Diastereoselective synthesis of the indenylruthenium(II) complexes [Ru(η5-C9H7){κ3(P,C,C)- Ph2P(CH2CR=CH2)}(PPh3)][PF 6] (R = H, Me)

Article abstract of DOI:10.1021/om040001q

The stereoselective synthesis and reactivity of the mixed-phosphine complexes [Ru(η ⁵-C₉H₇){k ³(P,C,C)- Ph₂P(CH₂CR=CH₂)}(PPh ₃)][PF ₆] (R=H, Me) bearing the hybrid hemilabile ligand allyldiphenylphosphine were discussed. It was found that the reaction of R=H with sodium methoxide in methanol yielded the hybride derivative complexes. The olefin exchange occurred with regard to parallel first-order and second-order pathways. The ruthenium fragment acting as a Lewis acid with chiral recognition provides an appropriate means to envisage potential enantioselective transformations of prochiral olefins.

Full text of DOI:10.1021/om040001q

2956
Organometallics 2004, 23, 2956-2966
Dia ster eoselective Syn th esis of th e
In d en ylr u th en iu m (II) Com p lexes
[Ru (η5-C9H7){K3(P ,C,C)-P h 2P (CH2CRdCH2)}(P P h 3)][P F 6]
(R ) H, Me): En a n tiofa cia l Coor d in a tion , Hem ila bile
P r op er ties, a n d Dia ster eoselective Nu cleop h ilic
Ad d ition s to K3(P ,C,C)-Allylp h osp h in e Liga n d s
Patricia AÄ lvarez,† Elena Lastra,† J ose´ Gimeno,*,† Pedro Bran˜a,‡ J ose´ A. Sordo,‡
J ulio Gomez,§ Larry R. Falvello,| and Mauro Bassetti
Departamento de Qu´ımica Orga´nica e Inorga´nica, Instituto de Quı´mica Organometa´lica
“Enrique Moles” (Unidad Asociada al CSIC), and Laboratorio de Quı´mica Computacional,
Departamento de Qu´ımica Fı´sica y Anal´ıtica, Universidad de Oviedo, Oviedo, Principado de
Asturias, Spain, Department of Chemistry, Universidad de La Rioja, Complejo Cient´ıfico
Tecnolo´gico, Calle Madre de Dios, 51, 26006 Logron˜o, Spain, Departamento de Qu´ımica
Inorga´nica, Facultad de Ciencias, Universidad de Zaragoza-CSIC, E-50009 Zaragoza, Spain,
and Istituto CNR di Metodologie Chimiche, Sezione Meccanismi di Reazione, and
Dipartimento di Chimica, Universita` “La Sapienza”, 00185 Roma, Italy
Received J anuary 8, 2004
The mixed-phosphine complexes [Ru(η5-C9H7)Cl{κ1(P)-Ph2P(CH2CRdCH2)}(PPh3)] (R )
H (1a ), Me (1b)) are prepared by phosphine exchange reactions (1:1 molar ratio) of [Ru(η5-
C9H7)Cl(PPh3)2] with the corresponding allylphosphines Ph2P(CH2CRdCH2) in refluxing THF.
The reaction of 1a with sodium methoxide in methanol yields the hydride derivative [Ru-
(η5-C9H7)H{κ1(P)-Ph2P(CH2CHdCH2)}(PPh3)] (1c). The treatment of complexes 1a and 1b
with NaPF6 in methanol diastereoselectively affords the cationic complexes [Ru(η5-C9H7)-
{κ3(P,C,C)-Ph2P(CH2CRdCH2)}(PPh3)][PF6] (R ) H (2a ), Me (2b)) in good yield. An X-ray
crystal structure determination of complex 2a shows that the si enantiofacial coordination
of the olefin group accompanies the R relative configuration of the metal center. No
epimerization process has been observed. Olefin exchange substitution reactions of complex
2a with MeCN and BzCN (1:1.5 molar ratio) in refluxing CH2Cl2 yield the cationic complexes
[Ru(η5-C9H7)(NCR){κ1(P)-Ph2P(CH2CHdCH2)}(PPh3)][PF6] (R ) Me (3a ), Bz (3b)). Similarly,
the neutral complexes [Ru(η5-C9H7)(N3){κ1(P)-Ph2P(CH2CRdCH2)}(PPh3)] (R ) H (4a ), Me
(4b)) are obtained by the treatment of complexes 2a ,b with sodium azide in THF/MeOH at
room temperature. The addition of lithium carbanions LiR′ (R′ ) Me, nBu) to solutions of
complexes 2a ,b in tetrahydrofuran results in regio- and stereoselective exo addition at the
Câ atom of the coordinated allylic group, affording the ruthenacyclopentane complexes [Ru-
(η5-C9H7){κ2(P,C)-Ph2P{CH2C(R)(R′)CH2}}(PPh3)] (R ) H, R′ ) Me (5a ), nBu (5b); R ) Me,
R′ ) Me (6a ), nBu (6b)) in 80-95% yield. Similarly, the complexes [Ru(η5-C9H7){κ2(P,C)-
Ph2P{CH2CH(R)CH2}}(PPh3)] (R ) H (5c), Me (6c)) are formed by the reaction of equimolar
mixtures of complexes 2a ,b with Li[B(C2H5)3H]. The molecular structure and relative
configurations RRuS/SRuR of the new stereogenic atoms of complex 5b have been determined
by X-ray diffraction. Kinetic studies on the substitution reaction of complex 2a with CD3CN
in CDCl3 indicate that the olefin exchange occurs via parallel first-order (dissociative) and
second-order (associative) pathways and highlight the intermediacy of a transient coordi-
natively unsaturated species, formed by olefin dissociation before attack of the nitrile.
In tr od u ction
methodologies involve transition-metal fragments which
either bear a chiral center or activate the substrate
toward the addition of a nucleophile in a stereoselective
manner. In particular, monosubstituted alkenes (RCHd
CH2) and unsymmetrically substituted geminal alkenes
(R(R′)CdCH2), bearing different CdC termini substit-
uents, feature binding modes that can give two enan-
tiotopic faces upon coordination to a metal center (con-
figurational diastereomers A and B: Chart 1). Moreover,
providing that rotation around the CdC π bond is
Prochiral alkenes are among the most common start-
ing materials for enantioselective synthesis. Reaction
† Departamento de Qu´ımica Orga´nica e Inorga´nica, Universidad de
Oviedo.
‡ Departamento de Qu´ımica F´ısica y Anal´ıtica, Universidad de
Oviedo.
§ Universidad de La Rioja.
| Universidad de Zaragoza-CSIC.
CNR, Instituto di Metodologie Chimiche.
10.1021/om040001q CCC: $27.50 © 2004 American Chemical Society
Publication on Web 05/11/2004

Diastereoselective Synthesis of Ru Indenyl Complexes
Organometallics, Vol. 23, No. 12, 2004 2957
a
Ch a r t 1
Sch em e 1
Ch a r t 2
a
Absolute configurations are not noted. Legend: (i) Ph2PCH2-
CRdCH2, THF reflux, 15 min; (ii) NaOMe, MeOH reflux, 30
min; (iii) NaPF6, MeOH reflux, 30 min; (iv) 1.5 RCN, CH2Cl2
reflux, 45 min; (v) NaN3, THF/MeOH, room temperature, 30
min; (vi) MeLi, THF, room temperature, 10 min; (vii) nBuLi,
THF, room temperature, 10 min; (viii) Li[B(C2H2)3H], THF,
room temperature, 10 min.
allowed, two M-(CdC) rotamers can exist for each of
the two isomers (A′ and B′). As a result, a new stereo-
genic carbon atom is generated, giving rise to chiral
complexes which normally are formed in equal amounts.
The use of chiral or prochiral metal fragments pro-
vides the most direct means of chiral recognition of these
alkenes, enabling their potential enantioface binding
selectivities. To fulfill this goal, considerable effort has
been devoted to the design of organo transition-metal
complexes with appropriate electronic and steric proper-
ties,1 which would promote high binding selectivities.
During the past few years we have extensively studied
the chemistry of indenylruthenium(II) bis(phosphine)
complexes [RuX(η5-C9H7)(L)2] and investigated the ster-
ic influence of the indenyl ring and of the ancillary
ligands in the selectivity of both stoichiometric2 and
catalytic transformations.3
In this paper we report the stereoselective synthesis
and reactivity of the mixed-phosphine complexes [Ru-
(η5-C9H7)(PPh3){κ3(P,C,C)-PPh2(CH2CRdCH2)}][PF6] (R
) H, Me) bearing the hybrid hemilabile ligand allyl-
diphenylphosphine, which provides a coordinated olefin
group attached to a chiral metal fragment (A in Chart
2). The enantiofacial binding ability of the indenylru-
thenium fragment with respect to the π-olefin group
prompted us to explore the selectivity of the enantiotopic
nucleophilic additions. The hemilabile properties of the
allylphosphine ligand raise the question of whether a
competition between olefin-nucleophile exchange (B in
Chart 2) and nucleophilic addition (C in Chart 2) can
occur. As is well-known, this is the main drawback in
studies of the reactivity of olefin complexes.
Resu lts a n d Discu ssion
Scheme 1 details the syntheses of the new complexes.
Syn th esis of th e P r ecu r sor Com p lexes [Ru (η5-
C9H7)X{K1(P )-P h 2P (CH2CRdCH2)}(P P h 3)] (X ) Cl,
R ) H (1a ), Me (1b); X ) H, R ) H (1c)). The chloride
mixed-phosphine complexes [Ru(η5-C9H7)Cl{κ1(P)-Ph2-
P(CH2CRdCH2)}(PPh3)] (R ) H (1a ), Me (1b)) are
obtained via a phosphine exchange reaction by treat-
ment of [Ru(η5-C9H7)Cl(PPh3)2] with 1 equiv of allyl-
diphenylphosphines Ph2PCH2CRdCH2 (R ) H, Me) in
refluxing THF for 10 min. They have been isolated as
air-stable red solids in 85% yield (Scheme 1).4 Elemental
analysis and NMR spectroscopic data (1H, 31P{1H}, 13C-
{1H}) of 1a ,b are in accord with the proposed formula-
tions. The 31P{1H} NMR spectra show two doublet
resonances at δ 48.0 and 45.3 (d, J PP ) 43.0 Hz) for 1a
and at δ 48.8 and 45.5 (J PP ) 42.2 Hz) for 1b, in accord
with the expected AB system arising from the presence
of inequivalent phosphorus nuclei in the two monoden-
1
tate phosphines. H and 13C{1H} NMR spectra confirm
the κ(P) coordination mode of the allylphosphines,
displaying resonances of the noncoordinated allyl groups.
The most significant features are as follows: (i) in the
1H NMR spectra, two dCH2 resonances at δ 3.03 (br s),
4.92 (m) (1a ) and δ 2.94 (s), 4.28 (s) (1b) and one CH at
δ 4.87 (m) (1a ) and Me at δ 0.89 (s) (1b); (ii) in the 13C-
{1H} NMR spectra, the resonances of olefinic carbons
dCH2 at δ 119.8 (d, J CP ) 8.5 Hz) (1a ) and 115.2 (d,
J CP ) 7.5 Hz) (1b) and dCR at δ 128.1 (s br) (1a ) and
δ 140.1 (d, J CP ) 13.9 Hz) (1b).
(1) Gladysz, J . A.; Boone, B. I. Angew. Chem., Int. Ed. Engl. 1997,
36, 550.
(2) Regio- and stereoselective nucleophilic additions to unsaturated
carbenes have been reported. For recent publications see for example:
(a) Cadierno, V.; Conejero, S.; Gamasa, M. P.; Gimeno, J .; Falvello, L.
R.; Llusar, R. M. Organometallics 2002, 21, 3716. (b) Cadierno, V.;
Gamasa, M. P.; Gimeno, J .; Perez-Carren˜o, E.; Garc´ıa-Granda, S. J .
Organomet. Chem. 2003, 670, 75.
(3) (i) Dimerization of terminal alkynes: (a) Bassetti, M.; Marini,
S.; Tortorella, F.; Cadierno, V.; Diez, J .; Gamasa, M. P.; Gimeno, J . J .
Organomet. Chem. 2000, 593-594, 292. (b) Bassetti, M.; Marini, S.;
Diez, J .; Gamasa, M. P.; Gimeno, J .; Rodr´ıguez-Alvarez, Y.; Garc´ıa-
Granda, S. Organometallics 2002, 21, 4815. (ii) Hydration of alkynes:
(c) Alvarez, P.; Gimeno, J .; Lastra, E.; Garc´ıa-Granda, S.; Van der
Maelen, J . F.; Bassetti, M. Organometallics 2001, 20, 3762. (d) Alvarez,
P.; Gimeno, J .; Bassetti, M.; Mancini, G. Tetrahedron Lett. 2001, 42,
8467. (iii) Polymerization processes: (e) Alvarez, P.; Gimeno, J .; Lastra,
E. Organometallics 2002, 21, 5678.
The hydride complex [Ru(η5-C9H7)H{κ1(P)-Ph2P(CH2-
CHdCH2)}(PPh3)] (1c) is obtained (80%) by treatment
of 1a with NaOMe/MeOH in refluxing MeOH. Complex
1c is isolated as an air-stable crystalline solid and has
been characterized by analytical and spectroscopic
means (see Experimental Section for details). In par-
1
ticular the H NMR spectrum shows the hydride reso-
(4) A longer reaction time leads to the simultaneous formation of
the bis-substituted complexes [Ru(η5-C9H7)Cl{κ1(P)-Ph2P(CH2CRd
CH2)}2]: Unpublished results.

2958 Organometallics, Vol. 23, No. 12, 2004
AÄ lvarez et al.
2
nance as a virtual triplet (δ -15.32, J HP ) 31.9 Hz),
which compares well with those shown by the analogous
indenyl complexes [Ru(η5-C9H7)HL2] in the range δ
-14.12 to -17.07.5 The 31P{1H} NMR spectrum shows
two doublet resonances at δ 62.2 and 53.3 (J PP ) 25.9
Hz), in agreement with the expected AB pattern.
K3(P ,C,C)-Allylp h osp h in e Com p lexes [Ru (η5-C9-
H7){K3(P ,C,C)-P h 2P (CH2CRdCH2)}(P P h 3)][P F 6] (R
) H (2a ), Me (2b)). Treatment of a solution of either
of the chloride complexes 1a and 1b in refluxing
methanol with 1 equiv of NaPF6 for 30 min gives a
yellowish solution from which the cationic complexes
[Ru(η5-C9H7){κ3(P,C,C)-Ph2P(CH2CRdCH2)}(PPh3)]-
[PF6] (R ) H (2a ), Me (2b)) are isolated as air-stable
yellow hexafluorophosphate salts (90%) (Scheme 1). The
products have been characterized by elemental analyses
and NMR data, which confirm the coordination mode
of the allyl phosphine as κ3(P,C,C). In particular, the
1H and 13C{1H} NMR spectra show CRdCH2 (R ) H,
Me) resonances which appear at higher field than those
observed in complexes 1a -c, bearing a noncoordinated
olefinic system κ1(P) (see Experimental Section). 31P-
{1H} NMR spectra at room temperature also reveal the
effect of the olefin coordination, showing the expected
resonances for an AB system with the signals for the
allylphosphine shifted toward higher field at δ 55.2 and
F igu r e 1. Molecular structure and atom-labeling scheme
for complex 2a . Non-hydrogen atoms are represented by
their 50% probability ellipsoids. Hydrogen atoms have been
omitted for clarity. Selected bond lengths (Å): Ru(1)-C*
) 1.910(3), Ru(1)-P(1) ) 2.3416(17), Ru(1)-P(2) ) 2.3078-
(17), Ru(1)-C(23) ) 2.228(5), Ru(1)-C(24) ) 2.243(5),
P(1)-C(22) ) 1.812(6), C(22)-C(23) ) 1.519(8), C(23)-
C(24) ) 1.391(8). Selected bond angles (deg): C*-Ru(1)-
P(1) ) 128.89(12), C*-Ru(1)-P(2) ) 120.92(11), C*-
Ru(1)-C(23) ) 121.57(18), C*-Ru(1)-C(24) ) 120.29(19),
P(1)-Ru(1)-P(2) ) 96.09(6), P(1)-Ru(1)-C(23) ) 65.14-
(15), P(1)-Ru(1)-C(24) ) 93.70(15), P(2)-Ru(1)-C(23) )
110.55(16), P(2)-Ru(1)-C(24) ) 86.51(16), C(23)-Ru(1)-
C(24) ) 36.2(2), Ru(1)-P(1)-C(22) ) 90.81(19), P(1)-
C(22)-C(23) ) 94.9(3), C(22)-C(23)-C(24) ) 123.8(5),
Ru(1)-C(24)-C(23) ) 71.3(3). C* ) centroid of the indenyl
ligand.
-69.9 (J PP ) 36.6 Hz) (2a ) and δ 51.4 and -63.9 (J PP
)
34.5 Hz) (2b) with respect to those of the corresponding
κ1(P) precursors6 (see Experimental Section). Since the
two olefin faces of the κ1(P)-Ph2P(CH2CRdCH2) (R )
H, Me) ligand in complexes 1a ,b are diastereotopic,1,7
the formation of only one isomer for each of the
complexes 2a ,b indicates that the generation of the
chelate ring [Ru{κ3(P,C,C)-Ph2P(CH2CRdCH2)}] pro-
ceeds in a highly diastereoselective manner. The rela-
tively large difference of geminal CH2 chemical shifts
in 1H NMR spectra points to a parallel orientation of
the olefin with respect to the indenyl ring. Similar data
have been reported in cyclopentadienyl and indenyl
π-olefin complexes.8 It is interesting to note that the 31P-
{1H} NMR spectra in acetone remain unchanged within
a wide range of temperature (-90 to +50 °C), obviating
the possibility of a dynamic process involving an equi-
librium between the two diastereomers. No epimeriza-
tion is observed in solution within 96 h. These results
contrast with those reported for the analogous complex
[Ru(η5-C5Me5){κ1(P)-Ph2PCH2CHdCH2}{κ3(P,C,C)-Ph2-
PCH2CHdCH2}][PF6],9a which is fluxional, giving rise
to a rapid equilibrium between the two diastereomers
on the NMR time scale.10
determined by X-ray crystallography. Suitable crystals
were obtained by slow diffusion of diethyl ether into a
solution of complex 2a in CH2Cl2. An ORTEP represen-
tation is shown in Figure 1, and selected bonding data
are collected in the caption.
The molecule exhibits a pseudooctahedral three-
legged piano-stool geometry with the η5-indenyl ligand
displaying the usual allylene coordination mode. The
interligand angles P(1)-Ru(1)-P(2), P(1)-Ru(1)-C(24),
and P(2)-Ru(1)-C(23) and those between the five-
membered-ring centroid C* and the legs, namely P(2)-
Ru(1)-C*, C(24)-Ru(1)-C*, C(23)-Ru(1)-C*, and P(1)-
Ru(1)-C*, show values typical of a pseudooctahedron
(see the caption to Figure 1). The Ru-C(23) and Ru-
C(24) bond distances reflect the coordination of the
olefin to the metal center, and the C(23)-C(24) bond
distance, 1.391(8) Å, is similar to those in the complex
[Ru(η5-C5Me5){κ1(P)-Ph2P(CH2CHdCH2)}{κ3(P,C,C)-
Ph2P(CH2CHdCH2)}][PF6].9a It is also interesting to
note that the benzo ring of the indenyl ligand is oriented
over the olefin ligand, slightly displaced toward P(1).
Both enantiomers are present in equal proportion in the
crystal, which belongs to a centrosymmetric space
group. Figure 1 shows the complex with relative con-
figuration RRu and olefin coordination through the si
enantioface.
To find out which of the two enantiotopic olefin faces
in the κ1(P)-Ph2P(CH2CRdCH2) ligand is most favored
for coordination, the structure of complex 2a has been
(5) Gamasa, M. P.; Gimeno, J .; Gonzalez-Bernardo, C.; Martin-Vaca,
B. M. Inorg. Chim. Acta 2003, 347, 181.
(6) Garrou, P. E. Chem. Rev. 1981, 81, 229.
(7) Eliel, E.; Wilen, S. H. Stereochemistry of Organic Compounds;
Wiley: New York, 1994.
(8) (a) Okuda, J .; Zimmermann, K. H. Chem. Ber. 1989, 122, 1645.
(b) Faller, J . W.; J ohnson, B. V. J . Organomet. Chem. 1975, 88, 101.
(c) Miguel-Garcia, J . A.; Adams, H.; Maitlis, P. M. J . J . Organomet.
Chem. 1991, 413, 427.
To rationalize the diastereoselective formation of 2a ,
the stability of both diastereomers and the correspond-
ing energy barrier for the isomerization process have
been estimated theoretically (B3LYP/6-31G(d,p) +
(9) (a) Barthel-Rosa, L. P.;. Maitra, K.; Nelson, J . H. Inorg. Chem.
1998, 37, 633. (b) This is in contrast to the dissociative mechanism
proposed for the derivative [Ru(η5-C5Me5){κ3(P,C,C)-Ph2P(CH2CRd
(10) Similar dynamic proceses have been described for other metal
complexes: (a) Clark, P. W.; Hanisch, P.; J ones, A. J . Inorg. Chem.
1979, 18, 2067. (b) Clark, P. W.; J ones, A. J . J . Organomet. Chem.
1976, 122, C41. See also ref 8c.
CH2)}{κ1(P)-Ph2P(CH2CHdCH2)}][PF6], in which
a coordinatively
unsaturated intermediate is required. However, no theoretical calcula-
tions have been performed with this system.

Diastereoselective Synthesis of Ru Indenyl Complexes
Organometallics, Vol. 23, No. 12, 2004 2959
Sch em e 2. B3LYP /6-31G(d ,p ) + LANL2DZ DH
Va lu es In clu d in g Solven t Effects
LANL2DZ level). Scheme 2 shows the energy profile for
the interconversion between the RRusi and RRure con-
formers of the model compound [Ru(η5-C9H7){κ3(P,C,C)-
PH2(C3H5)}(PH3)]+ used to carry out the calculations,
and the most representative geometrical parameters for
the RRusi and RRure diastereomers as well as the
transition structures connecting them are shown in
Figure 2. The thermodynamic parameters as computed
at the different levels of theory employed can be found
in the Supporting Information. The geometry of the
R
Rusi model compound is consistent with the experi-
mental X-ray data (see Figure 1).
The theoretical calculations indicate a single-step
mechanism for the interconversion between the RRusi
and RRure diastereomers, involving an 18e species in
which the double bond remains coordinated to ruthe-
nium.11 The calculated rotation barrier is relatively low
(9.9 kcal/mol), which would favor the existence of a fast
equilibrium between the two diastereomers. However,
the variable-temperature NMR spectra of complexes
2a ,b reveal the absence of a dynamic process involving
the coordination of both diastereotopic faces of the olefin.
This may be due to the relative stability of the isomers,
which has been estimated to be 4.4 kcal/mol in the
model system and which is likely to become even larger
in complexes 2, due to the larger steric requirements
arising from the presence of both indenyl and phenyl
groups in the ruthenium fragment [Ru(η5-C9H7){κ3-
(P,C,C)-PPh2(C3H5)}(PPh3)]. A large difference in rela-
tive stability would preclude the detection of the second
isomer and yield the observed enantiofacial chiral
recognition. Steric hindrance would also raise the
energy barrier for interconversion. Recent theoretical
calculations including explicitly phenyl groups on simi-
lar half-sandwich ruthenium complexes12 do confirm
such expectations. However, the huge computational
effort required in the present case prevented us from
making a quantitative exploration of the steric effects.
F igu r e 2. Geometrical parameters for the structures
located on the PES as computed at the B3LYP level using
the 6-31G(d,p) basis set and the LANL2DZ pseudopoten-
tial.
F igu r e 3. Space-filling representation for complex 2a .
(11) Alternatively, Gladysz has proposed
a mechanism for the
The space-filling representation of the crystal struc-
ture of complex 2a shown in Figure 3 is in accordance
with the steric effects, indicating that the space around
atom Câ is limited by the indenyl ring and the phenyl
groups. This highly congested space probably makes the
interconversion of both diastereomers in the complexes [Re(η5-C5H5)-
(NO)(PPh3)(H2CdCHR)][BF4] which proceeds also without alkene
dissociation involving a carbon-hydrogen σ-bond. However, no theo-
retical calculations have been performed. Peng, T.-S.; Gladysz, J . A.
J . Am. Chem. Soc. 1992, 114, 4174.
(12) Bran˜a, P.; Gimeno, J .; Sordo, J . A. J . Org. Chem., in press.

2960 Organometallics, Vol. 23, No. 12, 2004
AÄ lvarez et al.
motion required for the interconversion process de-
scribed in Scheme 2 much more difficult from an
energetic viewpoint (higher value of the TS energy).
Rea ctivity of th e Com p lexes [Ru (η5-C9H7){K3-
(P ,C,C)-P h 2P (CH2CRdCH2)}(P P h 3)][P F 6] (R ) H
(2a ), Me (2b)) tow a r d Nu cleop h iles. To study the
propensity of the coordinated π-olefinic system to un-
dergo nucleophilic addition, due to its electrophilic
character, or to behave as a leaving group in substitu-
tion reactions, we have explored the reactivity of
complexes 2a and 2b toward typical neutral and anionic
two-electron species such as nitriles, hydride, azide or
alkyl carbanions.
(a ) π-Olefin Exch a n ge Rea ction s: Syn th esis of
t h e Ca t ion ic [R u (η5-C9H 7){K1(P )-P h 2P (CH 2CR d
CH2)}(P P h 3)L][P F 6] (R ) H, L ) MeCN (3a ), BzCN
(3b )) a n d Neu t r a l [R u (η5-C9H 7)(N3){K1(P )-P h 2P -
(CH2CRdCH2)}(P P h 3)] (R ) H (4a ), Me (4b)) Com -
p lexes. Substitution of the coordinated π-olefin group
is achieved readily by refluxing a solution of complex
2a and either one of the nitriles RCtN (R ) Me, Bz) in
CH2Cl2 (1:1.5 molar ratio), yielding the complexes 3a ,b
(80%). Similarly, the addition of NaN3 to a THF/MeOH
solution of 2a ,b at room temperature results in the
formation of the neutral complexes [Ru(η5-C9H7)(N3)-
{κ1(P)-Ph2P(CH2CRCH2)}(PPh3)] (R ) H (4a ), Me (4b))
as orange solids in 80-90% yield.
Complexes 3a ,b and 4a ,b have been characterized by
elemental analysis and IR and NMR spectroscopy, and
the results obtained are in agreement with the proposed
formulations (see Experimental Section for details).
Thus, the 31P{1H} NMR spectra show the two doublet
resonances for the AB system at δ 49.0 and 44.1 (d, J PP
) 36.6 Hz) (3a ), δ 49.4 and 42.6 (J PP ) 36.6 Hz) (3b), δ
46.5 and 50.8 (d, J PP ) 41.5 Hz) (4a ), and δ 46.7 and
51.3 (J PP ) 41.1 Hz) (4b), values which are in agreement
with those found for complexes 1a ,b, in which the
allylphosphine acts as a monodentate ligand. The
coordination of the azide ligands to the metal center was
confirmed by IR spectroscopy, which shows the typical
ν(N-N) bands at 2003 cm-1 (4a ) and 2007 cm-1 (4b).
(b) Nu cleop h ilic Ad d ition s: Syn th esis of th e
Com p lexes [R u (η5-C9H 7){K2(P ,C)-P h 2P {CH 2C(R )-
(Nu )CH2}}(P P h 3)] (R ) H, Nu ) Me (5a ), n Bu (5b),
H (5c); R ) Me, Nu ) Me (6a ), n Bu (6b), H (6c)).
The treatment of THF solutions of complexes 2a ,b with
lithium carbanions R′Li (R′ ) Me, nBu), at room
temperature results in the regioselective addition at the
internal Câ atom of the coordinated allylic group to
afford the ruthenaphosphacyclopentane complexes [Ru-
{κ2(P,C)-Ph2P{CH2C(R)(R′)CH2}}(η5-C9H7)(PPh3)] (R )
H, R′ ) Me (5a ), nBu (5b); R ) Me, R′ ) Me (6a ), nBu
(6b)). Similarly, complexes 2a and 2b react with Li-
[B(C2H5)3H] to give, regioselectively, the analogous
addition products [Ru{κ2(P,C)-Ph2P{CH2CH(R)CH2}}(η5-
C9H7)(PPh3)] (R ) H (5c), Me (6c)). Complexes 5a -c
and 6a -c have been isolated as air-stable orange solids
in 80-95% yield after chromatographic workup.
F igu r e 4. Molecular structure and atom-labeling scheme
for one molecule of complex 5b. Non-hydrogen atoms are
represented by their 50% probability ellipsoids. Hydrogen
atoms have been omitted for clarity. Selected bond lengths
(Å): Ru(1)-C* ) 1.9405(19), Ru(1)-P(1) ) 2.2823(11), Ru-
(1)-P(2) ) 2.2719(12), Ru(1)-C(42) ) 2.131(4), P(2)-C(40)
) 1.843(4), C(40)-C(41) ) 1.523(6), C(41)-C(42) ) 1.532-
(6). Selected bond angles (deg): C*-Ru(1)-P(1) ) 127.46-
(7), C*-Ru(1)-P(2) ) 125.62(8), C*-Ru(1)-C(42) ) 117.30-
(14), P(1)-Ru(1)-P(2) ) 101.54(4), P(1)-Ru(1)-C(42) )
88.55(12), P(2)-Ru(1)-C(42) ) 81.65(13), Ru(1)-P(2)-
C(40) ) 105.00(15), P(2)-C(40)-C(41) ) 106.4(3). C(40)-
C(41)-C(42) ) 107.9(3), Ru(1)-C(42)-C(41) ) 110.6(3). C*
) centroid of the indenyl ligand.
prove that the additions also proceed in a stereoselective
manner, since only one diastereomer is obtained in each
case. This is readily assessed by the 31P{1H} NMR
spectra, which display only two doublet resonances at
δ 58.6-61.6 and 61.5-71.3 (see Experimental Section).
Other significant spectroscopic features are (i) the 13C-
{1H} NMR spectra (see Experimental Section), which
display the carbon atom CR(R′) signal as a doublet
resonance at δ 31.8-49.0 (J CP ) 6.8-19.1 Hz) (DEPT
experiments), and (ii) the 1H and 13C{1H} NMR spectra,
which show the typical CH2 resonances in the ranges δ
0.86-2.98 ppm (CH2) and 15.4-43.3 (CH2) as expected
for sp3 carbon nuclei (see Experimental Section). It is
worth mentioning that complexes 5a and 6c, resulting
from the additions of methyllithium and hydride to the
π-olefin complexes 2a and 2b, respectively, are diastereo-
mers, as expected from the diastereotopic coordination
of the olefin in the precursors.
Since the stereochemistry of the new chiral carbon
atoms was not revealed by the NMR data, a single-
crystal X-ray structure determination was carried out
for the complex 5b. An ORTEP view of the molecular
geometry is shown in Figure 4. Selected bond distances
and angles are collected in the caption.
The asymmetric unit consists of two molecules of
complex 5b, which differ significantly in the conforma-
tion of the butyl chain but which are essentially identi-
cal in all other aspects. Since the relevant structural
parameters are similar, only those corresponding to one
molecule will be discussed.13 The structure shows the
following: (i) The molecule exhibits a pseudooctahedral
three-legged piano-stool geometry with the η5-indenyl
ligand displaying the usual allylene coordination mode
with bonding parameters comparable to those of others
Analytical and NMR (1H, 31P{1H}, and 13C{1H})
spectroscopic data of 5a -c and 6a -c support the
proposed formulations (see the Experimental Section for
details), in which a regioselective addition at the
â-carbon atom of the coordinated allyl group has oc-
curred. Significantly, NMR spectra of 5a ,b and 6a ,c

Diastereoselective Synthesis of Ru Indenyl Complexes
Organometallics, Vol. 23, No. 12, 2004 2961
CH2}][PF6],9a and [RuTpCl{κ3(P,C,C)-Ph2PCHdCHCRd
CH2)]16 (Tp ) tris(pyrazolyl)borate). We have recently
reported that complexes 2a ,b react rapidly with termi-
nal alkynes to give the vinylidene complexes [Ru(η5-
C9H7)(dCdC(H)R}{κ1(P)-Ph2PCH2CHdCH2)}(PPh3)]-
[PF6],17 in which the allylphosphine has become mono-
dentate. Analogous behavior is also observed in the
formation of [Ru(η5-C5Me5){κ1(P)-Ph2PCH2CHdCH2)}2L]-
[PF6] from [Ru(η5-C5Me5){κ1(P)-Ph2PCH2CHdCH2}-
{κ3(P,C,C)-Ph2PCH2CHdCH2}][PF6], which occurs readily
through exchange of the coordinated olefin by two-
electron ligands.9a
F igu r e 5. Nucleophilic attacks on each of the enantiomers
of complex 2a .
The ligand exchange reactions of complex 2a in the
presence of neutral nitriles, MeCN and BzCN, with
formation of the cationic complexes 3a ,b, clearly indi-
cate the hemilabile character of the allylphosphine
ligand. Since no mechanistic studies have been reported
on these exchange processes to date, we have investi-
gated the kinetics of the reaction of complex 2a with
acetonitrile. In a series of 31P{1H} NMR spectra for the
reaction with MeCN (0.375 M), in CDCl3 at 38 °C, the
low-frequency peak at δ -69.9 ppm of complex 2a
(0.0013 M) decreases exponentially until it disappears
completely, with quantitative transformation into the
two doublet resonances of complex 3a . Intermediate
species were not detected during the measurements. A
plot of ln[2a ]t/[2a ]0 (see Supporting Information), which
is linear up to 93% of reaction corresponding to 4 half-
lives, t1/2, yields a value of the observed rate constant,
kobs ) 0.0016 s-1. When the same process is observed
reported by us previously.14 It is interesting to note that
the benzo ring of the indenyl ligand is located between
the two phosphorus atoms of the phosphines, resulting
in a formally trans orientation with respect to the Ru-
C(42) σ-bond. (ii) The skeleton of the metallaphos-
phacycle shows conventional single-bond distances (P(2)-
C(40), C(41)-C(40), C(42)-C(41), and Ru(1)-C(42)).
The torsion angle P(2)-C(40)-C(41)-C(42) is 50.4(4)°,
and the conformational helical chirality is δ. (iii) The
relative configurations of the new stereogenic carbon
atom C(41) and the ruthenium atom are RRuSC. The
other enantiomer SRuRC is present in equal proportion
in the crystal.
As expected, the addition occurs on the CdC face
opposite the ruthenium, generating a new stereogenic
Câ atom. The observed relative configuration S, for the
stereoisomer with absolute configuration R at Ru,
results from exo attack on the re face of the olefin in
the diastereomer RRusi (relative configuration R at the
Câ carbon atom results from exo attack on the si face of
the enantiomer SRure of the starting olefin; Figure 5).
This fact is also in accord with the formation of the
two diastereomers [Ru(η5-C9H7){κ2(P,C)-Ph2PCH2C(Me)-
HCH2}(PPh3)] (6c and 5a ), arising from the exo addition
of hydride and methyl anions to complexes 2b and 2a ,
respectively. This also rules out the alternative mech-
anism involving exchange of the coordinated olefin by
hydride and subsequent insertion of the allyl group into
the Ru-H bond. In fact, all attempts to promote
insertion reactions in the hydride complex [Ru(η5-
C9H7)H{κ1(P)-Ph2PCH2CHdCH2}(PPh3)] (1c) have been
unsuccessful.
1
by H NMR, using CD3CN as reagent, the disappear-
ance of the peak at δ 5.42 ppm, due to the H-2 proton
of the indenyl ligand, can be followed conveniently and
peak integration gives the concentration values of 2a
at different times. The first-order analysis yields a value
of kobs which is the same, within experimental error, as
that obtained in the 31P{1H} NMR experiment.
Since the reaction is first-order in complex 2a , the
dependence on the reagent has been investigated by a
1
series of kinetic experiments, performed by H NMR,
at different CD3CN concentrations. A plot of kobs values
vs [CD3CN] is shown in Figure 6. The dependence of
kobs on the concentration of deuterated acetonitrile is
linear, the slope of the line corresponding to the value
of the second-order rate constant, k2 ) [4.2((0.1)] × 10-3
M-1 s-1. In addition, the plot identifies a positive
intercept on the y axis, which indicates a contribution
to kobs independent of [CD3CN] and only first-order in
Kin et ic St u d ies. Hemilabile ligands containing
weakly coordinating carbon moieties and, in particular,
the olefins are of special interest, due to the well-known
lability of the metal-olefin bond, which enables the
facile generation of a free coordination site at the metal
center. In particular, only a few ruthenium derivatives
containing chelated alkenylphosphines have been de-
scribed: i.e., [Ru(η5-C5Me5){κ1(P)-Ph2PCHdCH2}{κ3-
(P,C,C)-Ph2PCHdCH2}][PF6],15 [Ru(η5-C5Me5){κ1(P)-
P h 2 P C H 2 C H dC H 2 }{κ3 (P , C , C )-P h 2 P C H 2 C H d
complex 2a , with a value of [1.5((0.6)] × 10-4 s-1
.
This is a classic case in the chemical kinetics of
transition-metal complexes, described by eq 1, which
implies the presence of parallel second- and first-order
routes, more specifically of an associative pathway, in
which both complex and reagent participate in the rate-
limiting step (k2), and of a dissociative pathway, in
which a step involving ligand dissociation is rate limit-
(13) The stereochemistry of the chiral centers is identical qualita-
tively and practically identical quantitatively in the two molecules of
a given asymmetric unit; for example, the chiral volumes calculated
for the chiral carbon atoms C41 and C87 are equal in sign and nearly
equal in magnitude.
(14) (a) Cadierno, V.; D´ıez, J .; Gamasa, M. P.;. Gimeno, J .; Lastra,
E. Coord.. Chem. Rev. 1999, 193-195, 147. (b) Cadierno, V.; Gamasa,
M. P.; Gimeno, J .; Gonzalez-Cueva, M.; Lastra, E.; Borge, J .; Pe´rez-
Carren˜o, E.; Garc´ıa-Granda, S. Organometallics 1996, 15, 2137. (c)
Cadierno, V.; Conejero, S.; Gamasa, M. P.; Gimeno, J .; Pe´rez-Carren˜o,
E.; Garc´ıa-Granda, S. Organometallics 2001, 20, 3175.
(15) Barthel-Rosa, L. P.; Maitra, K.; Fischer, J .; Nelson, J . H.
Organometallics 1997, 16, 1714.
(16) (a) Slugovc, C.; Mauthner, K.; Mereiter, K.; Schmid, R.; Kirch-
ner, K. Chem. Eur. J . 1998, 4, 2043. (b) Slugovc, C.; Wiede, P.; Mereiter,
K.; Schmid, R.; Kirchner, K. Organometallics 1997, 16, 2768.
(17) Alvarez, P.; Lastra, E.; Gimeno, J .; Bassetti, M.; Falvello, L.
R. J . Am. Chem. Soc. 2003, 125, 2386.

2962 Organometallics, Vol. 23, No. 12, 2004
AÄ lvarez et al.
Sch em e 3
F igu r e 6. Plot of kobs values vs [MeCN-d3], for the reaction
of complex 2a , in CDCl3 at 38 °C.
ing (k1).18 Substitution reactions via dissociative path-
kobs ) k1 + k2[CD3CN]
(1)
conforms with the mechanism described for the inser-
tion reaction of alkynes into the metal-hydrogen bond
of the indenylruthenium complex [RuH(η5-C9H7)(dp-
pm)].3b,25 The associative pathway of ligand substitution
reactions, characterized by second-order kinetics, is the
classic route followed by transition-metal indenyl com-
plexes,26 as in the seminal case of carbonyl substitution
by PPh3 in the complex [Rh(η5-C9H7)(CO)2].27
The interesting feature of the reactivity of complex
2a is the presence of parallel associative and dissociative
routes. The k1 value represents the rate of olefin
dissociation from ruthenium to yield a reactive 16-
electron, coordinatively unsaturated complex. This spe-
cies, due to its highly reactive character, can form only
as a transient, in competition between reversal to
substrate by double-bond recoordination and attack of
the neutral nitrile to form the product. In analogy to
the intramolecular ligand dissociative pathway proposed
for complex 2a , the diastereomeric equilibration ob-
served for the bis(allylphosphine) complex [Ru(η5-C5-
Me5){κ1(P)-Ph2PCH2CHdCH2}{κ3(P,C,C)-Ph2PCH2CHd
CH2}][PF6] as well as its substitution reactions have
been proposed to proceed via a dissociative mechanism
involving the allylic double bond.9a
ways have been described for indenyl complexes. This
is the case for phosphine substitution in the ruthenium
complex [RuCl(η5-C9H7)(PPh3)2], yielding chiral-at-metal
complexes [RuCl(η5-C9H7)(PPh3)(L′)],19 or carbonyl sub-
stitution in the iron complex [FeI(η5-C9H7)(CO)2].20
These dissociative routes do not involve η3 intermedi-
ates. Mixed associative and dissociative mechanisms are
also known, as in the case of [WCl(η5-C9H7)(CO)3].21
In the present case, the dissociative step is followed
by fast reaction with CD3CN, resulting in zero-order
dependence on this reagent. A contribution from the
solvent to the acetonitrile-independent pathway is
unlikely, due to the negligible nucleophilic character of
CDCl3. 22
The kinetic behavior of the reaction of complex 2a
with acetonitrile-d3 is interesting, in light of the bonding
modes of the allylphosphine complex and of the in-
tramolecular nature of the leaving group in the substi-
tution process. The substitution of the allylic double
bond by the neutral donor ligand occurs preferentially
via a rate-determining associative step23 (k2 route of eq
1 and Scheme 3). This pathway may involve the forma-
tion of an η3-indenyl intermediate,24 in which the ring
slippage from the η5 coordination of the substrate would
facilitate the accommodation of the nitrile reagent in
the ruthenium coordination sphere, and assist the olefin
decoordination in a subsequent rapid step. This picture
The overall mechanistic features of the ligand sub-
stitution process in complex 2a are described in Scheme
3.28 One special feature of this study is therefore the
kinetic detection of the hemilabile character of an
allylphosphine ligand, a finding which is unprecedented.
(18) Atwood, J . D. Inorganic and Organometallic Reaction Mecha-
nisms; Brooks/Cole: Monterey, CA, 1985; p 131.
(19) Gamasa, M. P.; Gimeno, J .; Gonzalez-Bernardo, C.; Mart´ın-
Vaca, B.; Monti, D.; Bassetti, M. Organometallics 1996, 15, 302.
(20) J ones, D. J .; Mawby, R. J . Inorg. Chim. Acta 1972, 6, 157-
160.
(21) Turaki, N. N.; Huggins, J . M.; Lebioda, L. Inorg. Chem. 1988,
27, 424-427.
(22) The existence of the dissociative equilibrium of the allylphos-
phine ligand from the κ3 coordinating mode to the monodentate species,
and its role in the reactivity of complex 2a , indicated by κ1, should be
independent of the reagent or of the specific reaction. Accordingly, the
reaction of complex 2a with phenylacetylene, yielding vinylidene
complexes,17 also proceeds by mixed first- and second-order pathways
and identifies a similar value of κ1, under the same experimental
conditions of solvent and temperature. Alvarez, P.; Bassetti, M.;
Gimeno, J .; Lastra, E. Unpublished results.
(23) Olefin substitution by two-electron ligands is also observed for
C5Me5 complexes.9 Although no kinetic studies have been carried out
for this reaction, a dissociative pathway has been proposed.
(24) (a) Calhorda, M. J .; Veiros, L. F. Coord. Chem. Rev. 1999, 185-
186, 37. (b) O’Connor, J . M.; Casey, C. P. Chem. Rev. 1987, 87, 307.
Con clu sion s
In this work the synthesis of diastereoselectively pure
indenyl complexes [Ru(η5-C9H7){κ3(P,C,C)-Ph2P(CH2-
CRdCH2)}(PPh3)][PF6] is reported. These products be-
(25) Bassetti, M.; Casellato, P.; Gamasa, M. P.; Gimeno, J .; Gonza-
lez-Bernardo, C.; Mart´ın-Vaca, B. Organometallics 1997, 16, 5470.
(26) (a) Bang, H.; Lynch, T. J .; Basolo, F. Organometallics 1992,
11, 40. (b) Foo, T.; Bergman, R. G. Organometallics 1992, 11, 1811. (c)
Bonifaci, C.; Carta, G.; Ceccon, A.; Gambaro, A.; Santi, S. Organome-
tallics 1996, 15, 1630.
(27) Rerek, M. E.; Basolo, F. J . Am. Chem. Soc. 1984, 106, 5908.
(28) A similar kinetic and mechanistic analysis has been recently
reported for the oxidative addition reaction of methyl iodide to a
cationic rhodium(I) complex of a hemilabile tridentate S,N,S ligand
(Bassetti, M.; Capone, A.; Salamone, M. Organometallics 2004, 23,
247).

Diastereoselective Synthesis of Ru Indenyl Complexes
Organometallics, Vol. 23, No. 12, 2004 2963
as standards. DEPT experiments were carried out for all the
compounds. Coupling constants J are given in hertz. Abbrevia-
tions used: Ar, aromatic; s, singlet; d, doublet; vt, virtual
triplet; m, multiplet. The following atom labels have been used
for the 1H and 13C{1H} spectroscopic data:
long to a very scarce series of chiral-at-metal semi-
sandwich complexes in which an effective chiral recogni-
tion of a prochiral allyl group has been achieved.1 Other
examples with high thermodynamic binding selectivities
are very rare, i.e. [RuH(η6-arene)(PR3)(styrene)][SbF6]
(R ) Ph, OMe),29 although in solution the configura-
tional diastereomers rapidly interconvert at low tem-
perature.30 Crystallographic data and theoretical cal-
culations support both ruthenium and olefin configura-
tions. Estimated values of the thermodynamic stabilities
found in both diastereomers are in agreement with the
experimentally observed enantioface binding selectivity.
The enantiofacial selectivity can be also established on
the basis of steric requirements, in which the phenyl
groups of both phosphines may generate a “chiral
pocket” for the allyl group, allowing formation of one of
the diastereomers. Exchange processes of the coordi-
nated olefin group in the complex [Ru(η5-C9H7){κ3-
(P,C,C)-Ph2P(CH2CRdCH2)}(PPh3)][PF6] by two-elec-
tron ligands reveal the hemilabile properties of the
allylphosphine. Kinetic studies on the substitution
reaction of complex 2a with a nitrile ligand indicate that
the olefin exchange occurs via parallel first-order (dis-
sociative) and second-order (associative) pathways and
highlight the involvement of a transient coordinatively
unsaturated species. This represents an unprecedented
kinetic detection of the hemilabile character of an
allylphosphine ligand. The capacity of the metal frag-
ment for the coordination of just one of the diaster-
eotopic olefin faces has permitted the study of nucleo-
philic additions, which proceed regioselectively on the
exo face, giving rise to chiral ruthenacyclopentane rings.
In summary, we have developed a ruthenium fragment
which is able to act as a Lewis acid with chiral
recognition, providing an appropriate means to envisage
potential enantioselective transformations of prochiral
olefins and similar unsaturated substrates. Further
work devoted to exploring the scope of this ability will
be undertaken.
Th eor etical Calcu lation s. Density functional theory (DFT)
calculations at the B3LYP level33 were carried out in order to
explore the potential energy surface (PES) of the model
compound [Ru(η5-C9H7){κ1(P)-PH2(CH2CHCH2)}(PH3)]+. The
LANL2DZ effective core potential34 was chosen for Ru and P,
while the standard 6-31G(d,p) basis sets35 were employed for
the rest of the atoms. Experience has shown that this level of
theory provides reasonable predictions for transition-metal-
containing compounds.36 Graphical analysis of the imaginary
frequencies of the transition structures as well as intrinsic
reaction coordinate (IRC)37 calculations allowed us to intercon-
nect the different structures located on the PES and then
construct the energy profiles.
Solvation effects were estimated by performing single-point
calculations with the self-consistent reaction field (SCRF)
Onsager model.38 A dielectric constant of 8.93 (corresponding
to dichloromethane) solute and radii of 5.30, 5.28, and 5.04 Å
were employed to emulate the solvent effects through single-
point calculations on RRusi, TS, and RRure , respectively.
Further optimizations, including solvent effects, on the RRusi
and RRure species were also accomplished in order to analyze
the role played by the solvent on the optimized geometries.
Two figures in the Supporting Information show the rather
small influence of the solvent on the geometrical parameters.
Thermochemical corrections for the liquid phase were not
included. The thermodynamic functions were estimated within
the ideal gas, rigid rotor, and harmonic oscillator approxima-
tions.39 The Gaussian 98 package of programs40 was used to
carry out the calculations. A temperature of 298.15 K and a
pressure of 1 atm were assumed.
Syn th esis of [Ru (η5-C9H7)Cl{K1(P )-P h 2P (CH2C(R)CH2)}-
(P P h 3)] (R ) H (1a ), Me (1b)). A mixture of [Ru(η5-C9H7)-
Cl(PPh3)2] (0.77 g, 1 mmol) and the corresponding allyldiphen-
Exp er im en ta l Section
Gen er a l Con sid er a tion s. All manipulations were per-
formed under an atmosphere of dry nitrogen using vacuum-
line and standard Schlenk techniques. All reagents were
obtained from commercial suppliers and used without further
purification. Solvents were dried by standard methods and
distilled under nitrogen before use. The compounds [Ru(η5-
C9H7)Cl(PPh3)2]31 and Ph2P(C3H5)32 were prepared by previ-
ously reported methods. Infrared spectra were recorded on a
Perkin-Elmer 1720-XFT or a Perkin-Elmer 599 IR spectrom-
eter. The C, H, and N analyses were carried out with a Perkin-
Elmer 240-B microanalyzer. NMR spectra were recorded on
Bruker AC300 and 300DPX instruments at 300 MHz (1H),
121.5 MHz (31P), or 75.4 MHz (13C) using SiMe4 or 85% H3PO4
(33) Cramer, C. S. Essentials of Computational Chemistry: Theories
and Models, Wiley: New York, 2002.
(34) (a) Hay, P. J .; Wadt, W. R. J . Chem. Phys. 1985, 82, 270. (b)
Wadt, W. R.; Hay, P. J . J . Chem. Phys. 1985, 82, 284. (c) Hay, P. J .;
Wadt, W. R. J . Chem. Phys. 1985, 82, 299.
(35) Hehre, W. J .; Radom, L.; Schleyer, P. v. R.; Pople, J . A. Ab Initio
Molecular Orbital Theory; Wiley: New York, 1986.
(36) Chem. Rev. 2000, 100, 351-818. The whole issue is devoted to
computational transition-metal chemistry.
(37) (a) Gonza´lez, C.; Schlegel, H. B. J . Chem. Phys. 1989, 90, 2154.
(b) Gonza´lez, C.; Schlegel, H. B. J . Chem. Phys. 1990, 94, 5523.
(38) (a) Wong, M. W.; Frisch, M. J .; Wiberg, K. B. J . Am. Chem.
Soc. 1991, 113, 4776. (b) Wong, M. W.; Wiberg, K. B.; Frisch, M. J . J .
Am. Chem. Soc. 1992, 114, 523.
(39) McQuarrie, D. A. Statistical Thermodynamics; University Sci-
ence Books: Mill Valley, CA, 1973.
(40) Frisch, M. J .; Trucks, G. W.; Schlegel, H. B.; Scuseria, G. E.;
Robb, M. A.; Cheeseman, J . R.; Zakrzewski, V. G.; Montgomery, J . A.,
J r.; Stratmann, R. E.; Burant, J . C.; Dapprich, S.; Millam, J . M.;
Daniels, A. D.; Kudin, K. N.; Strain, M. C.; Farkas, O.; Tomasi, J .;
Barone, V.; Cossi, M.; Cammi, R.; Mennucci, B.; Pomelli, C.; Adamo,
C.; Clifford, S.; Ochterski, J .; Petersson, G. A.; Ayala, P. Y.; Cui, Q.;
Morokuma, K.; Malick, D. K.; Rabuck, A. D.; Raghavachari, K.;
Foresman, J . B.; Cioslowski, J .; Ortiz, J . V.; Stefanov, B. B.; Liu, G.;
Liashenko, A.; Piskorz, P.; Komaromi, I.; Gomperts, R.; Martin, R. L.;
Fox, D. J .; Keith, T.; Al-Laham, M. A.; Peng, C. Y.; Nanayakkara, A.;
Gonzalez, C.; Challacombe, M.; Gill, P. M. W.; J ohnson, B. G.; Chen,
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(29) Faller, J . W.; Chase, K. J . Organometallics 1995, 14, 1592.
(30) Analogous chiral ruthenium complexes containing either η1(O)-
bonded or η2(CdC)-bonded methylacrylate and other enal ligands have
been described: (a) Carmona, D.; Cativiela, C.; Elipe, S.; Lahoz, F. J .;
Lamata, M. P.; Lo´pez-Ram de Viu, M. P.; Oro, L. A.; Vega, C.; Viguri,
F. J . Chem. Soc., Chem. Commun. 1997, 2351. (b) Kundig, E. P.;
Saudan, C. M.; Alezra, V.; Viton, F.; Bernardinelli, G. Angew. Chem.,
Int. Ed. 2001, 40, 4481. (c) Motoyama, Y.; Kurihara, O.; Murata, K.;
Aoki, K.; Nishiyama, H. Organometallics 2000, 19, 1025.
(31) Oro, L. A.; Ciriano, M. A.; Campo, M.; Foces-Foces, C.; Cano,
F. H. J . Organomet. Chem. 1985, 289, 117.
(32) Clark, P. W.; Curtis, J . L. S.; Garrou, P. E.; Hartwell, G. E.
Can. J . Chem. 1974, 52, 1714.

2964 Organometallics, Vol. 23, No. 12, 2004
AÄ lvarez et al.
ylphosphine (1.1 mmol) in thf (25 mL) was refluxed for 10 min.
The solution was evaporated to dryness to afford a red solid,
which was washed with hexane (20 mL) and vacuum-dried.
The excess of PPh3 was eliminated by sublimation at 80 °C on
a high-vacuum pump. R ) H (1a ): yield 85%; 31P{1H} NMR
C3a), 110.3 (s, C7a), 121.6-136.8 (m, Ar). Analytically pure
samples of this compound could not be obtained.
Syn th esis of [Ru (η5-C9H7)(NCR){K1(P )-P h 2P CH2CHCH2}-
(P P h 3)][P F 6] (R ) Me (3a ), Bz (3b)). To a solution of [Ru-
(η5-C9H7){κ3(P,C,C)-Ph2PCH2CHCH2}(PPh3)] (2a ; 0.85 g 1
mmol) in CH2Cl2 (25 mL) was added RCN (1.5 mmol), and the
solution was refluxed for 45 min. After it was cooled, the
solution was evaporated to dryness and the solid residue was
recrystallized from CH2Cl2, washed with diethyl ether (2 ×
10 mL), and vacuum-dried. R ) Me (3a ): yield 85%; 31P{1H}
NMR (121.5 MHz, CDCl3) δ 49.0 (d, J PP ) 36.6 Hz), 44.1 (d,
J PP ) 36.6 Hz); 1H NMR (300 MHz, CDCl3) δ 2.21 (m, 1H, CH2),
2.31 (s, 3H, CH3), 2.42 (m, 1H, CH2), 3.56 (s, 1H, dCH2), 4.48
(m, 1H, dCH2), 4.86 (m, 1H, H1), 4.91 (m, 1H, H3), 5.01 (m,
1H, H2), 5.26 (m, 1H, dCH), 6.71-7.61 (m, 29H, Ar H); 13C-
{1H} NMR (75.4 MHz, CDCl3) δ 46.4 (s br, CH2), 66.6 (s, C1),
70.0 (s, C3), 94.1 (s, C2), 101.2 (s, C3a), 103.2 (s, C7a), 119.3
(s br, dCH2), 123.6 (s br, dCH),125.5-136.4 (m, Ar), 137.9 (s,
CN); IR (Nujol) ν 2226 cm-1 (CN). Anal. Calcd for C44H40NF6P3-
Ru (890.8): C, 59.33; H, 4.53. Found: C, 59.19; H, 4.43. R )
Bz (3b): yield 85%; 31P{1H} NMR (121.5 MHz, CDCl3) δ 49.4
(d, J PP ) 36.6 Hz), 42.6 (d, J PP ) 36.6 Hz); 1H NMR (300 MHz,
CDCl3) δ 2.40 (m, 1H, CH2), 2.51 (m, 1H, CH2), 3.70 (s, 1H,
dCH2), 4.32 (m, 1H, H1), 4.63 (m, 1H, H2), 4.96 (m, 1H, H3),
5.22 (m, 1H, dCH2), 5.37 (m, 1H, dCH), 6.43-7.67 (m, 34H,
Ar H); 13C{1H} NMR (75.4 MHz, CDCl3) δ 31.9 (d, J CP ) 21.1
Hz, CH2), 66.6 (s, C1), 70.0 (s, C2), 94.1 (s, C3), 101.7 (s, C3a),
104.1 (s, C7a), 119.6 (s br, dCH2), 123.9 (s br, dCH), 125.5-
136.4 (m, Ar), 141.3 (s, CN); IR (Nujol) ν 2224 cm-1 (CN). Anal.
Calcd for C50H44NF6P3Ru (966.9): C, 62.11; H, 4.59. Found:
C, 62.40; H, 4.88.
(121.5 MHz, CDCl3): δ 48.0 (d, J PP ) 43.0 Hz), 45.3 (d, J PP
)
43.0 Hz); 1H NMR (300 MHz, CDCl3) δ 1.85 (m, 1H, CH2), 3.32
(m, 1H, CH2), 3.03 (s br, 1H, dCH2), 4.40 (s, 1H, H1), 4.57 (s,
1H, H3), 4.92 (m, 1H, dCH2), 4.85 (s, 1H, H2), 4.87 (m, 1H,
dCH), 6.3-7.7 (m, 24H, ArH); 13C{1H} NMR (75.4 MHz,
CDCl3) δ 30.8 (d, J CP ) 21.7 Hz, CH2), 64.1 (s, C1), 71.8 (d,
J CP ) 11.5 Hz, C3), 92.9 (s, C2), 112.2, 113.8 (both s, C3a, C7a),
119.8 (d, J CP ) 8.5 Hz, dCH2), 125.8, 126.8 (both s, C4,5,6,7),
128.1 (s, dCH), 129.3-139.6 (m, Ar). Anal. Calcd for C42H37
-
ClP2Ru (740.2): C, 68.15; H, 5.04. Found: C, 68.01; H, 5.21.
R ) Me (1b): yield 85%; 31P{1H} NMR (121.5 MHz, CDCl3) δ
48.8 (d, J PP ) 42.2 Hz), 45.5 (d, J PP ) 42.2 Hz); 1H NMR (300
MHz, CDCl3) δ 0.89 (s, 3H, CH3), 1.80 (dd, J PH ) 15.7 Hz, J HH
) 8.3 Hz, 1H, CH2), 2.94 (s, 1H, dCH2), 3.39 (dd, J PH ) 15.7
Hz, J HH ) 8.3 Hz, 1H, CH2), 4.04 (s, 1H, H2), 4.28 (s, 1H, d
CH2), 4.79 (s, 2H, H1,3), 6.3-7.7 (m, 24H, Ar H); 13C{1H} NMR
(75.4 MHz, CDCl3) δ 24.5 (s, CH3), 30.3 (d, J CP ) 17.4 Hz, CH2),
61.6 (s, C1), 69.8 (d, J CP ) 11.6 Hz, C3), 90.8 (s, C2), 109.6,
111.0 (both s, C3a, C7a), 115.2 (d, J CP ) 7.5 Hz, dCH2), 123.3,
124.9 (both s, C4,5,6,7), 129.3-139.6 (m, Ar), 140.1 (d, J CP
)
13.9 Hz, dCCH3). Anal. Calcd for C43H39ClP2Ru (754.2): C,
68.47; H, 5.21. Found: C, 68.51; H, 5.03.
Syn th esis of [Ru (η5-C9H7)H{K1(P )-P h 2P (C3H5)}(P P h 3)]
(1c). A solution of [Ru(η5-C9H7)Cl{κ1(P)-Ph2P(C3H5)}(PPh3)]
(1a ; 0.74 g, 1 mmol) and NaOMe (1 mmol) in MeOH (25 mL)
was refluxed for 30 min. Once the solution was cooled, the
resulting solid was recovered by filtration, washed with hexane
(2 × 10 mL), and dried under vacuum. Yield: 80%. 31P{1H}
NMR (121.5 MHz, C6D6): δ 66.2 (d, J PP ) 25.9 Hz, PPh3), 53.3
(d, J PP ) 25.9 Hz, ADPP). 1H NMR (300 MHz, C6D6): δ -15.32
Syn t h esis of [R u (η5-C9H 7)(N3){K1(P )-P h 2P (CH 2C(R )-
CH2)}(P P h 3)] (R ) H (4a ), Me (4b)). To a solution of [Ru-
(η5-C9H7)Cl{κ1(P)-Ph2P(CH2C(R)CH2)}(PPh3)] (R ) H (1a ), Me
(1b); 1 mmol) in THF/MeOH (10:1; 20 mL) was added dropwise
a solution of NaN3 (0.06 g, 1 mmol, in 2 mL of MeOH). The
solution was stirred for 2 h at room temperature. The resulting
solid was filtered, and the solution was evaporated to dryness
to afford a red solid, which was purified by column chroma-
tography by recovery of the fraction eluted with diethyl ether
and evaporation to dryness. R ) H (4a ): yield 90%; 31P{1H}
NMR (121.5 MHz, CDCl3) δ 46.5 (d, J PP ) 41.5 Hz), 50.8 (d,
J PP ) 41.5 Hz); 1H NMR (300 MHz, CDCl3) δ 1.88 (m, 1H, CH2),
2.80 (m, 1H, CH2), 3.16 (s, 1H, dCH2), 4.38 (s, 1H, H2), 4.60
(m, 1H, dCH2), 4.79 (s, 2H, H1, H3), 4.81 (m, 1H, dCH), 6.3-
7.7 (m, 29H, Ar H); 13C{1H} NMR (75.4 MHz, CDCl3) δ 30.0
(d, J CP ) 20.8 Hz, CH2), 62.5 (s, C1), 67.4 (d, J CP ) 11.1 Hz,
C3), 90.3 (s, C2), 109.0, 110.2 (both d, J CP ) 3.3 Hz, C3a, C7a),
117.6 (d, J CP ) 8.5 Hz, dCH2), 122.4 (d, J CP ) 14.8 Hz, dCH),
127.3-137.5 (m, Ar); IR (Nujol) ν 2003 cm-1 (N3). Analytically
pure samples of this compound could not be obtained. R ) Me
(4b): yield 80%; 31P{1H} NMR (121.5 MHz, CDCl3) δ 46.7 (d,
2
(vt, J HP ) 31.9 Hz, hydride), 1.98 (m, 2H, CH2), 2.79 (m, 1H,
dCH2), 2.84 (m, 1H, dCH2), 4.18 (m, 1H, CH), 5.31 (s, 1H,
H1), 5.36 (s, 1H, H2) 5.52 (s, 1H, H3), 6.25 (m, 2H, C9H7), 6.99-
7.83 (m, 27H, Ar H)). 13C{1H} NMR (75.4 MHz, C6D6): δ 31.1
(s br, CH2), 79.6 (s, C1), 80.8 (s, C3), 91.13 (s, C2), 105.5 (s,
C3a), 105.3 (s, C7a), 114.4 (s br, dCH2), 118.2 (s br, dCH),
125.9-136.2 (m, Ar). Anal. Calcd for C42H38P2Ru (705.8): C,
71.48; H, 5.43. Found: C, 71.03; H, 5.59.
Syn th esis of [Ru (η5-C9H7){K3(P ,C,C)-P h 2P CH2C(R)CH2}-
(P P h 3)][P F 6] (R ) H (2a ), Me (2b)). A solution of the complex
[Ru(η5-C9H7)Cl{κ1(P)-Ph2P(CH2C(R)CH2)}(PPh3)] (R ) H (1b),
Me (1b); 1 mmol) in MeOH (25 mL) was treated with NaPF6
(0.16 g, 1 mmol), and the mixture was refluxed for 30 min.
The solution was evaporated to dryness. The resulting solid
was extracted with dichloromethane (2 × 20 mL) and vacuum-
dried to give the desired complexes as yellow solids. R ) H
(2a ): yield 90%; 31P{1H} NMR (121.5 MHz, CDCl3) δ 55.2 (d,
J PP ) 36.6 Hz, PPh3), -69.9 (d, J PP ) 36.6 Hz, ADPP); 1H NMR
(300 MHz, CDCl3) δ 1.98 (m, 2H, CH2), 2.79 (m, 1H, dCH),
2.84 (m, 1H, dCH2), 4.18 (vt, 1H, J HH ) 10.6 Hz, dCH2), 4.78
(s, 1H, H1), 5.36 (s, 1H, H3) 5.42 (s, 1H, H2), 6.25 (m, 2H,
C9H7), 6.99-7.83 (m, 27H, Ar H); 13C{1H} NMR (75.4 MHz,
CDCl3) δ 31.1 (s br, CH2), 54.4 (d, J CP ) 20.6 Hz, dCH), 58.2
(s br, dCH2), 79.6 (s, C1), 80.8 (s, C2), 91.1 (s, C3), 105.5 (s,
C3a), 105.3 (s, C7a), 125.9-136.2 (m, Ar). Anal. Calcd for
1
J PP ) 41.1 Hz), 51.3 (d, J PP ) 41.1 Hz); H NMR (300 MHz,
CDCl3) δ 1.03 (m, 3H, CH3), 1.87 (m, 1H, CH2), 1.93 (m, 1H,
CH2), 4.19 (s, 1H, H2), 4.32 (s, 1H, dCH2), 4.59 (m, 1H, d
CH2), 4.32 (s, 2H, H1, H3), 6.3-7.7 (m, 29H, Ar H); 13C{1H}
NMR (75.4 MHz, CDCl3) δ 15.25 (s, CH3), 32.2 (d, J CP ) 17.5
Hz, CH2), 62.5 (s, C1), 67.8 (d, J CP ) 11.0 Hz, C3), 90.8 (s,
C2), 109.0, 110.2 (both d, J CP ) 4.0 Hz, C3a, C7a), 115.6 (d,
J CP ) 7.5 Hz, dCH2), 122.7 (d, J CP ) 15.6 Hz, dCH), 127.4-
141.5 (m, Ar); IR (Nujol) ν 2007 cm-1 (N3). Anal. Calcd for
C
42H37F6P3Ru (849.7): C, 59.37; H, 4.39. Found: C, 59.12; H,
C
43H39N3P2Ru (760.8): C, 67.88; H, 5.17. Found: C, 67.39; H,
5.40.
Syn th esis of [Ru (η5-C9H7){K2(P ,C)-P h 2P CH2CR(R’)CH2}-
4.42. R ) Me (2b): yield 90%; 31P{1H} NMR (121.5 MHz,
CDCl3) δ 51.4 (d, J PP ) 34.5 Hz, PPh3), -63.9 (d, J PP ) 34.5
1
Hz, ADPP); H NMR (300 MHz, CDCl3) δ 1.97 (s, 1H, CH3),
(P P h 3)] (R ) H, R’ ) Me (5a ), n Bu (5b), H (5c); R ) Me, R’
) Me (6a ), n Bu (6b), H (6c)). A stirred solution of [Ru(η5-
C9H7){κ3(P,C,C)-Ph2P(CH2C(R)CH2)}(PPh3)][PF6] (R ) H (2a ),
Me (2b); 1 mmol) in THF (10 mL) at room temperature was
treated dropwise with MeLi (5a , 6a ), nBuLi (5b, 6b) or LiB-
(C2H5)3H (5c, 6c) (2 mol). The solution immediately turned
orange. After 10 min, the solvents were evaporated to dryness
2.14 (m, 2H, CH2), 2.69 (d, 1H, J PH ) 15.09 Hz, dCH2), 4.18
(vt, 1H, J PH ) 13.1 Hz, dCH2), 4.55 (s, 1H, H1), 5.29 (s, 1H,
H3), 5.86 (s, 1H, H2), 6.05 (m, 2H, C9H7), 6.99-7.83 (m, 27H,
Ar H); 13C{1H} NMR (75.4 MHz, CDCl3) δ 26.8 (s, CH3), 35.5
(d, J CP ) 34.5 Hz, CH2), 55.8 (s br, dCH2), 67.5 (d, J CP ) 18.0
Hz, dCCH3), 76.8 (s, C1), 77.6 (s, C2), 92.2 (s, C3), 104.3 (s,

Diastereoselective Synthesis of Ru Indenyl Complexes
Organometallics, Vol. 23, No. 12, 2004 2965
Ta ble 1. Cr ysta l Da ta a n d Str u ctu r e Refin em en t
for 2a a n d 5b
and the resulting solid was extracted with dichloromethane
(20 mL) and vacuum-dried. The filtrate was washed with
hexane (3 × 20 mL), and the solvents were removed under
vacuum. The solid obtained was purified by column chroma-
tography by recovery of the fraction eluted with diethyl ether.
R ) H, R’ ) Me (5a ): yield 85%; 31P{1H} NMR (121.5 MHz,
C6D6) δ 61.5 (d, J PP ) 29.3 Hz), 60.0 (d, J PP ) 29.3 Hz); 1H
NMR (300 MHz, C6D6) δ 1.16 (m, 1H, CH2), 1.41 (d, J HH ) 5.9
Hz, 3H, Me), 1.47 (m, 1H, CH2), 2.28 (m, 1H, CH2), 2.71 (m,
1H, CH2), 2.85 (m, 1H, CH), 4.22 (s, 1H, H1), 4.35 (s, 1H, H3),
5.08 (s, 1H, H2), 6.54-7.91 (m, 29H, Ar H); 13C{1H} NMR (75.4
MHz, C6D6) δ 14.6 (s, Me), 23.9 (s, CH2), 31.8 (d, J CP ) 6.8 Hz,
CH), 37.9 (d, J CP ) 30.5 Hz, CH2), 71.9 (d, J CP ) 9.0 Hz, C1),
77.5 (d, J CP ) 8.9 Hz, C3), 97.2 (s, C2), 105.0 (s, C3a, C7a),
111.0 (s, C3a, C7a), 120.7 (s, C9H7), 121.2 (s, C9H7), 123.9-
148.6 (m, Ar). Anal. Calcd for C43H40P2Ru (719.8): C, 71.75;
H, 5.60. Found: C, 70.61; H, 5.42. R ) Me, R’ ) Me (6a ): yield
80%; 31P{1H} NMR (121.5 MHz, C6D6) δ 63.4 (d, J PP ) 27.3
Hz), 61.2 (d, J PP ) 27.3 Hz); 1H NMR (300 MHz, C6D6) δ 0.99
2a ‚CH2Cl2
5b
empirical formula
mol wt
temp, K
wavelength, Å
cryst syst
space group
unit cell dimens
a, Å
C44H41Cl4F6P3Ru C46H46P2Ru
1019.55
150(2)
0.710 73
monoclinic
P21/c
761.84
123(1)
0.710 73
triclinic
P1h
18.166(5)
15.0807(18)
17.655(6)
90
117.55(2)
90
10.0870(2)
19.3200(5)
19.5780(5)
86.7610(18)
83.9990(19)
78.4560(10)
3715.23(15)
4
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
4288.2(19)
4
Z
calcd density, g cm-3
abs coeff, mm-1
F(000)
1.579
1.362
0.786
0.540
(m, 1H, CH2), 1.31 (d, J HH ) 5.7 Hz, 3H, Me), 1.61 (d, J HH
)
2064
1584
cryst size, mm
θ range for data
collecn, deg
index ranges
0.44 × 0.23 × 0.13 0.35 × 0.12 × 0.03
6.0 Hz, 3H, Me), 1.92 (m, 1H, CH2), 2.31 (m, 1H, CH2), 3.07
(m, 1H, CH2), 4.34 (s, 1H, H1), 4.55 (s, 1H, H3), 5.18 (s, 1H,
H2), 6.64-7.89 (m, 29H, Ar H); 13C{1H} NMR (75.4 MHz, C6D6)
δ 13.2 (s, Me), 15.8 (s, Me), 31.2 (s, CH2), 35.3 (d, J CP ) 29.3
Hz, CH2), 41.5 (d, J CP ) 15.3 Hz, C(CH3)2), 68.9 (d, J CP ) 7.9
Hz, C1), 76.4 (d, J CP ) 6.9 Hz, C3), 98.8 (s, C2), 110.0, 111.6
(both s, C3a, C7a), 122.7 (s, C9H7), 124.2 (s, C9H7), 129.1-149.6
(m, Ar). Anal. Calcd for C44H42P2Ru (733.8): C, 72.02; H, 5.77.
Found: C, 73.01; H, 6.58. R ) H, R’ ) nBu (5b): yield 85%;
31P{1H} NMR (121.5 MHz, C6D6) δ 61.9 (d, J PP ) 29.1 Hz),
60.5 (d, J PP ) 29.1 Hz); 1H NMR (300 MHz, C6D6) δ 0.88-1.77
(m, 11H, Me, CH2), 1.99 (m, 1H, CH2), 2.64 (m, 1H, CH2), 2.78
(m, 1H, CH), 4.15 (s, 1H, H1), 4.28 (s, 1H, H3), 5.02 (s, 1H,
H2), 6.51-7.69 (m, 29H, Ar H); 13C{1H} NMR (75.4 MHz, C6D6)
δ 14.3 (s, Me), 18.4 (d, J CP ) 7.3 Hz, CH2), 23.9 (s, CH2), 31.8
(s, CH2), 38.0 (d, J CP ) 30.5 Hz, CH2), 40.4 (d, J CP ) 19.5 Hz,
CH2), 49.0 (d, J CP ) 17.0 Hz, CH), 71.8 (d, J CP ) 8.5 Hz, C1),
77.5 (d, J CP ) 8.5 Hz, C3), 97.2 (s, C2), 105.5 (s, C3a), 111.7
(s, C7a), 120.3 (s, C9H7), 123.4 (s, C9H7), 126.0-138.2 (m, Ar),
141.4 (d, J CP ) 30.5 Hz, Ph), 147.4 (d, J CP ) 32.7 Hz, Ph). Anal.
Calcd for C46H46P2Ru (761.9): C, 72.52; H, 6.09. Found: C,
72.54; H, 5.88. R ) Me; R’ ) nBu (6b): yield 80%; 31P{1H}
NMR (121.5 MHz, C6D6) δ 69.9 (d, J PP ) 21.3 Hz), 61.3 (d, J PP
) 21.3 Hz); 1H NMR (300 MHz, C6D6) δ 0.86-1.90 (m, 12H, 2
CH3, CH2), 2.03 (m, 2H, CH2), 2.98 (m, 1H, CH2), 2.81 (m, 1H,
CH2), 4.01 (s, 1H, H1), 4.44 (s, 1H, H3), 5.14 (s, 1H, H2), 6.51-
7.69 (m, 29H, Ar H); 13C{1H} NMR (75.4 MHz, C6D6) δ 11.2
(s, CH3), 19.3 (s, CH3), 20.9 (d, J CP ) 8.1 Hz, CH2), 25.4 (s,
CH2), 30.8 (s, CH2), 41.3 (d, J CP ) 19.1 Hz, CMeBu), 43.3 (d,
J CP ) 29.6 Hz, CH2), 51.4 (d, J CP ) 19.1 Hz, CH2), 65.8 (d, J CP
) 10.9 Hz, C1), 75.4 (d, J CP ) 8.1 Hz, C3), 99.2 (s, C2), 105.5
(s, C3a), 112.3 (s, C7a), 118.4 (s, C9H7), 125.9 (s, C9H7), 127.0-
140.4 (m, Ar), 145.3 (d, J CP ) 29.7 Hz, Ph) ppm. Anal. Calcd
for C47H48P2Ru (775.9): C, 72.75; H, 6.24. Found: C, 73.01;
H, 6.58. R ) H; R’ ) H (5c): yield 95%; 31P{1H} NMR (121.5
MHz, C6D6) δ 71.3 (d, J PP ) 29.0 Hz), 61.6 (d, J PP ) 29.0 Hz);
1H NMR (300 MHz, C6D6) δ 1.35 (m, 1H, CH2), 1.51 (m, 1H,
CH2), 1.71 (m, 1H, CH2), 2.34 (m, 1H, CH2), 2.65 (m, 1H, CH2),
2.98 (m, 1H, CH2), 4.22 (s, 1H, H1), 4.49 (s, 1H, H3), 5.07 (s,
1H, H2), 6.61-7.61 (m, 29H, Ar H); 13C{1H} NMR (75.4 MHz,
C6D6) δ 15.4 (s, CH2), 32.4 (d, J CP ) 31.2 Hz, CH2), 35.1 (s,
CH2), 72.0 (d, J CP ) 8.6 Hz, C1), 76.9 (d, J CP ) 8.8 Hz, C3),
96.9 (s, C2), 107.5 (s, C3a), 112.7 (s, C7a), 123.2 (s, C9H7), 123.7
(s, C9H7), 126.0-141.7 (m, Ar). Anal. Calcd for C42H38P2Ru
(705.8): C, 71.48; H, 5.43. Found: C, 71.32; H, 5.58. R ) Me;
R’) H (6c): yield 85%; 31P{1H} NMR (121.5 MHz, C6D6) δ 64.6
(d, J PP ) 29.7 Hz), 58.6 (d, J PP ) 29.7 Hz); 1H NMR (300 MHz,
C6D6) δ 0.98 (m, 1H, CH2), 1.18 (d, J HH ) 6.3 Hz, 3H, Me),
1.91 (m, 1H, CH2), 2.15 (m, 2H, CH2), 2.41 (m, 1H, CH), 4.31
(s, 1H, H1), 4.36 (s, 1H, H3), 5.01 (s, 1H, H2), 6.49-7.12 (m,
29H, Ar H); 13C{1H} NMR (75.4 MHz, C6D6) δ 11.2 (s, Me),
20.5 (d, J CP ) 6.0 Hz, CH2), 37.0 (d, J CP ) 13.0 Hz, CH), 39.0
2.31-25.01
1.05-27.92
-21 e h e 19,
-17 e k e 0,
0 e l e 20
7816
0 e h e 13,
-24 e k e 25,
-25 e l e 25
46 023
no. of rflns collected
no. of indep rflns
7533 (R(int) )
0.0495)
17 507 (R(int) )
0.0927)
max and min transmissn 0.824 and 0.792
no. of variables 540
final R index (I > 2σ(I)) R1 ) 0.0570,
wR2 ) 0.1274
R1 ) 0.1148,
wR2 ) 0.1489
1.099 and 0.917
883
R1 ) 0.0603,
wR2 ) 0.1433
R1 ) 0.1020,
wR2 ) 0.1656
R index (all data)
(d, J CP ) 30.7 Hz, CH2), 73.8 (d, J CP ) 8.2 Hz, C1), 74.3 (d, J CP
) 7.7 Hz, C3), 97.1 (s, C2), 105.7 (s, C3a, C7a), 110.3 (s, C3a,
C7a), 121.6-134.3 (m, C9H7, Ar). Anal. Calcd for C43H40P2Ru
(719.8): C, 71.75; H, 5.60. Found: C, 71.58; H, 5.64.
X-r a y Diffr a ction Stu d y of Com p lexes 2a a n d 5b. Data
for 2a were gathered on a CAD-4 diffractometer equipped with
an FR558 low-temperature device.41 After preliminary deter-
mination of the orientation matrix, axial photos were used to
verify the cell dimensions. Scan parameters for intensity data
collection were optimized with reference to two-dimensional
(ω-θ) scans of 11 reflections. During intensity data collection,
a variable counting time was used, depending on the intensity
measured in a rapid initial scan. The weakest reflections were
measured at the slowest speed; none were skipped. Absorption
corrections were based on nine ψ-scans of reflections with
Eulerian angle ø between -30.3 and +49.8°.42 For 5b (the
asymmetric unit contains two independent molecules), dif-
fraction data were gathered using a Nonius KappaCCD four-
circle diffractometer41 equipped with an Oxford Cryosystems
Model 600 cryostat. Integration of the 354 data frames was
followed by application of the usual corrections, including
absorption corrections.42 Both structures were solved by direct
methods43 and refined by full-matrix least-squares calcula-
tions.44 In 2a the asymmetric unit included two formula
equivalents of CH2Cl2, one ordered and one disordered;
similarity restraints were used for the two congeners at the
(41) (a) CAD-4 control program: CAD4/PC, version 2.0; Nonius BV,
Delft, The Netherlands, 1996. (b) KappaCCD control program: Collect;
Nonius BV, Delft, The Netherlands, 1997-2000.
(42) (a) Data reduction for CAD4: Harms K.; Wocadlo, S. XCAD4B;
1995. (b) Absorption correction for CAD4: SHELXTL release 5.05/V;
Siemens, 1996. (c) DENZO-SCALEPACK, data reduction for Kap-
paCCD: Otwinowski, Z.; Minor, W. Processing of X-ray Diffraction
Data Collected in Oscillation Mode. In Macromolecular Crystal-
lography, Part A; Methods Enzymol. No. 276; Carter, C. W., J r., Sweet,
R. M., Eds.; Academic Press: New York, 1997; pp 307-326. (d)
Absorption correction for KappaCCD-SORTAV:Blessing, R. H. Acta
Crystallogr., Sect. A 1995, 51, 33.

2966 Organometallics, Vol. 23, No. 12, 2004
AÄ lvarez et al.
observed rate constants for consumption of complex 2a (kobs
disordered site. For both refinements hydrogen atoms were
placed at calculated positionssincluding the methyl hydrogen
atoms in 5b, which were placed so as to give staggered
conformationssand refined as riding atoms with isotropic
displacement parameters assigned as 1.2 times the equivalent
isotropic displacement parameters of their respective parent
carbon atoms. Non-hydrogen atoms were refined anisotropi-
cally. The two refinements converged with the residuals given
in Table 1.
,
s-1) were obtained from nonlinear least-squares regression
analysis by fitting the exponential dependence of concentra-
tion, c, calculated via peak intensities for 31P, or peak integra-
tion for 1H, against time, according to the first-order rate
equation: Ct ) C∞ + (C0 - C∞) exp(-kobst). The procedure yields
values of c∞, kobs, and the correlation coefficient. The kobs values
were checked against those obtained from straight-line plots
of ln c vs time.
Kin etic Mea su r em en ts. A weighed amount of complex 2a
(11-13 mg) was dissolved in CDCl3 (0.5 mL) in an NMR tube
under argon, and the appropriate amount of MeCN-d3 was
added using a microsyringe. 31P NMR (Bruker AC 300 P) or
1H NMR spectra (Bruker AM 200) were collected immediately
after mixing, allowing about 1 min for thermal equilibration
and experiment setup and using a macro sequence. The
temperature in the NMR probe was determined from the
chemical shift difference between OH and CH2 signals of a
solution of ethylene glycol containing 20% DMSO-d6.45 The
Ack n ow led gm en t. This work was supported by the
Spanish MCT (Project Nos. 1FD97-0565, BQU2000-
0227, BQU-3660-C02-01, and BQU2002-00554) and
Working Group D24/0014/02 of COST CHEMISTRY
Action D24.
Su ppor tin g In for m ation Available: Tables giving B3LYP/
6-31G(d,p) + LANL2DZ absolute energy values, thermody-
namic data, and Cartesian coordinates for the computed
structures, two figures showing optimized structures including
solvent effects (ꢀ ) 9.83) and a ln[2a ]t/[2a ]0 plot, a table of
kinetic rate constants, and tables giving crystallographic data
for 2a and 5b. This material is available free of charge via
the Internet at http://pubs.acs.org. Crystallographic data are
also available from the Cambridge Crystallographic Data
Centre (CCDC-210218 (2a ) and CCDC-210219 (5b)).
(43) (a) For 2a : Sheldrick, G. M. SHELXS-97: FORTRAN Program
for Crystal Structure Solution; University of Go¨ttingen, Go¨ttingen,
Germany, 1997. (b) For 5b: Beurskens, P. T.; Beurskens, G.; Bosman,
W. P.; de Gelder, R.; Garcia-Granda, S.; Gould, R. O.; Israel, R; Smits,
J . M. M. DIRDIF96 Program System; Crystallography Laboratory,
University of Nijmegen, Nijmegen, The Netherlands, 1996.
(44) Sheldrick, G. M. SHELXL-97: FORTRAN Program for Crystal
Structure Refinement; University of Go¨ttingen, Go¨ttingen, Germany,
1997.
(45) Van Geet, A. L. Anal. Chem. 1968, 40, 2227.
OM040001Q