Coupling reactions of terminal acetylenes with ruthenium complexes containing the ortho-metalated ligand 2,6-(PPh2CH2)2C6H3

Article abstract of DOI:10.1021/om9700829

Reactions Of RuCl(PPh₃)(PCP) (PCP = 2,6-(PPh₂CHa)₂C₆H₃) with PhC≡CH and HC≡CC-(OH)Ph₂ gave the unusual coupling products RuCl(PPh₃)(η⁴-PhCH=C-2,6-(PPh₂CH

Full text of DOI:10.1021/om9700829

Organometallics 1997, 16, 3927-3933
3927
Cou p lin g Rea ction s of Ter m in a l Acetylen es w ith
Ru th en iu m Com p lexes Con ta in in g th e Or th o-Meta la ted
Liga n d 2,6-(P P h 2CH2)2C6H3
Hon Man Lee, J unzhi Yao, and Guochen J ia*
Department of Chemistry, The Hong Kong University of Science and Technology,
Clear Water Bay, Kowloon, Hong Kong
Received February 4, 1997X
Reactions of RuCl(PPh3)(PCP) (PCP ) 2,6-(PPh2CH2)2C6H3) with PhCtCH and HCtCC-
(OH)Ph2 gave the unusual coupling products RuCl(PPh3)(η4-PhCHdC-2,6-(PPh2CH2)2C6H3)
and RuCl(PPh3)(η4-Ph2C(OH)CHdC-2,6-(PPh2CH2)2C6H3), respectively. Dehydration was
observed in the coupling reactions of RuCl(PPh3)(PCP) with HCtCC(OH)PhMe and HCtC-
cyclo-C6H10(OH). Thus, the coupling products RuCl(PPh3)(η4-CH2dCPhCHdC-2,6-(PPh2-
CH2)2C6H3) and RuCl(PPh3)(η4-cyclo-C6H9-CHdC-2,6-(PPh2CH2)2C6H3) were obtained from
the reactions of RuCl(PPh3)(PCP) with HCtCC(OH)PhMe and HCtC-cyclo-C6H10(OH),
respectively. Treatment of [Ru(PMe3)2(PCP)]BF4 with PhCtCH produced [Ru(PMe3)2(η4-
PhCHdC-2,6-(PPh2CH2)2C6H3)]BF4.
In tr od u ction
metric organometallic reactions or in catalytic oligo-
merization of terminal acetylenes. However, reported
examples of couplings between vinylidene and other
ligands such as alkyls,11-13 vinyls,11,14,15 aryls,11 and
hydrides16 are still rather limited.
In our attempts to prepare neutral ruthenium vi-
nylidene or allenylidene complexes, we have studied the
reactions of the coordinatively unsaturated complex
The chemistry of carbene,1 vinylidene,2 and alle-
nylidene2 complexes has attracted considerable atten-
tion because of its relevance to catalysis and organic and
organometallic synthesis. One of the most interesting
properties of these complexes is that they promote CsR
bond formation reactions via migratory insertion of a
R group at the R-carbons of the unsaturated ligands.
Such reactions involving carbene ligands have been
frequently postulated as the key steps in organometallic
or catalytic reactions and have been explored in organic
and organometallic synthesis.3
(6) (a) Wakatsuki, Y.; Yamazaki, H.; Kumegawa, N.; Satoh, T.;
Satoh, J . Y. J . Am. Chem. Soc. 1991, 113, 9604. (b) Wakatsuki, Y.;
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Chem. Soc. J pn. 1993, 66, 987. (e) Wakatsuki, Y.; Satoh, M.; Yamazaki,
H. Chem. Lett. 1989, 1585.
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Chem. Eur. J . 1996, 2, 561. (b) Werner, H. J . Organomet. Chem. 1994,
475, 45. (c) Scha¨fer, M.; Mahr, N.; Wolf, J .; Werner, H. Angew. Chem.,
Int. Ed. Engl. 1993, 32, 1315.
(8) (a) Albertin, G.; Antoniutti, S.; Bordignon, E.; Cazzaro, F.; Ianelli,
S.; Pelizzi, G. Organometallics 1995, 14, 4114. (b) Albertin, G.;
Antoniutti, S.; Bordignon, E. J . Chem. Soc., Dalton Trans. 1995, 719.
(c) Albertin, G.; Antoniutti, S.; Bordignon, E.; Del Ministro, E.; Ianelli,
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G.; Antoniutti, S.; Del Ministro, E.; Bordignon, E. J . Chem. Soc., Dalton
Trans. 1992, 3203. (e) Albertin, G.; Amendola, P.; Antoniutti, S.; Ianelli,
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Organometallics 1992, 11, 3019. (b) Field, L. D.; George, A. V.; Malouf,
E. Y.; Slip, I. H. M.; Hambley, T. W. Organometallics 1991, 10, 3842.
(c) Field, L. D.; George, A. V.; Hambley, T. W. Inorg. Chem. 1990, 29,
4563.
Migratory insertion of a R group at the R-carbon of a
vinylidene ligand is even more interesting and poten-
tially useful, as vinylidene complexes can be readily
produced from the reactions of easily accessible HCtCR
with coordinated unsaturated or labile transition-metal
complexes.2 In this regard, there have been a consider-
able number of reports on the couplings between vi-
nylidene and acetylide ligands,4-10 either in stoichio-
X Abstract published in Advance ACS Abstracts, August 1, 1997.
(1) See for example: (a) Herrmann, W. A. Adv. Organomet. Chem.
1982, 20, 159. (b) Dotz, K. H. Transition Metal Carbene Complexes;
Verlag Chemie: Weinheim, Germany, 1983.
(2) (a) Bruce, M. I. Chem. Rev. 1991, 91, 197. (b) Bruce, M. I.;
Swincer, A. G. Adv. Organomet. Chem. 1983, 22, 59.
(3) See for example: (a) Muir, J . E.; Haynes, A.; Winter, M. J . J .
Chem. Soc., Chem. Commun. 1996, 1765 and references therein. (b)
Bergamini, P.; Costa, E.; Orpen, A, G.; Pringle, P. G.; Smith, M. B.
Organometallics 1995, 14, 3178 and references therein. (c) Bergamini,
P.; Costa, E.; Cramer, P.; Hogg, J .; Orpen, A. G.; Pringle, P. G.
Organometallics 1994, 13, 1058. (d) Adams, H.; Bailey, N. A.; Bentley,
G. W.; Tattershall, C. E.; Taylor, B. F.; Winter, M. J . J . Chem. Soc.,
Chem. Commun. 1992, 533. (e) Trace, R. L.; Sanchez, J .; Yang, J .; Yin,
J .; J ones, W. M. Organometallics 1992, 11, 1440. (f) Hoover, J . F.;
Stryker, J . M. J . Am. Chem. Soc. 1990, 112, 464.
(4) (a) Bianchini, C.; Innocenti, P.; Peruzzini, M.; Romerosa, A.;
Zanobini, F. Organometallics 1996, 15, 272. (b) Bianchini, C.; Frediani,
P.; Masi, D.; Peruzzini, M.; Zanobini, F. Organometallics 1994, 13,
4616. (c) Barbaro, P.; Bianchini, C.; Peruzzini, M.; Polo, P.; Zanobini,
F.; Frediani, P. Inorg. Chim. Acta 1994, 220, 5. (d) Bianchini, C.;
Bohanna, C.; Esteruelas, M. A.; Frediani, P.; Meli, A.; Oro, L. A.;
Peruzzini, M. Organometallics 1992, 11, 3837. (e) Bianchini, C.;
Peruzzini, M.; Zanobini, F.; Frediani, P.; Albinati, A. J . Am. Chem.
Soc. 1991, 113, 5453.
(10) Additional examples of acetylide-vinylidene coupling: (a)
Santos, A.; Lo´pez, J .; Matas, L.; Ros, J .; Gala´n, A.; Echavarren, A. M.
Organometallics 1993, 12, 4215. (b) Hills, H.; Hughes, D. L.; J imenez-
Tenorio, M.; Leigh, G. J .; McGeary, C. A.; Rowley, A. T.; Bravo, M.;
McKenna, C. E.; McKenna, M. C. J . Chem. Soc., Chem. Commun. 1991,
522. (c) Hughes, D. L.; J imenez-Tenorio, M.; Leigh, G. J .; McGeary, C.
A.; Rowley, A. T. J . Chem. Soc. Dalton Trans. 1993, 3151. (d), J ia, G.;
Rheingold, A. L.; Meek, D. W. Organometaliics 1989, 8, 1378. (e) J ia,
G.; Meek, D. W. Organometallics 1991, 10, 1444. (f) Gotzig, J .; Werner,
H. J . Organomet. Chem. 1985, 287, 247.
(11) (a) Wiedemann, R.; Steinert, P.; Scha¨fer, M.; Werner, H. J . Am.
Chem. Soc. 1993, 115, 9864. (b) Wiedemann, R.; Wolf, J .; Werner, H.
Angew. Chem., Int. Ed. Engl. 1995, 34, 1244.
(12) Ho¨hn, A.; Werner, H. J . Organomet. Chem. 1990, 382, 255.
(13) Fryzuk, M. D.; Huang, L.; McManus, N. T.; Paglia, P.; Rettig,
S. J .; White, G. S. Organometallics 1992, 11, 2979.
(14) Selnau, H. E.; Merola, J . S. J . Am. Chem. Soc. 1991, 113, 4008.
(15) Werner, H.; Scha¨fer, M.; Wolf, J .; Peters, K.; Von Schnering,
H. G. Angew. Chem., Int. Ed. Engl. 1995, 34, 191.
(5) McMullen, A. K.; Selegue, J . P.; Wang, J . G. Organometallics
1991, 10, 3421.
(16) Esteruelas, M. A.; Oro, L. A.; Valero, C. Organometallics 1995,
14, 3596.
S0276-7333(97)00082-4 CCC: $14.00 © 1997 American Chemical Society

3928 Organometallics, Vol. 16, No. 18, 1997
Lee et al.
RuCl(PPh3)(PCP) (PCP ) 2,6-(Ph2PCH2)2C6H3, a cyclo-
metalated tridentate ligand)17 with terminal acetylenes
HCtCPh and HCtCC(OH)RR′. To our surprise, these
reactions did not lead to the expected vinylidene or
allenylidene complexes but to unusual coupling prod-
ucts. Formation of the coupling products can be best
explained by the pathway of migratory insertion of the
aryl group of the PCP ligand at R-carbon atoms of
vinylidene ligands. These interesting reactions provide
rare examples of metal-assisted CsC bond formation
between vinylidene and aryl ligands.11 A preliminary
account of this work has been published.17a
Ph)) and actinides (e.g. Cp*3Th(ηn-CH2Ph)3) have been
reported,20 in which the CH2Ph group also functions as
a 3e donor. It is not clear to us which of the two
possibilities is the dominant factor in causing the close
contact between the ruthenium and the ipso carbon of
the central aromatic ring.
Interaction between ruthenium and the ipso carbon
of the central aromatic ring in complex 2 is consistent
with the 13C NMR spectrum (in CDCl3), which showed
signals at 164.1 ppm (td, J (PPh2-C) ) 12.8 Hz, J (PPh3-
C) ) 5.1 Hz) assignable to the R-carbon of the vinyl
ligand and at 113.2 ppm (t, J (PPh2-C) ) 6.7 Hz)
assignable to the ipso carbon of the central aromatic
ring. The 13C NMR assignments were fully supported
by its 13C DEPT, 1H-13C COLOC, 1H-13C COSY,
INAPT (a technique used to selective detect long-range
1H-13C interactions), and proton-coupled 13C NMR
spectra.21 In particular, the DEPT experiment indicates
that the signals at 164.1 and 113.2 ppm are both due
to quaternary carbons. In the INAPT experiment, the
13C signal at 113.2 ppm, but not the one at 164.1 ppm,
appeared when the 1H signal at 2.67 ppm of the
methylene protons was irradiated. This observation is
consistent with the assignment that the signal at 113.2
ppm is due to the ipso carbon of the central aromatic
ring (three bonds away from the CH2 protons) and that
the signal at 164.1 ppm is due to the R-carbon of the
vinyl group (four bonds away from the CH2 protons).
For comparison, the R-carbon signals of the vinyl groups
were observed at 164.32 ppm (t, J (PC) ) 15.1 Hz) for
Ru(Me)(CHdCHPh)(CO)2(P(i-Pr)3)222 and at 150.23 ppm
(t, J (PC) ) 11.0 Hz) for RuCl(CHdCHPh)(CO)(P(i-
Pr)3)2.23 The chemical shifts in the range of 104-120
ppm for the ipso carbon of the η2-benzyl ligand have
been reported for several W and Mo complexes with η2-
benzyl ligands.20a,c
Resu lts a n d Discu ssion
Rea ction s of Ru Cl(P P h 3)(P CP ) w ith P h CtCH.
Treatment of RuCl(PPh3)(PCP) (1) with PhCtCH pro-
duced the pale green compound RuCl(PPh3)(η4-PhCHdC-
2,6-(PPh2CH2)2C6H3) (2; eq 1). The structure of the
compound has been confirmed by X-ray diffraction, as
described in the preliminary report.17a Thus, one
molecule of PhCtCH is incorporated into the central
aromatic ring of the bis(phosphine) ligand in the form
of the vinyl substituent CdCHPh. The X-ray diffraction
study shows that the ruthenium center is bound to both
the vinyl group (r(Ru-C) ) 2.007(8) Å) and one of the
carbon atoms of the central aromatic ring (r(Ru-C) )
2.437(6) Å).
In principle, the carbons attached on ruthenium
should couple to the phosphorus atoms of both PPh2 and
PPh3 groups in complex 2. Such couplings were re-
solved for the R-carbon of the vinyl ligand. However,
only carbon-PPh2 coupling was resolved for the ipso
carbon of the central aromatic ring. The lack of observ-
able coupling between PPh3 and the ipso carbon of the
central aromatic ring is not unusual and could be
related to the fact that the Ru-C(aryl) interaction is
weak and/or the fact that the magnitude and sign of
2J (PMC) are angle-dependent24 (the C-Ru-P angle in
the solid-state structure of complex 2 is 142.1(2)°). In
The short distance between ruthenium and the ipso
carbon atom of the central aromatic ring could be
attributed to the geometry of the chelating ligand. Due
to the ligand geometry, the ruthenium has no choice but
to be close to the ipso carbon of the central aromatic
ring. Alternatively, there may be a real bonding
interaction between ruthenium and the central aromatic
ring. Thus, three electrons may formally be donated
from the arylvinyl ligand CArdCHPh to the ruthenium
center, which then satisfies the 18e rule. One electron
comes from the σ-bonded vinyl ligand and the other two
by π-donation from the aromatic ring. Close contact
between the metal center and the ipso carbon of the
central aromatic ring was also observed in the related
unsaturated complex [PtI(η3-Me-2,6-(Me2NCH2)2C6H3)]-
BF4.18 Interestingly, no close contact was observed
between the metal center and the central aromatic ring
of the related 18e complex RhHCl{P(i-Pr)2(n-Pr)}(η3-
CH2-2,6-(PPh2CH2)2-3,5-Me2C6H).19 Donation of 2e from
the central aromatic ring to the ruthenium center in
complex 2 is reasonable, as several η2- or ηn-benzyl
complexes of early transition metals (e.g. [Cp2Zr(η2-CH2-
Ph)(MeCN)]BPh4 and Cp*Mo(NO)(CH2SiMe3)(η2-CH2-
(20) (a) Legzdins, P.; J ones, R. H.; Phillips, E. C.; Yee, V. C.; Trotter,
J .; Einstein, F. W. B. Organometallics 1991, 10, 986. (b) Dryden, N.
H.; Legzdins, P.; Phillips, E. C.; Trotter, J .; Yee, V. C. Organometallics
1990, 9, 882. (c) Dryden, N. H.; Legzdins, P.; Trotter, J .; Yee, V. C.
Organometallics 1991, 10, 2857. (d) J ordan, R. F.; LaPointe, R. E.;
Baenziger, N.; Hinch, G. D. Organometallics 1990, 9, 1539. (e) Latesky,
S. L.; McMullen, A. K.; Niccolai, G. P.; Rothwell, I. P.; Huffmann, J .
C. Organometallics 1985, 4, 902. (f) J ordan, R. F.; LaPointe, R. E.;
Bajgur, C. S.; Echols, S. F.; Willett, R. J . Am. Chem. Soc. 1987, 109,
4111. (g) Mintz, E. A.; Moloy, K. G.; Marks, T. J .; Day, V. W. J . Am.
Chem. Soc. 1982, 104, 4692.
(21) Siegmar, B. 100 and More Basic NMR Experiments: A Practical
Course; VCH: New York, 1996.
(22) Bohanna, C.; Esteruelas, M. A.; Lahoz, F. J .; On˜ate, E.; Oro,
L. A. Organometallics 1995, 14, 4685.
(17) (a) J ia, G.; Lee, H. M.; Xia, H. P. Williams, I. D. Organometallics
1996, 15, 5453. (b) Karlen, T.; Dani, P.; Grove, D. M.; Steenwinkel, P.;
van Koten, G. Organometallics, 1996, 15, 5687.
(18) van Koten, G.; Timmer, K.; Noltes, J . G.; Spek, A. L. J . Chem.
Soc., Chem. Commun. 1978, 250.
(19) Liou, S. Y.; Gozin, M.; Milstein, D. J . Am. Chem. Soc. 1995,
117, 9774.
(23) Werner, H.; Esteruelas, M. A.; Otto, H. Organometallics 1986,
5, 2295.
(24) (a) J ameson, C. J . In Phosphorus-31 NMR Spectroscopy in
Stereochemical Analysis; Verkade, J . G., Quin L. D., Eds.; VCH:
Deerfield Beach, FL, 1987; p 205. (b) Quin, L. D. In Phosphorus-31
NMR Spectroscopy in Stereochemical Analysis; Verkade, J . G., Quin
L. D., Eds.; VCH: Deerfield Beach, FL, 1987; p 391.

Reactions of Terminal Acetylenes with Ru Compounds
Organometallics, Vol. 16, No. 18, 1997 3929
Sch em e 1
LiCtCPh (eq 2). It was characterized by NMR and IR
spectroscopy and elemental analysis. Treatment of
complex 3 with HBF4‚Et2O led to the formation of a
mixture of compounds. The mixture probably contained
vinylidene complexes, as indicated by the 1H NMR
signals in the region 4-6 ppm. Unfortunately, we have
not been able to isolate pure compounds from the
reaction mixture yet. If complex 3 was protonated with
a limited amount of HBF4‚Et2O in the presence of
PhCH2NEt3Cl, the coupling product 2 was produced
along with some uncharacterized complexes. The result
is consistent with the proposition that a vinylidene
intermediate is involved in the coupling reaction.
The CsC bond formation reaction is unexpected,
especially in view of the fact that CsC bond cleavage
reactions19,28 were observed in the reactions of related
bis(phosphine) ligands with rhodium complexes. For
example, 1,3,5-Me3-2,6-(PPh2CH2)2C6H reacted with
RhH(PPh3)4 under H2 pressure to give Rh(PPh3)(3,5-
Me2-2,6-(PPh2CH2)2C6H) and CH4.
Rea ction s of Ru Cl(P P h 3)(P CP ) w ith HCtCC-
(OH)RR′. Easy formation of the coupling product 2
from the reaction of PhCtCH with complex 1 prompted
us to investigate the reactivity of complex 1 with other
terminal acetylenes. As reactions of coordinatively
unsaturated or labile complexes with HCtCC(OH)RR′
can lead to the formation of hydroxyvinylidene,29
allenylidene,29-36 and vinylvinylidene37,38 complexes,
reactions of HCtCC(OH)RR′ with 1 are therefore
interesting because of the possibilities of obtaining
coupling products via hydroxyvinylidene, allenylidene,
or vinylvinylidene intermediates. The results of such
reactions are summarized in Scheme 2.
fact, there are many reported complexes not exhibiting
resolvable 2J (PMC) values. For example, 2J (PMC)
couplings were also not observed for the RusCH2 groups
in Ru(PP3)(η2-CH2dCHCO2R) (PP3 ) P(CH2CH2PPh2)3;
R ) Me, Et)4b and [Cp*Ru(P-O)2(CH2dCH2)]+ (P-O )
(1,3-dioxan-2-ylmethyl)diphenylphosphine)25a and the
ring carbons of C5R5 (R ) H, Me) in many complexes of
the formula [(η5-C5R5)Ru(PR3)2L]x (e.g. CpRu(CtCR)-
(PPh3)2,25b [CpRu(dCdCHR)(PMe3)2]PF6,26 and [Cp*Ru-
(dCdCHR)(PMe2Ph)2]PF627).
A proposed mechanism for the formation of complex
2 is shown in Scheme 1. The coordinatively unsaturated
complex RuCl(PPh3)(PCP) reacts with PhCtCH to give
initially the η2-acetylene complex RuCl(PhCtCH)(PPh3)-
(PCP) (A), which then rearranges to form the vinylidene
complex RuCl(dCdCHPh)(PPh3)(PCP) (B). Migratory
insertion of the aryl group of the PCP ligand at the
R-carbon atom of the vinylidene ligand would produce
the product 2. Unfortunately, we have not been able
to observe the vinylidene intermediate. Only starting
material 1 and complex 2 were observed, when the
reaction was monitored by 31P{1H} NMR in the tem-
perature range 220-298 K. Apparently the coupling
reaction is too fast to observe the vinylidene intermedi-
ate. Although we have not been able to detect the
vinylidene complex, reactions of terminal acetylenes
RCtCH with coordinatively unsaturated or labile tran-
sition-metal complexes to give vinylidene complexes are
now well-established.2 Precedence for CsC bond for-
mation between vinylidene and aryl ligands comes from
the recent report by Werner and co-workers, in which
RhPh(P(i-Pr)3)2dCdCHR reacts with CO to give Rh-
(CO)(P(i-Pr)3)2CPhdCHR (R ) Ph, t-Bu).11
(28) (a) Liou, S. Y.; Gozin, M.; Milstein, D. J . Chem. Soc., Chem.
Commun. 1995, 1965 and references therein. (b) Gozin, M.; Alzenberg,
M.; Liou, S. Y.; Welsman, A.; Ben-David, Y.; Milstein, D. Nature 1994,
370, 42. (c) Gozin, M.; Welsman, A.; Ben-David, Y.; Milstein, D. Nature
1993, 364, 699.
(29) (a) Werner, H.; Stark, A.; Steinert, P.; Gru¨nwald, C.; Wolf, J .
Chem. Ber. 1995, 128, 49. (b) Werner, H.; Rapport, T.; Wiedemann,
R.; Wolf, J .; Mahr, N. Organometallics 1994, 13, 2721 and references
therein.
Protonation of acetylide complexes is a well-estab-
lished route to prepare vinylidene complexes.2 Vi-
nylidene intermediates have been observed or proposed
in the protonation of some LnM(CtCR)2 complexes to
give [LnM(η3-RC3CHR)]+ complexes.8a,c,9a Thus, we have
prepared the acetylide complex 3 and investigated its
reactivity toward acid, in order to see if an vinylidene
intermediate could be detected. Complex 3 was isolated
as a purple solid from the reaction of complex 1 with
(30) Selegue, J . P. Organometallics 1982, 1, 217.
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Organomet. Chem. 1991, 420, 217.
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1993, 450, 209.
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H. Organometallics 1994, 13, 5030.

3930 Organometallics, Vol. 16, No. 18, 1997
Lee et al.
Sch em e 2
can be isolated with more electron rich metal centers
such as [Cp*Ru(PMe2Ph)2]+ 27 and RuCl2((i-Pr)2PCH2-
CO2Me)2.29a
The hydroxyvinyl complex 4 is stable with respect to
dehydration. Thus, no dehydration product was ob-
served when solutions of complex 4 were stored at room
temperature for several days, even in the presence of
alumina (a reagent commonly used to effect dehydration
reactions29b).
Two compounds can be isolated from the reaction of
HCtCC(OH)PhMe with complex 1 (see Scheme 2).
Stirring a mixture of complex 1 and excess HCtCC-
(OH)PhMe in undistilled CHCl3 or CH2Cl2 for 2 h or
longer produced the dehydrated coupling product RuCl-
(PPh3)(η4-CH2dCPhCHdC-2,6-(PPh2CH2)2C6H3) (6) as
the predominant metal-containing product along with
uncharacterized oligomers of the acetylene. If the
reaction time is shorter, we often obtained a mixture of
the nondehydrated product RuCl(PPh3)(η4-MePhC-
(OH)CHdC-2,6-(PPh2CH2)2C6H3) (5) and the dehy-
drated product 6. More careful study shows that the
relative amounts of complexes 5 and 6 are dependent
on the purity of the solvents used and reaction time.
Water and trace amounts of acids present in the
solvents catalyze the conversion of complex 5 to complex
6. Thus, complex 5 was produced exclusively as the
metal-containing product if the reaction was conducted
in freshly distilled drying chloroform or CH2Cl2 for a
short period of time. The dehydrated product 6 was
formed exclusively as the metal-containing product if a
catalytic amount of HBF4‚Et2O was added to the reac-
tion mixture. In solution, complex 5 will convert into
complex 6 in the presence of water or a trace amount of
acid, as monitored by 31P NMR. These experiments
imply that complex 5 is the intermediate for the
formation of complex 6 and that the dehydration reac-
tion occurred after the coupling reaction.
Treatment of RuCl(PPh3)(PCP) with HCtCC(OH)Ph2
in chloroform leads to the formation of a pale green
product. The analytical and spectroscopic data indicate
that the product of the reaction is the coupling product
RuCl(PPh3)(η4-Ph2C(OH)CHdC-2,6-(Ph2PCH2)2C6H3) (4).
1
The presence of the OH group is supported by the H
NMR spectrum (in CDCl3), which showed a broad OH
signal at 2.59 ppm, and the 13C NMR spectrum (in
CDCl3), which showed a singlet signal at 80.4 ppm for
the C(OH)Ph2 carbon. The mutually trans disposition
of the two PPh2 groups is supported by 13C NMR, which
showed a virtual triplet signal for the methylene carbons
of the PCP ligand.39 Formation of the coupling product
is supported by the 13C NMR spectrum, which displayed
the signals for the carbons attached to ruthenium with
chemical shifts very similar to those of complex 2. In
contrast to complex 2, small coupling between the ipso
carbon of the central aromatic ring and the PPh3 ligand
was resolved for complex 4. The similarity in the
coordination spheres of complexes 2 and 4 is also
reflected in their 31P NMR data.
Formation of complex 4 can be easily rationalized via
the hydroxyvinylidene intermediate RuCl(PPh3)(PCP)-
(dCdCHC(OH)Ph2). Migratory insertion of the aryl
group of the PCP ligand at the R-carbon atom of the
vinylidene ligand would produce the coupling product.
Apparently, the dehydration reaction of RuCl(PPh3)-
(PCP)(dCdCHC(OH)Ph2) to give an allenylidene inter-
mediate did not occur before the coupling reaction. It
has been shown that spontaneous dehydration of hy-
droxyvinylidene intermediates to give allenylidene com-
plexes only occurs on electrophilic ruthenium centers
such as [CpRu(PMe3)2]+,30 [(η5-C9H7)Ru(PR3)2]+,34 [Ru-
Cl(dppm)2]+,31 and [RuCl(N(CH2CH2PPh2)3)]+.33 In con-
trast, stable ruthenium hydroxyvinylidene complexes
Isolation of complex 5 free from oligomeric acetylenes
or complex 6 appears difficult because of the occurrence
of the dehydration reaction. Samples of 5 free from
complex 6 can be obtained from the reaction conducted
in dried dichloromethane, using ether extraction fol-
lowed by hexane precipitation (see Experimental Sec-
tion). The samples of 5 obtained in this way were often
contaminated with a small amount of uncharacterized
oligomeric acetylenes, as indicated by the appearance
1
of some broad signals in the H NMR spectra. Formu-
lation of compound 5 as the nondehydrated coupling
product is consistent with its spectroscopic data. The
presence of the CdCHC(OH)PhMe unit is indicated by
1
the H NMR (see Experimental Section). The 31P NMR
showed signals for the PPh2 groups and the PPh3 ligand
with chemical shifts very similar to those of other
coupling products, indicating that they have similar
structures in the coordination spheres. Interestingly,
the 31P NMR spectra of coupling products such as 2 and
4 appear as an AM2 pattern, but that of complex 5
appears as an ABM pattern. The ABM pattern 31P
NMR for 5 is expected because of the presence of the
chiral center C(OH)MePh. For comparison, it has been
reported that the two PMe2Ph ligands are also in-
equivalent in complexes such as [Cp*Ru(PMe2Ph)2d
CdCHC(OH)MeOMe]PF6 and Cp*Ru(PMe2Ph)2CtCC-
(OH)MeOMe, because of the presence of C(OH)Me-
OMe.27 Unfortunately, we have not been able to collect
(36) Allenylidene intermediates formed may undergo further reac-
tions, see for example: (a) Selegue, J . P. J . Am. Chem. Soc. 1983, 105,
5921. (b) Cadierno, V.; Gamasa, M. P.; Gimeno, J .; Lastra, E.; Borge,
J .; Garcˆıa-Granda, S. Organometallics 1994, 13, 745. (c) Matsuzaka,
H.; Koizumi, H.; Takagi, Y.; Nishio, M.; Hidai, M. J . Am. Chem. Soc.
1993, 115, 10396. (d) O’Connor, J . M.; Hiibner, K. J . Chem. Soc., Chem.
Commun. 1995, 1209. (e) Pilette, D.; Ouzzine, K.; Le Bozec, H.;
Dixneuf, P. H.; Rickard, C. E. F.; Roper, W. R. Organometallics 1992,
11, 809 and references therein.
(37) Selegue, J . P.; Young, B. A.; Logan, S. L. Organometallics 1991,
10, 1972.
(38) Zhang, L.; Gamasa, M. P.; Gimeno, J .; Carbajo, R. J .; Lo´pez-
Ortiz, F.; Lanfranchi, M.; Tiripicchio, A. Organometallics 1996, 15,
4274.
(39) Wilkes, L. M.; Nelson, J . H.; McCusker, L. B.; Seff, K.; Mathey,
F. Inorg. Chem. 1983, 22, 2476 and references therein.

Reactions of Terminal Acetylenes with Ru Compounds
Organometallics, Vol. 16, No. 18, 1997 3931
a good 13C NMR for complex 5 because it dehydrates to
give 6 during data acquisition.
Sch em e 3
Analytically pure samples of the coupling product 6
can be obtained from the reaction of 1 with HCtCC-
(OH)PhMe by column chromatography on alumina
using ether as the eluting solvent. The structure of
complex 6 is supported by its analytical and NMR
spectroscopic data. The presence of the CdCHCPhdCH2
unit is easily identified by the observation of three vinyl
signals at 4.51, 4.92, and 5.17 ppm in the 1H NMR
spectrum. Formation of the coupling product is sup-
ported by the 13C NMR spectrum, which displayed the
signals for the carbons attached to ruthenium with
chemical shifts very similar to those observed for 2 and
4. Consistent with the structure, the 31P NMR data of
compound 6 are also very similar to those of complexes
2 and 4.
Reactions of 1-ethynylcyclohexanol with RuCl(PPh3)-
(PCP) in chloroform or CH2Cl2 lead to the formation of
the dehydrated coupling product RuCl(PPh3)(η4-cyclo-
C6H9-CHdC-2,6-(PPh2CH2)2C6H3) (7) as the predomi-
nant metal-containing product, along with oligomeric
acetylenes. Pure samples of 7 can be obtained by
column chromatography on alumina using diethyl ether
as the eluting solvent. The structure assignment is fully
supported by NMR and analytical data. Complex 7 is
likely formed from the nondehydrated coupling inter-
mediate RuCl(PPh3)(η4-cyclo-C6H10(OH)-CHdC-2,6-(PPh2-
CH2)2C6H3), especially in view of the reactivity of
complex 1 toward HCtCC(OH)PhR (R ) Ph, Me) as
described above. However, we have not been able to
isolate or characterize the intermediate.
Easy formation of the dehydrated complexes 6 and 7
in the reactions of complex 1 with HCtCC(OH)PhMe
and HCtC-cyclo-C6H10(OH) is in sharp contrast to the
stability of complex 4 with respect to dehydration. The
difference can be traced to the availability of δ protons.
Because of the presence of δ protons in complex 5 and
RuCl(PPh3)(cyclo-C6H10(OH)-CHdC-2,6-(PPh2CH2)2-
C6H3), a stable conjugated dienyl structure can be
obtained by dehydration. However, such protons are
not present in complex 4. Dehydration of hydroxyvinyl
complexes to give dienyl complexes are known. For
example, Esteruelas et al. recently reported that heating
of RuCl(CHdCH-cyclo-C6H10(OH))(CO)(P(i-Pr)3)2 in tolu-
ene at 60 °C for 4 days could produce the dehydrated
product RuCl(CHdCH-cyclo-C6H9)(CO)(P(i-Pr)3)2 in mod-
erate yield.40 Similarly, Hill et al. noted that prolonged
storage (1 week) of solutions of RuCl(CO)(CHdCHC-
(OH)Me2)(PPh3)2(BSD) (BSD ) 2,1,3-benzoselenadiaz-
ole) in chloroform produced the dehydrated product
RuCl(CO)(CHdCHCMedCH2)(PPh3)2(BSD).41 Interest-
ingly, Esteruelas et al. recently reported that Rh(acac)H-
(SnPh3)(PCy3) reacted with HCtC-cyclo-C6H10(OH) to
give the nondehydrated insertion product Rh(acac)-
(SnPh3)(PCy3)(CHdCH-cyclo-C6H10(OH)) but with
HCtCC(OH)Ph2 to give the dehydrated product Rh-
(acac)(SnPh3)(PCy3)(CHdCdCPh2).42
reactions also occurred between complex 1 and terminal
acetylenes such as HCtCC(OH)Me2 and HCtCC(OH)-
MeEt, as indicated by the appearance of 31P NMR
signals similar to those of the well-characterized cou-
pling products mentioned above. However, the products
were contaminated with uncharacterized species and we
have not been able to isolate analytically pure samples
from these reactions. Interestingly, complex 1 decom-
posed to give unknown species on treatment with the
activated terminal acetylene HCtCCO2Et. No 31P
signals similar to those of the coupling products were
observed.
Rea ction s of [Ru (P Me3)2(P CP )]+ w ith P h CtCH.
It has been shown that reactions of terminal acetylenes
with transition-metal complexes to give vinylidene
complexes may proceed by η2-acetylene intermediates.
The acetylene-vinylidene rearrangement is promoted by
an unfavorable four-electron-two-center dπ-π conflict
in d6 complexes.43 The relative stability of the vi-
nylidene over the acetylene complex increases with
increasing electron density at the metal. Thus, forma-
tion of vinylidene complexes from terminal acetylenes
occurs most readily on electron-rich metal centers. In
this regard, it would be interesting to see if coupling
reactions would also occur with relatively electron poor
Ru(PCP) complexes. To this end, we have studied the
reaction of PhCtCH with [Ru(PMe3)2(PCP)]+ (generated
in situ from the reaction of RuCl(PMe3)2(PCP) (8) with
AgBF4). Reaction of [Ru(PMe3)2(PCP)]+ with PhCtCH
in THF led to the formation of [Ru(PMe3)2(η4-PhCHdC-
2,6-(PPh2CH2)2C6H3)]BF4 (9A) (see Scheme 3).
Complex 9A was characterized by its analytical and
spectroscopic data. The A2MX pattern 31P NMR spec-
trum indicates that the PCP ligand is meridional and
that the two PMe3 ligands are cis to each other.
Formulation of complex 9A as the coupling product is
inferred from the 13C NMR spectrum, which displayed
the signal for the R-carbon of the vinyl group at 167.6
ppm and that for the ipso carbon of the central aromatic
ring at 108.7 ppm. Further support for the structure
comes from the reaction of complex 2 with excess PMe3,
which produced [Ru(PMe3)2(η4-PhCHdC-2,6-(PPh2-
We have briefly studied the reactions of other termi-
nal acetylenes with complex 1. Apparently coupling
1
CH2)2C6H3)]Cl (9B), as indicated by its H and 31P NMR
spectra.
Attem pted Reaction of P dCl(P CP ) with P h CtCH.
Facile formation of coupling products from the reactions
(40) Esteruelas, M. A.; Lahoz, F. J .; On˜ate, E.; Oro, L. A.; Zeier, B.
Organometallics 1994, 13, 4258.
(41) Harris, M. C. J .; Hill, A. F. J . Organomet. Chem. 1992, 438,
209.
(42) Esteruelas, M. A.; Lahoz, F. J .; On˜ate, E.; Oro, L. A.; Rodrˆıguez,
L. Organometallics 1996, 15, 3670.
(43) Templeton, J . L.; Winston, P. B.; Ward, B. C. J . Am. Chem.
Soc. 1981, 103, 7713.

3932 Organometallics, Vol. 16, No. 18, 1997
Lee et al.
MHz, CDCl3): δ 2.75 (dt, J (HH) ) 13.0 Hz, J (PH) ) 4.4 Hz, 2
H, CHH(C6H3)CHH), 3.80 (dt, J (HH) ) 13.0 Hz, J (PH) ) 5.3
Hz, 2 H, CHH(C6H3)CHH), 6.54-7.87 (m, 43 H, PPh3, 2 PPh2,
C6H3, Ph). 31P{1H} NMR (121.50 MHz, CDCl3): δ 16.4 (d,
J (PP) ) 20.1 Hz), 35.1 (t, J (PP) ) 20.1 Hz). 13C{1H} NMR
(75.49 MHz, CDCl3): δ 36.6 (t, J (PC) ) 13.6 Hz, CH2), 113.1
(q, J (PC) ) 2.3 Hz, tCâ), 115.3 (q, J (PC) ) 13.8 Hz, Ru-CR),
174.4 (dt, J (PC) ) 47.5, 13.6 Hz, RusC(aryl)), 122.2-140.4
(m, other aromatic and olefinic carbons).
P r oton a tion of Ru (P P h 3)(CtCP h )(P CP ). Appropriate
amounts of Ru(PPh3)(CtCPh)(PCP), dried PhCH2NEt3Cl, and
acetone-d6 were loaded in an NMR tube. Then a limited
amount of HBF4‚Et2O was added to the NMR tube. 31P and
1H NMR spectra of the mixture were collected. The NMR
spectra showed signals assignable to the starting material Ru-
(PPh3)(CtCPh)(PCP) and the coupling product 2. In addition,
signals due to uncharacterized species were also observed.
Ru Cl(P P h 3)(η4-P h 2C(OH)CHdC-2,6-(P P h 2CH2)2C6H3) (4).
A mixture of 0.20 g of RuCl(PPh3)(PCP) (0.23 mmol) and 0.050
g of 1,1-diphenylpropyn-1-ol (0.86 mmol) in 20 mL of dried
dichloromethane was stirred overnight to give a dark solution.
The solvent was removed completely under vacuum. A brown
solid was obtained when 30 mL of diethyl ether was added.
The solid was collected on a filter frit, washed with hexane,
and dried under vacuum overnight. Yield: 0.22 g, 89%. Anal.
of terminal acetylenes with ruthenium PCP complexes
promoted us to study the reactions of PhCtCH with
other related PCP complexes.17,19,28,44 To this end, we
have studied the reaction of PhCtCH with PdCl(PCP)
(10).44a Complex 10 is related to RuCl(PPh3)(PCP) and
[Ru(PMe3)2(PCP)]+ in that all of them are coordinatively
unsaturated and all of them contain a PCP ligand.
However, it was observed that complex 10 is unreactive
toward PhCtCH in CHCl3 or CH2Cl2, either at room
temperature or at reflux temperature.
Exp er im en ta l Section
Microanalyses were performed by M-H-W Laboratories
(Phoenix, AZ). 1H, 13C, and 31P NMR spectra were collected
on a J EOL EX-400 spectrometer (400 MHz) or a Bruker ARX-
300 spectrometer (300 MHz). 1H and 13C NMR chemical shifts
are relative to TMS and 31P NMR chemical shifts relative to
85% H3PO4.
All manipulations were carried out at room temperature
under a nitrogen atmosphere using standard Schlenk tech-
niques, unless otherwise stated. Solvents were distilled under
nitrogen from sodium-benzophenone (hexane, diethyl ether,
THF, benzene) or calcium hydride (dichloromethane, CHCl3).
The compounds RuCl2(PPh3)3,45 RuCl(PPh3)(PCP),17a RuCl-
Calcd for
C
65H54ClOP3Ru‚0.5CH2Cl2: C, 70.05; H, 4.94.
47
(PMe3)2(PCP),46 PdCl(PCP),44a and HCtCC(OH)Ph2 were
Found: C, 70.06; H, 5.39. 31P{1H} NMR (121.50 MHz,
CDCl3): δ -5.2 (J (PP) ) 32.6 Hz, PPh2), 67.5 (t, J (PP) ) 32.5
Hz, PPh3). 1H NMR (300 MHz, CDCl3): δ 2.59 (s, OH), 2.67
(dt, J ) 13.5, 4.4 Hz, 2 H, CHH(C6H3)CHH), 3.88 (dt, J ) 13.5,
6.7 Hz, 2 H, CHH(C6H3)CHH), 5.38 (s, 1 H, dCH), 6.53-7.45
(m, 48 H, PPh3, 2 PPh2, C6H3, Ph). 13C{1H} NMR (75.49 MHz,
CDCl3): δ 37.0 (t, J ) 12.5 Hz, CH2), 80.4 (s, C(OH)), 110.8
(td, J (PC) ) 9.1, 3.1 Hz, RusC(aryl)), 166.9 (dt, J (PC) ) 12.5,
5.1 Hz, RusC(vinyl)), 126.1-136.3 (m, other aromatic and
olefinic carbons).
prepared according to literature methods. All other reagents
were used as purchased from Aldrich or Strem.
R u Cl(P P h 3)(η4-P h CH dC-2,6-(P P h 2CH 2)2C6H 3) (2).
A
mixture of 0.16 g of RuCl(PPh3)(PCP) (0.18 mmol) and 0.10
mL of PhCtCH (0.91 mmol) in dichloromethane was stirred
for 2 h to give a dark green solution. The solvent was pumped
away under vacuum. A pale green solid was obtained when
diethyl ether was added. The solid was collected on a filter
frit, washed with hexane, and dried under vacuum overnight.
Yield: 0.16 g, 82%. Anal. Calcd for C58H48ClP3Ru: C, 71.49;
H, 4.97. Found: C, 71.32; H, 4.91. 31P{1H} NMR (161.70
MHz, CDCl3): δ -7.4 (d, J (PP) ) 33.3 Hz, PPh2), 69.3 (t, J (PP)
) 33.3 Hz, PPh3). 1H NMR (400 MHz, CDCl3): δ 2.67 (dt, J
) 13.7, 4.2 Hz, 2 H, CHH(C6H3)CHH), 3.89 (m, 2 H,
CHH(C6H3)CHH), 4.98 (s, 1 H, CdCHPh), 6.60-8.24 (m, 43
H, PPh3, 2 PPh2, C6H3, Ph). 13C{1H} NMR (75.49 MHz,
CDCl3): δ 37.8 (t, J ) 12.8 Hz, CH2), 113.2 (t, J (PC) ) 6.7 Hz,
RusC(aryl)), 164.1 (td, J (PC) ) 12.8, 5.1 Hz, RusC(vinyl)),
124.0-139.1 (m, other aromatic and olefinic carbons).
Ru (P P h 3)(CtCP h )(P CP ) (3). A THF solution of lithium
phenylacetylide (1.0 mmol) was added dropwise to a 10 mL
solution of 0.4 g of RuCl(PPh3)(PCP) (0.5 mmol) in THF.
During the addition, the color changed from green to dark
yellow. The mixture was stirred for 10 min. Then the volume
of the reaction mixture was reduced to ca. 1 mL under vacuum.
A dark purple solid was obtained when 20 mL of methanol
was added. The solid was collected on a filter frit and washed
with methanol and a small amount of cold diethyl ether.
Yield: 0.41 g, 83%. Anal. Calcd for C58H47P3Ru: C, 74.37;
H, 5.11. Found: C, 74.27; H, 5.05. IR (KBr, cm-1): ν(CtC)
2068 m; phenyl reinforced vibration 1589 (m). 1H NMR (300
R u C l(P P h 3)(η4-P h Me C (O H )C H dC -2,6-(P P h 2C H 2)2-
C6H3) (5). A mixture of 0.20 g of RuCl(PPh3)(PCP) (0.23 mmol)
and 0.34 g of 2-phenyl-3-butyn-2-ol (2.3 mmol) in 20 mL of
dried dichloromethane was stirred for 2 h to give a dark green
solution. The solvent was removed under vacuum. A green
solution with brown solid was obtained when 50 mL of diethyl
ether was added. The solution was filtered through a filter
frit, and the volume of the filtrate was reduced to ca. 1 mL
under vacuum. A green solid was obtained when 30 mL of
hexane was added. The solid was collected on a filter frit,
washed with hexane, and dried under vacuum overnight.
Yield: 0.12 g, 51%. Anal. Calcd for C60H52ClOP3Ru: C, 70.76;
H, 5.14. Found: C, 70.27; H, 5.26. 31P{1H} NMR (121.50
MHz, CDCl3): ABM pattern, δ(PA) -8.04, δ(PB) -7.12, δ(PC)
69.0 ppm; J (AB) ) 300, J (AM) ) J (BM) ) 32.1 Hz. The
chemical shifts and coupling constants were obtained by
simulation. 1H NMR (300 MHz, CDCl3): δ 1.72 (s, 3 H, Me),
2.28 (s, OH), 2.42 (m, 1 H, CH2), 2.70 (m, 1 H, CH2), 3.90 (m,
1 H, CH2), 4.22 (s, 1 H, dCH), 4.45 (m, 1 H, CH2), 6.52-8.63
(m, 43 H, PPh3, 2 PPh2, C6H3, Ph).
Ru Cl(P P h 3)(η4-CH2dCP h CHdC-2,6-(P P h 2CH2)2C6H3) (6).
A mixture of 0.20 g of RuCl(PPh3)(PCP) (0.23 mmol) and
2-phenyl-3-butyn-2-ol (0.34 g, 2.3 mmol) in 20 mL of dichlo-
romethane was stirred for 8 h to give a dark green solution.
The solution was passed through a column of alumina using
diethyl ether as the eluting solvent. The green band was
collected, and the solvent was removed completely under
vacuum to give a green solid. Yield: 0.17 g, 74%. Anal. Calcd
for C60H50ClP3Ru: C, 72.03; H, 5.04. Found: C, 72.25; H, 5.50.
31P{1H} NMR (121.50 MHz, CDCl3): δ -7.3 (J (PP) ) 31.8 Hz,
PPh2), 68.8 (t, J (PP) ) 31.8 Hz, PPh3). 1H NMR (300 MHz,
CDCl3): δ 2.71 (dt, J ) 13.8, 4.4 Hz, 2 H, CHH(C6H3)CHH),
3.96 (m, 2 H, CHH(C6H3)CHH), 4.51 (s, 1 H, dCH), 4.92 (s, 1
H, dCH), 5.17 (s, 1 H, dCH), 6.70-8.21 (m, 43 H, PPh3, 2
PPh2, C6H3, Ph). 13C{1H} NMR (75.49 MHz, CDCl3): δ 38.1
(t, J ) 12.7 Hz, CH2), 107.5 (s, dCH2), 112.5 (t, J (PC) ) 7.6
(44) A number of metal complexes with PCP and related ligands
have been reported; for example: (a) Rimml, H.; Venanzi, L. M. J .
Organomet. Chem. 1983, 259, C6. (b) Rimml, H.; Venanzi, L. M. J .
Organomet. Chem. 1984, 260, C52. (c) Gorla, F.; Venanzi, L. M.;
Albinati, A. Organometallics 1994, 13, 43. (d) Gola, F.; Togni, A.;
Venanzi, L. M.; Albinati, A.; Lianza, F. Organometallics 1994, 13, 1607.
(e) Moulton, C. J .; Shaw, B. L. J . Chem. Soc., Dalton Trans. 1976, 1020.
(f) Cross, R. J .; Kennedy, A. R.; Manojlovˆıc-Muir, L.; Muir, K. W. J .
Organomet. Chem. 1995, 493, 243. (g) Kaska, W. C.; Nemeh, S.; Shirazi,
A.; Potuznik, S. Organometallics 1988, 7, 13. (h) Nemeh, S.; J ensen,
C.; Binamira-Soriaga, E.; Kaska, W. C. Organometallics 1983, 2, 1442.
(45) Hallman, P. S.; Stephenson, T. A.; Wilkinson, G. Inorg. Synth.
1970, 12, 237.
(46) J ia, G.; Lee, H. M.; Williams, I. D. J . Organomet. Chem. 1997,
534, 173.
(47) Midland, M. M. J . Org. Chem. 1975, 40, 2250.

Reactions of Terminal Acetylenes with Ru Compounds
Organometallics, Vol. 16, No. 18, 1997 3933
Hz, RusC(aryl)), 166.9 (dt, J (PC) ) 12.8, 5.7 Hz, RusC(vinyl)),
126.7-144.8 (m, other aromatic and olefinic carbons).
stirred for 2 h at room temperature, during which time the
color gradually changed to dark yellow. The solution was then
filtered through a column of Celite. The volume of the filtrate
was reduced to ca. 1 mL under vacuum. A pale gray solid was
obtained when 40 mL of diethyl ether was added. The solid
was collected on a filter frit, washed with diethyl ether and
hexane, and dried under vacuum overnight. Yield: 0.31 g,
86%. Anal. Calcd for C46H51BF4P4Ru: C, 60.34; H, 5.61.
Found: C, 60.04; H, 5.92. 31P{1H} NMR (121.50 MHz,
CDCl3): δ 25.8 (td, J (PP) ) 25.6, 31.8 Hz, PMe3), 8.7 (dd, J (PP)
) 15.1, 31.8 Hz, PPh2), -26.9 (dt, J (PP) ) 25.6, 15.1 Hz, PMe3).
1H NMR (CDCl3): δ 0.33 (d, J (PH) ) 6.7 Hz, PMe3), 1.42 (d,
J (PH) ) 9.7 Hz, PMe3), 3.10 (dt, J ) 4.5, 14.3 Hz, CHH(C6H3)-
CHH), 3.65 (m, 2 H, CHH(C6H3)CHH), 6.20 (br, dCH), 6.67-
8.00 (m, 38 H, PPh3, 2 PPh2, C6H3). 13C NMR (CDCl3): δ 17.7
(d, J (PC) ) 23.5 Hz, PMe3), 24.8 (dq, J (PC) ) 32.6, 4.3 Hz,
PMe3), 37.8 (t, J ) 14.6 Hz, CH2), 108.7 (tt, J (PC) ) 7.3, 2.7
Hz, RusC(aryl)), 167.6 (dtd, J (PC) ) 41.5, 14.9, 4.6 Hz, RusC-
(vinyl)), 124.5-143.4 (m, other aromatic and olefinic carbons).
Ru Cl(P P h 3)(η4-cyclo-C6H9CHdC-2,6-(P P h 2CH2)2C6H3) (7).
A mixture 0.20 g of RuCl(PPh3)(PCP) (0.23 mmol) and 1-ethy-
nylcyclohexanol (0.32 g, 2.6 mmol) in 20 mL of dichlo-
romethane was stirred for 8 h to give a dark green solution.
The solution was passed through a column of alumina using
diethyl ether as the eluting solvent. The green band was
collected and the solvent was removed completely under
vacuum to give a green solid. Yield: 0.18 g, 80%. Anal. Calcd
for C58H52ClP3Ru: C, 71.20; H, 5.36. Found: C, 71.57; H, 5.13.
1H NMR (300 MHz, CDCl3): δ 1.23-1.94 (m, (CH2)4), 2.65 (dt,
J
) 13.6, 4.4 Hz, 2 H, CHH(C6H3)CHH), 4.04 (m, 2 H,
CHH(C6H3)CHH), 4.64 (s, 1 H, RudCdCH), 5.05 (br, 1 H,
dCHCH2), 6.63-8.25 (m, 38 H, PPh3, 2 PPh2, C6H3). 31P{1H}
NMR (121.50 MHz, CDCl3): δ -8.5 (d, J (PP) ) 32.1 Hz, PPh2),
68.9 (t, J (PP) ) 32.1 Hz, PPh3). 13C NMR (CDCl3): δ 22.7 (s,
CH2), 23.3 (s, CH2), 25.8 (s, CH2), 26.3 (s, CH2), 37.9 (t, J )
12.9 Hz, CH2), 113.6 (td, J (PC) ) 6.6, 3.1 Hz, RusC(aryl)),
153.9 (td, J ) 13.4, 4.9 Hz, RusC(vinyl)), 120.5-139.4 (m,
other aromatic and olefinic carbons).
[Ru (P Me3)2(η4-P h CHdC-2,6-(P P h 2CH2)2C6H3)]BF 4 (9A).
A mixture of 0.30 g of RuCl(PMe3)2(PCP) (0.39 mmol) and
0.080 g of AgBF4 (0.39 mmol) were stirred in 30 mL of THF
for 1 min to give a dark red solution. To the solution was
added 0.43 mL of PhCtCH (3.9 mmol). The solution was
Ack n ow led gm en t. We acknowledge financial sup-
port from the Hong Kong Research Grants Council and
the Croucher Foundation.
OM9700829