the stoichiometric reaction of C5Me5Ru(PPh3)-
(Cl)dCdCHPh (2) with the dimer 3 in the presence of NEt3. The formation of an
intermediate η2-alkyne complex C5Me5Ru(PPh3)(η2-PhCHdCHCtCPh)(CtCPh) (6) was
observed during the reaction.
In tr od u ction
of terminal alkynes. The stereoselective formation of
cis-1,4-disubstituted butatrienes has also been achieved
from the dimerization of alkyl-substituted alkynes.4 We
recently reported the ruthenium-catalyzed dimerization
of terminal alkynes to produce both 1,3- and 1,4-
disubstituted enynes and butatrienes and proposed a
mechanism involving a coordinatively unsaturated ru-
thenium-acetylide species.5 We also developed an
effective route to the coordinatively unsaturated acetyl-
ide species C5Me5Ru(PPh3)CtCPh (1) from the reaction
of the vinylidene complex C5Me5Ru(PPh3)(Cl)dCdCHPh
(2) with a base and found that the ruthenium acetylide
1 was reactive toward a variety of small molecules such
as CO, H2, and CO2.6 Herein, we report the ruthenium-
acetylide-mediated catalytic dimerization of terminal
alkynes and the formation of a new (η3-butadienyl)-
ruthenium complex.
The transition-metal-mediated dimerization of ter-
minal alkynes is of considerable current interest because
it can lead to a wide variety of organic enyne and
oligoacetylene products that are useful synthetic pre-
cursors for organic conducting polymers and other
carbon-rich allotropes.1-4 For example, the copper-
acetylide catalysts have been employed in an industrial-
scale dimerization of HCtCH to produce CH2dCH-
CtCH, a key precursor for neoprene rubber.1a Recently,
transition-metal-based catalysts have been shown to
selectively produce both the 1,3-disubstituted enynes2
and the 1,4-disubstituted enynes3 from the dimerization
X Abstract published in Advance ACS Abstracts, August 1, 1997.
(1) For recent reviews and monographs, see: (a) Parshall, G. W.;
Ittel, S. D. Homogeneous Catalysis, 2nd ed.; J ohn Wiley & Sons: New
York, 1992. (b) Henkelmann, J . In Applied Homogeneous Catalysis with
Organometallic Compounds; Cornils, B., Herrmann, W. A., Eds.;
VCH: New York, 1996. (c) Modern Acetylene Chemistry; Stang, P. J .,
Diederich, F., Eds.; VCH: New York, 1995. (d) Farina, V. In Compre-
hensive Organometallic Chemistry II; Abel, E. W., Stone, F. G. A.,
Wilkinson, G., Eds.; Pergamon Press: New York, 1994; Vol. 12. (e)
Sonogashira, K. In Comprehensive Organic Synthesis; Trost, B. M.,
Ed.; Pergamon Press: New York, 1990; Vol. 2. (f) Kanis, D. R.; Ratner,
M. A.; Marks, T. J . Chem. Rev. 1994, 94, 195. (g) Materials for
Nonlinear Optics: Chemical Perspectives; Stucky, G. D., Marder, S.
R., Sohn, J ., Eds.; ACS Symposium Series 455; American Chemical
Society: Washington, DC, 1991. (h) Lang, H. Angew. Chem., Int. Ed.
Engl. 1994, 33, 547.
(2) For leading examples of 1,3-enynes, see: (a) Thompson, M. E.;
Baxter, S. M.; Bulls, A. R.; Burger, B. J .; Nolan, M. C.; Santarsiero, B.
D.; Schaefer, W. P.; Bercaw, J . E. J . Am. Chem. Soc. 1987, 109, 203.
(b) Trost, B. M.; Chan, C.; Ruhter, G. J . Am. Chem. Soc. 1987, 109,
3486. (c) Ohshita, J .; Furumori, K.; Matsuguchi, A.; Ishikawa, M. J .
Org. Chem. 1990, 55, 3277 and references therein. (d) Boese, W. T.;
Goldman, A. S. Organometallics 1991, 10, 782. (e) Horton, A. D. J .
Chem. Soc., Chem. Commun. 1992, 185. (f) Barluenga, J .; Gonza´lez,
J . M.; Llorente, I.; Campos, P. J . Angew. Chem., Int. Ed. Engl. 1993,
32, 893. (g) Straub, T.; Haskel, A.; Eisen, M. S. J . Am. Chem. Soc.
1995, 117, 6364. (h) Trost, B. M.; Sorum, M. T.; Chan, C.; Harms, A.
E.; Ru¨hter, G. J . Am. Chem. Soc. 1997, 119, 698 and references cited
therein.
(3) For leading examples of 1,4-enynes, see: (a) Ohshita, J .; Furu-
mori, K.; Matsuguchi, A.; Ishikawa, M. J . Org. Chem. 1990, 55, 3277.
(b) Bianchini, C.; Peruzzini, M.; Zanobini, F.; Frediani, P.; Albinati,
A. J . Am. Chem. Soc. 1991, 113, 5453. (c) J un, C.-H.; Lu, Z.; Crabtree,
R. H. Tetrahedron Lett. 1992, 33, 7119. (d) Duchateau, R.; van Wee,
C. T.; Meetsma, A.; Teuben, J . H. J . Am. Chem. Soc. 1993, 115, 4931.
(e) Evans, W. J .; Keyer, R. A.; Ziller, J . W. Organometallics 1993, 12,
2618. (f) Bianchini, C.; Frediani, P.; Masi, D.; Peruzzini, M.; Zanobini,
F. Organometallics 1994, 13, 4616. (g) Matsuzaka, H.; Takagi, Y.; Ishii,
Y.; Nishio, M.; Hidai, M. Organometallics 1995, 14, 2153. (h) Bianchini,
C.; Innocenti, P.; Peruzzini, M.; Romerosa, A.; Zanobini, F. Organo-
metallics 1996, 15, 272. (i) Slugovc, C.; Mereiter, K.; Zobetz, E.; Schmid,
R.; Kirchner, K. Organometallics 1996, 15, 5275.
(4) For leading examples of 1,4-disubstituted butatrienes, see: (a)
Wakatsuki, Y.; Yamazaki, H.; Kumegawa, N.; Satoh, T.; Satoh, J . Y.
J . Am. Chem. Soc. 1991, 113, 9604. (b) Scha¨fer, M.; Mahr, N.; Wolf,
J .; Werner, H. Angew. Chem., Int. Ed. Engl. 1993, 32, 1315. (c) Heeres,
H. J .; Nijhoff, J .; Teuben, J . H.; Rogers, R. D. Organometallics 1993,
12, 2609. (d) Wakatsuki, Y.; Koga, N.; Yamazaki, H.; Morokuma, K.
J . Am. Chem. Soc. 1994, 116, 8105.
(5) Yi, C. S.; Liu, N. Organometallics 1996, 15, 3968.
(6) Yi, C. S.; Liu, N.; Rheingold, A. L.; Liable-Sands, L. M.; Guzei,
I. A. Organometallics 1997, 16, 3729.
S0276-7333(97)00366-X CCC: $14.00 © 1997 American Chemical Society

Ruthenium-Acetylide-Mediated Dimerization
Organometallics, Vol. 16, No. 18, 1997 3911
Resu lts a n d Discu ssion
In an attempt to establish the intermediacy of the
ruthenium-acetylide complex 1 during the dimerization
of terminal alkynes,5 the reaction of in-situ-generated
1 with PhCtCH was investigated. In a typical reaction,
a catalytic amount of 2 (10 mg, 0.016 mmol) and Et3N
(22 µL, 0.16 mmol) in CH2Cl2 was treated with excess
PhCtCH (57 µL, 0.52 mmol) at room temperature for
1
24 h. The H NMR spectrum of the reaction mixture
showed a predominant formation of the trans dimer
trans-PhCHdCHCtCPh (3a ) over the cis isomer cis-
PhCHdCHCtCPh (3b) (3a :3b ) 4:1). The organic
products were isolated from simple column chromatog-
raphy on silica gel (3:1 Et2O/hexanes), and the structure
of the products was completely established by spectro-
scopic methods (TON ) 607 h-1, 75% yield). The
present dimeric product ratio was complementary to the
previously reported dimerization of PhCtCH by the
ruthenium-hydride complex C5Me5Ru(PPh3)H3, which
produced a 35:65 mixture of 3a and 3b.5
The ruthenium-acetylide complex 1 also displayed
an unusual selectivity toward the dimerization of other
functionalized alkynes. For instance, the acetylide
1-catalyzed dimerization reaction of HCtCCO2Me pro-
duced exclusively the linear dimer trans-MeO2C-
CHdCHCtCCO2Me (4) in an 80% isolated yield. The
rate of the formation of 4 at room temperature was
slightly faster than that of the formation of 3 (TON )
975 h-1), and no other dimeric or higher oligomeric
products was detected by 1H NMR. Normally, a metal-
mediated homocoupling reaction of HCtCCO2Me has
been well-known to preferentially give the cyclotrimer-
ization products,7 and to the best of our knowledge, this
is the first example of metal-catalyzed linear dimeriza-
tion of HCtCCO2Me.
F igu r e 1. Molecular structure of 5‚1.5C6H6 drawn with
35% thermal ellipsoids.
Ta ble 1. Selected Bon d Len gth s (Å) a n d Bon d
An gles (d eg)
Bond Distances
Ru-C(12)
Ru-C(14)
Ru-P
C(12)-C(13)
C(11)-C(15)
2.026(3)
2.282(3)
2.322(1)
1.426(5)
1.443(5)
Ru-C(13)
2.124(3)
1.889(3)
1.361(5)
1.431(5)
1.199(5)
Ru-Cp*(cent)
C(11)-C(12)
C(13)-C(14)
C(15)-C(16)
Bond Angles
C(12)-C(13)-C(14) 117.9(3)
95.64(10) C(14)-Ru-P 83.43(10)
147.0(3) C(12)-Ru-C(13) 40.11(13)
68.95(13) C(12)-C(11)-C(15) 120.0(3)
C(11)-C(12)-C(13) 136.5(3)
C(12)-Ru-P
C(11)-C(12)-Ru
C(12)-Ru-C(14)
C(13) ) 1.426(5) Å, C(13)-C(14) ) 1.431(5) Å) are
indicated of a substantial delocalization of π-electrons.
The apparent distortion of the butadienyl ligand may
be due in part to the steric interaction between the Ph
group and the PPh3 ligand, as indicated by the solid-
state structure and a notably small trans allylic proton
coupling constant (J ) 8.8 Hz). Similar ruthenium η3-
butadienyl complexes have been previously prepared
from the [2 + 2]-cycloaddition reaction of ruthenium-
acetylide complexes with electron-deficient alkenes.8
Complex 5 was shown to be inactive toward the dimer-
ization of PhCtCH.
A small amount of a new ruthenium species was
isolated at the end of the catalytic dimerization reaction
of PhCtCH (81% based on Ru). The 1H NMR spectrum
of the new species exhibited two allyl protons at δ 3.68
(dd, J HH ) 8.8 Hz, J PH ) 3.7 Hz) and 3.00 (dd, J HH
)
To gain some insight on the formation of 5, the
stoichiometric reaction of the vinylidene complex 2 (10
mg, 0.016 mmol) with PhCtCH (3 µL, 0.032 mmol) and
8.8 Hz, J PH ) 14.0 Hz) which were coupled both to each
other and with the phosphorus atom. The structure of
the complex was determined as the η3-butadienyl com-
plex 5 from the single-crystal X-ray crystallography
(Figure 1). The molecular structure of 5 can be de-
scribed best as a distorted η3-butadienyl complex, where
the ruthenium center is bonded to three butadienyl
carbons with an overall exo,syn-π-allyl geometry. Sig-
nificantly longer distances for two of the allyl carbons
from the ruthenium center (Ru-C(14) ) 2.282(3) Å,
Ru-C(13) ) 2.124(3) Å) compared to that of the enynyl
carbon (Ru-C(12) ) 2.026(3) Å) indicated that the
complex has a major resonance contribution from the
vinyl-alkene structure (Table 1). Also, relatively uni-
form bond distances between three alllyl carbons (C(12)-
1
Et3N (4 µL, 0.032 mmol) in CD2Cl2 was followed by H
NMR spectroscopy at room temperature (Figure 2).
Initially, rapid formation of the dimers 3a and 3b was
observed. After ∼20 min, new ruthenium species began
to appear, as indicated by the new Cp* resonance at δ
1.44 and the vinyl protons at δ 6.73 and 6.50 (d, J )
15.9 Hz) as well as the resonances due to 5. The
spectroscopic data of the new ruthenium species was
consistent with the η2-alkyne complex 6.9 The ruthe-
nium product 5 was gradually formed over 12 h at the
(8) (a) Bruce, M. I.; Rodgers, J . R.; Snow, M. R.; Swincer, A. G. J .
Chem. Soc., Chem. Commun. 1981, 271. (b) Bruce, M. I.; Hambley, T.
W.; Snow, M. R.; Swincer, A. G. Organometallics 1985, 4, 501. (c) Bruce,
M. I.; Duffy, D. N.; Liddell, M. J .; Tiekink, E. R. T.; Nicholson, B. K.
Organometallics 1992, 11, 1527.
(7) (a) Vollhart, K. P. C. Angew. Chem., Int. Ed. Engl. 1984, 23, 539.
(b) Schore, N. E. Chem. Rev. 1988, 88, 1081.

3912 Organometallics, Vol. 16, No. 18, 1997
Yi et al.
sequent acetylide migration,3,5 the direct insertion
pathway seems to be preferred for alkynes with electron-
withdrawing groups at relatively low temperature,
where the acetylene-to-vinylidene tautomerization is
relatively slow.1c,2 The formation of η3-butadienyl com-
plex 5 can be rationalized similarly by invoking the
intramolecular migratory insertion of the enyne 3 via
the alkyne-coordinated 6 in which the acetylide ligand
is selectively added to the phenyl-substituted acetylenic
carbon. Since the acetylide migration has been com-
monly known to occur at the most electrophilic alkyne
substrate,1c,d a relatively more electron-withdrawing
vinyl group of 3 should facilitate the acetylide migration
to a relatively more electrophilic phenyl-substituted
alkyne carbon.
In summary, the ruthenium-acetylide 1 was shown
to be an effective catalyst for the dimerization of
RCtCH (R ) Ph, CO2Me). A new ruthenium η3-
butadienyl species 5 was formed from the reaction of 1
with the dimeric product 3 via an intermediate 6.
Further studies on the ruthenium-acetylide-mediated
coupling reactions of alkenes and alkynes are currently
in progress.
F igu r e 2. Stoichiometric reaction profile of 2 (10 mg, 0.016
mmol) with PhCtCH (3 µL, 0.032 mmol, 2 equiv) and Et3N
1
(4 µL, 0.032 mmol, 2 equiv) in CD2Cl2, as monitored by H
NMR at 20 °C. For clarity, only complexes 2 (0), 5 (9), 6
(2), and the dimer 3a (b) are shown.
Sch em e 1
Exp er im en ta l Section
Gen er a l In for m a tion . All reactions were carried out in
an inert-atmosphere glovebox or by using standard high-
vacuum and Schlenk-line techniques unless otherwise men-
tioned. Tetrahydrofuran, benzene, and Et2O were distilled
from purple solutions of sodium and benzophenone immedi-
ately prior to use. The NMR solvents, C6D6 and CD2Cl2, were
dried from activated molecular sieves (4 Å). The ruthenium
complexes,
C5Me5Ru(PPh3)2Cl10
and
C5Me5Ru(PPh3)-
(Cl)dCdCHPh (2),6,11 were prepared according to literature
procedures. Organic alkynes RCtCH (R ) Ph, CO2Me) were
received from a commercial source (Aldrich Chemical Co.) and
used without further purification. The 1H and 13C NMR
spectra were recorded on a GE GN-Omega 300 MHz FT-NMR
spectrometer. Mass spectra were recorded on a Hewlett-
Packard HP 5970 GC/MS spectrometer. Elemental analyses
were performed at the Midwest Microlab, Indianapolis, IN.
expense of both complexes 6 and 3a . Interestingly, no
notable change in concentration of the cis dimer 3b was
observed during the entire reaction period.
The fact that 5 was generated even after most of
PhCtCH was converted to dimer 3 and that 5 was
formed at the expense of both 6 and dimer 3 suggested
that 5 was obtained from the coupling reaction of 1 with
3 (Scheme 1). In support of this hypothesis, reaction of
2 with <1 equiv of PhCtCH produced a relatively long-
lived complex 6, as in this case, it could not be converted
to 5 in the absence of 3. Also, complex 5 was formed
independently from a stoichiometric reaction of 2 (500
mg, 0.79 mmol) with PhCtCH (0.86 mL, 7.9 mmol) and
Et3N (1.1 mL, 7.9 mmol) in 81% isolated yield. The syn
geometry between the -CtCPh group and the PPh3
ligand of 5 was also consistent with the intramolecular
migration of the acetylide to the coordinated enyne 3
via the alkyne intermediate 6.
The formation of 1,4-disubstituted enynes 3 can be
rationalized readily from a migratory insertion of the
coordinated RCtCH (R ) Ph, CO2Me) to the ruthenium-
acetylide and the subsequent reductive coupling with
another alkyne substrate.1b,3 While the formation of the
1,4-enynes has been previously explained by invoking
an acetylene-to-vinylidene rearrangement and the sub-
F or m a t ion
of
C5Me5R u (P P h 3)(η3-P h CH CH CdC-
P h CtCP h ) (5). The ruthenium complex C5Me5Ru(PPh3)-
(Cl)dCdCHPh (2) (500 mg, 0.79 mmol), Et3N (1.10 mL, 10
equiv), and PhCtCH (0.86 mL, 10 equiv) were charged with
30 mL of CH2Cl2 in a 100 mL round-bottom flask. The reaction
mixture was stirred at room temperature for 24 h. After the
solvent was evaporated under high vacuum, the residue was
dissolved in C6H6 and the solution filtered through a frit. The
filtrate was evaporated under vacuum, and the remaining solid
was washed with small amounts of Et2O (3 × 5 mL) and
hexanes (3 × 5 mL) to afford 5 as a yellow solid in 81% yield
(513 mg).
1H NMR (CD2Cl2, 300 MHz): δ 7.8-7.0 (m, Ph), 3.68 (dd,
J HH ) 8.8 Hz, J PH ) 3.7 Hz, PhCHCH), 3.00 (dd, J PH ) 14.0
Hz, J HH ) 8.8 Hz, PhCHCH), 1.36 (s, C5Me5). 13C{1H} NMR
(CD2Cl2, 75 MHz): δ 192.6 (d, J PC ) 17.1 Hz, Ru-CdC), 144.8,
143.3, 133.2, 130.0, 129.3, 129.0, 128.8, 127.8, 127.0, 126.0 (Ph
carbons), 125.3 (dC(Ph)CtC), 114.8 (d, J PC ) 6.4 Hz, CHPh),
96.4 (CHPhd), 96.3 (CtCPh), 93.4 (C5Me5), 88.0 (CtCPh),
(10) (a) Serron, S. A.; Luo, L.; Li, C.; Cucullu, M. E.; Stevens, E. D.;
Nolan, S. P. Organometallics 1995, 14, 5290. (b) Luo, L.; Nolan, S. P.;
Fagan, P. J . Organometallics 1993, 12, 4305. (c) Conroy-Lewis, F. M.;
Simpson, S. J . J . Organomet. Chem. 1987, 322, 221.
(11) (a) Bianchini, C.; Casares, J . A.; Peruzzini, M.; Romerosa, A.;
Zanobini, F. J . Am. Chem. Soc. 1996, 118, 4585. (b) Bianchini, C.;
Innocenti, P.; Peruzzini, M.; Romerosa, A.; Zanobini, F. Organometal-
lics 1996, 15, 272. (c) Slugovc, C.; Mereiter, K.; Zobetz, E.; Schmid, R.;
Kirchner, K. Organometallics 1996, 15, 5275.
(9) Selected spectral data for 6: 1H NMR (CD2Cl2, 300 MHz) δ 6.73
(d, J ) 15.9 Hz, CHdCHPh), 6.50 (d, J ) 15.9 Hz, CHdCHPh), 1.44
(s, C5Me5); 31P{1H} NMR (CD2Cl2, 121.6 MHz) δ 53.7 (s, PPh3).

Ruthenium-Acetylide-Mediated Dimerization
Organometallics, Vol. 16, No. 18, 1997 3913
10.8 (C5Me5). 31P{1H} NMR (CD2Cl2, 121.6 MHz): δ 60.9 (s,
PPh3). Anal. Calcd for C52H47PRu: C, 77.68; H, 5.89. Found
C, 77.65; H, 6.05.
X-r a y Cr ysta llogr a p h ic Deter m in a tion of 5. Bright
yellow single crystals of 5 were obtained from the layering of
hexanes to a benzene solution at room temperature. A yellow
crystal (0.30 × 0.30 × 0.20 mm) was mounted on a Siemens
P4/CCD diffractometer equipped with a graphite monochro-
mator. Empirical methods were used to correct for absorption.
No symmetry greater than triclinic was evident from the
diffraction data. The asymmetric unit consists of one Ru
complex and 1.5 molecules of benzene. The half molecule is
Gen er a l P r oced u r e of t h e R u t h en iu m -Ca t a lyzed
Dim er iza tion of RCtCH (R ) P h , CO2Me). In a 25 mL
Schlenk tube equipped with a Teflon stopcock, the ruthenium
catalyst 1 (3-5 mol %) was generated from the treatment of
C5Me5Ru(PPh3)(Cl)dCdCHPh (10 mg, 0.016 mmol) with Et3N
(22 µL, 10 equiv) in 10 mL of CH2Cl2. Excess alkyne (0.60
mmol) was added to the solution, and the reaction mixture
was stirred at room temperature. Small samples were peri-
odically drawn out from the solution and analyzed by the GC-
MS. After 10 h, the solution was evaporated under high
vacuum. The residue was extracted with Et2O, and the Et2O
solution was chromatographed on silica gel (hexane/Et2O) in
air. The rotary evaporation led to the dimeric products as a
pale-yellow oil. The spectroscopic data for both 3a and 3b have
been previously reported.5
located on
a crystallographic inversion center. All non-
hydrogen atoms were treated as idealized contributions. All
software used were included in the SMART, SAINT, and
SHELXTL program libraries (Siemens XRD, Madison, WI).
Crystal data for 5: C52H47PRu‚1.5C6H6: yellow block, triclinic,
a ) 10.2582(1) Å, b ) 15.8273(2) Å, c ) 16.9688(2) Å, R )
101.0450(1)°, â ) 107.5713(2)°, γ ) 108.5520(1)°, V )
2360.54(4) Å3, Z ) 2, T ) 223 K, R(F) ) 0.0508, R(wF2) )
0.1046.
For trans-PhCHdCHCtCPh (3a ): 1H NMR (C6D6, 300
MHz) δ 8.10-6.80 (m, Ph), 7.04 (d, J ) 16.2 Hz, dCHPh), 6.30
(d, J ) 16.2 Hz, dCHCtC); 13C{1H} NMR (C6D6, 75 MHz) δ
142.3 (dCHPh), 137.3, 132.2, 129.7, 129.4, 129.2, 127.3, 124.4
(Ph carbons), 109.0 (dCHCtC), 92.3 (dCHCtC), 89.8
(dCHCtCPh); GC-MS m/z 204 (M+).
Ack n ow led gm en t. Financial support from Marque-
tte University, Committee on Research, is gratefully
acknowledged. The authors from The University of
Delaware acknowledge the National Science Foundation
for their support in purchasing the CCD-based X-ray
diffractometer (Grant No. CHE-9628768).
For cis-PhCHdCHCtCPh (3b): 1H NMR (C6D6, 300 MHz)
δ 8.10-6.80 (m, Ph), 6.40 (d, J ) 11.8 Hz, dCHPh), 5.79 (d, J
) 11.8 Hz, dCHCtC); 13H{1H} NMR (C6D6, 75 MHz) δ 139.1
(dCHPh), 137.1, 131.7, 129.2, 128.7, 128.5, 128.4, 124.0 (Ph
carbons), 107.7 (dCHCtC), 96.7 (dCHCtCPh), 88.9
(dCHCtCPh); GC-MS m/z 204 (M+).
For trans-MeO2CCHdCHCtCCO2Me (4): 1H NMR (C6D6,
300 MHz) δ 6.45 (d, J ) 16.2 Hz, dCHCO2Me), 6.03 (d, J )
16.2 Hz, dCHCtC), 3.23, 3.21 (s, CO2Me); 13C{1H} NMR
(C6D6, 75 MHz) δ 164.6 (dCHCO2Me), 153.4 (CtCCO2Me),
135.1 (dCHCO2Me), 121.3 (dCHCtCCO2Me), 87.3 (CtCCO2-
Me), 81.9 (CtCCO2Me), 52.6, 51.5 (CO2Me); GC-MS m/z 168
(M+).
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
data and structure refinement, atomic coordinates, bond
lengths and angles, anisotropic displacement parameters, and
hydrogen coordinates for 5 (9 pages). Ordering information
is given on any current masthead page.
OM970366T