Control of stereochemistry at the metal center in planar-chiral cyclopentadienyl ruthenium complexes with anchor phosphine on complexation with salicylideneaminato ligands

Article abstract of DOI:10.1021/om0102246

Reactions of planar-chiral cyclopentadienyl-phosphine ruthenium complexes [η⁵,η¹-{C₅H₂-(Me)(R)COO (CH₂)₂PPh₂}Ru(MeCN)₂] [PF₆] (1a, R = Me; 1b, R = Ph) with sodium salicylideneaminato (2) led to the formation of salicylideneaminato complexes [η⁵,η¹-{C₅H₂(Me)(R)- COO(CH₂)₂)PPh₂}Ru(OArc=NR′)] (3 and 4, R% = Me; R = Me; 5 and 6, R = Ph) inducing metal-centered chirality with a high selectivity (up to >99% de). The diastereoiselectivity of products did not depend on the substituent on aromatic ring of salicylideneaminato ligands, but upon the substituents on the cyclopentadienyl group and on nitrogen of the imino group. X-ray diffraction and NMR studies including NOE measurements revealed that the configuration of the major isomers is S_CpR_Ru/R_CpS_Ru. Similar reactions of planar-chiral cyclopentadienyl ruthenium complexes [η⁵-{C₅H₂(Me)(R)COOEt}Ru(PPh₃) (MeCN)₂][PF₆] (7) (7a, R = Me; 7b, R = Ph) having no anchor phosphine ligands with 2 also gave salicylideneamiato complexes [η⁵-{C₅H₂(Me)(R)COOEt}Ru(PPh₃) (OC₆H₄C=NR′)] (8 and 9) with a low selectivity. Epimerization of a pure sampled of the major product 5a into a diastereomeric mixture of 5a and 6a showed that the diastereoselectivity at the ruthenium center is governed by the difference in thermodynamic stability between 3 and 4, or 5 and 6.

Full text of DOI:10.1021/om0102246

3274
Organometallics 2001, 20, 3274-3282
Con tr ol of Ster eoch em istr y a t th e Meta l Cen ter in
P la n a r -Ch ir a l Cyclop en ta d ien yl Ru th en iu m Com p lexes
w ith An ch or P h osp h in e on Com p lexa tion w ith
Sa licylid en ea m in a to Liga n d s
Kiyotaka Onitsuka, Yoshiki Ajioka, Yuji Matsushima, and
Shigetoshi Takahashi*
The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki,
Osaka 567-0047, J apan
Received March 21, 2001
Reactions of planar-chiral cyclopentadienyl-phosphine ruthenium complexes [η5,η1-{C5H2-
(Me)(R)COO(CH2)2PPh2}Ru(MeCN)2][PF6] (1a , R ) Me; 1b, R ) Ph) with sodium salicylide-
neaminato (2) led to the formation of salicylideneaminato complexes [η5,η1-{C5H2(Me)(R)-
COO(CH2)2PPh2}Ru(OArCdNR′)] (3 and 4, R ) Me; 5 and 6, R ) Ph) inducing metal-centered
chirality with a high selectivity (up to >99% de). The diastereoselectivity of products did
not depend on the substituent on aromatic ring of salicylideneaminato ligands, but upon
the substituents on the cyclopentadienyl group and on nitrogen of the imino group. X-ray
diffraction and NMR studies including NOE measurements revealed that the configuration
of the major isomers is SCpRRu/RCpSRu. Similar reactions of planar-chiral cyclopentadienyl
ruthenium complexes [η5-{C5H2(Me)(R)COOEt}Ru(PPh3)(MeCN)2][PF6] (7) (7a , R ) Me; 7b,
R ) Ph) having no anchor phosphine ligands with 2 also gave salicylideneaminato complexes
[η5-{C5H2(Me)(R)COOEt}Ru(PPh3)(OC6H4CdNR′)] (8 and 9) with a low selectivity. Epimer-
ization of a pure sample of the major product 5a into a diastereomeric mixture of 5a and 6a
showed that the diastereoselectivity at the ruthenium center is governed by the difference
in thermodynamic stability between 3 and 4, or 5 and 6.
In tr od u ction
ity by using chiral ligands is a main subject to develop
novel asymmetric reactions.5 Recently, some attempts
Extensive studies on diastereoselectivity in the reac-
tions of optically active organometallic complexes have
been made in terms of molecular design of catalysts and
understanding of the mechanism in asymmetric organic
reactions.1 Although organometallic complexes having
chiral ligands such as chiral phosphines and amines
have been the main objects of such studies for a long
time, other types of optically active complexes have
attracted much attention in recent years. Three-legged
piano-stool complexes with three different ligands have
metal-centered chirality,2 while π-coordination of un-
symmetrically substituted η2-olefin and η5-cyclopenta-
dienyl (Cp) ligands generates planar chirality.3 In
particular, metal-centered chiral complexes, in which
a metal atom serves as a reactive and asymmetric
center, are of interest. However, application of those
complexes is limited to stoichiometric reactions since
racemization at the chiral metal center often takes place
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10.1021/om0102246 CCC: $20.00 © 2001 American Chemical Society
Publication on Web 06/28/2001

Planar-Chiral Cyclopentadienyl Ru Complexes
Organometallics, Vol. 20, No. 15, 2001 3275
Sch em e 1
of catalysis of metal-centered chiral complexes with
chiral ligands in asymmetric Diels-Alder reactions were
found in the literature.6
In the course of our study on planar-chiral complexes
of late transition metals,7 we prepared planar-chiral Cp′-
phosphine ruthenium complexes [η5,η1-{C5H2(Me)(R)-
COO(CH2)2PPh2}Ru(MeCN)2][PF6] (1) (R ) Me, Ph,
But),8 in which the anchor phosphine prevents the
rotation of the Cp′ ring, constructing a good asymmetric
environment around the ruthenium atom.9 Efficiency
of the planar-chiral Cp′-phosphine ligand was proved
by the induction of metal-centered chirality with a high
selectivity in the ligand exchange reactions with various
phosphines and phosphites10 and enantioface-selective
π-coordination of prochiral dienes.11 Similar results have
been reported by Bergman12 and Tani et al.13 Now we
have examined the selectivity at a metal center on
complexation of salicylideneaminato ligands to planar-
chiral Cp′-phosphine ruthenium complexes. Stereo-
chemistry of metal-centered chirality in (η6-arene)ruthe-
nium complexes involving chiral salicylideneaminato
ligands has been investigated by Chakravarty14 and
Brunner.15 In their studies, relatively high selectivity
was achieved by the chiral groups on the imino nitrogen.
Application of these complexes as an enantioselective
catalyst was attempted in olefin isomerization.16 Herein
we describe effective control of metal-centered chirality
by planar-chiral Cp′-P ligands in ruthenium complexes
having salicylideneaminato ligands. Since racemic mix-
tures were used as starting materials, resulting com-
plexes form two pairs of diastereomers, each of which
consists of a pair of enantiomers, as shown in Scheme
1. In this paper, all the stereostructures of the com-
plexes are drawn with planar chirality of SCp for clarity.
(6) (a) Davis, D. L.; Fawcett, J .; Garratt, S. A.; Russell, D. R. Chem.
Commun. 1997, 1531. (b) Carmona, D.; Lahoz, F. J .; Elipe, S.; Oro, L.
A.; Lamata, M. P.; Viguri, F.; Mir, C.; Cativiela, C.; Lo´pez-Ram de V´ıu,
M. P.; Organometallics 1998, 17, 2986. (c) Carmona, D.; Vega, C.;
Lahoz, F. J .; Elipe, S.; Oro, L. A.; Lamata, M. P.; Viguri, F.; Garc´ıa-
Correas, Cativiela, C.; Lo´pez-Ram de V´ıu, M. P.; Organometallics
1999, 18, 3364. (d) Faller, J . W.; Parr, J . Organometallics 2001, 20,
697.
Resu lts a n d Discu ssion
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N.; Tanaka, T.; Sawada, M.; Takahashi, S. J . Chem. Soc., Chem.
Commun., 1993, 1549. (c) Uno, M.; Komatsuzaki, N.; Shirai, K.;
Takahashi, S. J . Organomet. Chem. 1993, 462, 343. (d) Uno, M.; Ando,
K.; Komatsuzaki, N.; Tsuda, T.; Tanaka, T.; Sawada, M.; Takahashi,
S. J . Organomet. Chem. 1994, 473, 303. (e) Komatsuzaki, N.; Uno, M.;
Shirai, K.; Tanaka, T.; Sawada, M.; Takahashi, S. J . Organomet. Chem.
1995, 498, 53. (f) Uno, M.; Shirai, K.; Ando, K.; Komatsuzaki, N.;
Tanaka, T.; Sawada, M.; Takahashi, S. Chem. Lett. 1995, 7. (g)
Komatsuzaki, N.; Uno, M.; Kikuchi, H.; Takahashi, S. Chem. Lett.
1996, 677. (h) Morimoto, Y.; Ando, K.; Uno, M.; Takahashi, S. J . Chem.
Soc., Chem. Commun. 1997, 1795. (i) Katayama, T.; Morimoto, Y.;
Yuge, M.; Uno, M.; Takahashi, S. Organometallics 1999, 18, 3087. (j)
Matsushima, Y.; Komatsuzaki, N.; Ajioka, Y.; Yamamoto, M.; Kikuchi,
H.; Takata, Y.; Dodo, N.; Onitsuka, K.; Uno, M.; S. Takahashi Bull.
Chem. Soc. J pn. 2001, 74, 527.
Treatment of planar-chiral cyclopentadienyl-phos-
phine ruthenium complex [η5,η1-{C5H2(Me)2COO(CH2)2-
PPh2}Ru(MeCN)2][PF6] (1a ) with sodium salicyliden-
emethylaminato (2a ) in THF at room temperature
resulted in the formation of a diastereomeric mixture
of [η5,η1-{C5H2(Me)2COO(CH2)2PPh2}Ru(OC6H4CdNMe)]
(3a and 4a ) in 50% yield (eq 1). The 31P NMR spectrum
of the product exhibited two singlet signals at δ 40.2
and 28.0 with an integral ratio of 74:26, indicating that
1
the selectivity is 48% de. In the H NMR spectrum, two
(8) Dodo, N.; Matsushima, Y.; Uno, M.; Onitsuka, K.; Takahashi,
S. J . Chem. Soc., Dalton Trans. 2000, 35.
(9) For reviews, see: (a) J utzi, P.; Redeker, T. Eur. J . Inorg. Chem.
1998, 663. (b) Buntenscho¨n, H. Chem. Rev. 2000, 100, 1527.
(10) Onitsuka, K.; Dodo, N.; Matsushima, Y.; Takahashi, S. Chem.
Commun. 2001, 521.
(11) Matsushima, Y.; Onitsuka, K.; Takahashi, S. Chem. Lett. 2000,
760.
(12) Mobley, T. A.; Bergman, R. G. J . Am. Chem. Soc. 1998, 120,
3253.
(13) (a) Kataoka, Y.; Shibahara, A.; Saito, Y.; Yamagata, T.; Tani,
K. Organometallics 1998, 17, 4338. (b) Kataoka, Y.; Iwato, Y.; Yama-
gata, T.; Tani, K. Organometallics 1999, 18, 5423. (c) Kataoka, Y.;
Iwato, Y.; Shibahara, A.; Yamagata, T.; Tani, K. Chem. Commun. 2000,
841.
(14) (a) Mandal, S. K.; Chakravarty, A. R. J . Chem. Soc., Dalton
Trans. 1992, 1627. (b) Mandal, S. K.; Chakravarty, A. R. Inorg. Chem.
1993, 32, 3851.
(15) (a) Brunner, H.; Oeschey, R.; Nuber, B. Angew. Chem., Int. Ed.
Engl. 1994, 33, 866. (b) Brunner, H.; Oeschey, R.; Nuber, B. Inorg.
Chem. 1995, 34, 3349. (c) Brunner, H.; Oeschey, R.; Nuber, B. J . Chem.
Soc., Dalton Trans. 1996, 1499.
(16) Brunner, H.; Prommesberger, M. Tetrahedron Asymmetry 1998,
8, 3231.

3276 Organometallics, Vol. 20, No. 15, 2001
Onitsuka et al.
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for Com p lexes 3g a n d 5a
3g
5a
Ru(1)-P(1)
Ru(1)-O(3)
Ru(1)-N(1)
Ru(1)-C(1)
Ru(1)-C(2)
Ru(1)-C(3)
Ru(1)-C(4)
Ru(1)-C(5)
2.336(2)
2.092(4)
2.105(5)
2.153(6)
2.239(7)
2.251(7)
2.199(7)
2.135(6)
2.325(2)
2.105(4)
2.077(5)
2.164(7)
2.228(7)
2.250(7)
2.202(6)
2.150(6)
O(3)-C(23 or 28)
1.298(8)
1.296(8)
81.2(1)
93.9(2)
87.4(2)
1.292(8)
1.286(9)
86.8(1)
90.5(2)
85.7(2)
20.4(4)
24.9(5)
N(1)-C(29 or 34)
P(1)-Ru(1)-O(3)
P(1)-Ru(1)-N(1)
O(3)-Ru(1)-N(1)
Ru(1)-O(3)-C(23 or 28)
Ru(1)-N(1)-C(29 or 34)
1129.8(4)
1125.1(5)
Ta ble 2. Rea ction s of Com p lex 1a w ith Sod iu m
Sa licylid en ea m in a to Der iva tives 2
yield
F igu r e 1. ORTEP view of 5a with 50% probability ellips-
entry NaOArCdNR2 products (%)a % deb
configc
oids. Hydrogen atoms are omitted for clarity.
1
2
3
4
5
2a
2b
2c
2d
2e
3a + 4a 50
3b + 4b 30d
3c + 4c 57d
3d + 4d 81
3e + 4e 87
48
47e
29
52
47
SCpRRu/RCpSRu
SCpRRu/RCpSRu
SCpRRu/RCpSRu
SCpRRu/RCpSRu
SCpRRu/RCpSRu
sets of signals due to salicylidenemethylaminato com-
plexes 3a and 4a appeared in the same integral ratio
as mentioned above. To determine the configuration of
the products, the differential NOE spectra were mea-
sured. For the major product 3a , irradiation of the
methyl signal at δ 1.91 gave rise to the NOE signals of
two Cp′ protons and methyl protons on the imino
nitrogen, suggesting that the signal at δ 1.91 is assign-
able to the methyl protons at the 4-position on the Cp′
ring and the imino group is close to the methyl group
at the 4-position. On the other hand, no NOE was
observed for the signal of methyl protons on the imino
nitrogen but one Cp′ proton by irradiation of the methyl
signal at δ 1.77. These data reveal that the signal at δ
1.77 is due to the methyl protons at the 2-position on
the Cp′ ring and the imino group is situated apart from
the methyl group at the 2-position. In the differential
NOE spectra of the minor product 4a , no NOE was
observed between methyl protons on the imino nitrogen
and those at the 4-position on the Cp′ ring for 4a , while
an NOE was observed between methyl protons on the
imino nitrogen and those at the 2-position on the Cp′
ring. These results clearly show that the configuration
of the major product 3a is SCpRRu/RCpSRu on the basis
Isolated yields. Determined by 31P NMR. c Configuration of
a
b
major products determined by NOE spectra. NMR yields. e De-
d
termined by 1H NMR.
ruthenium atom (Table 1) are similar to those of (η6-
arene)Ru analogues.14,15
To elucidate the substituent effect on the aromatic
ring of salicylideneaminato ligands toward the selectiv-
ity of the products (3/4), reactions with several kinds of
salicylidenemethylaminato derivatives were performed
(Table 2). Although reactions of 1a with 2b and 2c,
having a methoxy or nitro group, generated the corre-
sponding salicylidenemethylaminato complexes (3b/4b
and 3c/4c), we could not isolate the products owing to
of the priority sequence Cp′ > P > O > N, and the minor
2
product 4a has a configuration of SCpSRu/RCpRRu
.
Although similar reaction of [η5,η1-{C5H2(Me)(Ph)-
COO(CH2)2PPh2}Ru(MeCN)2][PF6] (1b), having a phen-
yl group at the 4-position instead of a methyl group as
in 1a , gave analogous products [η5,η1-{C5H2(Me)(Ph)-
COO(CH2)2PPh2}Ru(OC6H4CdNMe)] (5a and 6a ), the
selectivity (90% de) was higher than that observed in
the reaction of 1a . The configuration of the major
product 5a was also suggested to be SCpRRu/ RCpSRu by
the NOE spectrum. Fortunately, single crystals of the
major product 5a were obtained by recrystallization
from CH2Cl2-hexane. X-ray crystallography unequivo-
cally revealed that the configuration of the major
product 5a is SCpRRu/RCpSRu, as suggested from the
NOE spectrum. The molecular structure of 5a is il-
lustrated in Figure 1. Structural parameters around the
their low stability. Thus, yields, selectivity, and the
configuration of the main products were determined by
1H NMR spectra of the reaction mixtures. No significant
differences in the selectivity of the products from that
of 3a /4a were observed in these reactions (entries 2 and
3). On treatment of complex 1a with 2d and 2e, which
have a naphthalene ring instead of a benzene ring, the
products (3d /4d and 3e/4e) were isolated in relatively
high yields, but the selectivities were similar to that of
3a /4a (entries 4 and 5). These results suggest that the
electronic and steric effects of the substituents on the

Planar-Chiral Cyclopentadienyl Ru Complexes
Organometallics, Vol. 20, No. 15, 2001 3277
Ta ble 3. Rea ction s of Com p lexes 1 w ith Sod iu m Sa licylid en ea m in a to Der iva tives
entry
complex
NaOC6H4CdNR2
products
yield (%)a
% deb
configc
d
1
2
3
4
5
1a
1a
1a
1b
1b
2a (R2 ) Me)
2f (R2 ) Pri)
2g (R2 ) Ph)
2a (R2 ) Me)
2g (R2 ) Ph)
3a + 4a
3f + 4f
3g + 4g
5a + 6a
5b
50
11e
62
54
67
48
44
94
90
>99
SCpRRu/RCpSRu
SCpRRu/RCpSRu
SCpRRu/RCpSRu
SCpRRu/RCpSRu
SCpRRu/RCpSRu
f
g
g
f
Isolated yields. Determined by 31P NMR. c Configuration of major products. Determined by NOE spectra. e NMR yield. f Determined
a
b
d
by comparison of chemical shifts in 31P NMR spectra with those of other major products. Determined by X-ray analyses.
g
products. However, the reaction of complex [η5,η1-{C5H2-
(Me)(But)COO(CH2)2PPh2}Ru(MeCN)2][PF6] (1c) with
2a was accompanied by decomposition to give a complex
mixture.
When planar-chiral cyclopentadienyl ruthenium com-
plexes [η5-{C5H2(Me)(R)COOEt}Ru(PPh3)(MeCN)2][PF6]
(7), having no anchor phosphine ligands, were treated
with 2a , salicylideneaminato complexes [η5-{C5H2(Me)-
(R)COOEt}Ru(PPh3)(OC6H4CdNR′)] (8 and 9) were
obtained in moderate yields. Although the conforma-
tions of the major products 8a and 8b could not be
assigned, the selectivities of the products (8/9) were
lower than those in the corresponding reactions of 1,
suggesting that the anchor phosphine ligand has an
important role of controlling the stereochemistry at
metal center.10,11
aromatic ring of salicylideneaminato ligands do not
affect the selectivity of the products (3/4).
Then we investigated the substituent effect on the
imino nitrogen and on the Cp′ ring (Table 3). While
reaction of 1a with sodium salicylideneisopropylaminato
(2f) gave products 3f and 4f with a selectivity similar
to that of 3a /4a in a low yield (entry 2), the reaction
with sodium salicylidenephenylaminato (2g) led to an
increase in the selectivity of products 3g/4g to 94% de
(entry 3). The configuration of main product 3g was
determined by X-ray analysis to be SCpRRu/RCpSRu. It
should be noted that reaction of complex 1b with 2g
gave a single product (5b), of which the stereochemistry
Configuration at the metal center is fairly stable in
chloroform at room temperature since a diastereomeri-
cally pure sample of 5a slowly became a mixture of 5a
and 6a in 94% de for 24 h, and 90% de for 4 days, of
which the latter is the same composition as that of the
products (5a and 6a ) formed from the reaction of 1b
with 2a . Addition of 10% acetonitrile (v/v) into a
chloroform solution of 5a accelerated the epimerization
of 5a , giving a mixture of 5a and 6a in 90% de within
1 h. Rapid epimerization was observed in THF. When
could not be determined by NOE spectra due to overlap
of signals in the area of aromatic protons. However,
comparison of the chemical shift (δ 35.3) in the 31P NMR
spectrum of 5b with those of the major products 3g and
5a (δ 36.7 and 39.5), in contrast to those of the minor
products 4g and 6a (δ 28.2 and 30.6), indicates that the
configuration of 5b is identical with those of 3g and 5a ,
and thus must be SCpRRu/RCpSRu. These results clearly
show that the phenyl groups on the Cp′ ring and/or on
the imino nitrogen affect the diastereoselectivity of the
5a was dissolved in THF, the 31P NMR spectrum of the
solution showed within 15 min the signals of not only
5a but also 6a with 90% de. Furthermore, the ratio of
3a /4a was dependent on the solvent, and the ratio
lowered to 6% de (3a : major) in benzene, whereas in
chloroform it was 48% de (Table 2, entry 1). These
results clearly suggest that there is equilibrium between
two diastereomers in a solution and the selectivity of
products 3/4 or 5/6 could be determined by the difference
of their thermodynamic stability.15

3278 Organometallics, Vol. 20, No. 15, 2001
Onitsuka et al.
F igu r e 2. ORTEP view of 3g with 50% probability
ellipsoids. Hydrogen atoms are omitted for clarity.
From the results mentioned above, it became appar-
ent that the selectivity of salicylideneaminato complexes
3/4 and 5/6 is under thermodynamic control and is
improved by the 4-phenyl substituent on the cyclopen-
tadienyl ligand and/or by the phenyl group on the
nitrogen of the imino group. Especially, in the case
where both substituents are phenyl groups (Table 3,
entry 5), complex 5b was produced as the sole product,
suggesting that thermodynamic stability of diastere-
omer 5b is much higher than that of diastereomer 6b.
To obtain information on the thermodynamic stability
of complex 5b, we have investigated the structure of 5b
using an optimized space-filling model as shown in
Figure 3.17 In this model, two phenyl rings bound to the
cyclopentadienyl group and the imino nitrogen are
almost parallel (the dihedral angle: 6°) with a distance
of approximately 3.4 Å, suggesting a π-π stacking
between the two phenyl groups.13c Furthermore, a π-π
stacking was also found between one of the two phenyl
rings on the phosphorus atom and the aromatic ring of
the salicylideneaminato ligand since the distance and
dihedral angle between them are about 3.4 Å and 16°,
respectively. A similar phenomenon of the latter π-π
stacking was also found in the X-ray structure of 3g
shown in Figure 2. In contrast to 5b, such π-π stacking
was not observed in the model of diastereomer 6b.
Therefore, the π-π stacking makes a large contribution
to improvement of the thermodynamic stability of 5b
compared with 6b.
F igu r e 3. Space-filling model of 5b.
comparable to those observed in transition metal com-
plexes with CH-π interaction.19 It is noteworthy that
in the 1H NMR spectra signals due to the methyl
protons with CH-π interaction shifted to a higher
magnetic field relative to those with no CH-π interac-
tion, and 3a exhibited a signal due to the methyl protons
on the Cp′ group at δ 1.91, while 3g exhibited a signal
at δ 0.59. The methyl protons on the imino group of 3a
and 5a appeared at δ 3.43 and 2.75, respectively. These
phenomena are caused by shielding due to the ring
current of the phenyl groups, supporting the CH-π
interaction (see Scheme 2).
Sch em e 2. CH-π In ter a ction
The CH-π interaction between phenyl and methyl
groups seems to play an important role for the prefer-
able formation of 3g and 5a relative to 4g and 6a .18
X-ray crystallography showed that the distances be-
tween the methyl proton and phenyl carbons lie in the
range 3.33(1)-4.01(1) Å for 3g and 3.52(1)-4.58(1) Å
for 5a , of which the minimum values are smaller than
the sum (3.7 Å) of van der Waals radii of the methyl
group (2.0 Å) and aromatic carbon (1.7 Å), and are
Although we do not have enough evidence on the
mechanism of epimerization between two diastereo-
mers, a dissociative route may be reasonable taking
account of remarkable acceleration by addition of ac-
etonitrile. When an equimolar mixture of 3g and 5a was
allowed to epimerize in THF, both complexes indepen-
dently epimerized to give the corresponding diastereo-
meric mixtures 3g/4g (94% de) and 5a /6a (90% de), and
(17) MM calculation was performed by the PC Spartan Pro program.
(18) For reviews, see: Okawa, H. Coord. Chem. Rev. 1988, 92, 1.
(b) Nishio, M.; Hirota, M. Tetrahedron 1989, 45, 7201.
(19) (a) J itsukawa, K.; Iwai, K.; Masuda, H.; Ogoshi, H.; Einaga,
H. Chem. Lett. 1994, 303. (b) Yamanori, K.; Nozaki, K.; Fuyuhiro, A.;
Kushi, Y.; Kaizaki, S. J . Chem. Soc., Dalton Trans. 1996, 2851.

Planar-Chiral Cyclopentadienyl Ru Complexes
Organometallics, Vol. 20, No. 15, 2001 3279
Hz, 1H, naphthyl), 7.42 (dt, J ) 1.5, 7.4 Hz, 1H, naphthyl),
7.52-7.60 (m, 2H, naphthyl), 7.79 (d, J ) 10.0 Hz, 1H,
naphthyl), 8.45 (d, J ) 8.1 Hz, 1H, NdCH), 13.39 (br, 1H, OH).
13C NMR (CDCl3, 150 MHz): δ 37.73 (s, CH3), 108.82 (s,
naphthyl), 114.37 (s, naphthyl), 124.98 (s, naphthyl), 125.37
(s, naphthyl), 127.21 (s, naphthyl), 127.83 (s, naphthyl), 130.10
(s, naphthyl), 130.23 (s, naphthyl), 137.60 (s, naphthyl), 162.45
(s, naphthyl), 177.33 (s, CdN). FAB MS: m/z 185 (M+). Mp:
114-115 °C. Anal. Calcd for C12H11NO: C, 77.81; H, 5.99; N,
7.56. Found: C, 77.91; H, 6.01; N, 7.67.
no intermolecular processes forming 3a /4a and 5b/6b
were observed. Thus, we propose that the epimerization
proceeds via an intramolecular process involving dis-
sociation and recoordination of the imino group.
In conclusion, we described thermodynamical control
of metal-centered chirality in planar-chiral Cp′-P ru-
thenium complexes on complexation with salicylidene-
aminato ligands. Thermodynamic stability of the prod-
ucts is strongly influenced by π-π stacking and CH-π
interaction between substituents on the Cp′ and the
imino groups. Since an imino group increases the
reactivity toward nucleophiles by coordination to a
metal, we are making an effort to apply this finding to
the development of a novel asymmetric reaction.
2-OH-1-(MeNdCH)C10H6 (1-(m eth ylim in om eth yl)n a p h -
th a len -2-ol):24 yellow powder, yield 96%. IR (cm-1, KBr): 1635
1
(νCdN). H NMR (CDCl3, 400 MHz): δ 3.45 (d, J ) 2.1 Hz, 3H,
NCH3), 6.92 (d, J ) 9.5 Hz, 1H, naphthyl), 7.23 (t, J ) 7.5 Hz,
1H, naphthyl), 7.43 (dt, J ) 1.1, 7.7 Hz, 1H, naphthyl), 7.61
(d, J ) 7.6 Hz, 1H, naphthyl), 7.68 (d, J ) 9.2 Hz, 1H,
naphthyl), 7.85 (d, J ) 8.2 Hz, 1H, naphthyl), 8.71 (d, J ) 8.9
Hz, 1H, NdCH), 14.36 (br, 1H, -OH).
Exp er im en ta l Section
1-OH-2-(P r iNdCH)C6H4 (salicyliden eisopr opylam in e):21
yellow oil, yield 99%. IR (cm-1, neat): 1632 (νCdN). 1H NMR
(CDCl3, 400 MHz): δ 1.30 (d, J ) 6.3 Hz, 6H, NCH(CH3)2),
3.55 (sept, J ) 5.9 Hz, 1H, NCH(CH3)2), 6.86 (dt, J ) 1.0, 7.4
Hz, 1H, Ph), 6.95 (d, J ) 8.3 Hz, 1H, Ph), 7.24 (dd, J ) 1.7,
7.6 Hz, 1H, Ph), 7.29 (dt, J ) 1.8, 7.7 Hz, 1H, Ph), 8.36 (s, 1H,
NdCH), 13.71 (br, 1H, OH).
Gen er a l P r oced u r es. All reactions were carried out under
an argon atmosphere. Hexane and THF were distilled over
calcium hydride and sodium benzophenone ketyl, respectively.
Other chemicals available commercially were used without
further purification. The starting ruthenium complexes
[η5,η1-{C5H2(Me)(R)COO(CH2)2PPh2}Ru(MeCN)2][PF6] (1) were
prepared as reported previouly.8
NMR spectra were taken on J EOL J NM-LA400, J EOL
J NM-LA600, and Bruker ARX400 spectrometers. In 1H and
13C NMR spectra, SiMe4 was used as an internal standard,
and an external 85% H3PO4 reference was used for 31P NMR.
IR spectra were obtained on a Perkin-Elmer system 2000 FT-
IR and FAB mass spectra on a J EOL J MS-600H instrument.
Elemental analyses were performed at The Material Analysis
Center, ISIR, Osaka University.
1-OH-2-(P h NdCH)C6H4 (sa licylid en ep h en yla m in e):21
yellow powder, yield 99%. IR (cm-1, KBr): 1617 (νCdN). 1H
NMR (CDCl3, 400 MHz): δ 6.95 (dt, J ) 1.0, 7.4 Hz, 1H, Ph),
7.03 (d, J ) 7.8 Hz, 1H, Ph), 7.28-7.31 (m, 2H, Ph), 7.37-
7.45 (m, 5H, Ph), 8.64 (s, 1H, NdCH), 13.27 (s, 1H, OH).
[η5,η1-{C5H2(Me)2COO(CH2)2P P h 2}Ru (OC6H4CdNMe)]
(3a a n d 4a ). NaH (60% oil suspension) (12 mg, 0.30 mmol)
was washed with dry hexane (1 mL) three times and sus-
pended in THF (1 mL). To this suspension was added sali-
cylidenemethylamine (41 mg, 0.30 mmol), and the reaction
mixture was stirred at room temperature for 15 min. After
the reaction mixture was filtered, the filtrate was poured into
a suspension of 1a (136 mg, 0.20 mmol) in THF (10 mL), and
the mixture was stirred at room temperature for 1 h. The
solvent was removed under reduced pressure, and the residue
was dissolved in dichloromethane (1 mL) followed by the
addition of hexane (5 mL). After insoluble materials were
removed by filtration, the filtrate was concentrated under
reduced pressure. Recrystallization from dichloromethane-
hexane gave a mixture of 3a and 4a (59 mg, 50% yield, 48%
de) as red crystals. IR (cm-1, KBr): 1615 (νCdN), 1688 (νCdO).
1H NMR (CDCl3, 600 MHz): for 3a , δ 1.77 (s, 3H, Cp′CH3),
1.91 (s, 3H, Cp′CH3), 2.25 (dt, J ) 4.8, 14.8 Hz, 1H, PCH2),
3.22-3.28 (m, 1H, PCH2), 3.43 (d, J ) 0.9 Hz, 3H, NCH3), 3.91
(ddt, J ) 2.7, 4.7, 11.8 Hz, 1H, OCH2), 4.42 (s, 1H, Cp′), 4.82
(d, J ) 2.0 Hz, 1H, Cp′), 5.14 (ddd, J ) 7.5, 11.0, 20.9 Hz, 1H,
OCH2), 6.14 (dt, J ) 0.6, 7.2 Hz, 1H, Ph), 6.43 (dd, J ) 1.8,
7.5 Hz, 1H, Ph), 6.77 (d, J ) 8.4 Hz, 1H, Ph), 6.79-6.84 (m,
2H, Ph), 6.92-6.99 (m, 2H, Ph), 7.03 (t, J ) 8.5 Hz, 2H, Ph),
7.24-7.35 (m, 1H, Ph), 7.42 (s, 1H, NdCH), 7.52-7.57 (m, 2H,
Ph), 7.74-7.78 (m, 2H, Ph); for 4a , δ 1.74 (s, 3H, Cp′CH3),
2.07 (s, 3H, Cp′CH3), 2.59-2.64 (m, 1H, PCH2), 2.86-2.92 (m,
1H, PCH2), 3.27 (s, 3H, NCH3), 4.11-4.17 (m, 1H, OCH2), 4.15
(s, 1H, Cp′), 4.75 (d, J ) 2.2 Hz, 1H, Cp′), 5.06-5.13 (m, 1H,
OCH2), 6.12-6.14 (m, 1H, Ph), 6.45 (dd, J ) 1.7, 7.6 Hz, 1H,
Ph), 6.57 (d, J ) 8.6 Hz, 1H, Ph), 6.79-6.84 (m, 2H, Ph), 6.92-
6.99 (m, 2H, Ph), 7.11 (t, J ) 9.0 Hz, 2H, Ph), 7.15 (s, 1H,
NdCH), 7.24-7.35 (m, 1H, Ph), 7.52-7.57 (m, 2H, Ph), 7.85-
7.88 (m, 2H, Ph). 31P NMR (CDCl3, 160 MHz): for 3a , δ 40.2
(s); for 4a , δ 28.0 (s). FAB MS: m/z 585 (M+). Anal. Calcd for
P r ep a r a tion of Sa licylid en ea m in es.20 To a solution of a
salicylaldehyde derivative (1.45 mmol) in hexane (10 mL) was
added methylamine (40% in water) (0.20 mL), and the reaction
mixture was stirred at room temperature for 1 h. After drying
over Na2SO4, the reaction mixture was filtered, and the filtrate
was concentrated under reduced pressure to give a salicylide-
neamine derivative. When salicylideneamine was obtained as
a solid, the resulting residue was washed with pentane.
1-OH-2-(MeNdCH)C6H3 (sa licylid en em eth yla m in e):21
1
yellow oil, yield >99%. IR (cm-1, neat): 1638 (νCdN). H NMR
(CDCl3, 400 MHz): δ 3.49 (d, J ) 1.5 Hz, 3H, NCH3), 6.87 (dt,
J ) 1.0, 7.4 Hz, 1H, Ph), 6.96 (d, J ) 8.3 Hz, 1H, Ph), 7.24
(dd, J ) 1.6, 7.7 Hz, 1H, Ph), 7.30 (dt, J ) 1.5, 7.8 Hz, 1H,
Ph), 8.35 (d, J ) 1.2 Hz, 1H, NdCH), 13.50 (s, 1H, OH).
1-OH-2-(MeNdCH)-4-MeOC6H3 (4-m eth oxysalicyliden e-
m eth yla m in e):22 yellow oil, yield >99%. IR (cm-1, neat): 1642
1
(νCdN). H NMR (CDCl3, 400 MHz): δ 3.49 (d, J ) 1.2 Hz, 3H,
NCH3), 3.78 (s, 3H, OCH3), 6.77 (d, J ) 2.2 Hz, 1H, Ph), 6.88-
6.93 (m, 2H, Ph), 8.31 (d, J ) 1.5 Hz, 1H, NdCH), 12.95 (br,
1H, OH).
1-OH-2-(MeNdCH)-4-NO2C6H3 (4-n itr osalicyliden em eth -
yla m in e):23 orange powder, yield 62%. IR (cm-1, KBr): 1298
(νN-O), 1667 (νCdN). 1H NMR (CDCl3, 400 MHz): δ 3.55 (d, J )
1.2 Hz, 3H, NCH3), 6.96 (d, J ) 9.2 Hz, 1H, Ph), 8.19 (dd, J )
2.7, 9.2 Hz, 1H, Ph), 8.23 (d, J ) 2.7 Hz, 1H, Ph), 8.36 (d, J )
0.9 Hz, 1H, NdCH), 14.80 (br, 1H, OH).
1-OH-2-(MeNdCH)C10H6 (2-(m eth ylim in om eth yl)n a p h -
th a len -1-ol): yellow powder, yield 78%. IR (cm-1, KBr): 1649
1
(νCdN). H NMR (CDCl3, 400 MHz): δ 3.37 (d, J ) 1.0 Hz, 3H,
NCH3), 6.79 (d, J ) 8.8 Hz, 1H, naphthyl), 6.94 (d, J ) 8.8
(20) Ishihara, K.; Miyata, M.; Hattori, K.; Tada, T.; Yamamoto, H.
J . Am. Chem. Soc. 1994, 116, 10520.
(21) Tripathi, S. M.; Tandon, J . P. J . Inorg. Nucl. Chem. 1978, 40,
983.
(22) Rozwadowski, Z.; Majewski, E.; Dziembowski, T.; Hansen, P.
E. J . Chem. Soc., Perkin Trans. 2 1999, 2809.
(23) Frey, P. A.; Kokesh, F. C.; Westheimer, F. H. J . Am. Chem.
Soc. 1971, 93, 7266.
C
30H30NO3PRu: C, 61.64; H, 5.17; N, 2.40. Found: C, 61.38;
H, 5.04; N, 2.55.
(24) (a) Dudek, G. O.; Holm, R. H J . Am. Chem. Soc. 1962, 84, 2691.
(b) Dudek, G. O. J . Am. Chem. Soc. 1963, 85, 694.

3280 Organometallics, Vol. 20, No. 15, 2001
Onitsuka et al.
(cm-1, KBr): 1614 (νCdN), 1696 (νCdO). 1H NMR (CDCl3, 600
MHz): for 3e, δ 1.76 (s, 3H, Cp′CH3), 1.93 (s, 3H, Cp′CH3),
2.29 (dt, J ) 4.9, 14.4 Hz, 1H, PCH2), 3.18-3.24 (m, 1H, PCH2),
3.44 (s, 3H, NCH3), 3.94-3.99 (m, 1H, OCH2), 4.38 (s, 1H, Cp′),
4.83 (d, J ) 3.3 Hz, 1H, Cp′), 5.17 (ddd, J ) 7.4, 11.4, 20.6 Hz,
1H, OCH2), 6.78-7.89 (m, 16H, Ar), 7.81 (s, 1H, NdCH); for
4e, δ 1.74 (s, 3H, Cp′CH3), 2.08 (s, 3H, Cp′CH3), 2.64-2.71
(m, 1H, PCH2), 2.90-2.96 (m, 1H, PCH2), 3.24 (s, 1H, NCH3),
4.17 (s, 1H, Cp′), 4.21 (ddd, J ) 5.9, 11.1, 16.7 Hz, 1H, OCH2),
4.77-4.78 (m, 1H, Cp′), 5.08-5.17 (m, 1H, OCH2), 6.78-7.89
(m, 16H, Ar), 8.02 (s, 1H, NdCH). 31P NMR (CDCl3, 160
MHz): for 3e, δ 39.0 (s); for 4e, δ 27.7 (s). FAB MS: m/z 635
(M+). Anal. Calcd for C34H32NO3PRu: C, 64.34; H, 5.08; N,
2.21. Found: C, 64.47; H, 4.99; N, 2.42.
[η5,η1-{C5H2(Me)2COO(CH2)2P P h 2}Ru (OC6H3(OMe)CdN-
Me)] (3b a n d 4b). These complexes were prepared from 1a
and 2b by a method similar to that for 3a and 4a , but were
not isolated. Yield and selectivity were determined by NMR
spectra of the reaction mixture to be 30% and 47% de,
respectively. 1H NMR (CDCl3, 400 MHz) for 3b: δ 1.77 (s, 3H,
Cp′CH3), 1.91 (s, 3H, Cp′CH3), 3.62 (s, 3H, NCH3), 3.73 (s, 3H,
OCH3), 4.40 (s, 1H, Cp′), 4.82 (d, J ) 2.2 Hz, 1H, Cp′), signals
due to phenyl, NdCH, and CH2CH2P protons could not be
assigned due to overlap of those of other products; for 4b, δ
1.73 (s, 3H, Cp′CH3), 2.06 (s, 3H, Cp′CH3), 3.42 (d, J ) 0.7
Hz, 3H, NCH3), 4.13 (s, 1H, Cp′), 4.75 (s, 1H, Cp′), signals due
to OCH3, phenyl, and NdCH CH2CH2P protons could not be
assigned due to overlap of those of other products. 31P NMR
(CDCl3, 160 MHz): for 3b, δ 39.5 (s); for 4b, δ 27.0 (s).
[η5,η1-{C5H2(Me)2COO(CH 2)2P P h 2}Ru (OC6H4CdNP r i)]
(3f a n d 4f). These complexes were prepared from 1a and 2f
by a method similar to that for 3a and 4a , but were not
isolated. Yield and selectivity were determined by 31P NMR
spectra of the reaction mixture to be 11% and 44% de,
respectively. Assignment of the 1H NMR spectrum was difficult
owing to overlap of those of other products. 31P NMR (CDCl3,
160 MHz): for 3f, δ 39.3 (s); for 4f, δ 27.6 (s).
[η5,η1-{C5H2(Me)2COO(CH2)2P P h 2}Ru (OC6H3(NO2)CdN-
Me)] (3c a n d 4c). These complexes were prepared from 1a
and 2c by a method similar to that for 3a and 4a , but were
not isolated. Yield and selectivity were determined by NMR
spectra of the reaction mixture to be 57% and 29% de,
respectively. 1H NMR (CDCl3, 400 MHz): for 3c, δ 1.75 (s, 3H,
Cp′CH3), 1.91 (s, 3H, Cp′CH3), 3.55 (d, J ) 0.9 Hz, 3H, NCH3),
4.51 (s, 1H, Cp′), 4.85 (d, J ) 2.1 Hz, 1H, Cp′), signals due to
phenyl, NdCH, and CH2CH2P protons could not be assigned
due to overlap of those of other products; for 4c, δ 2.22 (s,
3H, Cp′CH3), 3.41 (s, 3H, NCH3), 4.59 (s, 1H, Cp′), signals
due to Cp′CH3, Cp-H, phenyl, NdCH, and CH2CH2P protons
could not be assigned due to overlap of those of other products.
31P NMR (CDCl3, 160 MHz): for 3c, δ 38.8 (s); for 4c, δ 29.8
(s).
[η5,η1-{C5H 2(Me)2COO(CH 2)2P P h 2}R u (OC6H 4CdNP h )]
(3g a n d 4g). Reaction of 1a (136 mg, 0.20 mmol) with sodium
salicylidenephenylaminate (2g), prepared from salicylidene-
phenylamine (59 mg, 0.30 mmol) and NaH (60% oil suspen-
sion) (12 mg, 0.30 mmol), by a method similar to that for 3a
and 4a gave a mixture of 3g and 4g (82 mg, 62% yield, 94%
de) as red crystals. IR (cm-1, KBr): 1605 (νCdN), 1705 (νCdO).
1H NMR (CDCl3, 600 MHz): for 3g, δ 0.59 (s, 3H, Cp′CH3),
1.76 (d, J ) 1.0 Hz, 3H, Cp′CH3), 2.18 (dt, J ) 4.3, 14.6 Hz,
1H, PCH2), 3.26-3.31 (m, 1H, PCH2), 3.75 (ddt, J ) 2.7, 4.4,
11.7 Hz, 1H, OCH2), 4.56 (s, 1H, Cp′), 4.57 (s, 1H, Cp′), 5.08
(ddd, J ) 7.2, 10.9, 21.7 Hz, 1H, OCH2), 6.12 (dt, J ) 1.0, 7.8
Hz, 1H, Ph), 6.41 (dd, J ) 1.7, 7.9 Hz, 1H, Ph), 6.79 (dt, J )
1.8, 7.8 Hz, 2H, Ph), 6.85 (d, J ) 8.5 Hz, 1H, Ph), 6.91-6.94
(m, 3H, Ph), 7.02-7.04 (m, 2H, Ph), 7.07-7.12 (m, 2H, Ph),
7.21 (d, J ) 1.5 Hz, 1H, NdCH), 7.25 (t, J ) 7.8 Hz, 2H, Ph),
7.53-7.58 (m, 3H, Ph), 7.76 (dt, J ) 1.5, 9.8 Hz, 2H, Ph); for
4g, δ 0.89 (s, 3H, Cp′CH3), 1.70 (d, J ) 1.0 Hz, 3H, Cp′CH3),
2.61 (dt, J ) 4.4, 15.1 Hz, 1H, PCH2), 3.05-3.11 (m, 1H, PCH2),
3.70 (br, 1H, OCH2), 3.98 (s, 1H, Cp′), 4.38 (s, 1H, Cp′), 5.13-
5.23 (m, 1H, OCH2), 5.98 (t, J ) 7.7 Hz, 1H, Ph), 6.27 (dd, J
) 1.7, 7.8 Hz, 1H, Ph), 6.50 (d, J ) 8.8 Hz, 1H, Ph), 8.01 (t, J
) 9.6 Hz, 2H, Ph); other phenyl and NdCH signals were not
detected due to overlapping with those of 3g. 31P NMR (CDCl3,
160 MHz): for 3g, δ 36.7 (s); for 4g, δ 28.2 (s). FAB MS: m/z
647 (M+). Anal. Calcd for C35H32NO3PRu: C, 65.01; H, 4.99;
N, 2.17. Found: C, 65.08; H, 4.80; N, 2.35.
[η5,η1-{C5H2(Me)2COO(CH2)2P P h 2}Ru (1-OC10H6CdNMe-
2)] (3d a n d 4d ). A THF solution (1 mL) of sodium 2-(methyl-
iminomethyl)naphthalen-1-olate (2d ) prepared from 2-(meth-
yliminomethyl)naphthalen-1-ol (56 mg, 0.30 mmol) and NaH
(60% oil suspension) (12 mg, 0.30 mmol) as described above
was added into a suspension of 1a (136 mg, 0.20 mmol) in THF
(10 mL), and the reaction mixture was stirred at room
temperature for 1 h. After removal of the solvent under
reduced pressure, the residue was purified by alumina column
chromatography using benzene-dichloromethane ) 1:1 (v/v)
as an eluent. Evaporation of the solvent followed by drying in
vacuo gave a mixture of 3d and 4d (102 mg, 81% yield, 52%
de) as red powder. IR (cm-1, KBr): 1595 (νCdN), 1696 (νCdO).
1H NMR (CDCl3, 600 MHz): for 3d , δ 1.79 (s, 3H, Cp′CH3),
1.95 (s, 3H, Cp′CH3), 2.23 (dt, J ) 4.6, 14.6 Hz, 1H, PCH2),
3.25-3.31 (m, 1H, PCH2), 3.50 (d, J ) 1.1 Hz, 3H, NCH3),
3.94-3.99 (m, 1H, OCH2), 4.50 (t, J ) 1.8 Hz, 1H, Cp′), 4.88
(d, J ) 2.2 Hz, 1H, Cp′), 5.20 (ddd, J ) 7.1, 11.2, 20.8 Hz, 1H,
OCH2), 6.42 (d, J ) 8.4 Hz, 1H, Ar), 6.49 (s, 1H, Ar), 6.52 (d,
J ) 8.4 Hz, 1H, Ar), 6.63 (dt, J ) 1.1, 8.6 Hz, 2H, Ar), 6.68
(dt, J ) 2.0, 7.7 Hz, 2H, Ar), 6.77 (t, J ) 7.0 Hz, 1H, Ar), 6.97
(s, 1H, NdCH), 7.36-7.56 (m, 5H, Ar), 7.73-7.76 (m, 2H, Ar),
8.67 (dd, J ) 0.7, 8.1 Hz, 12H, Ar); for 4d , δ 1.87 (s, 3H,
Cp′CH3), 2.11 (s, 3H, Cp′CH3), 2.56-2.62 (m, 1H, PCH2), 2.91-
2.96 (m, 1H, PCH2), 3.25 (s, 1H, NCH3), 4.15-4.20 (m, 1H,
OCH2), 4.34 (s, 1H, Cp′), 4.78 (d, J ) 2.0 Hz, 1H, Cp′), 5.05-
5.12 (m, 1H, OCH2), 6.89-6.96 (m, 2H, Ar), 7.14 (s, 1H, Nd
CH), 7.23-7.26 (m, 1H, Ar), 7.36-7.56 (m, 8H, Ar), 7.95-7.99
(m, 2H, Ar), 8.36 (d, J ) 7.9 Hz, 1H, Ar). 31P NMR (CDCl3,
160 MHz): for 3d , δ 39.9 (s); for 4d , δ 30.0 (s). FAB MS: m/z
635 (M+). Anal. Calcd for C34H32NO3PRu: C, 64.34; H, 5.08;
N, 2.21. Found: C, 64.15; H, 4.91; N, 2.43.
[η5,η1-{C5H 2(Me)(P h )COO(CH 2)2P P h 2}R u (OC6H 4CdN-
Me)] (5a a n d 6a ). Reaction of 1b (148 mg, 0.20 mmol) with
sodium salicylidenemethylaminate (2a ), prepared from sali-
cylidenemethylamine (41 mg, 0.30 mmol) and NaH (60% oil
suspension) (12 mg, 0.30 mmol), by a method similar to that
for 3a and 4a gave a mixture of 5a and 6a (54% yield, 90%
de) as red crystals. IR (cm-1, KBr): 1619 (νCdN), 1700 (νCdO).
1H NMR (CDCl3, 400 MHz): for 5a , δ 1.90 (s, 3H, Cp′CH3),
2.27 (dt, J ) 4.4, 14.9 Hz, 1H, PCH2), 2.75 (d, J ) 0.7 Hz, 3H,
NCH3), 3.15-3.23 (m, 1H, PCH2), 4.05 (ddt, J ) 2.2, 4.6, 12.0
Hz, 1H, OCH2), 5.06 (t, J ) 2.0 Hz, 1H, Cp′), 5.21 (ddd, J )
7.6, 11.2, 20.7 Hz, 1H, OCH2), 5.45 (d, J ) 1.7 Hz, 1H, Cp′),
6.21 (t, J ) 7.2 Hz, 1H, Ph), 6.49 (dd, J ) 1.8, 7.7 Hz, 1H, Ph),
6.73-6.82 (m, 6H, Ph), 6.92 (s, 1H, NdCH), 6.96 (dt, J ) 1.5,
6.6 Hz, 1H, Ph), 7.07 (dt, J ) 2.0, 7.7 Hz, 1H, Ph), 7.30 (d, J
) 7.1 Hz, 1H, Ph), 7.35 (t, J ) 7.3 Hz, 1H, Ph), 7.46 (d, J )
6.8 Hz, 2H, Ph), 7.52-7.61 (m, 3H, Ph), 7.69 (t, J ) 8.4 Hz,
2H, Ph); for 6a , δ 2.18 (d, J ) 3.2 Hz, 3H, Cp′CH3), 3.11 (s,
3H, NCH3), 4.91 (s, 1H, Cp′), 5.36 (s, 1H, Cp′); signals
assignable to phenyl, NdCH, and PCH2CH2 were not detected
[η5,η1-{C5H2(Me)2COO(CH2)2P P h 2}Ru (2-OC10H6CdNMe-
1)] (3e a n d 4e). Reaction of 1a (136 mg, 0.20 mmol) with
sodium 1-(methyliminomethyl)naphthalen-2-olate (2e), pre-
pared from 1-(methyliminomethyl)naphthalen-2-ol (56 mg,
0.30 mmol) and NaH (60% oil suspension) (12 mg, 0.30 mmol),
by a method similar to that for 3d and 4d gave a mixture of
3e and 4e (110 mg, 87% yield, 47% de) as a red powder. IR

Planar-Chiral Cyclopentadienyl Ru Complexes
Organometallics, Vol. 20, No. 15, 2001 3281
Ta ble 4. Cr ysta llogr a p h ic Da ta for Com p lexes 3g a n d 5a
3g
5a
empirical formula
fw
C
35H32NO3PRu
C35H32NO3PRu
646.69
646.69
cryst color, habit
cryst dimens
cryst system
lattice params
red, prismatic
0.30 × 0.15 × 0.10 mm
monoclinic
a ) 12.558(7) Å
b ) 15.632(4) Å
c ) 15.330(4) Å
â ) 95.76(3)°
V ) 2994(1) Å3
P21/c (# 14)
4
red, plate
0.40 × 0.40 × 0.05 mm
monoclinic
a ) 13.949(3) Å
b ) 16.400(5) Å
c ) 12.994(2) Å
â ) 106.91(1)°
V ) 2844(1) Å3
P21/n (# 14)
4
space group
Z value
Dcalcd
F(000)
µ(Mo KR)
temperature
no. of reflns measd
total
1.434 g cm-3
1328
1.510 g cm-3
1328
6.13 cm-1
-75 °C
6.46 cm-1
-75 °C
7175
7826
unique
abs corr
p-factor
6864 (Rint ) 0.063)
6519 (Rint ) 0.085)
ψ-scan
ψ-scan
0.088
0.132
no. observations
no. variables
3569 (I > 3.0σ(I))
370
3852 (I > 3.0σ(I))
370
reflection/param ratio
residuals: R; Rw
goodness of fit indicator
max. shift/error in final cycle
max. peak in final diff map
min. peak in final diff map
9.65
0.052; 0.067
1.02
10.41
0.058; 0.084
1.11
0.00
0.01
1.46 e Å-3
-0.92 e Å-3
2.21 e Å-3 (near Ru)
-1.40 e Å-3
due to overlapping with those of the major product. 31P NMR
(CDCl3, 160 MHz): for 5a , δ 39.5 (s); for 6a , δ 30.6 (s). FAB
MS: m/z 647 (M+). Anal. Calcd for C35H32NO3PRu: C, 65.01;
H, 4.99; N, 2.17. Found: C, 64.79; H, 4.78; N, 2.23.
O). 31P NMR (CDCl3, 160 MHz): δ 48.7 (s). FAB MS: m/z 611
(M+ - PF6). Anal. Calcd for C32H34F6N2O2P2Ru: C, 50.86; H,
4.54; N, 3.71. Found: C, 51.04; H, 4.26; N, 3.86.
[η5-{C5H2(Me)(P h )COOEt}Ru (P P h 3)(MeCN)2][P F6] (7b).
This complex was obtained from the reaction of ruthenium
complex [η5-{C5H2(Me)(Ph)COOEt}Ru(CH3CN)3][PF6] (600 mg,
1.00 mmol) with PPh3 (260 mg, 1.00 mmol) by a procedure
similar to that for 7a as a yellow powder (810 mg, 99% yield).
[η5,η1-{C5H 2(Me)(P h )COO(CH 2)2P P h 2}R u (OC6H 4CdN-
P h )] (5b). Reaction of 1b (148 mg, 0.20 mmol) with sodium
salicylidenephenylaminate (2g), prepared from salicylidene-
phenylamine (59 mg, 0.30 mmol) and NaH (60% oil suspen-
sion) (12 mg, 0.30 mmol), by a method similar to that for 3a
and 4a gave complex 5b (67% yield, >99% de) as an orange
powder. IR (cm-1, KBr): 1604 (νCdN), 1712 (νCdO). 1H NMR
(CDCl3, 400 MHz): δ 1.86 (s, 3H, Cp′CH3), 2.19 (dt, J ) 4.1,
14.3 Hz, 1H, PCH2), 3.20-3.29 (m, 1H, PCH2), 3.84-3.93 (m,
1H, OCH2), 5.12 (ddd, J ) 7.1, 10.5, 20.9 Hz, 1H, OCH2), 5.20
(s, 1H, Cp′), 5.36 (s, 1H, Cp′), 6.14 (t, J ) 7.3 Hz, 1H, Ph),
6.40 (dd, J ) 1.5, 7.7 Hz, 1H, Ph), 6.66-6.76 (m, 7H, Ph), 6.80-
6.93 (m, 8H, Ph), 7.17 (s, 1H, NdCH), 7.51-7.59 (m, 3H, Ph),
7.77 (t, J ) 8.8 Hz, 2H, Ph). 31P NMR (CDCl3, 160 MHz): δ
35.3 (s). FAB MS: m/z 709 (M+). Anal. Calcd for C40H34NO3-
PRu: C, 67.79; H, 4.84; N, 1.98. Found: C, 67.53; H, 4.44; N,
1.90.
1
IR (cm-1, KBr): 839 (νP-F), 1711 (νCdO). H NMR (CDCl3, 400
MHz): δ 1.10 (t, J ) 7.1 Hz, 3H, OCH2CH3), 1.90 (d, J ) 1.2
Hz, 3H, Cp′CH3), 2.15 (d, J ) 1.2 Hz, 3H, NCCH3), 2.31 (d, J
) 1.0 Hz, 3H, NCCH3), 3.78-3.86 (m, 1H, OCH2CH3), 4.05-
4.13 (m, 1H, OCH2CH3), 4.46 (s, 1H, Cp′), 5.27 (s, 1H, Cp′),
7.13-7.46 (m, 20H, Ph). 31P NMR (CDCl3, 160 MHz): δ 46.3
(s). FAB MS: m/z 673 (M+ - PF6). Anal. Calcd for C37H36F6N2O2-
P2Ru: C, 54.35; H, 4.44; N, 3.43. Found: C, 54.12; H, 4.32; N,
3.52.
[η5-{C5H 2(Me)2COOE t }R u (P P h 3)(OC6H 4CdNMe)] (8a
a n d 9a ). Reaction of 7a (151 mg, 0.20 mmol) with sodium
salicylidenemethylaminate (2a ), prepared from salicylidene-
methylamine (41 mg, 0.30 mmol) and NaH (60% oil suspen-
sion) (12 mg, 0.30 mmol), by a method similar to that for 3a
and 4a gave a mixture of 8a and 9a (62 mg, 50% yield, 22%
de) as an orange powder. IR (cm-1, KBr): 1620 (νCdN), 1696
[η5-{C5H2(Me)2COOEt}Ru (P P h 3)(MeCN)2][P F 6] (7a ). To
a dichloromethane solution (50 mL) of tris(acetonitrile) ruthe-
nium complex [η5-{C5H2(Me)2COOEt}Ru(MeCN)3][PF6] (550
mg, 1.02 mmol) was added PPh3 (270 mg, 1.02 mmol) at -78
°C, and the reaction mixture was stirred for 1 h at the same
temperature. After removal of the solvent under reduced
pressure, the residue was washed with ether. Drying in vacuo
1
(νCdO). H NMR (CDCl3, 600 MHz): for the major product, δ
1.12 (s, 3H, Cp′CH3), 1.14 (t, J ) 7.1 Hz, 3H, OCH2CH3), 1.60
(s, 3H, Cp′CH3), 3.38 (s, 3H, NCH3), 3.75 (s, 1H, Cp′), 3.86-
3.93 (m, 1H, OCH2CH3), 3.97-4.05 (m, 1H, OCH2CH3), 4.47
(s, 1H, Cp′), 6.13 (t, J ) 7.2 Hz, 1H, Ph), 6.55-6.63 (m, 2H,
Ph), 6.92 (dt, J ) 1.7, 15.2 Hz, 1H, Ph), 7.23-7.30 (m, 5H,
Ph), 7.39 (s, 1H, NdCH), 7.43-7.50 (m, 10H, Ph); for the minor
product, δ 1.03 (t, J ) 7.2 Hz, 3H, OCH2CH3), 1.53 (s, 3H,
Cp′CH3), 1.87 (s, 3H, Cp′CH3), 3.42 (s, 3H, NCH3), 3.72-3.85
(m, 2H, OCH2CH3), 3.91 (s, 1H, Cp′), 4.40 (s, 1H, Cp′), 6.22 (t,
J ) 7.4 Hz, 1H, Ph), 6.55-6.63 (m, 1H, Ph), 6.77 (dd, J ) 1.7,
7.3 Hz, 1H, Ph), 6.98 (dt, J ) 1.7, 15.4 Hz, 1H, Ph), 7.23-7.30
(m, 5H, Ph), 7.43-7.50 (m, 10H, Ph), 7.57 (s, 1H, NdCH). 31P
NMR (CDCl3, 160 MHz): for the major product, δ 51.2 (s); for
the minor product, δ 49.5 (s). FAB MS: m/z 663 (M+). Anal.
Calcd for C36H36NO3PRu: C, 65.24; H, 5.48; N, 2.11. Found:
C, 65.01; H, 5.24; N, 2.28.
gave complex 7a (770 mg, 99%) as a yellow powder. IR (cm-1
,
1
KBr): 840 (νP-F), 1711 (νCdO). H NMR (CDCl3, 400 MHz): δ
1.09 (t, J ) 8.2 Hz, 3H, OCH2CH3), 1.52 (s, 3H, Cp′CH3), 2.00
(d, J ) 1.0 Hz, 3H, Cp′CH3), 2.03 (d, J ) 1.2 Hz, 3H, NCCH3),
2.33 (d, J ) 0.7 Hz, 3H, NCCH3), 3.80-3.88 (m, 1H, OCH2-
CH3), 3.96 (s, 1H, Cp′), 4.06-4.14 (m, 1H, OCH2CH3), 4.40 (s,
1H, Cp′), 7.26-7.34 (m, 5H, Ph), 7.45-7.46 (m, 10H, Ph). 13C
NMR (CDCl3, 100 MHz): δ 3.3 (s, NCCH3), 3.7 (s, NCCH3),
12.2 (s, CH3), 12.8 (s, CH3), 14.1 (s, CH3), 60.4 (s, OCH2), 67.6
(s, Cp′), 77.6 (d, J P-C ) 5.8 Hz, Cp′), 81.6 (s, Cp′), 91.8 (s, Cp′),
106.2 (d, J P-C ) 2.5 Hz, Cp′), 126.6 (s, NCCH3), 127.3 (s,
NCCH3), 128.5 (d, J P-C ) 9.9 Hz, Ph), 130.8 (s, Ph), 132.9 (s,
Ph), 133.3 (s, Ph), 133.6 (d, J P-C ) 11.6 Hz, Ph), 169.1 (s, Cd

3282 Organometallics, Vol. 20, No. 15, 2001
Onitsuka et al.
ments; however no damage was observed in both measure-
ments. Intensities were corrected for Lorentz and polarization
effects, and for absorption using ψ-scan technique. The struc-
tures were solved by Patterson methods and refined by full-
matrix least-squares minimizing of ∑w(|Fo| - |Fc|)2, w )
1/[σc2(Fo) + 1/4(p2Fo2)]. Anisotropic thermal parameters were
used for all non-hydrogen atoms, while hydrogen atoms were
included at the calculated positions (dC-H ) 0.95 Å), and their
parameters were not refined. The fine cycles of full matrix least
squares refinement were converged. All calculations were
performed using the teXsan crystallographic software package.
Crystallographic data are listed in Table 4.
[η5-{C5H2(Me)(P h )COOEt}Ru (P P h 3)(OC6H4CdNMe)] (8b
a n d 9b). Reaction of 7b (164 mg, 0.2 mmol) with sodium
salicylidenemethylaminate (2a ), prepared from salicylidene-
methylamine (41 mg, 0.30 mmol) and NaH (60% oil suspen-
sion) (12 mg, 0.30 mmol), by a method similar to that for 3b
and 4a gave a mixture of 8b and 9b (78 mg, 54% yield, 5% de)
as an orange powder. IR (cm-1, KBr): 1620 (νCdN), 1698 (νCdO).
1H NMR (CDCl3, 600 MHz): for the major product, δ 1.04 (t,
J ) 7.1 Hz, 3H, OCH2CH3), 1.93 (s, 3H, Cp′CH3), 2.58 (s, 3H,
NCH3), 3.59-3.67 (m, 1H, OCH2CH3), 3.97-4.03 (m, 1H,
OCH2CH3), 4.21 (s, 1H, Cp′), 5.14 (s, 1H, Cp′), 6.28 (t, J ) 7.8
Hz, 1H, Ph), 6.70 (d, J ) 8.5 Hz, 1H, Ph), 6.91-6.93 (m, 2H,
Ph), 6.96-7.34 (m, 13H, Ph), 7.37 (s, 1H, NdCH), 7.49-7.53
(m, 7H, Ph); for the minor product, δ 1.09 (t, J ) 7.2 Hz, 3H,
OCH2CH3), 1.99 (s, 3H, Cp′CH3), 3.36 (s, 3H, NCH3), 3.81-
3.95 (m, 2H, OCH2CH3), 4.71 (d, J ) 1.0 Hz, 1H, Cp′), 5.02 (d,
J ) 1.2 Hz, 1H, Cp′), 6.24 (t, J ) 7.8 Hz, 1H, Ph), 6.56 (d, J )
8.3 Hz, 1H, Ph), 6.79-6.80 (m, 2H, Ph), 6.96-7.34 (m, 20H,
Ph), 7.56 (s, 1H, NdCH). 31P NMR (CDCl3, 160 MHz): for the
major product, 47.1 (s); for the minor product, 48.6 (s). FAB
MS: m/z 725 (M+). Anal. Calcd for C41H38NO3PRu: C, 67.94;
H, 5.28; N, 1.93. Found: C, 67.73; H, 5.08; N, 1.91.
Ack n ow led gm en t. This work was supported by a
Grant-in-Aid for Scientific Research from the Ministry
of Education, Science, Sports and Culture. The author
(K.O.) gratefully acknowledges partial support of this
work by Mitsubishi Chemical Corporation Fund. We
thank The Material Analysis Center, ISIR, Osaka
University, for support of spectral and X-ray measure-
ments as well as microanalyses.
X-r a y Diffr a ction An a lyses of Com p lexes 3g a n d 5a .
Crystals suitable for X-ray diffraction were mounted on a glass
fiber with epoxy resin. All measurements were performed on
a Rigaku AFC7R automated four-circle diffractometer using
graphite-monochromated Mo KR radiation (λ ) 0.71069 Å) at
-75 °C. Reflections were collected by a ω-2θ scan technique
in the range 6° < 2θ < 55° with a scan rate 16° min-1. Three
standard reflections were monitored at every 150 measure-
Su p p or tin g In for m a tion Ava ila ble: Tables of atomic
coordinates, all bond lengths and bond angles, and anisotropic
displacement parameters for complexes 3g and 5a . This
material is available free of charge via the Internet at
http://pubs.acs.org.
OM0102246