Synthesis and properties of planar-chiral (η6-benzene)(η5-cyclopentadienyl)ruthenium(II) complexes in an optically pure form

Article abstract of DOI:10.1246/bcsj.74.527

Planar-chiral cyclopentadienylruthenium complexes [Ru(η⁵-1-CO₂R*-2-Me-4-R¹ C₅H₂)(η⁶-C₆H₆)] [X] (4 and 8) (R= (l)- or (d)-menthyl; R¹ = Me, Ph, t-Bu, 2-Naphthyl, or 4-BrC₆H₄; X = PF₆ or BPh₄) were synthesized in a diastereomerically pure form. The absolute configuration of 8b and 4c (R¹ = Ph, t-Bu) were determined by an X-ray crystallographic analysis and those of the others were assigned on the basis of their optical properties including their CD spectra. Enantiopure complexes (S_C1)-[Ru(η⁵-1-CONHBu^t-2-Me-4- R¹C₅H₂)(η⁶-C₆ H₆)][PF₆] 9 and -[Ru(η⁵-1-CONHBu^t-2-Me-4-R¹ C₅H₂)(η⁶-C₆H₆)] [BPh₄] 10, and (R_C1-9 and -10 were prepared from direct hydrolysis of diastereomeric complexes, followed by the reaction of amines. Replacement reactions of the bromo group in 9e (R¹ = 4-BrC₆H₄) gave alkyl, phenyl, and ethynyl derivatives. Complexes [Ru(η⁵-1-CO₂Et-2-Me-4-R¹ C₅ H₂)(η⁶-C₆H₆)] [PF₆] 6 were also transformed to planar-chiral [Ru(η⁵-1-CO₂Et-2-Me-4-R¹ C₅H₂)(CH₃CN)₃][X], which underwent ligand exchange reactions to afford carbonyl, phosphine, and π-arene complexes.

Full text of DOI:10.1246/bcsj.74.527

© 2001 The Chemical Society of Japan
527
Bull. Chem. Soc. Jpn., 74, 527–537 (2001)
6
5
Synthesis and Properties of Planar-Chiral ( -Benzene)( -cyclo-
η
η
pentadienyl)ruthenium(II) Complexes in an Optically Pure Form
Yuji Matsushima, Nobuko Komatsuzaki, Yoshiki Ajioka, Mari Yamamoto, Hidetomo Kikuchi,
Yasuyuki Takata, Noriko Dodo, Kiyotaka Onitsuka, Mitsunari Uno, and Shigetoshi Takahashi*
The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047
(Received September 14, 2000)
5
1
6
*
Planar-chiral cyclopentadienylruthenium complexes [Ru(η -1-CO2R -2-Me-4-R C5H2)(η -C6H6)][X] (4 and 8)
1
*
(R = (l)- or (d)-menthyl; R = Me, Ph, t-Bu, 2-Naphthyl, or 4-BrC6H4; X = PF6 or BPh4) were synthesized in a diastere-
omerically pure form. The absolute configuration of 8b and 4c (R1 = Ph, t-Bu) were determined by an X-ray crystallo-
graphic analysis and those of the others were assigned on the basis of their optical properties including their CD spectra.
Enantiopure complexes (SC1)-[Ru(η5-1-CONHBut-2-Me-4-R1C5H2)(η6-C6H6)][PF6] 9 and -[Ru(η5-1-CONHBut-2-Me-
4-R1C5H2)(η6-C6H6)] [BPh4] 10, and (RC1)-9 and -10 were prepared from direct hydrolysis of diastereomeric complexes,
followed by the reaction of amines. Replacement reactions of the bromo group in 9e (R1 = 4-BrC6H4) gave alkyl, phenyl,
and ethynyl derivatives. Complexes [Ru(η5-1-CO2Et-2-Me-4-R1C5H2)(η6-C6H6)][PF6] 6 were also transformed to pla-
nar-chiral [Ru(η5-1-CO2Et-2-Me-4-R1C5H2)(CH3CN)3][X], which underwent ligand exchange reactions to afford car-
bonyl, phosphine, and π-arene complexes.
The chemistry of chiral organometallic complexes is attract-
ing increasing interest, particularly in organic syntheses and in
materials science. There are three types of chiral organometal-
lic complexes1: one bearing chiral ligands and others contain-
ing a metal-centered chirality or a planar chirality. Most of
known chiral organometallic complexes belong to the former
category and bear chiral phosphine and amine ligands, whereas
relatively few examples have been known so far for the latter
two types of chiral complexes. Planar chirality arises from the
π-coordination of prochiral ligands such as unsymmetrically
substituted cyclopentadienyls,2 arenes,3 and olefins,4 and is
thus characteristic of organometallic π-complexes. Currently
several efforts have been made to facilitate the syntheses of
planar-chiral cyclopentadienyl metal complexes in terms of
their potentials as mediators or catalysts in asymmetric organic
syntheses.2 Planar-chiral cyclopentadienyl metal complexes
have advantages in use as a catalyst since coordination of a cy-
clopentadienyl ligand to a metal atom is generally so strong
that there is almost no chance of ligand dissociation resulting
in racemization. In fact planar-chiral cyclopentadienyl-group 4
metal complexes are successfully used as catalysts in asym-
metric organic syntheses and stereoregular polymerizations.5
However, there are few examples of planar-chiral cyclopenta-
dienyl complexes of late transition metals except for planar-
chiral ferrocene,6 ruthenocene,7 and their derivatives, which are
extremely stable. Recently we have found a new method for the
synthesis of planar-chiral (η5-cyclopentadienyl)iron,8 -cobalt,9
and -rhodium.10 Now we apply our method with modification
to the synthesis of ruthenium analogs, planar-chiral (η5-cyclo-
pentadienyl)ruthenium(II) complexes. The complexes, [Ru(η5-
Cp′)(η6-benzene)]+, are easily transformed to [Ru(η5-
Cp′)(CH3CN)3]+ by a photoreaction with acetonitrile,11 which
may be a precursor for a coordinatively unsaturated Cp′Ru+
species possessing a planar chirality. Since several reports have
revealed the novel reactivity and catalysis of ruthenium com-
plexes,12 new types of chiral ruthenium complexes are of spe-
cial interest as catalysts for asymmetric organic syntheses.
Here we wish to report# the convenient and useful synthesis of
planar-chiral [Ru(η5-Cp′)(η6-benzene)]+[X]– in an optically
pure form.
Results and Discussion
Although some preparative methods for ligand-chiral cyclo-
pentadienyl-ruthenium complexes are already known,13 no
general methods have appeared in the literature so far for the
synthesis of enantiopure planar-chiral cyclopentadienyl-ruthe-
nium complexes, except ruthenocene derivatives.7 Previously
we showed a new method for the synthesis of planar-chiral cy-
clopentadienyl-metal complexes by use of 1,2,4-trisubstituted
cyclopentadienes 2 bearing a removable chiral auxiliary like an
(l)-menthyl group. By essentially the same procedure as uti-
lized for the preparation9 of planar-chiral cyclopentadienyl co-
balt complexes, [Ru(η5-Cp′)(η6-benzene)]+[PF6]– (4a), was
prepared by use of 1-(l)-menthyloxycarbonyl-2,4-dimethylcy-
clopentadiene 2a as a 1 :1 mixture of diastereomers (Synthetic
Route A in Scheme 1).
Separation of 4a into a pair of diastereomers 4a-1 and 4a-2
was successfully performed by fractional recrystallization
A preliminary result has already communicated in Ref. 14.
#

528 Bull. Chem. Soc. Jpn., 74, No. 3 (2001)
Synthesis of Planar-Chiral Ru(η5-Cp)(η6-C6H6) Complexes
Scheme 1.
from EtOH/H2O.14 Diastereopure complexes 4a-1 and 4a-2
were isolated as hexafluorophosphate and characterized by
spectroscopic analyses including mass spectra (See Experi-
mental Section). The absolute configuration of 4a-1 was estab-
amine gave enantiopure amide derivative 9a-1 (R = t-Bu)
(Scheme 2). Similarly, enantiopure RC1 isomer 9a-2 (R = t-Bu)
was prepared from 4a-2. Complexes 9a-1 and 9a-2 were con-
firmed to be a pair of enantiomers by melting points and by op-
tical rotatory powers (Table 1) as well as by circular dichroism
(CD) spectra.
It should be noted that the ester group on cyclopentadienyl
ligand in cationic cyclopentadienylruthenium complex 4a un-
dergoes hydrolysis to give carboxylic acid 7a without any de-
composition, although an attempt to prepare cyclopentadiene-
carboxylic acid from free alkoxycarbonylcyclopentadiene 1 by
hydrolysis resulted in failure and 1 decomposed to form no
definite products under the hydrolysis conditions. The hydroly-
sis of 4a to a carboxylic acid, followed by transformation to an
acid chloride and then re-esterification with an appropriate al-
##
lished to be SC1 on the basis of the absolute structure of the
(l)-menthyl group by an X-ray crystallographic method.14
To obtain planar-chiral ruthenium complexes in an enantio-
merically pure form, we attempted to remove the chiral auxilia-
ry on the cyclopentadienyl ligand from 4a, and successfully
found that direct hydrolysis of the ester group in cationic com-
plexes 4a under basic conditions gave carboxylic acid 7a.
Treatment of 7a with oxalyl chloride and then with t-butyl-
The representation of planar chirality is based on the absolute
##
cofiguration of the 1-position of cyclopentadienyl ligand.

Y. Matsushima et al.
Bull. Chem. Soc. Jpn., 74, No. 3 (2001) 529
Scheme 2.
The trisubstituted cyclopentadienyl ligands have advantages
in that they can modulate their steric and electronic properties
by varying the substituents on the ligand. We prepared 1,2,4-
trisubstituted cyclopentadienes having phenyl (1b), t-butyl
(1c), 2-naphthyl (1d), and 4-bromophenyl (1e) groups at the 4-
position of cyclopentadienyl ligand.15 Such use leads to the
synthesis of planar-chiral cyclopentadienylruthenium com-
plexes bearing a variety of substituents on the cyclopentadienyl
ligand. Thus, 1-ethoxycarbonyl-2-methyl-4-phenylcyclopenta-
diene 1b was converted to racemic (η6-benzene)(η5-1-ethoxy-
carbonyl-2-methyl-4-phenylcyclopentadienyl)ruthenium hexa-
fluorophosphate 6b in 73% yield according to the reaction in
Scheme 1. Hydrolysis of 6b, followed by transformation to
acid chloride and then by esterification with (l)-menthol, af-
forded a mixture of diastereomers 4b in 76% yield. Some at-
tempts to separate the mixture into a pair of diastereomers 4b-1
and 4b-2 by fractional recrystallization failed. As the solubility
and crystallinity of cationic complexes depend on the kind of
Table 1. Optical Rotation and Melting Point of Ruthe-
nium Complexes
Complex
[α]2D0/◦
Melting point/◦C
S C1-4a-1
RC1-4a-2
S C1-8b-1
RC1-8b-2
RC1-8ꢀb-2
S C1-4c-1
RC1-4ꢀc-2
S C1-8d-1
RC1-8d-2
S C1-8e-1
RC1-8ꢀe-2
S C1-9a-1
RC1-9a-2
S C1-9b-1
RC1-9b-2
S C1-10e-1
RC1-10e-2
+3.00 (c 0.222)a)
−54.7 (c 0.220)a)
−17.0 (c 0.252)a)
−1.00 (c 0.279)a)
+17.3 (c 0.244)a)
−43.4 (c 0.445)b)
+43.4 (c 0.453)b)
−21.6 (c 0.534)b)
−1.25 (c 0.583)b)
−27.8 (c 0.404)b)
+27.3 (c 0.524)b)
−41.6 (c 0.327)b)
+42.3 (c 0.329)b)
−29.0 (c 0.381)b)
+28.9 (c 0.397)b)
−22.0 (c 0.450)b)
+22.0 (c 0.514)b)
209.5–210.5
175.0–175.5
178.0–179.0
186.0–187.0
178.0–179.0
244.0–245.0
244.0–245.0
189.0–189.5
120.5–121.5
122.0–122.5
122.0–122.5
197.0–197.5
197.0–197.5
225.0–225.5
225.0–225.5
203.0–206.0c)
202.0–206.0c)
–
–
anions, the counter anion, PF6 , in 4b was replaced for BPh4
by treatment with NaBPh4 in methanol (Scheme 3).
a) In chloroform. b) In acetonitrile. c) Decomposition point.
Fortunately the tetraphenylborate complexes 8b were suc-
cessfully separated into a pair of diastereomers 8b-1 and 8b-2
by fractional recrystallization from ethyl acetate (Scheme 2).
Diastereomer 8b-1 was obtained in 48% yield, whereas 8b-2
was isolated in a lower yield (7%), since the latter is much
cohol, provides us an alternative and convenient method for the
synthesis of various planar-chiral cyclopentadienylruthenium
complexes. Thus, a racemic mixture of planar-chiral (η6-ben-
zene)(η5-1-ethoxycarbonyl-2,4-dimethylcyclopentadienyl)ru-
thenium hexafluorophosphate 6a, which was prepared directly
from cyclopentadiene 1a, was easily transformed into a mix-
ture of diastereomers (η6-benzene)[η5-1-(l)-menthyloxycarbo-
nyl-2,4-dimethylcyclopentadienyl]ruthenium hexafluorophos-
phate 4a by hydrolysis in aqueous acetonitrile under basic con-
ditions at 80 °C, followed by esterification with (l)-menthol
(Synthetic Route B in Scheme 1).
Scheme 3.

530 Bull. Chem. Soc. Jpn., 74, No. 3 (2001)
Synthesis of Planar-Chiral Ru(η5-Cp)(η6-C6H6) Complexes
more soluble in ethyl acetate. As mentioned below, the abso-
lute configuration of 8b-1 has been established to be an SC1
configuration. To obtain more efficiently a planar-chiral com-
plex possessing an RC1 configuration, we prepared (η6-ben-
zene)[η5-1-(d)-menthyloxycarbonyl-2-methyl-4-phenylcyclo-
pentadienyl]ruthenium tetraphenylborate 8′b from 6b by use of
(d)-menthol. Fractional recrystallization of 8′b from ethyl ace-
tate gave diastereomer 8′b-2 in a higher isolated yield. The
physical data on 8b and 8′b are shown in Table 1. The CD
spectra of 8b-1 and 8′b-2 exhibited mirror-symmetry, clearly
indicating that they are a pair of enantiomers (Fig. 1).
The absolute configuration around Cp′-Ru of 8b-1 has been
established to be SC1 on the basis of the absolute structure of the
(l)-menthyl group by an X-ray crystallographic analysis. Fig-
ure 2 depicts an ORTEP drawing of the molecular structure of
8b-1. The bond distances and angles found in 8b-1 are very
similar to those found in 4a-114 and [(CpRu)2(η6,η6-dibenzo-p-
quinodimethane)][PF6]2.16 The absolute configuration of 8b-2,
therefore, should be RC1.
respective pairs of diastereomers 4c-1 and 4′c-2, 8d-1 and 8d-
2, and 8e-1 and 8′e-2 by fractional recrystallization. Especially,
the planar-chiral complex 4c-1 (R = t-Bu) was obtained in a
high yield (82%) simply by recrystallization from ethanol.
Their physical data are listed in Table 1, and the CD spectra are
shown in Fig. 3. Fortunately, we could obtain good single crys-
tals of 4c-1 by recrystallization from ethanol, and X-ray crys-
tallographic analysis has established the absolute configuration
of 4c-1. The ORTEP diagram (Fig. 4) reveals that the absolute
configuration around Cp′-Ru of 4c-1 is SC1. CD spectra of
enantiomers 4c-1 and 4′c-2 resemble those of diastereomers
4a-1 and 4a-2, respectively, indicating that the CD spectra re-
flect the absolute configuration around Cp′-Ru.14 Although we
have not yet established the absolute configurations of diastere-
omers other than 4a, 8b, and 4c by a crystallographic method,
the similarity in CD spectra of the complexes suggests their ab-
solute configurations. Thus, the CD spectra of 8d-1 and 8e-1
closely resemble that of 8b-1, suggesting an SC1 configuration,
whereas an RC1 configuration may be assigned for 8d-2 and
8′e-2.
Similarly, planar-chiral cyclopentadienylruthenium com-
plexes 4c, 4d, and 4e were also synthesized starting from cy-
clopentadienes 1c, 1d, and 1e, respectively, and separated into
Fig. 3. CD spectra of ruthenium complexes 4c, 8d, and 8e.
Fig. 1. CD spectra of ruthenium complexes 8b-1 and 8ꢀb-2.
Fig. 4. ORTEP drawing of ruthenium complex S C1-4c-
1. Hydrogen atoms, a counter anion and the disordered
η6-benzene group with low occupancy are omitted for
clarity.
Fig. 2. ORTEP drawing of ruthenium complex S C1-8b-
1. Hydrogen atoms and a counter anion are omitted for
clarity.

Y. Matsushima et al.
Bull. Chem. Soc. Jpn., 74, No. 3 (2001) 531
Hydrolysis of diastereomers 8b-1, 8b-2, 8e-1, and 8′e-2, fol-
lowed by treatment with oxalyl chloride and then with t-butyl-
amine, afforded pairs of enantiopure amide derivatives 9b-1
and 9b-2, and 10e-1 and 10e-2, respectively, in good yields
(Scheme 2). Their optical data are shown in Table 1, and the
CD spectra in Fig. 5. These data give us the valuable informa-
tion that, simply on the basis of the optical rotation as well as
CD spectrum, we may predict the absolute configuration of
planar-chiral 4-phenylcyclopentadienylruthenium complexes;
that is, a positive optical rotation suggests an RC1 configuration
of the complexes, whereas a negative one may be assigned to
an SC1 configuration.
Diastereomers 4e and enantiomers 8e serve as useful start-
ing materials for the further variations of planar-chiral cyclo-
pentadienylruthenium complexes, because 4e and 8e have an
exchangeable bromo group on the ligand. For example, 8e was
at first transformed to an amido derivative (9e), since the ester
group of 8e possibly undergoes hydrolysis in the presence of
water under basic conditions. Then, treatments of 9e with
alkyllithium,17 phenylboronic acid,18 and trimethylsilyl-
acetylene19 in the presence of a palladium catalyst gave com-
plexes 11, 12, and 13, respectively, which carry alkylphenyl,
biphenylyl, and (trimethylsilylethynyl)phenyl groups on the
cyclopentadienyl ligand (Scheme 4).
The η6-benzene complexes, [Ru(η5-Cp′)(η6-benzene)]+,
have a stable 18-electron configuration; however, they are easi-
ly transformed by a photoreaction in acetonitrile to versatile
tris(acetonitrile)cyclopentadienylruthenium complexes 14,
[Ru(η5-Cp′)(CH3CN)3]+,11 which may be regarded as a precur-
sor of coordinatively unsaturated Cp′Ru+ species. Thus, irradi-
ation to complex 6a in acetonitrile gave tris(acetonitrile) com-
plexes 14a in almost quantitative yield (Scheme 5). However
similar treatment of 8b having BPh4– as a counter anion gave a
mixture of 15b and 16b (Scheme 6). The latter product in-
volves a coordination of the phenyl group of the counter anion.
To avoid the participation of the anion, we tried replacement of
the BPh4 for another anion and found that the treatment of
[RuCp′(L)][BPh4] with NH4PF6 in ethyl acetate yielded a de-
sired salt, [RuCp′(L)][PF6], due to the low solubility of
NH4BPh4 in ethyl acetate (Scheme 3). Thus obtained tris(ace-
tonitrile) complexes 14 are reactive and undergo several
ligand-exchange reactions. For example, the acetonitrile
ligands in 14 are easily replaced with carbon monoxide and
triphenylphosphine to produce new planar-chiral cyclopentadi-
enyl ruthenium complexes 17 and 18.11 Treatment of 14 with
arenes reproduces η6-arene complexes 19.
In conclusion, we have synthesized a variety of planar-chiral
trisubstituted cyclopentadienylruthenium complexes in an op-
tically pure form. They provide the first examples of optically
pure planar-chiral ruthenium complexes with a half-sandwich
Fig. 5. CD spectra of ruthenium complexes 9b and 10e.
Scheme 4.

532 Bull. Chem. Soc. Jpn., 74, No. 3 (2001)
Synthesis of Planar-Chiral Ru(η5-Cp)(η6-C6H6) Complexes
Scheme 5.
Scheme 6.
3.86 (d, 2H, J = 2.2 Hz, CH2), 2.44 (d, 3H, J = 2.2 Hz, CH3), 1.37 (t,
3H, J = 7.1 Hz, CH2CH3). IR (KBr) 1682 cm–1 (C=O). MS (FAB)
m/z 278. Found: C, 81.72; H, 6.38%. Calcd for C19H18O2: C, 81.99;
H, 6.52%.
Synthesis of 1-Ethoxycarbonyl-2-methyl-4-(4-bromophe-
nyl)cyclopentadiene (1e). This compound was prepared by the
method reported previously15 from 4-bromophenacyl bromide
(44% yield). Mp 178.0–178.5 °C. 1H NMR (CDCl3, 400 MHz) δ
7.47 (d, 2H, J = 8.5 Hz, C6H4), 7.41 (d, 2H, J = 8.5 Hz, C6H4), 4.26
(q, 2H, J = 7.1 Hz, CH2CH3), 3.68 (s, 2H, CH2), 2.39 (s, 3H, CH3),
1.35 (t, 3H, J = 7.1 Hz, CH2CH3). IR (KBr) 1682 cm–1 (C=O). MS
(FAB) m/z 307. Found: C, 58.43; H, 4.71; Br, 25.89%. Calcd for
C15H15BrO2: C, 58.65; H, 4.92; Br, 26.01%.
Synthesis of (η6-Benzene)(η5-1-ethoxycarbonyl-2,4-dimeth-
ylcyclopentadienyl)ruthenium Hexafluorophosphate (6a). To
a solution of sodium hydride (60% in oil, 0.88 g, 22 mmol) in THF
(10 ml) was added a THF (20 ml) solution of 1-ethoxycarbonyl-
2,4-dimethylcyclopentadiene 1a (3.32 g, 20 mmol) at 0 °C. The re-
action mixture was stirred for 1 h at room temperature. This solu-
tion was added dropwise to an aqueous solution of thallium(I) sul-
fate (5.0 g, 9.5 mmol), and the mixture was stirred overnight at
room temperature to give a pale brown precipitate, which was col-
lected and washed with ether several times. The resulting solid was
dried in vacuo and then dissolved in acetonitrile. To this solution
was added (η6-benzene)dichlororuthenium dimer, [(η6-
C6H6)Cl2Ru]2, (5.0 g, 10 mmol). The reaction mixture was stirred
overnight at room temperature and then filtered through Celite. The
filtrate was concentrated and to the residual oil was added an aque-
ous solution of ammonium hexafluorophosphate (6.54 g, 40
mmol). The aqueous solution was extracted with dichloromethane
(200 ml × 3) and the combined extracts were dried over MgSO4,
and filtered. After removal of the solvent under reduced pressure,
structure.
Experimental
All reactions were carried out under an atmosphere of nitrogen
or argon, but the workup was performed in air. Melting and decom-
position points are corrected. 1H and 13C NMR spectra were mea-
sured in acetone-d6 or CDCl3 with SiMe4 as an internal standard
and recorded on JEOL EX-270 (270 MHz), JEOL JNM-LA400
(400 MHz), and JEOL JNM-LA600 (600 MHz) spectrometers.
Chemical shifts are given in ppm. IR and mass spectra were taken
on a Perkin–Elmer system 2000 FT-IR and a JEOL JMS-600H in-
strument, respectively. Optical rotations and CD spectra were mea-
sured on a JASCO DIP-1000 polarimeter and a JASCO J-725 spec-
tropolarimeter, respectively. Optical purity was determined by
1
HPLC using a DAICEL chiral cell OD column or by H NMR
spectrum using a shift reagent [Eu(hfc)3] [hfc = 3-(heptafluoropro-
pylhydroxymethylene)-D-camphorate]. Elemental analyses were
performed by the MaterialsAnalysis Center, ISIR, Osaka Universi-
ty. Diethyl ether and THF were distilled over benzophenone ketyl
under argon just before use. Dichloromethane and acetonitrile
were dried over calcium hydride and then distilled. 1-Ethoxycarbo-
nyl-2,4-dimethylcyclopentadiene 1a, 1-ethoxycarbonyl-2-methyl-
4-phenylcyclopentadiene 1b, 1-ethoxycarbonyl-2-methyl-4-(t-bu-
tyl)cyclopentadiene 1c, and 1-(l)-menthyloxycarbonyl-2,4-dime-
thylcyclopentadiene [2a, [α]25: –58.9° (c 1.12, acetone)] were pre-
D
pared by the method previously reported.9,15 Other chemicals avail-
able commercially were used without further purification.
Synthesis of 1-Ethoxycarbonyl-2-methyl-4-(2-naphthyl)cy-
clopentadiene (1d). This compound was prepared by the method
reported previously15 from 2-bromoacetonaphthone. (52% yield).
Mp 94.0–94.5 °C. H NMR (CDCl3, 400 MHz) δ 7.97–7.69 (m,
7H, C10H7), 6.89 (s, 1H, CH), 4.29 (q, 2H, J = 7.1 Hz, CH2CH3),
1

Y. Matsushima et al.
Bull. Chem. Soc. Jpn., 74, No. 3 (2001) 533
the residual oil was placed on a column of alumina and eluted with
acetone. The acetone solution was evaporated, and the residue was
purified by recrystallization from ethanol to give 6.22 g (67%
yield) of ruthenium complex 6a as pale yellow needles. Mp
over MgSO4 and filtered. After removal of the solvent, the residue
was washed with dichloromethane several times. To the suspension
of the resulting solid in dichloromethane (20 ml) were added oxalyl
chloride (1 ml) and DMF (a catalytic amount) with stirring in the
dark at room temperature.After 2 h, the solvent was evaporated un-
der reduced pressure, and the residue was dissolved in acetonitrile
(10 ml). This solution was added to an acetonitrile solution (20 ml)
containing (l)-menthol (1.40 g, 9 mmol), triethylamine (3 ml), and
4-dimethylaminopyridine (5 mg). The reaction mixture was stirred
for 3 h and the precipitate formed was removed by filtration. The
filtrate was concentrated and to the residual oil was added an aque-
ous solution of ammonium hexafluorophosphate (1.47 g, 9 mmol).
The aqueous solution was extracted with dichloromethane (10 ml ×
3) and the combined extracts were dried over MgSO4, and filtered.
After removal of the solvent under reduced pressure, the residual
oil was placed on a column of alumina and eluted with acetone. The
acetone solution was evaporated, and then the resulting solid was
purified by recrystallization from ethanol to give 0.88 g (49%
yield) of ruthenium complex 4a as pale yellow needles. Diastere-
omers were separated with recrystallization by EtOH–H2O (5:1).
1
178.0–178.5 °C. H NMR (acetone-d6, 270 MHz) δ 6.53 (s, 6H,
C6H6), 5.90 (d, 1H, J = 1.7 Hz, CpH), 5.74 (d, 1H, J = 1.7 Hz,
CpH), 4.32 (dq, 1H, J = 1.7, 7.3 Hz, CH2CH3), 4.31 (dq, 1H, J =
1.7, 7.3 Hz, CH2CH3), 2.31 (s, 3H, CpCH3), 2.09 (s, 3H, CpCH3),
1.35 (t, 3H, J = 7.3 Hz, CH2CH3). IR (KBr) 1712 cm–1 (C=O). MS
(FAB) m/z 345 (M+ – PF6). Found: C, 39.49; H, 3.84; F, 23.21; P,
6.20%. Calcd for C16H19F6O2PRu: C, 39.27; H, 3.91; F, 23.29; P,
6.33%.
Synthesis of (η6-Benzene)(η5-1-ethoxycarbonyl-2-methyl-4-
phenylcyclopentadienyl)ruthenium
Hexafluorophosphate
(6b). This complex was prepared using 1b by the same method as
that for 6a (73% yield). Mp 145.0–146.0 °C. 1H NMR (acetone-d6,
270 MHz) δ 7.74–7.69 (m, 2H, Ph), 7.45–7.42 (m, 3H, Ph), 6.51
(d, 1H, J = 1.7 Hz, CpH), 6.39 (d, 1H, J = 1.7 Hz, CpH), 6.28 (s, 6H,
C6H6), 4.90 (dq, 1H, J = 2.3, 7.3 Hz, CH2CH3), 4.89 (dq, 1H, J =
2.3, 7.3 Hz, CH2CH3), 2.43 (s, 3H, CpCH3), 1.39 (t, 3H, J = 7.3 Hz,
CH2CH3). IR (KBr) 1725 cm–1 (C=O). MS (FAB) m/z 407 (M+ –
PF6). Found: C, 45.79; H, 3.82; F, 20.57; P, 5.63%. Calcd for
C21H21F6O2PRu: C, 45.74; H, 3.84; F, 20.67; P, 5.62%.
1
4a-1(SC1 form): 26% yield. Mp 209.5–210.5 °C. H NMR (ace-
tone-d6, 270 MHz) δ 6.34 (s, 6H, C6H6), 5.92 (s, 1H, CpH), 5.76 (s,
1H, CpH), 4.87 (dt, 1H, J = 4.3, 10.6 Hz, OCH), 2.33 (s, 3H,
CpCH3), 2.09 (s, 3H, CpCH3), 1.80–1.00 (m, 9H, menthyl), 0.98
(d, 3H, J = 7.3 Hz, menthyl), 0.95 (d, 3H, J = 6.6 Hz, menthyl), 0.86
(d, 3H, J = 6.9 Hz, menthyl). IR (KBr) 1722 cm–1 (C=O). Mass
(FAB) m/z 455 (M+ – PF6). Found: C, 48.04; H, 5.50; F, 19.23; P,
5.23%. Calcd for C24H33F6O2PRu: C, 48.08; H, 5.55; F, 19.01; P,
5.17%. 4a-2(RC1 form): 4% yield. Mp 175.0–175.5 °C. 1H NMR
(acetone-d6, 270 MHz) δ 6.36 (s, 6H, C6H6), 5.93 (s, 1H, CpH),
5.76 (s, 1H, CpH), 4.87 (dt, 1H, J = 4.6, 10.9 Hz, OCH), 2.32 (s,
3H, CpCH3), 2.10 (s, 3H, CpCH3), 1.82–1.00 (m, 9H, menthyl),
0.97 (d, 3H, J = 6.6 Hz, menthyl), 0.94 (d, 3H, J = 6.9 Hz, menthyl),
0.82 (d, 3H, J = 6.9 Hz, menthyl). IR (KBr) 1728 cm–1 (C=O). MS
(FAB) m/z 455 (M+ – PF6). Found: C, 48.07; H, 5.40; F, 19.20; P,
5.07%. Calcd for C24H33F6O2PRu: C, 48.08; H, 5.55; F, 19.01; P,
5.17%.
Synthesis of (η6-Benzene)[η5-1-ethoxycarbonyl-2-methyl-4-
(t-butyl)cyclopentadienyl]ruthenium
Hexafluorophosphate
(6c). This complex was prepared using 1c by the same method as
that for 6a (45% yield). Mp 160.5–162.0 °C. 1H NMR (CDCl3, 270
MHz) δ 6.13 (s, 6H, C6H6), 5.64 (d, 1H, J = 2.0 Hz, CpH), 5.62 (d,
1H, J = 2.0 Hz, CpH), 4.36 (q, 2H, J = 7.3 Hz, CH2CH3), 2.30 (s,
3H, CpCH3), 1.39 (t, 3H, J = 7.3 Hz, CH2CH3), 1.18 (s, 9H,
C(CH3)3). IR (KBr) 1724 cm–1 (C=O). MS (FAB) m/z 387 (M+ –
PF6). Found: C, 42.89; H, 4.68; F, 21.49; P, 5.65%. Calcd for
C19H25F6O2PRu: C, 42.94; H, 4.74; F, 21.45; P, 5.83%.
Synthesis of (η6-Benzene)[η5-1-ethoxycarbonyl-2-methyl-4-
(2-naphthyl)cyclopentadienyl]ruthenium
Hexafluorophos-
phate (6d). This complex was prepared using 1d by the same
method as that for 6a (72% yield). Mp 223.0–224.0 °C. 1H NMR
(acetone-d6, 400 MHz) δ 8.29 (s, 1H, C10H7), 7.96–7.92 (m, 3H,
C10H7), 7.80–7.78 (m, 1H, C10H7), 7.60–7.57 (m, 2H, C10H7), 6.64
(s, 1H, CpH), 6.52 (s, 1H, CpH), 6.30 (s, 6H, C6H6), 4.43–4.34 (m,
2H, CH2CH3), 2.46 (s, 3H, CpCH3), 1.40 (t, 3H, J = 7.1 Hz,
CH2CH3). IR (KBr) 1714 cm–1 (C=O). MS (FAB) m/z 457 (M+ –
PF6). Found: C, 50.01; H, 3.68%. Calcd for C25H23F6O2PRu: C,
49.92; H, 3.85%.
Synthesis of (η6-Benzene)[η5-1-(l)-menthyloxycarbonyl-2-
methyl-4-phenylcyclopentadienyl]ruthenium Hexafluorophos-
phate (4b). This complex was prepared using 6b by the same
method as that for 4a (76% yield). 1H NMR (acetone-d6, 400 MHz)
δ 7.71–7.68 (m, 3H, Ph), 7.42–7.40 (m, 2H, Ph), 6.52 (t, 1H, J = 1.7
Hz, CpH), 6.39 (s, 1H, CpH), 6.25 (s, 6H, C6H6), 4.92 (dt, 1H, J =
4.4, 11.0 Hz, OCH), 2.42 (s, 3H, CpCH3), 2.10–1.98 (m, 2H, men-
thyl), 1.79–1.74 (m, 2H, menthyl), 1.61–1.53 (m, 2H, menthyl),
1.28–1.11 (m, 2H, menthyl), 0.99–0.94 (m, 7H, menthyl),
0.88–0.82 (m, 3H, menthyl). IR (KBr) 1725 cm–1 (C=O). MS
(FAB) m/z 517 (M+ – PF6). Found: C, 52.38; H, 5.13%. Calcd for
C29H35F6O2PRu: C, 52.65; H, 5.33%.
Synthesis of (η6-Benzene)[η5-1-ethoxycarbonyl-2-methyl-4-
(4-bromophenyl)cyclopentadienyl]ruthenium
Hexafluoro-
phosphate (6e). This complex was prepared using 1e by the
same method as that for 6a (58% yield). Mp 239.0–239.5 °C.
1H NMR (acetone-d6, 400 MHz) δ 7.68 (d, 2H, J = 8.5 Hz, C6H4),
7.58 (d, 2H, J = 8.5 Hz, C6H4), 6.54 (s, 1H, CpH), 6.04 (s, 1H,
CpH), 6.03 (s, 6H, C6H6), 4.42–4.30 (m, 2H, CH2CH3), 2.42 (s, 3H,
CpCH3), 1.38 (t, 3H, J = 7.1 Hz, CH2CH3). IR (KBr) 1722 cm–1
(C=O). MS (FAB) m/z 485 (M+ – PF6). Found: C, 40.05; H, 3.27;
Br, 12.69; F, 17.87; P, 4.80%. Calcd for C21H20BrF6O2PRu: C,
40.02; H, 3.20; Br, 12.68; F, 18.08; P, 4.91%.
Synthesis of (η6-Benzene)[η5-1-(l)-menthyloxycarbonyl-2-
methyl-4-(t-butyl)cyclopentadienyl]ruthenium
Hexafluoro-
phosphate (4c). This complex was prepared using 6c by the
same method as that for 4a (72% yield). Diastereomers were sepa-
rated by recrystallization from ethanol. 4c-1(SC1 form): 82% yield.
1
Mp 244.0–245.0 °C. H NMR (acetone-d6, 400 MHz) δ 6.40 (s,
Synthesis of (η6-Benzene)[η5-1-(l)-menthyloxycarbonyl-2,4-
dimethylcyclopentadienyl]ruthenium Hexafluorophosphate
(4a). To a solution of 6a (1.47 g, 3 mmol) in acetonitrile (50 ml)
was added K2CO3 (5% in water, 50 ml) and the mixture was re-
fluxed for 3 h. This solution was neutralized by 6 M HCl ( 1 M = 1
mol dm–3). The solvent was evaporated under reduced pressure and
the residue was dissolved in acetonitrile. This solution was dried
6H, C6H6), 5.88 (t, 1H, CpH), 5.77 (s, 1H, CpH), 4.89 (dt, 1H, J =
4.4, 10.7 Hz, OCH), 2.33 (s, 3H, CpCH3), 2.13–2.10 (m, 1H, men-
thyl), 1.97–1.88 (m, 2H, menthyl), 1.77–1.72 (m, 2H, menthyl),
1.57–1.51 (m, 2H, menthyl), 1.21 (s, 9H, C(CH3)3), 1.19–1.09 (m,
2H, menthyl), 0.94 (dd, 6H, J = 7.1, 8.8 Hz, menthyl), 0.81 (d, 3H,
J = 7.1 Hz, menthyl). IR (KBr) 1723 cm–1 (C=O). Mass (FAB) m/z
497 (M+ – PF6). Found: C, 50.26; H, 6.03%. Calcd for

534 Bull. Chem. Soc. Jpn., 74, No. 3 (2001)
Synthesis of Planar-Chiral Ru(η5-Cp)(η6-C6H6) Complexes
C27H39F6O2PRu: C, 50.54; H, 6.13%.
6.9 Hz, menthyl). IR (KBr) 1722 cm–1 (C=O). Mass (FAB) m/z 517
(M+ – BPh4). Found: C, 76.11; H, 6.44%. Calcd for C53H55BO2Ru:
C, 76.15; H, 6.63%.
Synthesis of (η6-Benzene)[η5-1-(d)-menthyloxycarbonyl-2-
methyl-4-(t-butyl)cyclopentadienyl]ruthenium
Hexafluoro-
phosphate (4′c). This complex was prepared using (d)-menthol
by the same method as that for 4c (71% yield). Diastereomers were
separated by recrystallization from ethanol. 4′c-2(RC1 form): 82%
yield. The spectroscopic data indicated (RC1)-4′c-2 and (SC1)-4c-1
to be a pair of enantiomers. Found: C, 50.32; H, 6.38%. Calcd for
C27H39F6O2PRu: C, 50.54; H, 6.13%.
Synthesis of (η6-Benzene)[η5-1-(d)-menthyloxycarbonyl-2-
methyl-4-phenylcyclopentadienyl]ruthenium Tetraphenylbo-
rate (8′b-2). This complex was prepared using 6′b by the same
method as that for 8b (99% yield). Diastereomers were separated
by recrystallization from ethyl acetate. The spectroscopic data in-
dicated (RC1)-8′b-2 and (SC1)-8b-1 to be a pair of enantiomers.
Found: C, 75.61; H, 6.20%. Calcd for C53H55BO2Ru: C, 76.15; H,
6.63%.
Synthesis of (η6-Benzene)[η5-1-(l)-menthyloxycarbonyl-2-
methyl-4-(2-naphthyl)cyclopentadienyl]ruthenium Hexafluo-
rophosphate (4d). This complex was prepared using 6d by the
same method as that for 4a (70% yield). 1H NMR (acetone-d6, 400
MHz) δ 8.28 (d, 1H, J = 2.4 Hz, C10H7), 7.96–7.93 (m, 3H, C10H7),
7.79–7.77 (m, 1H, C10H7), 7.61–7.56 (m, 2H, C10H7), 6.67 (d, 1H,
J = 3.2 Hz, CpH), 6.53 (s, 1H, CpH), 6.21 (s, 6H, C6H6), 4.97–4.93
(m, 1H, OCH), 2.47 (d, 3H, J = 3.2 Hz, CpCH3), 2.16 (br, 1H, men-
thyl), 1.77 (br, 2H, menthyl), 1.61–1.58 (m, 2H, menthyl),
1.39–0.76 (m, 13H, menthyl). IR (KBr) 1728 cm–1 (C=O). Mass
(FAB) m/z 567 (M+ – PF6). Found: C, 55.41; H, 5.18; F, 15.82; P,
4.26%. Calcd for C33H37F6O2PRu: C, 55.69; H, 5.24; F, 16.02; P,
4.35%.
Synthesis of (η6-Benzene)[η5-1-(l)-menthyloxycarbonyl-2-
methyl-4-(2-naphthyl)cyclopentadienyl]ruthenium Tetraphe-
nylborate (8d). This complex was prepared using 4d by the
same method as that for 8b (99% yield). Diastereomers were sepa-
rated by recrystallization from chloroform–hexane. 8d-1(SC1
form): 24% yield. Mp 189.0–189.5 °C. 1H NMR (acetone-d6, 400
MHz) δ 8.25 (s, 1H, C10H7), 7.95–7.90 (m, 3H, C10H7), 7.76 (m,
1H, C10H7), 7.59–7.58 (m, 2H, C10H7), 7.34–7.33 (m, 8H, Ph), 6.91
(t, 8H, J = 7.3 Hz, Ph), 6.76 (t, 4H, J = 7.3 Hz, Ph), 6.67 (s, 1H,
CpH), 6.50–6.48 (m, 1H, CpH), 6.27–6.22 (m, 6H, C6H6), 4.95 (dt,
1H, J = 6.3, 11.0 Hz, OCH), 2.45 (d, 3H, J = 2.7 Hz, CpCH3),
2.18–2.15 (br, 1H, menthyl), 1.78–1.76 (br, 2H, menthyl),
1.59–1.57 (br, 2H, menthyl), 1.30–1.14 (m, 2H, menthyl),
0.98–0.95 (m, 7H, menthyl), 0.84 (d, 3H, J = 7.1 Hz, menthyl). IR
(KBr) 1728 cm–1 (C=O). Mass (FAB) m/z 567 (M+ – BPh4). Found:
C, 77.11; H, 6.20%. Calcd for C57H57BO2Ru: C, 77.27; H, 6.48%.
Synthesis of (η6-Benzene)[η5-1-(l)-menthyloxycarbonyl-2-
methyl-4-(4-bromophenyl)cyclopentadienyl]ruthenium Hexa-
fluorophosphate (4e). This complex was prepared using 6e by
the same method as that for 4a (76% yield). 1H NMR (acetone-d6,
400 MHz) δ 7.65–7.62 (m, 2H, C6H4), 7.58–7.56 (m, 2H, C6H4),
6.55 (s, 1H, CpH), 6.37 (s, 1H, CpH), 6.24 (s, 6H, C6H6), 4.96–4.87
(m, 1H, OCH), 2.42 (d, 3H, J = 3.4 Hz, CpCH3), 1.95–1.88 (br, 3H,
menthyl), 1.79–1.75 (br, 2H, menthyl), 0.99–0.93 (m, 6H, menth-
yl), 0.85 (d, 3H, J = 7.1 Hz, menthyl). IR (KBr) 1725 cm–1 (C=O).
Mass (FAB) m/z 597 (M+ – PF6). Found: C, 47.03; H, 4.81%. Calcd
for C29H34BrF6O2PRu: C, 47.04; H, 4.63%.
1
8d-2(RC1 form): 10% yield. Mp 120.5–121.5 °C. H NMR (ace-
tone-d6, 400 MHz) δ 8.27 (s, 1H, C10H7), 7.95–7.90 (m, 3H,
C10H7), 7.76 (dd, 3H, J = 1.7, 8.5 Hz, C10H7), 7.60–7.57 (m, 2H,
C10H7), 7.33 (br, 8H, Ph), 6.91 (t, 8H, J = 7.3 Hz, Ph), 6.76 (t, 4H,
J = 7.3 Hz, Ph), 6.66 (s, 1H, CpH), 6.50 (s, 1H, CpH), 6.24 (d, 6H,
J = 2.4 Hz, C6H6), 4.95 (dt, 1H, J = 6.3, 11.0 Hz, OCH), 2.46 (s, 3H,
CpCH3), 2.16–2.13 (br, 1H, menthyl), 1.80–1.75 (br, 2H, menthyl),
1.63–1.57 (br, 2H, menthyl), 1.26–1.13 (m, 3H, menthyl), 0.98 (dd,
J = 6.6, 15.1 Hz, 6H, menthyl), 0.89 (d, 3H, J = 6.8 Hz, menthyl).
IR (KBr) 1717 cm–1 (C=O). Mass (FAB) m/z 567 (M+ – BPh4).
Found: C, 77.01; H, 6.59%. Calcd for C57H57BO2Ru: C, 77.27; H,
6.48%.
Synthesis of (η6-Benzene)[η5-1-(d)-menthyloxycarbonyl-2-
methyl-4-(4-bromophenyl)cyclopentadienyl]ruthenium Hexa-
fluorophosphate (4′e). This complex was prepared using (d)-
menthol by the same method as that for 4e (73% yield). Spectro-
scopic data of 4′e are the same as 4e within experimental error.
Found: C, 47.00; H, 4.59%. Calcd for C29H34BrF6O2PRu: C, 47.04;
H, 4.63%.
Synthesis of (η6-Benzene)[η5-1-(l)-menthyloxycarbonyl-2-
methyl-4-(4-bromophenyl)cyclopentadienyl]ruthenium Tetra-
phenylborate (8e). This complex was prepared using 4e by the
same method as that for 8b (99% yield). Diastereomers were sepa-
rated by recrystallization from ethyl acetate. 8e-1(SC1 form): 31%
yield. Mp 122.0–122.5 °C. 1H NMR (acetone-d6, 400 MHz) δ 7.64
(d, 2H, J = 8.8 Hz, C6H4), 7.57 (d, 2H, J = 8.8 Hz, C6H4), 7.33 (br,
8H, Ph), 6.91 (t, 8H, J = 7.3 Hz, Ph), 6.77 (t, 4H, J = 7.3 Hz, Ph),
6.55 (d, 1H, J = 1.7 Hz, CpH), 6.37 (d, 1H, J = 1.7 Hz, CpH), 6.24
(s, 6H, C6H6), 4.93 (dt, 1H, J = 4.4, 11.0 Hz, OCH), 2.41 (s, 3H,
CpCH3), 1.78–1.74 (br, 2H, menthyl), 1.60–1.54 (br, 2H, menthyl),
0.97–0.93 (m, 7H, menthyl), 0.83 (d, 3H, J = 6.8 Hz, menthyl). IR
(KBr) 1725 cm–1 (C=O). Mass (FAB) m/z 596 (M+ – BPh4). Found:
C, 69.93; H, 5.58; Br, 8.71%. Calcd for C53H54BBrO2Ru: C, 69.59;
H, 5.95; Br, 8.73%.
Synthesis of (η6-Benzene)[η5-1-(l)-menthyloxycarbonyl-2-
methyl-4-phenylcyclopentadienyl]ruthenium Tetraphenylbo-
rate (8b). To a solution of 4b (1.72 g, 2 mmol) in methanol was
added a methanol solution of NaBPh4 (2.05 g, 6 mmol). This solu-
tion was stirred for 30 min at room temperature. The precipitate
was filtrated. The resulting solid was washed with methanol and
dried under vacuum (99% yield). Diastereomers were separated by
recrystallization from ethyl acetate. 8b-1(SC1 form): 48% yield.
Mp 178.0–179.0 °C. 1H NMR (acetone-d6, 270 MHz) δ 7.46–7.36
(m, 2H, Ph), 7.23–7.19 (m, 3H, Ph), 7.04 (t, 8H, J = 7.3 Hz, Ph),
6.91 (t, 4H, J = 7.3 Hz, Ph), 5.97 (d, 1H, J = 1.7 Hz, CpH), 5.57 (d,
1H, J = 1.7 Hz, CpH), 5.19 (s, 6H, C6H6), 4.89 (dt, 1H, J = 4.5 Hz,
OCH), 2.21 (s, 3H, CpCH3), 2.05–1.07 (m, 11H, menthyl), 0.96 (d,
6H, J = 5.6 Hz, menthyl), 0.82 (d, 3H, J = 6.9 Hz, menthyl). IR
(KBr) 1724 cm–1 (C=O). Mass (FAB) m/z 517 (M+ – BPh4). Found:
C, 76.05; H, 6.45%. Calcd for C53H55BO2Ru: C, 76.15; H, 6.63%.
Synthesis of (η6-Benzene)[η5-1-(d)-menthyloxycarbonyl-2-
methyl-4-(4-bromophenyl)cyclopentadienyl]ruthenium Tetra-
phenylborate (8′e). This complex was prepared using 4′e by the
same method as that for 8b (99% yield). Diastereomers were sepa-
rated by recrystallization from ethyl acetate. 8′e-2(RC1 form): 35%
yield. The spectroscopic data indicated (RC1)-8′e-2 and (SC1)-8e-1
to be a pair of enantiomers. Found: C, 69.33; H, 5.70%. Calcd for
C53H54BBrO2Ru: C, 69.59; H, 5.95%.
1
8b-2(RC1 form): 7% yield. Mp 186.0–187.0 °C. H NMR (ace-
tone-d6, 270 MHz) δ 7.45–7.34 (m, 2H, Ph), 7.26–7.18 (m, 3H,
Ph), 7.03 (t, 8H, J = 7.3 Hz, Ph), 6.91 (t, 4H, J = 7.3 Hz, Ph), 5.97
(d, 1H, J = 1.7 Hz, CpH), 5.53 (s, 1H, CpH), 5.16 (s, 6H, C6H6),
4.88 (dt, 1H, J = 4.6 Hz, OCH), 2.18 (s, 3H, CpCH3), 2.04–1.07 (m,
11H, menthyl), 0.99 (d, 6H, J = 6.6 Hz, menthyl), 0.83 (d, 3H, J =

Y. Matsushima et al.
Bull. Chem. Soc. Jpn., 74, No. 3 (2001) 535
Synthesis of (SC1)-[(η6-Benzene)(η5-1-t-butylcarbamoyl-2,4-
dimethylcyclopentadienyl)ruthenium] Hexafluorophosphate
(9a-1). To a solution of 4a-1 (1.20 g, 2 mmol) in acetonitrile (30
ml) was added K2CO3 (5% in water, 30 ml) and the mixture was re-
fluxed for 3 h. This solution was neutralized by 6 M HCl. The sol-
vent was evaporated under reduced pressure and the residue was
dissolved in acetonitrile. This solution was dried over MgSO4 and
filtered. After removal of the solvent, the residue was washed with
dichloromethane several times. To the suspension of the resulting
solid in dichloromethane (10 ml) were added oxalyl chloride (1 ml)
and DMF (a catalytic amount) with stirring in the dark at room tem-
perature. After 2 h, the solvent was evaporated under reduced pres-
sure, and the residue was dissolved in acetonitrile (10 ml). This so-
lution was added to an acetonitrile solution (20 ml) containing t-
butylamine (1 ml) and 4-dimethylaminopyridine (5 mg). The reac-
tion mixture was stirred for 3 h and the precipitate formed was re-
moved by filtration. The filtrate was concentrated under reduced
pressure. The residual oil was placed on a column of alumina and
eluted with acetone. The acetone solution was evaporated, and then
the resulting solid was purified by recrystallization from ethanol to
give 0.78 g (75% yield) of ruthenium complex 9a-1 as white pow-
der. Mp 197.0–197.5 °C. 1H NMR (acetone-d6, 400 MHz) δ 6.97
(br, 1H, NH), 6.27 (s, 6H, C6H6), 5.90 (s, 1H, CpH), 5.62 (s, 1H,
CpH), 2.28 (s, 3H, CpCH3), 2.07 (s, 3H, CpCH3), 1.42 (s, 9H,
C(CH3)3). IR (KBr) 3426 (NH), 1662 cm–1 (C=O). MS (FAB) m/z
372 (M+ – PF6). Found: C, 41.90; H, 4.58; N, 2.77%. Calcd for
C18H24F6NOPRu: C, 41.86; H, 4.68; N, 2.71%.
Synthesis of (SC1)-[(η6-Benzene){η5-1-t-butylcarbamoyl-
2-methyl - 4 - (4 - bromophenyl)cyclopentadienyl}ruthenium]
Hexafluorophosphate (10e-1). This complex was prepared us-
ing 8e-1 by the same method as that for 9a-1 (76% yield). Mp
203.0–206.0 °C (decomp). 1H NMR (acetone-d6, 400 MHz) δ
7.60–7.55 (m, 4H, C6H4), 7.33 (br, 8H, Ph), 7.21 (br, 1H, NH), 6.91
(t, 8H, J = 7.3 Hz, Ph), 6.77 (t, 4H, J = 7.3 Hz, Ph), 6.56 (s, 1H,
CpH), 6.27 (s, 1H, CpH), 6.23 (s, 6H, C6H6), 2.38 (s, 3H, CpCH3),
1.43 (s, 9H, C(CH3)3). IR (KBr) 3427 (NH), 1666 cm–1 (C=O). MS
(FAB) m/z 512 (M+ – BPh4). Found: C, 67.92; H, 5.20; Br, 9.69; N,
1.65%. Calcd for C47H45BBrNORu: C, 67.88; H, 5.45; Br, 9.61; N,
1.68%.
Synthesis of (RC1)-[(η6-Benzene){η5-1-t-butylcarbamoyl-
2 - methyl - 4 - (4 - bromophenyl)cyclopentadienyl}ruthenium]
Hexafluorophosphate (10e-2). This complex was prepared us-
ing 8e-2 by the same method as that for 9a-1 (75% yield). The spec-
troscopic data indicated (RC1)-10e-2 and (SC1)-10e-1 to be a pair of
enantiomers. Found: C, 67.68; H, 5.35; Br, 9.51; N, 1.69%. Calcd
for C47H45BBrNORu: C, 67.88; H, 5.45; Br, 9.61; N, 1.68%.
Synthesis of (η6-Benzene)(η5-1-t-butylcarbamoyl-2-methyl-
4-tolylcyclopentadienyl)ruthenium
Hexafluorophosphate
(11a). To a solution of zinc dibromide (0.68 g, 3 mmol) in THF (1
ml) was added methyllithium (1.4 M in THF, 2 ml) at 0 °C for 30
min. This solution was added to an acetonitrile-THF solution (1:4,
2.5 ml) containing 9e (0.33 g, 0.5 mmol), Pd(dba)2 (14 mg, 0.025
mmol), and dppf (14 mg, 0.025 mmol). The reaction mixture was
refluxed for 12 h and, after removal of the solvent, to the residual
oil was added an aqueous solution of ammonium hexafluorophos-
phate (0.24 g, 1.5 mmol). The aqueous solution was extracted with
dichloromethane (20 ml × 3) and the combined extracts were dried
over MgSO4, and filtered. After removal of the solvent under re-
duced pressure, the residual oil was placed on a column of alumina
and eluted with acetone. The acetone solution was evaporated, and
the residue was purified by recrystallization from ethanol to give
0.24 g (79% yield) of ruthenium complex 11a as pale yellow nee-
dles. Mp 266.5–267.0 °C. 1H NMR (acetone-d6, 400 MHz) δ 7.51
(d, 2H, J = 8.3 Hz, C6H4), 7.21 (m, 3H, C6H4, NH), 6.50 (s, 1H,
CpH), 6.22 (s, 1H, CpH), 6.19 (s, 6H, C6H6), 2.36 (s, 3H, CH3),
2.33 (s, 3H, CH3), 1.42 (s, 9H, C(CH3)3). IR (KBr) 3427 (NH),
1663 cm–1 (C=O). MS (FAB) m/z 448 (M+ – PF6). Found: C, 48.38;
H, 4.82; N, 2.30; F, 18.99; P, 5.00%. Calcd for C24H28F6NOPRu: C,
48.65; H, 4.76; N, 2.36; F, 19.24; P, 5.23%.
Synthesis of (RC1)-[(η6-Benzene)(η5-1-t-butylcarbamoyl-2,4-
dimethylcyclopentadienyl)ruthenium] Hexafluorophosphate
(9a-2). This complex was prepared using 4a-2 by the same meth-
od as that for 9a-1 (74% yield). The spectroscopic data indicated
(RC1)-9a-2 and (SC1)-9a-1 to be a pair of enantiomers. Found: C,
41.99; H, 4.54; N, 2.76%. Calcd for C18H24F6NOPRu: C, 41.86; H,
4.68; N, 2.71%.
Synthesis of (SC1)-[(η6-Benzene)(η5-1-t-butylcarbamoyl-2-
methyl-4-phenylcyclopentadienyl)ruthenium]
Hexafluoro-
phosphate (9b-1). This complex was prepared using 8b-1 by the
same method as that for 9a-1 (42% yield). Mp 225.0–225.5 °C.
1H NMR (acetone-d6, 400 MHz) δ 7.65–7.60 (m, 2H, Ph),
7.40–7.38 (m, 3H, Ph), 7.18 (br, 1H, NH), 6.51 (s, 1H, CpH), 6.24
(s, 1H, CpH), 6.19 (s, 6H, C6H6), 2.37 (s, 3H, CpCH3), 1.43 (s, 9H,
C(CH3)3). IR (KBr) 3430 (NH), 1664 cm–1 (C=O). MS (FAB) m/z
434 (M+ – PF6). Found: C, 47.51; H, 4.33; N, 2.32%. Calcd for
C23H26F6NOPRu: C, 47.75; H, 4.53; N, 2.42%.
Synthesis of (η6-Benzene)[η5-1-t-butylcarbamoyl-2-methyl-
4-(4-butylphenyl)cyclopentadienyl]ruthenium Tetraphenylbo-
rate (11b). This complex was prepared using n-butyllithium and
NaBPh4 by the same method as that for 11a (72% yield). Mp
202.0–202.5 °C. 1H NMR (acetone-d6, 400 MHz) δ 7.52 (d, 2H, J =
8.3 Hz, C6H4), 7.35–7.30 (m, 8H, Ph), 7.24 (d, 2H, J = 8.3 Hz,
C6H4), 6.91 (t, 8H, J = 7.3 Hz, Ph), 6.76 (t, 4H, J = 7.3 Hz, Ph), 6.49
(s, 1H, NH), 6.23 (s, 1H, CpH), 6.19 (s, 1H, CpH), 6.16 (s, 6H,
C6H6), 2.62 (t, 2H, J = 7.8 Hz, CH2), 2.36 (s, 3H, CpCH3),
1.62–1.55 (m, 2H, CH2), 1.43 (s, 9H, C(CH3)3), 1.39–1.30 (m, 2H,
CH2), 0.92 (t, 3H, J = 7.3 Hz, CH3). IR (KBr) 3393 (NH), 1663
cm–1 (C=O). MS (FAB) m/z 490 (M+ – PF6). Found: C, 75.51; H,
6.68; N, 1.60%. Calcd for C51H54BNORu: C, 75.73; H, 6.73; N,
1.73%.
Synthesis of (RC1)-[(η6-Benzene)(η5-1-t-butylcarbamoyl-2-
methyl-4-phenylcyclopentadienyl)ruthenium]
Hexafluoro-
phosphate (9b-2). This complex was prepared using 8′b-2 by the
same method as that for 9a-1 (49% yield). The spectroscopic data
indicated (RC1)-9b-2 and (SC1)-9b-1 to be a pair of enantiomers.
Found: C, 47.77; H, 4.43; N, 2.33%. Calcd for C23H26F6NOPRu: C,
47.75; H, 4.53; N, 2.42%.
Synthesis of (η6-Benzene)[η5-1-t-butylcarbamoyl-2-methyl-
4-(4-bromophenyl)cyclopentadienyl]ruthenium Hexafluoro-
phosphate (9e). This complex was prepared using 6e by the
same method as that for 9a-1 (66% yield). Mp 257.0–257.5 °C.
1H NMR (acetone-d6, 400 MHz) δ 7.60–7.55 (m, 4H, C6H4), 7.21
(br, 1H, NH), 6.56 (s, 1H, CpH), 6.27 (s, 1H, CpH), 6.23 (s, 6H,
C6H6), 2.38 (s, 3H, CpCH3), 1.43 (s, 9H, C(CH3)3). IR (KBr) 3426
(NH), 1665 cm–1 (C=O). MS (FAB) m/z 512 (M+ – PF6). Found: C,
42.09; H, 3.80; Br, 11.88; F, 17.56; N, 2.32; P, 4.76%. Calcd for
C23H25BrF6NOPRu: C, 42.02; H, 3.83; Br, 12.15; F, 17.34; N, 2.13;
P, 4.71%.
Synthesis of (η6-Benzene)(η5-1-t-butylcarbamoyl-2-methyl-
4-biphenylylcyclopentadienyl)ruthenium
Hexafluorophos-
phate (12). A mixture of 9e (0.66 g, 1 mmol), PhB(OH)2 (0.69 g,
6 mmol), Na2CO3 (0.63 g, 6 mmol), and [Pd(PPh3)4] (10 mg, 0.01
mmol) in 1,2-dimethoxyethane (12 ml) and water (8 ml) was re-
fluxed for 3 h. This solution was neutralized by 6 M HCl. After re-

536 Bull. Chem. Soc. Jpn., 74, No. 3 (2001)
Synthesis of Planar-Chiral Ru(η5-Cp)(η6-C6H6) Complexes
moval of the solvent, to the residual oil was added an aqueous solu-
tion of ammonium hexafluorophosphate (0.48 g, 3 mmol). The
aqueous solution was extracted with dichloromethane (40 ml × 3)
and the combined extracts were dried over MgSO4, and filtered.
After removal of the solvent under reduced pressure, the residual
oil was placed on a column of alumina and eluted with acetone. The
acetone solution was evaporated, and the residue was purified by
recrystallization from ethanol to give 0.43 g (66% yield) of ruthe-
nium complex 12 as pale yellow needles. Mp 224.0–224.5 °C.
1H NMR (acetone-d6, 400 MHz) δ 7.74–7.67 (m, 6H, Ph), 7.59 (t,
2H, J = 7.1 Hz, Ph), 7.42–7.40 (m, 1H, Ph), 6.59 (s, 1H, CpH), 6.31
(s, 1H, CpH), 6.23 (s, 6H, C6H6), 2.40 (s, 3H, CpCH3), 1.44 (s, 9H,
C(CH3)3). IR (KBr) 3428 (NH), 1668 cm–1 (C=O). MS (FAB) m/z
510 (M+ – PF6). Found: C, 53.09; H, 4.37; N, 2.18%. Calcd for
C29H30F6NOPRu: C, 53.21; H, 4.62; N, 2.14%.
rophosphate (14e). This complex was prepared using 6e by the
same method as that for 14a (99% yield). Mp 138.5–139.0 °C.
1H NMR (CDCl3, 400 MHz) δ 7.48 (d, 2H, J = 8.5 Hz, C6H4), 7.26
(d, 2H, J = 8.5 Hz, C6H4), 5.21 (s, 1H, CpH), 4.51 (s, 1H, CpH),
4.34–4.24 (m, 2H, CH2CH3), 2.34 (s, 9H, CH3CN), 2.17 (s, 3H,
CpCH3), 1.35 (t, 3H, J = 7.1 Hz, CH2CH3). IR (KBr) 1714 cm–1
(C=O). Found: C, 37.08; H, 3.18; Br, 11.77; F, 16.86; N, 6.11; P,
4.55%. Calcd for C21H23BrF6N3O2PRu: C, 37.35; H, 3.43; Br,
11.83; F, 16.88; N, 6.22; P, 4.59%.
Synthesis of Bis(acetonitrile)(carbonyl)(η5-1-ethoxycarbon-
yl-2-methyl-4-phenylcyclopentadienyl)ruthenium Hexafluoro-
phosphate (17). Ruthenium complex 14b (0.42 g, 0.7 mmol)
was dissolved in acetonitrile (20 ml) under an argon atmosphere
and the carbon monoxide was bubbled through this solution for 30
min. Removal of the solvent under reduced pressure gave 0.39 g
(95% yield) of ruthenium complex 17 as a reddish-brown powder.
Synthesis of (η6-Benzene)[η5-1-t-butylcarbamoyl-2-methyl-
4-(4-trimethylsilyletynylphenyl)cyclopentadienyl]ruthenium
Hexafluorophosphate (13). A mixture of 9e (0.74 g, 1.16
mmol), trimethylsilylacetylene (0.66 g, 6.6 mmol), [PdCl2(PPh3)2]
(40 mg, 0.05 mmol), PPh3 (30 mg, 10 mmol), and CuI (11 mg, 5
mmol) in acetonitrile (5 ml) and piperidine (10 ml) was refluxed for
12 h. After removal of the solvent, to the residual oil was added an
aqueous solution of ammonium hexafluorophosphate (0.48 g, 3
mmol). The aqueous solution was extracted with dichloromethane
(40 ml × 3) and the combined extracts were dried over MgSO4, and
filtered. After removal of the solvent under reduced pressure, the
residual oil was placed on a column of alumina and eluted with ac-
etone. The acetone solution was evaporated, and the residue was
purified by recrystallization from ethanol to give 0.50 g (64%
yield) of ruthenium complex 13 as pale yellow needles. Mp
146.5–147.0 °C. 1H NMR (acetone-d6, 400 MHz) δ 7.63 (d, 2H, J
= 8.3 Hz, C6H4), 7.45 (d, 2H, J = 8.3 Hz, C6H4), 6.59 (s, 1H, CpH),
6.30 (s, 1H, CpH), 6.22 (s, 6H, C6H6), 2.38 (s, 3H, CpCH3), 1.43 (s,
9H, C(CH3)3), 0.23 (s, 9H, Si(CH3)3). IR (KBr) 3422 (NH), 2159
(C2), 1669 cm–1 (C=O). MS (FAB) m/z 530 (M+ – PF6). Found: C,
49.70; H, 4.86; F, 17.05; N, 2.29; P, 4.49%. Calcd for
C28H34F6NOPRuSi: C, 49.85; H, 5.08; F, 16.89; N, 2.08; P, 4.59%.
Synthesis of Tris(acetonitrile)(η5-1-ethoxycarbonyl-2,4-
dimethylcyclopentadienyl)ruthenium Hexafluorophosphate
(14a). Ruthenium complex 6a (0.98 g, 2 mmol) was dissolved in
acetonitrile (100 ml) under an argon atmosphere and the solution
was irradiated with ultraviolet light for 18 h. Removal of the sol-
vent under reduced pressure gave 1.07 g (99% yield) of ruthenium
complex 14a as an orange powder. Mp 98.0–102.0 °C (decomp).
1H NMR (acetone-d6, 270 MHz) δ 4.66 (s, 1H, CpH), 4.22 (dq, 1H,
J = 3.0, 7.3 Hz, CH2CH3), 4.19 (dq, 1H, J = 3.0, 7.3 Hz, CH2CH3),
2.55 (s, 9H, CH3CN), 1.97 (s, 3H, CpCH3), 1.77 (s, 3H, CpCH3),
1.30 (t, 3H, J = 7.3 Hz, CH2CH3). IR (KBr) 1708 cm–1 (C=O).
Found: C, 35.77; H, 4.12; F, 21.22; N, 7.71; P, 5.77%. Calcd for
C16H22F6N3O2PRu: C, 35.96; H, 4.15; F, 21.33; N, 7.86; P, 5.80%.
Synthesis of Tris(acetonitrile)(η5-1-ethoxycarbonyl-2-meth-
1
Mp 37.0–46.0 °C. H NMR (acetone-d6, 270 MHz) δ 7.72–7.60
(m, 3H, Ph), 7.49–7.45 (m, 2H, Ph), 6.47 (d, 1H, J = 1.7 Hz, CpH),
5.94 (d, 1H, J = 1.7 Hz, CpH), 4.39–4.26 (m, 2H, CH2CH3), 2.56 (s,
3H, CH3), 2.49 (s, 3H, CH3), 2.27 (s, 3H, CH3), 1.35 (t, 3H, J = 7.3
Hz, CH2CH3). IR (KBr) 1991 (C=O), 1721 cm–1 (C=O). MS (FAB)
m/z 439 (M+ – PF6). Found: C, 41.16; H, 3.44; F, 19.55; N, 4.63; P,
5.57%. Calcd for C20H21F6N2O3PRu: C, 41.17; H, 3.63; F, 19.54;
N, 4.80; P, 5.31%.
Synthesis
of
(Acetonitrile)(η5-1-ethoxycarbonyl-2,4-
dimethylcyclopentadienyl)bis(tirphenylphosphine)ruthenium
Hexafluorophosphate (18). A mixture of 14a (0.53 g, 1.0 mmol)
and triphenylphosphine (2.62 g, 10 mmol) in acetonitrile (50 ml)
was stirred at room temperature for 12 h. After removal of the sol-
vent under reduced pressure, the precipitate was washed with ether
several times and the residue was dissolved in dichloromethane.
This solution was placed on a column of alumina and eluted with
acetone. The acetone solution was evaporated and dried in vacuo
(99% yield). Mp 119.5–120.0 °C. 1H NMR (CDCl3, 400 MHz) δ
7.44–7.11 (m, 24H, Ph), 6.82–6.78 (m, 6H, Ph), 4.53 (s, 1H, CpH),
4.21–4.13 (m, 1H, CH2CH3), 4.12 (s, 1H, CpH), 4.02–3.94 (m, 1H,
CH2CH3), 2.34 (s, 3H, CH3), 1.92 (s, 3H, CH3), 1.32 (s, 3H, CH3),
1.18 (t, 3H, J = 7.3 Hz, CH2CH3). IR (KBr) 1709 cm–1 (C=O). MS
(FAB) m/z 832 (M+ – PF6). Found: C, 59.20; H, 4.83; F, 11.57; N,
1.25; P, 9.32%. Calcd for C48H46F6NO2P3Ru: C, 59.02; H, 4.75; F,
11.67; N, 1.43; P, 9.51%.
Synthesis of (η6-Chlorobenzene)(η5-1-ethoxycarbonyl-2,4-
dimethylcyclopentadienyl)ruthenium Hexafluorophosphate
(19). A mixture of 14a (0.17 g, 0.32 mmol) and chlorobenzene
(179 mg, 1.6 mmol) in 1,2-dichloroethane (50 ml) was refluxed for
12 h. After removal of the solvent under reduced pressure, the pre-
cipitate was washed with ether several times and the residue was
dissolved in dichloromethane. This solution was placed on a col-
umn of alumina and eluted with acetone. The acetone solution was
evaporated and the residue was purified by recrystallization from
ethanol to give 0.13 g (80% yield) of ruthenium complex 19 as col-
1
yl-4-phenylcyclopentadienyl)ruthenium
Hexafluorophos-
orless needles. Mp 142.0–142.5 °C. H NMR (acetone-d6, 270
phate (14b). This complex was prepared using 6b by the same
MHz) δ 6.74 (dd, 2H, J = 5.6, 6.6 Hz, Ph), 6.51 (dd, 2H, J = 5.9, 6.6
Hz, Ph), 6.41 (d, 1H, J = 5.9 Hz, Ph), 5.98 (d, 1H, J = 1.7 Hz, CpH),
5.80 (d, 1H, J = 1.7 Hz, CpH), 4.33 (q, 2H, J = 7.3 Hz, CH2CH3),
2.30 (s, 3H, CpCH3), 2.08 (s, 3H, CpCH3), 1.36 (t, 3H, J = 7.3 Hz,
CH2CH3). IR (KBr) 1717 cm–1 (C=O). MS (FAB) m/z 379 (M+ –
PF6). Found: C, 36.88; H, 3.41; F, 21.65; P, 5.67%. Calcd for
C16H18ClF6O2PRu: C, 36.69; H, 3.46; F, 21.76; P, 5.91%.
1
method as that for 14a (99% yield). Mp 65.0–68.0 °C. H NMR
(acetone-d6, 270 MHz) δ 7.59–7.56 (m, 3H, Ph), 7.41–7.39 (m, 2H,
Ph), 5.43 (s, 1H, CpH), 4.85 (s, 1H, CpH), 4.33–4.23 (m, 2H,
CH2CH3), 2.45 (s, 9H, CH3CN), 1.35 (t, 3H, J = 7.3 Hz, CH2CH3).
IR (KBr) 1716 cm–1 (C=O). Found: C, 42.07; H, 3.85; F, 19.01; N,
6.97; P, 5.00%. Calcd for C21H24F6N3O2PRu: C, 42.29; H, 4.06; F,
19.11; N, 7.04; P, 5.19%.
X-ray Diffraction Analysis of (η6-Benzene)[η5-1-(l)-menthy-
loxycarbonyl-2-methyl-4-phenylcyclopentadienyl]ruthenium
Tetraphenylborate (SC1-8b-1) and (η6-Benzene)[η5-1-(l)-men-
Synthesis of Tris(acetonitrile)[η5-1-ethoxycarbonyl-2-meth-
yl-4-(4-bromophenyl)cyclopentadienyl]ruthenium Hexafluo-

Y. Matsushima et al.
Bull. Chem. Soc. Jpn., 74, No. 3 (2001) 537
thyloxycarbonyl-2-methyl-4-(t-butyl)cyclopentadienyl]ruthe-
nium Hexafluorophosphate (SC1-4c-1). Crystals suitable for X-
ray diffraction were mounted on a glass fiber with epoxy resin. All
measurements were performed on Rigaku AFC5R and AFC7R au-
tomated four-circle diffractometer using graphite monochromated
Mo-Kα radiation (λ = 0.71069 Å). Reflections were collected in
the range of 6° < 2θ < 55° at –70 °C with a scan rate 8° min–1 for
SC1-8b-1 and at –75 °C with a scan rate 16° min–1 for SC1-4c-1.
Three standard reflections were monitored at every 150 measure-
ments and no damage was observed in any measurements. Intensi-
ties were corrected for Lorentz and polarization effects and for ab-
sorption using ψ-scan technique. The structures were solved by
Patterson methods and refined by full-matrix least-squares mini-
mizing of Σw(|Fo| – |Fc|)2 (w = 1/σ2 (Fo)). Absolute configurations
were based on the stereochemistry of the (l)-menthyl group.Aniso-
tropic thermal parameters were used for all non-hydrogen atoms
except for carbon atoms of the η6-benzene ligands and fluorine at-
oms of the hexafluorophosphate anion, which were refined as a rig-
id group, for SC1-4c-1. The η6-benzene ligands and the hexafluoro-
phosphate anion of SC1-4c-1 were disordered. The hydrogen atoms
were included at calculated positions (dC-H = 0.95 Å) and their pa-
rameters were not refined. The final cycles of full matrix least
squares refinements converged. Crystallographic data are as fol-
lows.
SC1-8b-1: C53H55BO2Ru, MW = 835.90, yellow, monoclinic,
P21 (#4), a = 9.836(1), b = 20.625(6), c = 11.313(2) Å, β =
106.24(1)°, V = 2203.4(8) Å3, Z = 2, µ = 3.95 cm–1, R = 0.038 and
Rw = 0.044 for 514 parameters against 4386 reflections with I >
3σ(I) out of 5212 unique reflections (Rint = 0.026), GOF = 1.09.
SC1-4c-1: C27H39F6O2PRu, MW = 641.64, colorless, monoclin-
ic, C2 (#5), a = 14.876(2), b = 10.615(2), c = 18.632(2) Å, β =
94.222(8)°, V = 2934.3(5) Å3, Z = 4, µ = 6.49 cm–1, R = 0.060 and
Rw = 0.083 for 274 parameters against 2572 reflections with I >
3σ(I) out of 3546 unique reflections (Rint = 0.029), GOF = 1.14.
Crystallographic data have been deposited at the CCDC, 12
Union Road, Cambridge CB2 1EZ, UK and copies can be obtained
on request, free of charge, by quoting the publication citation and
the deposition numbers 153431–153432, and the final atomic pa-
rameters and structure factors have been deposited as Document
No. 74018 at the Office of the Editor of Bull. Chem. Soc. Jpn.
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