Cycloaddition between a transition-metal phenylallenylidene complex and allyl alcohol

Article abstract of DOI:10.1021/om980132p

The allenylidene complex [Ru(η⁵-C₅H₅)(C=C=CPh ₂)(CO)(PⁱPr₃)]BF₄ (1) reacts with allyl alcohol to give the α,β-unsaturated alkoxycarbene derivative [Ru(η⁵-C₅H₅){C(OCH₂-CH=CH ₂)CH=CPh₂}(CO)(PⁱPr₃)]BF₄ (2), which affords the alkoxyallenyl compound Ru(η⁵-C₅H₅){C(OCH₂CH=CH ₂)=C=CPh₂}(CO)(PⁱPr₃) (3) by deprotonation at -78 °C. At room temperature, in solution, complex 3 undergoes an intramolecular Diels-Alder reaction to form the tricyclic tetraenyl complex Ru(η⁵-C₅H ₅)(9-phenyl-3,3a,4,4a-tetrahydronaphtho[2,3-c]-1-furanyl)(CO)(P ⁱPr₃) (4). This isomerization is highly stereospecific due to the chiral nature of 3 and gives a single pair of enantiomers of 4. For this reaction, first-order constants k_obs were obtained in toluene-d₈, which gave activation parameters of ΔH^? = 18 ± 2 kcal mol^-1 and ΔS^? = -18 ± 3 cal K⁺¹ mol^-1. The structure of 4 was determined by an X-ray investigation, revealing a Ru-C(tricyclic) distance of 2.088(3) A°. Complex 4 reacts with HBF₄ to give the tricyclic carbene compound [Ru(η⁵-C₅H ₅)(9-phenyl-1,3,3a,4,4a,9a-hexahydronaphtho[2,3-c]-1-furanylidene) (CO)(PⁱPr₃)]BF₄ (5). Similarly, the reaction of 4 with DBF₄ affords [Ru(η⁵-C₅H ₅)(9-phenyl-9a-deutero-1,3,3a,4,4a-pentahydronaphtho[2,3-c]-1- furanylidene)-(CO)(PⁱPr₃)]BF₄ (5-d₁). At room temperature with chloroform and tetrahydrofuran as the solvents, complex 5 is unstable and evolves into the cationic acyclic alkoxycarbene derivative [Ru(η⁵-C₅H₅){C(OCH ₂[1-phenyl-3,4-dihydro-3-naphthyl])H}(CO)(PⁱPr ₃)]⁺ (6), which was isolated as the PF₆ salt by addition of NaPF₆. For the isomerization of 5 into 6, first-order constants k_obs were obtained in chloroform-d, which gave activation parameters of ΔH^? = 20.8 ± 0.9 kcal mol^-1 and ΔS^? = -10.6 ± 0.7 cal K^-1 mol^-1. At room temperature with methanol as the solvent, complex 6 loses the alkoxy group to afford the alcohol 3-hydroxymethyl-1-phenyl-3,4-dihydronaphthalene (7) and the organometallic methoxycarbene [Ru(η⁵-C₅H₅){C(OCH ₃)H}(CO)(PⁱPr₃)]PF₆ (8).

Full text of DOI:10.1021/om980132p

Organometallics 1998, 17, 2297-2306
2297
Cycloa d d ition betw een a Tr a n sition -Meta l
P h en yla llen ylid en e Com p lex a n d Allyl Alcoh ol†
Miguel A. Esteruelas,* Angel V. Go´mez, Ana M. Lo´pez, Enrique On˜ate, and
Natividad Ruiz
Departamento de Quı´mica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n,
Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain
Received February 24, 1998
The allenylidene complex [Ru(η5-C5H5)(CdCdCPh2)(CO)(PiPr3)]BF4 (1) reacts with allyl
alcohol to give the R,â-unsaturated alkoxycarbene derivative [Ru(η5-C5H5){C(OCH2-
CHdCH2)CHdCPh2}(CO)(PiPr3)]BF4 (2), which affords the alkoxyallenyl compound Ru(η5-
C5H5){C(OCH2CHdCH2)dCdCPh2}(CO)(PiPr3) (3) by deprotonation at -78 °C. At room
temperature, in solution, complex 3 undergoes an intramolecular Diels-Alder reaction to
form the tricyclic tetraenyl complex Ru(η5-C5H5)(9-phenyl-3,3a,4,4a-tetrahydronaphtho[2,3-
c]-1-furanyl)(CO)(PiPr3) (4). This isomerization is highly stereospecific due to the chiral
nature of 3 and gives a single pair of enantiomers of 4. For this reaction, first-order constants
kobs were obtained in toluene-d8, which gave activation parameters of ∆Hq ) 18 ( 2 kcal
mol-1 and ∆Sq ) -18 ( 3 cal K-1 mol-1. The structure of 4 was determined by an X-ray
investigation, revealing a Ru-C(tricyclic) distance of 2.088(3) Å. Complex 4 reacts with
HBF4 to give the tricyclic carbene compound [Ru(η5-C5H5)(9-phenyl-1,3,3a,4,4a,9a-hexahy-
dronaphtho[2,3-c]-1-furanylidene)(CO)(PiPr3)]BF4 (5). Similarly, the reaction of 4 with DBF4
affords [Ru(η5-C5H5)(9-phenyl-9a-deutero-1,3,3a,4,4a-pentahydronaphtho[2,3-c]-1-furanylidene)-
(CO)(PiPr3)]BF4 (5-d1). At room temperature with chloroform and tetrahydrofuran as the
solvents, complex 5 is unstable and evolves into the cationic acyclic alkoxycarbene derivative
[Ru(η5-C5H5){C(OCH2[1-phenyl-3,4-dihydro-3-naphthyl])H}(CO)(PiPr3)]+ (6), which was iso-
lated as the PF6 salt by addition of NaPF6. For the isomerization of 5 into 6, first-order
constants kobs were obtained in chloroform-d, which gave activation parameters of ∆Hq )
20.8 ( 0.9 kcal mol-1 and ∆Sq ) -10.6 ( 0.7 cal K-1 mol-1. At room temperature with
methanol as the solvent, complex 6 loses the alkoxy group to afford the alcohol 3-hydroxy-
methyl-1-phenyl-3,4-dihydronaphthalene (7) and the organometallic methoxycarbene [Ru(η5-
C5H5){C(OCH3)H}(CO)(PiPr3)]PF6 (8).
In tr od u ction
synthesis of (()-torreyol.3 Allenes, acting as dieno-
philes, have been used to develop a new approach for
the synthesis of N-substituted indoles, which are useful
intermediates in the synthesis of indol alkaloids.4
The formation of carbon-carbon bonds mediated by
transition-metal compounds has emerged in its own
right over the past few years as an important step in
organic synthesis.5 In this context, allenylidene com-
plexes are attracting considerable interest as precursors
The Diels-Alder reaction is one of the most funda-
mental reactions in synthetic organic chemistry. It is
a widely used method for forming carbon-carbon,
carbon-heteroatom, and heteroatom-heteroatom bonds.
It is a [π4σ + 2σ] cycloaddition in which a conjugated
π
diene compound undergoes a stereospecific addition
reaction with another component, called a dienophile.
The diene is the 4π component of the reaction, and they
may be classified as (i) open ring, (ii) outer ring, (iii)
inner-outer ring, (iv) across rings, and (v) inner ring.
The dienophile, the 2π reacting partner, is a molecule
containing a double or triple bond, which is activated
by electron-withdrawing substituents.1
The intramolecular version of the Diels-Alder reac-
tion has been used in the total synthesis of natural
products.2 For example, the spontaneous cyclization of
an intermediate trienol in the course of the oxidation
reaction is the key step in the stereoselective total
(2) (a) Desimoni, G.; Tacconi, G.; Barco, A.; Pollini, G. P. Natural
Product Synthesis through Pericyclic Reactions; ACS Monograph 180;
American Chemical Society, Washington, DC, 1983. (b) Ciganek, E.
Org. React. 1984, 32, 1. (c) Weinreb, S. M. Acc. Chem. Res. 1985, 18,
16.
(3) Taber, D. F.; Gunn, B. P. J . Am. Chem. Soc. 1979, 101, 3992.
(4) Hayakawa, K.; Yasukouchi, T.; Kanematsu, K. Tetrahedron Lett.
1986, 27, 1837.
(5) (a) Stille, J . K. Chemistry of the Metal-Carbon Bond; Hartley,
F. R., Patai, S., Eds.; Wiley: Chichester, 1985; Vol. 2. (b) Hagashi, T.;
Kumada, M.; Asymmetric Synthesis; Morrison, J . D., Ed.; Academic:
New York, 1985; Vol. 5. (c) Yamamoto, A. Organotransition Metal
Chemistry; Wiley: New York, 1986. (d) Collman, J . P.; Hegedus, L. S.;
Norton, J . R.; Finke, R. G. Principles and Applications of Organo-
transition-metal Chemistry; University Science Books: Mill Valey, CA,
1987. (e) Brown, J . M.; Cooley, N. A. Chem. Rev. 1988, 88, 1031. (f)
Brookhart, M.; Volpe, A. F., J r.; Yoon, J . Comprehensive Organic
Synthesis; Trost, B. M., Fleming, I., Ed.; Pergamon Press: New York,
1991; Vol. 4. (g) Houri, A. F.; Xu, Z.; Cogan, D. A.; Hoveyda, A. H. J .
Am. Chem. Soc. 1995, 117, 2943.
† Dedicated to Prof. Pascual Royo on the occasion of his 60th
birthday.
(1) (a) Fringuelli, F.; Taticchi, A. Dienes in the Diels-Alder Reaction;
J ohn Wiley and Sons: New York, 1990. (b) Winkler, J . D. Chem. Rev.
1996, 96, 167.
S0276-7333(98)00132-0 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 04/30/1998

2298 Organometallics, Vol. 17, No. 11, 1998
Esteruelas et al.
of new carbon-carbon coupling reactions,6 in particular,
since Selegue reported that propargylic alcohols HCC-
CRR′OH could be converted quite smoothly into
CdCdCRR′ units in the coordination sphere of an
electron-rich transition-metal center by elimination of
water.7 Thus, Werner recently proved that in the series
carbene-vinylidene-allenylidene, not only carbene and
vinylidene complexes but also allenylidene compounds
can be used in metal-assisted C-C bond-forming reac-
tions.8 In agreement with this, Gimeno et al. have
observed that the ruthenium allenylidene derivative
[Ru(η5-C9H7)(CdCdCPh2)L2]PF6 (L2 ) 2PPh3, dppm,
dppe) underwent regioselective carbon-nucleophilic at-
tacks at Cγ to yield alkynyl derivatives,9 and Kolobova
et al. have shown that the allenylidene ligand of the
complex Mn(η5-C5H5)(CdCdCPh2)(CO)2 can be coupled
with tert-butylisocyanide to form a cumulenylidene
derivative.10 Fischer et al. have also reported on the
formation of binuclear cyclobutenylidene complexes by
cycloaddition of the carbon-carbon triple bond of al-
kynyl complexes to the CR-Câ double bond of allenyl-
idene compounds.11
Sch em e 1
We recently reported that the solvated complex
[Ru(η5-C5H5){η1-OC(CH3)2}(CO)(PiPr3)]BF4 reacts with
1,1-diphenyl-2-propyn-1-ol to afford the allenylidene
derivative [Ru(η5-C5H5)(CdCdCPh2)(CO)(PiPr3)]BF4,
which adds water, alcohols, thiols, and benzophenone
imine at the CR-Câ double bond of the allenylidene
group, to afford diphenyl-R,â-unsaturated-hydroxycar-
bene, -alkoxycarbene, -(alkylthio)carbene, and -2-aza-
allenyl compounds, respectively. By deprotonation, the
hydroxycarbene compounds give acyl derivatives and
the alkoxycarbene, (alkylthio)carbene, and 2-azaallenyl
complexes yield the corresponding diphenyl-allenyl
derivatives.12
Resu lts a n d Discu ssion
1. Ad d ition of Allyl Alcoh ol to th e Allen ylid en e
Liga n d of [Ru (η5-C5H5)(CdCdCP h 2)(CO)(P iP r 3)]-
BF 4. Complex [Ru(η5-C5H5)(CdCdCPh2)(CO)(PiPr3)]-
BF4 (1) adds not only water and saturated alcohols, such
as methanol and ethanol, at the CR-Câ double bond of
the allenylidene group but also unsaturated alcohols,
such as allyl alcohol. Thus, at room temperature with
allyl alcohol as the solvent, complex 1 evolves to the R,â-
unsaturated alkoxycarbene derivative [Ru(η5-C5H5)-
{C(OCH2CHdCH2)CHdCPh2}(CO)(PiPr3)]BF4 (2, in
Scheme 1). These reactions probably require transition
states that favor the transfer of the electrophilic OH-
hydrogen atom from the alcohols to the Câ atom of the
allenylidene by means of an oxygen-CR interaction. In
this context, it should be mentioned that EHT-MO
calculations on the model cation [Ru(η5-C5H5)-
(CdCdCH2)(CO)(PH3)]+ indicate that 23% of the LUMO
is located on CR and 26% of the HOMO on Câ.13
Complex 2 was isolated as a yellow solid in 82% yield
by addition of diethyl ether. The presence of the
unsaturated η1-carbon ligand in this compound is
strongly supported by the 1H and 13C{1H} NMR spectra.
In the 1H NMR spectrum, the CH proton of the
-CHdCPh2 unit gives rise to a singlet at 6.58 ppm
while the alkoxy group displays a multiplet at 6.01
(-CHd) ppm, two doublets at 5.41 (J (HH) ) 16.5 Hz)
and 5.37 (J (HH) ) 10.0 Hz) ppm due to the dCH2
protons, and a multiplet at 5.1 ppm corresponding to
the -OCH2- group. In the 13C{1H} NMR spectrum, the
most noticeable resonances appear at 304.0 (br), 136.9
(s), 129.8 (s), 122.7 (s), and 81.1 (s) ppm. Taking into
account the 1H-13C HETCOR spectrum, these reso-
nances were assigned to the RudC, -CHdCPh2, -CH),
dCH2, and -OCH2- carbon atoms, respectively.
Although the number and variety of dienes in inter-
and intramolecular Diels-Alder reactions is very high,
(phenyl)allenes have not been previously used. From
the organometallic chemist point of view, this is sur-
prising because transition-metal diphenylallenes, in
general, and transition-metal diphenylallenyl com-
plexes, in particular, should be useful inner-outer ring
dienes. Our curiosity prompted us to study the reactiv-
ity of the diphenylallenylidene complex [Ru(η5-
C5H5)(CdCdCPh2)(CO)(PiPr3)]BF4 toward allyl alcohol.
In this paper, we report new transition-metal organo-
metallic compounds and new reactions including an
intramolecular Diels-Alder reaction on a transition-
metal phenylallene complex, where the phenylallene
unit acts as an inner-outer ring diene.
(6) (a) Bruce, M. I. Chem. Rev. 1991, 91, 197. (b) Werner, H. J . Chem.
Soc., Chem. Commun. 1997, 903. (c) Beckhans, R. J . Chem Soc., Dalton
Trans. 1997, 1991.
(7) Selegue, J . P. Organometallics 1982, 1, 217.
(8) (a) Wiedemann, R.; Steinert, P.; Gevert, O.; Werner, H. J . Am.
Chem. Soc. 1996, 118, 2495. (b) Braun, T.; Meuer, P.; Werner, H.
Organometallics 1996, 15, 4075.
(9) (a) Cadierno, V.; Gamasa, M. P.; Gimeno, J .; Borge, J .; Garc´ıa-
Granda, S. J . Chem. Soc., Chem. Commun. 1994, 2495. (b) Cadierno,
V.; Gamasa, M. P.; Gimeno, J .; Lastra, E. J . Organomet. Chem. 1994,
474, C27.
(10) Kalinin, V. N.; Derunov, V. V.; Lusenkova, M. A.; Petrovsky,
P. V.; Kolobova, N. E. J . Organomet. Chem. 1989, 379, 303.
(11) Fischer, H.; Leroux, F.; Stumpt, R.; Roth, G. Chem. Ber. 1996,
129, 1475.
Treatment of 2 with sodium methoxide in tetra-
hydrofuran at -78 °C produces the deprotonation of the
olefinic group of the alkoxycarbene ligand to give the
alkoxyallenyl
derivative
Ru(η5-C5H5){C(OCH2-
(12) Esteruelas, M. A.; Go´mez, A. V.; Lahoz, F. J .; Lo´pez, A. M.;
On˜ate, E.; Oro, L. A. Organometallics 1996, 15, 3423.
(13) Esteruelas, M. A.; Go´mez, A. V.; Lo´pez, A. M.; Modrego, J .;
On˜ate, E. Organometallics 1997; 26, 5826.

Cycloaddition with a Phenylallenylidene Complex
Organometallics, Vol. 17, No. 11, 1998 2299
OCH3}(CO)(PiPr3)2.15 In addition, it should be men-
tioned that rhodium-containing γ-functionalized alkynyl
groups have been recently prepared by migratory inser-
tion of an allenylidene unit into Rh-OR (R ) Ph, CH3-
CO) bonds.16
2. Syn th esis a n d Ch a r a cter iza tion of Ru (η5-
C5H 5)(9-p h en yl-3,3a ,4,4a -t et r a h yd r on a p h t h o[2,3-
c]-1-fu r a n yl)(CO)(P iP r 3) (4). At room temperature,
complex 3 evolves, with pentane and toluene as the
solvents, into the tricyclic tetraenyl complex 4, which
is a result from two spontaneous carbon-carbon cou-
plings in 3, the Câ atom of the allenyl unit with the -CH
atom of the alkoxy group and, at a time, an ortho-carbon
atom of one of the two phenyl groups with the dCH2
atom of the alkoxy fragment (eq 1).
F igu r e 1. Molecular diagram for Ru(η5-C5H5)(9-phenyl-
3,3a,4,4a-tetrahydronaphtho[2,3-c]-1-furanyl)(CO)(PiPr3) (4).
Thermal ellipsoids are shown at 50% probability.
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for Ru (η5-C5H5)(9-p h en yl-3,3a ,4,4a -
tetr a h yd r on a p h th o[2,3-c]-1-fu r a n yl)(CO)(P iP r 3) (4)
Bond Lengths
Ru-P
2.355(1)
1.858(3)
2.088(3)
1.359(4)
1.479(3)
1.500(4)
1.374(4)
1.458(4)
1.350(4)
1.458(5)
C(28)-C(29)
C(29)-C(30)
C(30)-C(31)
C(31)-C(32)
C(32)-C(33)
C(33)-O(1)
O(1)-C(16)
C(25)-C(30)
C(17)-C(32)
1.334(5)
1.517(4)
1.555(4)
1.561(4)
1.533(4)
1.462(4)
1.424(3)
1.537(4)
1.537(4)
Ru-C(15)
Ru-C(16)
C(16)-C(17)
C(17)-C(18)
C(18)-C(19)
C(18)-C(25)
C(25)-C(26)
C(26)-C(27)
C(27)-C(28)
Bond Angles
P-Ru-C(15)
P-Ru-C(16)
P-Ru-G(1)a
91.94(9)
94.05(8)
125.8(2)
C(15)-Ru-C(16)
C(15)-Ru-G(1)a
C(16)-Ru-G(1)a
88.6(2)
125.5(2)
121.0(2)
a
G(1) is the midpoint of the C(1)-C(5) Cp ligand.
Complex 4 was isolated as a yellow solid in 80% yield
and characterized by elemental analysis, IR and 1H,
13C{1H}, and 31P{1H} NMR spectroscopy, and an X-ray
diffraction study. A view of the molecular geometry is
shown in Figure 1. Selected bond distances and angles
are listed in Table 1.
CHdCH2)dCdCPh2}(CO)(PiPr3) (3, Scheme 1), which
was isolated at -78 °C as a pale yellow solid in 81%
yield.
In agreement with the presence of an allenyl ligand
in 3, the IR spectrum of this compound in Nujol shows
the characteristic ν(CdCdC) band for this type of
ligand6a at 1891 cm-1 and the 13C{1H} NMR spectrum
contains a doublet at 136.2 ppm with a C-P coupling
constant of 13.8 Hz, which was assigned to the CR atom,
and two singlets at 197.9 and 107.1 ppm corresponding
to that Câ and Cγ atoms, respectively. Furthermore the
spectrum shows singlets at 135.8, 115.4, and 72.0 ppm
due to the -CHd, dCH2, and -OCH2- carbon atoms
of the alkoxy group, respectively.
The geometry around the ruthenium center is close
to octahedral, with the cyclopentadienyl ligand occupy-
ing three sites of a face. The angles formed by the
triisopropylphosphine, carbonyl, and the tetraenyl ligand
are all close to 90°. The Ru-C(16) distance (2.088(3)
Å) is slightly longer than those found in the alkenyl
complexes Ru(η5-C5H5){CCdCHCO2CH3)OC(O)CH3}-
(PPh3) (2.002(2) Å),17 Ru{C[dC(CO2CH3)CHdCHC-
Alkoxyallenyl complexes are rare, and the only pre-
cedent is the previously mentioned complexes Ru(η5-
C5H5){C(OR)dCdCPh2}(CO)(PiPr3) (R ) Me, Et), which
were prepared in a manner similar to 3.12 Attempts to
obtain alkoxyallenyl compounds by attack of alkoxy
groups at the CR atom of an allenylidene ligand have
been unsuccessful. Thus, Gimeno has found that CH3O-
is added to the Cγ atom of the allenylidene ligand of the
complexes [Ru(η5-C9H7)(CdCdCPh2)L2]PF6 (L2 ) 2PPh3,
dppm, dppe).9b In agreement with this, we have re-
(CH3)3]C(O)OCH3}Cl(CO)(PPh3)2 (2.03(1) Å),18 Ru{(E)-
CHdCHC3H7}Cl(CO)(Me2Hpz)(PPh3)2 (2.05(1) Å),19
R u {(E )-C H dC H C M e 3 }C l(C O )(M e 2 H p z)(P P h 3 )2
(2.063(7) Å),20 and [Ru{(E)-CHdCHCMe3}(CO)-
(14) Esteruelas, M. A.; Go´mez, A. V.; Lo´pez, A. M. Manuscript in
preparation.
(15) Bohanna, C.; Callejas, B.; Edwards, A. J .; Esteruelas, M. A.;
Lahoz, F. J .; Oro, L. A.; Ruiz, N.; Valero, C. Organometallics 1998,
17, 373.
(16) Werner, H.; Wiedemann, R.; Laubender, M.; Wolf, J .; Wind-
mu¨ller; B. J . Chem. Soc., Chem. Commun. 1996, 1413.
(17) Daniel, T.; Mahr, N.; Braun, T.; Werner, H. Organometallics
1993, 12, 1475.
(18) Torres, M. R.; Vegas, A.; Santos, A.; Ros, J . J . Organomet. Chem.
1987, 326, 413.
cently observed that complex 1 and [Os{C[C(O)-
OCH3]dCH2}(CdCdCPh2)(CO)(PiPr3)2]BF4 react with
CH3O- to give the corresponding γ-functionalized alky-
nyl complexes Ru(η5-C5H5){CtC-C(Ph)2OCH3}(CO)-
(19) Torres, M. R.; Santos, A.; Perales, A.; Ros, J . J . Organomet.
Chem. 1988, 353, 221.
(20) Romero, A.; Santos, A.; Vegas, A. Organometallics 1988, 7, 1988.
(PiPr3)14 and [Os{C[C(O)OCH3]dCH2}{CtCC(Ph)2-

2300 Organometallics, Vol. 17, No. 11, 1998
Esteruelas et al.
F igu r e 2. Molecular diagram for the tricyclic ligand of
complex 4.
F igu r e 4. Stacked 31P{1H} NMR spectra illustrating the
isomerization of complex 3 to 4 in toluene-d8 at 293 K.
support the tetraenyl formulation. In this context, it
should be mentioned that the distance values for the
short-long-short bond sequences are in agreement
with those found in the dienyl complex Ru{(E)-CHdCH-
C(CH3)dCH2}Cl(CO)(PiPr3)2 (1.340(4), 1.469(5), and
1.342(5) Å).25
1
In the H NMR spectrum, the CH- hydrogen atoms
of the tricyclic group give rise to resonances at 6.94,
6.11, 6.04, 5.74, 3.20, and 2.76 ppm, which, on the basis
1
of the H-1H COSY NMR spectrum shown in Figure 3,
were assigned to the hydrogen atoms bonded to the
C(26), C(28), C(29), C(27), C(30), and C(32) carbon
atoms, respectively. The -CH2- hydrogen atoms dis-
play four resonances at 4.54, 3.52, 1.92, and 1.74 ppm.
The assignment of these resonances was carried out on
the basis of NOE experiments. Irradiation of the
resonance at 2.76 ppm gave an increase in the intensi-
ties of the signals at 4.54 and 1.74 ppm. From this, we
conclude that these resonances correspond to the H(33)
and H′(31) hydrogen atoms, respectively (Figure 3). In
a further NOE experiment, it was shown that saturation
of the resonance at 3.20 ppm increased the intensity of
the resonance at 1.92 ppm. In agreement with this, we
assign this resonance to the H(31) hydrogen atom.
In the 13C{1H} NMR spectrum, the most noticeable
resonance is a doublet at 175.8 ppm, with a C-P
coupling constant of 10.5 Hz, which corresponds to the
Ru-Cd carbon atom.
F igu r e 3. Some selected NOEs and 1H,1H COSY NMR
spectra of Ru(η5-C5H5)(9-phenyl-3,3a,4,4a-tetrahydronaph-
tho[2,3-c]-1-furanyl)(CO)(PiPr3) (4).
{NHdC(Me)(Me2pz}(PPh3)2]PF6 (2.067(8) Å)21 and is
slightly shorter than the Ru-C bond lengths in the
complexes Ru(η5-C5H5){C(dCHPh)OiPr}(CO)(PPh3)
(2.103(6) Å),22 [Ru{C(dCHCO2CH3)CO2CH3}(CO)-
(NCCH3)2(PPh3)2]ClO4 (2.12(5) Å),23 and Ru(CH3){(E)-
CHdCHPh}(CO)2(PiPr3)2 (2.141(3) Å),24 where a Ru-
C(sp2) single bond has been also proposed.
Figure 2 shows the skeleton of the tricyclic tetraenyl
ligand. The six-membered ring of the corner is almost
planar, while the central six-membered ring signifi-
cantly deviates from planarity, showing a boat confor-
mation. The five-membered heterocycle adopts an
envelope conformation with the C(33) atom out from the
plane defined by the other four atoms. The structural
parameters for the sequence C(16)-C(17)-C(18)-C(25)-
C(26)-C(27)-C(28)-C(29) (1.359(4), 1.479(3), 1.374(4),
1.458(4), 1.350(4), 1.458(5), and 1.334(5) Å) strongly
The isomerization of 3 into 4 was followed by 31P{1H}
NMR spectroscopy by measuring the disappearance of
the PiPr3 resonance of 3 (δ ) 72.6) as a function of time.
As shown in Figure 4, the decrease of 3 (with the
corresponding increase of 4 (δ ) 72.2)) in toluene-d8 is
an exponential function of time, in agreement with a
first-order process. The values obtained for the first-
order rate constant kobs in the temperature range
studied are reported in Table 2. The activation param-
eters of the reaction were obtained from the Eyring
analysis shown in Figure 5, giving values of ∆Hq ) 18
( 2 kcal mol-1 and ∆Sq ) -18 ( 3 cal K-1 mol-1. The
(21) Lo´pez, J .; Santos, A.; Romero, A.; Echavarren, A. M. J .
Organomet. Chem. 1993, 443, 221.
(22) Bruce, M. I.; Duffy, D. N.; Humphrey, M. G.; Swincer, A. G. J .
Organomet. Chem. 1985, 282, 383.
(23) Lo´pez, J .; Romero, A.; Santos, A.; Vegas, A.; Echavarren, A.
M.; Noheda, P. J . Organomet. Chem. 1989, 373, 249.
(24) Bohanna, C.; Esteruelas, M. A.; Lahoz, F. J .; On˜ate, E.; Oro,
L. A. Organometallics 1995, 14, 4685.
(25) Esteruelas, M. A.; Liu, F.; On˜ate, E.; Sola, E.; Zeier, B.
Organometallics 1997, 16, 2919.

Cycloaddition with a Phenylallenylidene Complex
Organometallics, Vol. 17, No. 11, 1998 2301
Ta ble 2. Ra tes of Isom er iza tion of Com p lex 3 to 4
values of the H-H coupling constants (see Experimental
1
Section) were inferred from selective homonuclear H{1H}
in Tolu en e-d 8
kobs (105 s-1
)
spectra.
temp (K)
1
In the H NMR spectrum, the most noticeable reso-
293
297
303
308
311
6.6 ( 0.5
9.0 ( 0.6
17 ( 2
nance is that corresponding to the H(9a) hydrogen atom.
It appears at 4.65 ppm as a doublet with a H(9a)-H(3a)
coupling constant of 7.8 Hz and shows a positive NOE
effect with the resonance due to H(3a), which strongly
supports the mutually cis disposition of these atoms.
This indicates that the protonation of 4 is also a
stereospecific process. Thus, the attack of the proton
at the tetraenyl ligand takes place in the direction of
the carbonyl group.
30 ( 2
37 ( 3
In the 13C{1H} NMR spectrum, the resonance corre-
sponding to the RudC (C(1)) carbon atom is observed
at 310.4 ppm as a doublet with a C-P coupling constant
of 9.2 Hz. The rest of the carbon atoms of the tricyclic
ligand give rise to singlets between 139.6 and 28.6 ppm
(Figure 6).
Previous studies on alkenyl compounds have identi-
fied the localization of electron density at the Câ atom
of the alkenyl ligand. The chemical reactivity at this
atom is, thus, oriented toward electrophiles.26 However,
the protonation of dienyl complexes occurs at the δ
carbon atom of the dienyl ligand, suggesting that in this
type of ligands the electron density is located at the Cδ
atom.25,27 The formation of 5 by protonation of 4
suggests that in a tetraenyl ligand the nucleophile
center is the Câ atom, as in a simple alkenyl ligand. To
confirm this finding and to preclude hypothetical inter-
mediates for the formation of 5, we carried out the
protonation of 4 with DBF4. Under the same conditions
as those previously mentioned for the formation of 5,
we have obtained [Ru(η5-C5H5)(9-phenyl-9a-deutero-
1,3,3a,4,4a-pentahydronaphtho[2,3-c]-1-furanylidene)-
(CO)(PiPr3)]BF4 (5-d1, eq 2), which contains the deute-
rium atom at the Câ carbon atom of the tricyclic carbene
ligand. The position of the deuterium atom at the Câ
F igu r e 5. Eyring plot of the first-order rate constants (kobs
for the isomerization of 3 to 4 in toluene-d8 at 293 K.
)
large negative value of the activation entropy suggests
a concerted mechanism with a geometrically highly
oriented transition state. In addition, the stereochem-
istry observed for the tricyclic ligand (i.e. the relative
configurations of the chiral carbons C(30) and C(32))
agrees well with an intramolecular Diels-Alder reaction
in 3, where the Câ-Cγ double bond and one of the two
phenyl groups of the allenyl unit act as an inner-outer
ring diene and the CHdCH2 double bond of the alkoxy
fragment acts as dienophile.
The high degree of stereocontrol directed by the
ruthenium center in the formation of 4 deserves to be
mentioned. In fact, according to the spectroscopic and
X-ray diffraction experiments, only one pair of enanti-
omers is generated of the two possible pairs that could
be expected from the concerted mechanism. As il-
lustrated in eq 1, for the R enantiomer of 3, only the
enantiomer Ru-R, C(30)-R, C(32)-S of 4 is obtained. This
suggests that the dienophile should approach only one
of the two phenyl rings, just that which is away from
the bulky PiPr3 ligand.
carbon atom in 5-d1 is supported by the 2H NMR
spectrum, which shows a broad singlet at 4.59 ppm.
Consequently, the resonance corresponding to H(9a) is
absent in the H NMR spectrum of 5-d1.
At room temperature with chloroform and tetrahy-
3. P r oton a tion of 4: P r ep a r a tion of New Cyclic
a n d Acyclic Ca r ben e Der iva tives. Treatment of
diethyl ether solutions of 4 with 2 equiv of HBF4 at -78
°C after 3 h leads to the tricyclic carbene derivative
[Ru(η5-C5H5)(9-phenyl-1,3,3a,4,4a,9a-hexahydronaph-
tho[2,3-c]-1-furanylidene)(CO)(PiPr3)]BF4 (5, in Scheme
2), which is a result of the addition of the proton of the
acid to the C(17) atom (Câ-alkenyl carbon atom) of 4.
Complex 5 was isolated as a white solid in 84% yield
1
drofuran as the solvents, complex 5 is unstable and
(26) (a) Kremer, K. A. M.; Kuo, G. H.; O’Connor, E. J .; Helquist, P.;
Kerber, R. C. J . Am. Chem. Soc. 1982, 104, 6119. (b) Bodner, G. S.;
Smith, D. E.; Hatton, W. G.; Heah, P. C.; Georgion, S.; Rheingold, A.
A.; Geib, S. J .; Hutchinson, J . P.; Gladysz, J . A. J . Am. Chem. Soc.
1987, 109, 7688. (c) Feng, S. G.; White, P. S.; Templeton, J . L.
Organometallics 1993, 12, 2131.
(27) (a) Esteruelas, M. A.; Lahoz, F. J .; On˜ate, E.; Oro, L. A.; Zeier,
B. Organometallics 1994, 13, 1662. (b) Esteruelas, M. A.; Lahoz, F. J .;
On˜ate, E.; Oro, L. A.; Zeier, B. Organometallics 1994, 13, 4258. (c)
Esteruelas, M. A.; Lahoz, F. J .; On˜ate, E.; Oro, L. A.; Valero, C.; Zeier,
B. J . Am. Chem. Soc. 1995, 117, 7935.
1
and characterized by elemental analysis and IR and H,
13C{1H}, and 31P{1H} NMR spectroscopy. Figure 6
shows the 1H-13C HETCOR spectrum. The resonances
1
of the H NMR spectrum were assigned on the basis of
1
a H-1H COSY spectrum and NOE experiments. The

2302 Organometallics, Vol. 17, No. 11, 1998
Esteruelas et al.
Sch em e 2
Ta ble 3. Ra tes of Isom er iza tion of Com p lex 5 to 6
in CDCl3
temp (K)
kobs (105 s-1
)
303
308
313
318
323
328
3.61 ( 0.08
6.0 ( 0.2
11.6 ( 0.3
16.7 ( 0.4
33.9 ( 0.8
52 ( 2
mol-1
.
The large negative value of the activation
entropy suggests that, in fact, the hydrogen transfer
from C(4a) to C(1) is an intramolecular process, which
could proceed by a concerted mechanism with a geo-
metrically highly oriented transition state, as shown in
Figure 9.
F igu r e 6. Selected NOE and 1H,13C HETCOR NMR
spectra of [Ru(η5-C5H5)(9-phenyl-1,3,3a,4,4a,9a-hexahydro-
naphtho[2,3-c]-1-furanylidene)(CO)(PiPr3)]BF4 (5).
At room temperature with methanol as the solvent,
complex 6 losses the alkoxy group to afford the alcohol
3-hydroxymethyl-1-phenyl-3,4-dihydronaphthalene (7,
Scheme 2) and the methoxycarbene derivative [Ru(η5-
C5H5){C(OCH3)H}(CO)(PiPr3)]PF6 (8, Scheme 2), which
were isolated as white (7) and pink (8) solids in 81%
and 96% yield, respectively.
evolves into the cationic acyclic alkoxycarbene derivative
[Ru(η5-C5H5){C(OCH2[1-phenyl-3,4-dihydro-3-naph-
thyl])H}(CO)(PiPr3)]+ (6, Scheme 2) as a result of the
intramolecular hydrogen transfer from C(4a) to C(1)
with the concomitant aromatization of one of the rings.
Complex 6 was isolated as the PF6 salt in 63% yield by
addition of NaPF6 to the tetrahydrofuran solution.
The presence of the alkoxycarbene ligand in this
1
In the H NMR spectrum of 8, the methoxycarbene
ligand displays a singlet at 11.93 ppm, assigned to the
RudCH proton, and a singlet at 3.45 ppm corresponding
to the methoxy group. In the 13C{1H} NMR spectrum,
the carbene ligand gives rise to a doublet at 299.4 ppm,
with a C-P coupling constant of 11.3 Hz, and a singlet
at 73.7 ppm, which were assigned to the RudC and
OCH3 carbon atoms, respectively.
1
complex is strongly supported by the H and 13C{1H}
NMR spectra. In the 1H NMR spectrum, the most
noticeable resonance is a singlet at 13.65 ppm, which
was assigned to the RudCH proton, and in the 13C{1H}
NMR spectrum, a broad resonance at 302.0 ppm corre-
sponding to the RudC carbon atom is the most promi-
nent.
The isomerization of 5 into 6 was also followed by
31P{1H} NMR spectroscopy, by measuring the disap-
pearance of the PiPr3 resonance of 5 (δ ) 66.9) as a
function of time. As shown in Figure 7, the decrease of
5 (with the corresponding increase of 6 (δ ) 73.5)) in
chloroform is an exponential function of time, in agree-
ment with a first-order process. The values obtained
for the first-order rate constant kobs in the temperature
range studied are reported in Table 3. The activation
parameters of the reaction were obtained from the
Eyring analysis shown in Figure 8, giving values of ∆Hq
) 20.8 ( 0.9 kcal mol-1 and ∆Sq ) -10.6 ( 0.7 cal K-1
Con clu d in g Rem a r k s
This study has revealed that the allenylidene complex
[Ru(η5-C5H5)(CdCdCPh2)(CO)(PiPr3)]BF4 (1) adds allyl
alcohol to give the R,â-unsaturated alkoxycarbene [Ru(η5-
C5H5){C(OCH2CHdCH2)CHdCPh2}(CO)(PiPr3)]BF4 (2),
which by deprotonation affords the alkoxyallenyl com-
plex Ru(η5-C5H5){C(OCH2CHdCH2)dCdCPh2}(CO)-
(PiPr3) (3).
In solution, complex 3 is stable at low temperature.
At room temperature, it evolves into the unprecedented

Cycloaddition with a Phenylallenylidene Complex
Organometallics, Vol. 17, No. 11, 1998 2303
F igu r e 7. Stacked 31P{1H} NMR spectra illustrating the isomerization of complex 5 to 6 in CDCl3 at 303 K.
F igu r e 9. Transition state for the isomerization of 5 to 6.
edented tricyclic carbene [Ru(η5-C5H5)(9-phenyl-
1,3,3a ,4,4a ,9a -h exa h ydr on a ph t h o[2,3-c]-1-fu r a n yl-
idene)(CO)(PiPr3)]BF4 (5) by direct attack of the proton
of the acid to the Câ atom of the tetraenyl unit of 4. The
attack is also stereospecific, and the proton makes its
entry in the direction pointed by the carbonyl group of
4.
In solution, complex 5 is also unstable and evolves
into the acyclic alkoxycarbene [Ru(η5-C5H5){C(OCH2[1-
phenyl-3,4-dihydro-3-naphthyl])H}(CO)(PiPr3)]+ (6) by
a concerted intramolecular hydrogen transfer reaction.
At room temperature with methanol as the solvent,
complex 6 losses the alkoxy group to afford the alcohol
3-hydroxymethyl-1-phenyl-3,4-dihydronaphthalene (7)
and the methoxycarbene organometallic cation [Ru(η5-
C5H5){C(OCH3)H}(CO)(PiPr3)]+ (8).
In conclusion, we report a step-by-step study of a new
cycloaddition reaction involving a transition-metal phen-
ylallenylidene complex and allyl alcohol, which has
usefulness in organic synthesis.
F igu r e 8. Eyring plot of the first-order rate constants (kobs
for the isomerization of 5 to 6 in CDCl3 at 303 K.
)
tricyclic tetraenyl derivative Ru(η5-C5H5)(9-phenyl-
3,3a,4,4a-tetrahydronaphtho[2,3-c]-1-furanyl)(CO)-
(PiPr3) (4) by an intramolecular Diels-Alder reaction,
where the Câ-Cγ double bond and one of the two phenyl
groups of the allenyl unit act as an inner-outer ring
diene and the CHdCH2 double bond of the alkoxy
fragment acts as a dienophile. The isomerization is
highly stereospecific due to the chiral nature of 3. Thus,
the approach of the dienophile to the diene is deter-
mined by the R or S configuration of the metallic center
of 3.
The Câ atom of the tetraenyl ligand of 4 is the
nucleophilic center of the molecule. As a consequence,
the reaction of 4 with HBF4 leads to the also unprec-

2304 Organometallics, Vol. 17, No. 11, 1998
Esteruelas et al.
Ru-Cd), 135.8 (s, OCH2CHdCH2), 129.1, 129.0, 128,2, 126.0
(all s, Ph), 115.4 (s, OCH2CHdCH2), 107.1 (s, dCPh2), 85.8 (s,
Cp), 72.0 (s, OCH2CHdCH2), 27.4 (d, J (PC) ) 23.0, PCHCH3),
19.7, 19.3 (both s, PCHCH3).
Exp er im en ta l Section
All reactions were carried out with rigorous exclusion of air
using Schlenk-tube techniques. Solvents were dried by the
usual procedures and distilled under argon prior to use. The
starting material [Ru(η5-C5H5)(CdCdCPh2)(CO)(PiPr3)]BF4 (1)
was prepared by the published method.12
P r ep a r a tion of Ru (η5-C5H5)(9-p h en yl-3,3a ,4,4a -tetr a h y-
d r on a p h th o[2,3-c]-1-fu r a n yl)(CO)(P iP r 3) (4). A solution of
3 (250 mg, 0.63 mmol) in 30 mL of pentane was stirred at room
temperature for 20 h, and the color changed from pale yellow
to yellow. The solution was concentrated to ca. 2 mL, and a
yellow solid precipitated, which was washed with cold pentane.
Yield: 200 mg (80%). Anal. Calcd for C33H41O2PRu: C, 65.87;
H 6.87. Found: C, 65.63; H, 6.46. IR (Nujol, cm-1): ν(CO)
1935 (vs); ν(CdC, Ph) 1595 (w), 1553 (m), 1521 (s). 1H NMR
(300 MHz, 293 K, C6D6, plus COSY, plus NOE): δ 7.65 (m,
2H, Ph), 7.27 (m, 2H, Ph), 7.13 (m, 1H, Ph), 6.94 (dd, 1H,
J (H26H27) ) 9.6, J (H26H28) ) 0.9, H26), 6.11 (dddd, 1H,
J (H28H29) ) 9.3, J (H27H28) ) 5.4, J (H28H30) ) J (H26H28) ) 0.9,
NMR spectra were recorded on either a Varian UNITY 300,
a Varian GEMINI 2000, or a Bruker 300 ARX spectrometer.
Chemical shifts are expressed in ppm upfield from Me4Si (1H
and 13C) and 85% H3PO4 (31P). Coupling constants, J , are
given in hertz. IR spectra were run on a Nicolet 550 spectro-
photometer (Nujol mulls on polyethylene sheets or KBr pel-
lets). Elemental analyses were carried out on a Perkin-Elmer
2400 CHNS/O analyzer. MS data were recorded on a VG
Autospec double-focusing mass spectrometer operating in the
positive mode; ions were produced with the standard Cs+ gun
at ca. 30 kV, and 3-nitrobenzyl alcohol (NBA) was used as the
matrix.
H28), 6.04 (ddd, 1H, J (H28H29) ) 9.3, J (H29H30) ) 4.2, J (H27H29
) 0.9, H29), 5.74 (dddd, 1H, J (H26H27) ) 9.6, J (H27H28) ) 5.4,
J (H27H30) ) 1.5, J (H27H29) ) 0.9, H27), 4.54 (dd, 1H, J (H33H33′
)
)
P r ep a r a t ion
of
[R u (η5-C5H 5){C(OCH 2CH dCH 2)-
) J (H32H33) ) 9.0, H33), 4.48 (s, 5H, Cp), 3.52 (dd, 1H,
J (H33H33′) ) 9, J (H32H33′) ) 12, H33′), 3.20 (ddddd, 1H,
CHdCP h 2}(CO)(P iP r 3)]BF 4 (2). A 120 mg amount of 1 was
dissolved in 5 mL of allyl alcohol, and the solution was stirred
for 2 h. The color changed from deep red to deep orange, and
the solvent was removed in vacuo. The residue was repeatedly
washed with diethyl ether, affording a yellow solid. Yield: 113
mg (86.2%). Anal. Calcd for C33H42BF4O2PRu: C, 57.48; H,
6.14. Found: C, 57.02; H, 5.98. IR (Nujol, cm-1): ν(CO) 1955
(s); ν(Ph, CdC) 1585, 1564 (both m); ν(C-O) 1262 (s); ν(BF4)
1056 (br). 1H NMR (300 MHz, 293 K, CDCl3): δ 7.5-7.1 (m,
10H, Ph), 6.58 (s, 1H, HCd), 6.01 (m, 1H, OCH2CHdCH2), 5.41
(d, 1H, J trans ) 16.5, OCH2CHdCHH), 5.37 (d, 1H, J cis ) 10.0,
OCH2CHdCHH), 5.10 (m, 2H, OCH2CHdCH2), 4.97 (s, 5H,
Cp), 2.26 (m, 3H, PCHCH3), 1.24 (dd, 9H, J (HH) ) 7.2, J (PH)
) 15.3, PCHCH3), 1.18 (dd, 9H, J (PH) ) 7.2, J (PH) ) 16.1,
PCHCH3). 31P{1H} NMR (121.4 MHz, 293 K, CDCl3): δ 65.9
(s). 13C{1H} NMR (75.4 MHz, 293 K, CDCl3, plus HETCOR):
δ 304.0 (br, RudC), 202.9 (d, J (PC) ) 15.7, CO), 139.6, 137.7
(both s, Cipso-Ph + HCdCPh2), 136.9 (br s, HCdCPh2), 131.1,
129.7, 129.6, 128.7, 128.6, 128.4 (all s, Ph), 129.8 (s,
OCH2CHdCH2), 122.7 (s, OCH2CHdCH2), 89.6 (s, Cp), 81.1
(s, OCH2CHdCH2), 29.3 (d, J (PC) ) 24.3, PCHCH3), 19.7, 19.4
(both s, PCHCH3).
J (H30H31′) ) 9.6, J (H30H31) ) 6.3, J (H29H30) ) 4.2, J (H27H30
)
) 1.5, J (H28H30) ) 0.9, H30), 2.76 (dddd, 1H, J (H32H33′) ) 12,
J (H31′H32) ) 9.6, J (H32H33) ) 9.0, J (H31H32) ) 3.6, H32), 1.92
(m, 3H, PCHCH3), 1.81 (ddd, J (H31H31′) ) 12.6, J (H30H31) )
6.3, J (H31H32) ) 3.6, H31), 1.74 (ddd, J (H31H31′) ) 12.6,
J (H30H31′) ) J (H31′H32) ) 9.6, H31′), 1.01 (dd, 9H, J (HH) ) 7.2,
J (PH) ) 14.4, PCHCH3), 0.81 (dd, 9H, J (HH) ) 6.9, J (PH) )
12.3, PCHCH3). 31P{1H} NMR (121.4 MHz, 293 K, C6D6): δ
72.2 (s). 13C{1H} NMR (75.4 MHz, 293 K, C6D6, plus DEPT):
δ 207.2 (d, J (PC) ) 18.9, CO), 175.8 (d, J (PC) ) 10.5, C16),
142.3, 137.2, 133.8, 128.1 (all s, Cipso-Ph, C17, C18, C25), 133.0,
131.8, 127.5 (all s, Ph), 126.0, 125.8, 123.4, 119.8 (all s, C26
C29), 85.7 (s, Cp), 78.0 (s, C33), 40.8 (s, C31), 38.4, 36.8 (both s,
30, C32), 27.6 (d, J (PC) ) 22.1, PCHCH3), 20.7, 19.6 (both s,
-
C
PCHCH3).
P r ep a r a tion of [Ru (η5-C5H5)(9-p h en yl-1,3,3a ,4,4a ,9a -
h exa h yd r on a p h t h o[2,3-c]-1-fu r a n ylid en e)(CO)(P iP r 3)]-
BF 4 (5). A stirred solution of 4 (200 mg, 0.33 mmol) in 10 mL
of diethyl ether at -70 °C was treated with tetrafluoroboric
acid (91 µL, 0.66 mmol, 54% in diethyl ether), and the mixture
was stirred for 3 h. A white solid precipitated, which was
washed with cold diethyl ether. Yield: 192 mg (84%). Anal.
Calcd for C33H42BF4O2PRu: C, 57.48; H, 6.14. Found: C,
57.05; H, 6.08. IR (Nujol, cm-1): ν(CO) 1960 (vs); ν(Ph) 1599
(w); ν(C-O) 1232 (s); ν(BF4) 1061 (s). 1H NMR (300 MHz, 293
K, CDCl3, plus COSY, plus NOE): δ 7.60 (m, 2H, Ph), 7.47
(m, 2H, Ph), 7.31 (m, 1H, Ph), 6.69 (d, 1H, J (H8H7) ) 9.6, H8),
5.98 (dd, 1H, J (H6H5) ) 9.3, J (H7H6) ) 6.0, H6), 5.92 (dd, 1H,
J (H8H7) ) 9.6, J (H7H6) ) 6.0, H7), 5.79 (dd, 1H, J (H6H5) )
9.3, J (H5H4a) ) 4.5, H5), 5.56 (dd, 1H, J (H3H3′) ) 9.6, J (H3aH3)
) 7.2, H3), 5.10 (s, 5H, Cp), 5.08 (dd, 1H, J (H3H3′) ) 9.6,
J (H3aH3′) ) 8.1, H3′), 4.65 (d, 1H, J (H9aH3a) ) 7.8, H9a), 2.79
(ddddd, 1H, J (H4H3a) ) 1.0, J (H4′H3a) ) 9.6, J (H3aH3) ) 7.2,
P r ep a r a t ion of R u (η5-C5H 5){C(OCH2CH dCH 2)dCd
CP h 2}(CO)(P iP r 3) (3). A yellow solution of 2 (200 mg, 0.29
mmol) in 10 mL of THF at -50 °C was treated with sodium
methoxide (31.3 mg, 0.58 mmol). The mixture was stirred for
20 min, and the color changed to pale yellow. Solvent was
slowly evaporated to dryness. The temperature was decreased
to -78 °C, and 15 mL of pentane was carefully added. The
suspension was very rapidly filtered to eliminate NaBF4, and
the solution recovered at -78 °C. Solvent was slowly evapo-
rated in vacuo to afford a pale yellow solid. Yield: 141 mg
(81%). Anal. Calcd for C33H41O2PRu: C, 65.87; H 6.87.
Found: C, 65.46; H, 6.91. IR (Nujol, cm-1): ν(CO) 1942 (s);
ν(CdCdC) 1891 (w); ν(Ph, CdC) 1643 (w) 1596 (m); ν(C-O)
1030 (s). 1H NMR (300 MHz, 293 K, C6D6): δ 7.71 (m, 4H,
Ph), 7.25 (m, 4H, Ph), 7.11 (m, 2H, Ph), 5.94 (dddd, 1H, J (HaHb)
) J (Ha′Hb) ) 5.4, J trans ) 17.1, J cis ) 10.5, OCHaHa′CHbdCHcHd),
J (H3aH3′) ) 8.1, J (H9aH3a) ) 7.8, H3a), 2.25 (ddd, 1H, J (H5H4a
) 4.5, J (H4aH4) ) 3.6, J (H4aH4′) ) 13.2, H4a), 2.19 (m, 3H,
PCHCH3), 1.84 (ddd, J (H4H4′) ) 13.2, J (H4aH4) ) 3.6, J (H4H3a
)
)
) 1.0, H4), 1.64 (ddd, J (H4H4′) ) 13.2, J (H4aH4′) ) 13.2,
J (H4′H3a) ) 9.6, H4′), 1.11 (dd, 9H, J (HH) ) 7.3, J (PH) ) 14.7,
PCHCH3), 1.09 (dd, 9H, J (HH) ) 7.3, J (PH) ) 14.1, PCHCH3).
31P{1H} NMR (121.4 MHz, 293 K, CDCl3): δ 66.9 (s). 13C{1H}
NMR (75.4 MHz, 293 K, CDCl3, plus HETCOR): δ 310.4 (d,
J (PC) ) 9.2, C1), 203.4 (d, J (PC) ) 16.1, CO), 139.6, 139.0,
129.5 (all s, Cipso-Ph, C9, C8a), 131.8 (s, C5), 129.3, 128.8, 127.6
(all s, Ph), 125.6 (s, C7), 123.0 (s, C6), 122.9 (s, C8), 93.9 (s, C3),
87.4 (s, Cp), 80.9 (s, C9a), 39.0 (s, C4a), 38.1 (s, C4), 28.6 (s, C3a),
28.2 (d, J (PC) ) 23.4, PCHCH3), 19.8 (s, PCHCH3), 19.4 (d,
J (PC) ) 1.8, PCHCH3). MS (FAB+): m/z 603 (M+).
5.25 (dddd, 1H, J (HaHd) ) J (Ha′Hd) ) J (HcHd) ) 1.8, J trans
)
17.1, OCHaHa′CHbdCHcHd), 5.01 (dddd, 1H, J (HaHc) ) J (Ha′Hc)
) J (HcHd) ) 1.8, J cis ) 10.5, OCHaHa′CHbdCHcHd), 4.94 (s,
5H, Cp), 4.37, 4.31 (both dddd, 2H, J (HaHa′) ) J (HaHc) )
J (HaHd) ) J (Ha′Hc) ) J (Ha′Hd) ) 1.8, J (HaHb) ) J (Ha′Hb) )
5.4, OCHaHa′CHbdCHcHd), 1.97 (m, 3H, PCHCH3), 0.96 (dd,
9H, J (HH) ) 6.9, J (PH) ) 13.5, PCHCH3), 0.85 (dd, 9H, J (PH)
) 7.2, J (PH) ) 13.2, PCHCH3). 31P{1H} NMR (121.4 MHz,
293 K, C6D6): δ 72.6 (s). 13C{1H} NMR (75.4 MHz, 235 K,
toluene-d8, plus apt): δ 207.1 (d, J (PC) ) 25.8, CO), 197.9 (s,
dCd), 141.9, 141.7 (both s, Cipso-Ph), 136.2 (d, J (PC) ) 13.8,

Cycloaddition with a Phenylallenylidene Complex
Organometallics, Vol. 17, No. 11, 1998 2305
P r ep a r a t ion of [R u (η5-C5H 5)(9-p h en yl-9a -d eu t er o-
1,3,3a ,4,4a -p en t a h yd r on a p h t h o[2,3-c]-1-fu r a n ylid en e)-
(CO)(P iP r 3)]BF 4 (5-d 1). The same method as for the prepa-
ration of 5 was used but with deuterated tetrafluoroboric acid.
1H NMR (300 MHz, 293 K, CDCl3): Absence of the doublet at
4.65 ppm is observed. 2D{1H} NMR (46.07 MHz, 293 K,
CHCl3): δ 4.59 (br, D9a).
P r ep a r a tion of [Ru (η5-C5H5){C(OCH2[1-p h en yl-3,4-d i-
h yd r o-3-n a p h th yl])H }(CO)(P iP r 3)]P F 6 (6). A solution of 5
(200 mg, 0.29 mmol) in 10 mL of tetrahydrofuran at 50 °C
was stirred for 10 h, and the color changed from yellow to
orange. Sodium hexafluorophosphate (49 mg, 0.58 mmol) was
added, and the mixture was stirred for 30 min. Solvent was
evaporated in vacuo, and 10 mL of dichloromethane was
added. The mixture was filtered to eliminate excess of sodium
hexafluorophosphate and sodium tetrafluoroborate. Solvent
was removed in vacuo, and the residue was washed with
diethyl ether to afford 6 as a salmon solid. Yield: 137 mg
(63%). Anal. Calcd for C33H42F6O2P2Ru: C, 53.01; H, 5.66.
Found: C, 52.70; H, 5.15. IR (Nujol, cm-1): ν(CO) 1992 (vs);
Ta ble 4. Cr ysta l Da ta a n d Da ta Collection a n d
Refin em en t for Ru (η5-C5H5)(9-p h en yl-3,3a ,4,4a -
tetr a h yd r on a p h th o[2,3-c]-1-fu r a n yl)(CO)(P iP r 3) (4)
Crystal Data
formula
mol wt
color and habit
symmetry
space group
a, Å
C33H41O2PRu
601.70
yellow, prismatic block
triclinic
P1h
10.415(3)
11.819(4)
14.114(5)
68.15(2)
86.69(2)
69.110(10)
1500.9(9)
2
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
Z
D
calc, g cm-3
1.331
Data Collection and Refinement
diffractometer
λ(Mo KR), Å; technique
monochromator
µ, mm-1
four-circle Siemens-P4
0.710 73; bisecting geometry
graphite oriented
0.60
θ/2θ
3 e 2θ e 50
200.0(2)
7179
5120 (Rint ) 0.0495)
335
scan type
2θ range, deg
temp, K
no.of data collect
no. of unique data
no. of params refined
a
R1 (F2 > 2σ(F2))
0.0297
0.0755
1.059
wR2b(all data)
Sc (all data)
R1(F) ) ∑||Fo| - |Fc||/∑|Fo|. wR2(F2) ) {∑[w(Fo - Fc2)2]/
a
b
2
∑[w(Fo2)2]}1/2
.
c Goof ) S ) {∑[w(Fo - Fc2)2]/(n - p)}1/2, where n
2
is the number of reflections and p is the number of refined
ν(Ph) 1599 (w); ν(PF6) 850 (vs). 1H NMR (300 MHz, 293 K,
CDCl3, plus COSY): δ 13.65 (s, 1H, RudCH), 7.34 (m, 5H,
Ar), 7.19 (m, 2H, Ar), 7.12 (m, 1H, Ar), 7.02 (m, 1H, Ar), 5.91
(d, 1H, J (H2H3) ) 3.6, H2), 5.54 (s, 5H, Cp), 4.66 (d, 2H, J (HH3)
) 6.6, CH2O), 3.02 (m, 2H, H3 + H4), 2.85 (dd, 1H, J (H4H4′) )
16.8, J (H4′H3) ) 11.7, H4′), 2.22 (m, 3H, PCHCH3), 1.22 (dd,
9H, J (HH) ) 7.2, J (PH) ) 15.0, PCHCH3), 1.10 (dd, 9H, J (HH)
) 6.9, J (PH) ) 15.0, PCHCH3). 31P{1H} NMR (121.4 MHz,
293 K, CDCl3): δ 73.5 (s, PCHCH3), -144.4 (sept, J (PF) )
717.0, PF6). 13C{1H} NMR (75.4 MHz, 293 K, CDCl3, plus
HETCOR): δ 302.0 (br, RudCH), 201.2 (d, J (PC) ) 14.8, CO),
142.0, 139.8, 134.5, 134.1 (all s, Cipso-Ph, C1, C4a, C8a), 129.6,
128.4, 128.2, 127.8, 127.7, 126.7, 125.5 (all s, Ph + C5-C8),
125.9 (s, C2), 90.5 (s, Cp), 89.5 (s, CH2O), 35.1 (s, C3), 30.7 (s,
C4), 28.0 (d, J (PC) ) 25.3, PCHCH3), 19.3, 19.1 (both s,
PCHCH3). MS (FAB+): m/z 603 (M+).
parameters.
and the solid was solved in n-pentane and stored at -78 °C to
afford 7 as thin white needles. Yield: 30 mg (81%). IR (KBr,
cm-1): ν(OH) 3399 (br); ν(C-O) 1084 (s). 1H NMR (300 MHz,
293 K, C6D6): δ 7.34-6.93 (m, 9H, Ar), 5.87 (d, 1H, J (H2H3)
) 3.0, H2), 3.32 (d, 2H, J (HH3) ) 5.7, CH2O), 2.69 (d, 2H,
J (H4H3) ) 9.0, H4) 2.48 (m, 1H, H3), 1.23 (br s, 1H, OH).
13C{1H} NMR (75.4 MHz, 293 K, C6D6, plus HETCOR):
δ
141.1, 141.0, 136.1, 135.2 (all s, Cipso-Ph, C4a, C8a, C1), 129.2 (s,
C2), 129.1, 128.5, 128.4, 127.6, 127.5, 126.7, 126.1 (all s, C5-
C8 + Ph), 64.9 (s, CH2O), 37.6 (s, C3), 31.3 (s, C4). MS (FAB+):
m/z 236 (M+).
P r ep a r a tion of 3-Hyd r oxym eth yl-1-p h en yl-3,4-d ih y-
d r on a p h th a len e (7) a n d [Ru (η5-C5H5){C(OCH3)H}(CO)-
(P iP r 3)]P F 6 (8). A solution of 6 (117 mg, 0.16 mmol) in 10
mL of methanol was stirred for 30 min. Solvent was removed
in vacuo, and the residue was extracted with diethyl ether,
affording a yellow solution and 8 as a salmon solid. Yield: 82
mg (96%). Anal. Calcd for C17H30F6O2P2Ru: C, 37.57; H, 5.56.
Found: C, 37.83; H, 5.06. IR (Nujol, cm-1): ν(CO) 1986 (vs);
ν(PF6) 850 (vs). 1H NMR (300 MHz, 293 K, CDCl3): δ 11.93
(s, 1H, RudCH), 4.97 (s, 5H, Cp), 3.45 (s, 3H, OCH3), 1.94 (m,
3H, PCHCH3), 1.01 (dd, 9H, J (HH) ) 7.2, J (PH) ) 14.7,
PCHCH3), 0.87 (dd, 9H, J (HH) ) 6.6, J (PH) ) 15.0, PCHCH3).
31P{1H} NMR (121.4 MHz, 293 K, CDCl3): δ 73.7 (s, PCHCH3),
-145.3 (sept, J (PF) ) 716.0, PF6). 13C{1H} NMR (75.4 MHz,
293 K, CDCl3, apt): δ 299.4 (d, J (PC) ) 11.3, RudC), 202.7
(d, J (PC) ) 16.2, CO), 90.2 (s, Cp), 73.7 (s, OCH3), 27.8 (d,
J (PC) ) 25.3, PCHCH3), 19.3 (s, PCHCH3), 18.9 (d, J (PC) )
0.9, PCHCH3). MS (FAB+): m/z 399 (M+).
X-r a y Str u ctu r e An a lysis of Ru (η5-C5H5)(9-p h en yl-
3,3a ,4,4a -t e t r a h y d r o n a p h t h o [2,3-c]-1-fu r a n y l)(C O )-
(P iP r 3) (4). Crystals suitable for the X-ray diffraction study
were obtained from a saturated solution of 4 in pentane stored
at 4 °C. A summary of crystal data and refinement parameters
is reported in Table 4. The yellow, prismatic crystal, of
approximate dimensions 0.5 × 0.5 × 0.8 mm, was glued on a
glass fiber and mounted on a Siemens-P4 diffractometer. A
group of 62 reflections in the range 20° e 2θ e 35 ° were
carefully centered at 200 K and used to obtain the unit cell
dimensions by least-squares methods. Three standard reflec-
tions were monitored at periodic intervals throughout data
collection: no significant variations were observed. All data
were corrected for absorption using a semiempirical method.28
The structure was solved by Patterson (Ru atom, SHELXTL-
The yellow solution was concentrated to ca. 1 mL and
chromatographed on a 10 cm neutral silica-gel column (eluent,
pentane-diethyl ether, 1:1). Solvent was removed in vacuo,
(28) North, A. C. T.; Phillips, D. C.; Mathews, F. S. Acta Crystallogr.
1968, A24, 351.

2306 Organometallics, Vol. 17, No. 11, 1998
Esteruelas et al.
PLUS29) and conventional Fourier techniques and refined by
full-matrix least-squares on F2 (SHELXL9330). Anisotropic
parameters were used in the last cycles of refinement for all
non-hydrogen atoms. The hydrogen atoms were located from
difference Fourier maps or fixed in idealized positions and
refined riding on carbon atoms with a common isotropic
thermal parameter. Atomic scattering factors, corrected for
anomalous dispersion for Ru and P, were implemented by the
were obtained by fitting the data to an exponential decay
function, using the routine programs of the spectrometer.
Activation parameters ∆Hq and ∆Sq were obtained by least-
squares fit of the Eyring plot. Error analysis assumed a 6.1%
and 2.1% in the rate constants, respectively (the maximum
values found in the experimental determinations), and 1 K in
the temperature. Errors were computed by published meth-
ods.31
program. The refinement converged to R1 ) 0.0297 (F2
>
Ack n ow led gm en t. We thank the DGES (Project
PB-95-0806, Programa de Promocio´n General del Cono-
cimiento) for financial support. E.O. thanks the DGA
(Diputacio´n General de Arago´n) for a grant.
2σ(F2)) and wR2 ) 0.0755 (all data), with weighting parameters
x ) 0.0393 and y ) 0.60.
Kin etic An a lysis. The isomerizations of complexes 3 to 4
and 5 to 6 were followed quantitatively by 31P{1H} NMR
spectroscopy in toluene-d8 and CDCl3, respectively. The
decrease of the intensity of the signal of PiPr3 in complexes 3
and 5 was measured automatically at intervals in a Varian
GEMINI 2000 spectrometer. The rate constants and the errors
Su p p or tin g In for m a tion Ava ila ble: Tables of atomic
coordinates, anisotropic and isotropic thermal parameters,
experimental details of the X-ray study, bond distances and
angles, and selected least-squres planes (13 pages). Ordering
information is given on any current masthead page.
(29) Sheldrick, G. SHELXTL-PLUS; Siemens Analytical X-ray
Instruments, Inc.: Madison WI, 1990.
(30) Sheldrick, G. SHELXL-93. Program for Crystal Structure
Refinement; Institu¨t fu¨r Anorganische Chemie der Universita¨t: Go¨t-
tingen, Germany, 1993.
OM980132P
(31) Morse, P. M.; Spencer, M. O.; Wilson, S. R.; Girolami; G. S.
Organometallics 1994, 13, 1646.