Cp*(PiPr3)RuOTf: A reagent for access to ruthenium silylene complexes

Article abstract of DOI:10.1021/om200795x

The ruthenium triflate complex Cp*(PiPr₃)RuOTf (1) was generated from the reaction of Cp*(PiPr₃)RuCl with Me ₃SiOTf in dibutyl ether. Complex 1 reacted with primary and secondary silanes to produce a family of Ru(IV) silyl dihydride complexes of the type Cp*(PiPr₃)Ru(H)₂(SiRR′OTf) (3-12). Structural analyses of complexes 8 (R = R′ = Ph) and 12 (R = R′ = fluorenyl) revealed the presence of a tetrahedral silicon center and a four-legged piano stool geometry about ruthenium. Anion abstraction from Cp*(PiPr ₃)Ru(H)₂(SiHROTf) by [Et₃Si?toluene] [B(C₆F₅)₄] afforded hydrogen-substituted cationic ruthenium silylene complexes [Cp*(PiPr₃)Ru(H) ₂(=SiHR)][B(C₆F₅)₄] (R = Mes (13), R = Si(SiMe₃) (14)) that display a significant Ru- H???Si interaction, as indicated by relatively large ²J_SiH coupling constants (²J_SiH = 58.2 Hz (13), ²J_SiH = 37.1 Hz (14)). The syntheses of secondary silylene complexes [Cp*(PiPr₃)Ru(H) ₂(=SiRR′)][B(C₆F₅)₄] (R = R′ = Ph (15); R = Ph, R′ = Me (16), R = R′ = fluorenyl (17)) were also achieved by anion abstraction with [Et₃Si?toluene] [B(C₆F₅)₄]. Complexes 15-17 do not display strong Ru-H???Si secondary interactions, as indicated by very small ²J_SiH coupling constant values.

Full text of DOI:10.1021/om200795x

ARTICLE
pubs.acs.org/Organometallics
Cp*(PiPr3)RuOTf: A Reagent for Access to Ruthenium Silylene
Complexes
Meg E. Fasulo, Paul B. Glaser,† and T. Don Tilley
Department of Chemistry, University of California, Berkeley, Berkeley, California 94720-1460, United States
S Supporting Information
b
ABSTRACT:
The ruthenium triflate complex Cp*(PiPr3)RuOTf (1) was generated from the reaction of Cp*(PiPr3)RuCl with Me3SiOTf in
dibutyl ether. Complex 1 reacted with primary and secondary silanes to produce a family of Ru(IV) silyl dihydride complexes of the
type Cp*(PiPr3)Ru(H)2(SiRR0OTf) (3ꢀ12). Structural analyses of complexes 8 (R = R0 = Ph) and 12 (R = R0 = fluorenyl) revealed
the presence of a tetrahedral silicon center and a four-legged piano stool geometry about ruthenium. Anion abstraction from
Cp*(PiPr3)Ru(H)2(SiHROTf) by [Et3Si toluene][B(C6F5)4] afforded hydrogen-substituted cationic ruthenium silylene com-
3
plexes [Cp*(PiPr3)Ru(H)2(dSiHR)][B(C6F5)4] (R = Mes (13), R = Si(SiMe3) (14)) that display a significant RuꢀH Si
3 3 3
interaction, as indicated by relatively large 2JSiH coupling constants (2JSiH = 58.2 Hz (13), 2JSiH = 37.1 Hz (14)). The syntheses of
secondary silylene complexes [Cp*(PiPr3)Ru(H)2(dSiRR0)][B(C6F5)4] (R = R0 = Ph (15); R = Ph, R0 = Me (16), R = R0 =
fluorenyl (17)) were also achieved by anion abstraction with [Et3Si toluene][B(C6F5)4]. Complexes 15ꢀ17 do not display strong
3
RuꢀH Si secondary interactions, as indicated by very small 2JSiH coupling constant values.
3 3 3
Scheme 1
’ INTRODUCTION
Transition metal complexes with silylene ligands have been an
active area of research for the last twenty years due to their
potential applications in transformations involving organosilanes,
such as hydrosilylation and silane redistribution.1 A silylene-
mediated olefin hydrosilylation mechanism that fundamentally
differs from the ChalkꢀHarrod mechanism2 has been proposed
for two systems, involving [Cp*(PiPr3)Ru(H)2(dSiHPh Et2O)]-
3
[B(C6F5)4]3 and [PNPIrH(dSiHPh)][B(C6F5)4]4 (Scheme 1).
These hydrosilylations are selective for the anti-Markovnikov pro-
duct and occur only with primary silanes. Importantly, the cationic
sp2-hybridized silicon center is required for this reactivity.5
Several reliable synthetic routes to silylene complexes have
been established, including the general reaction types of Scheme 2.6
One straightforward strategy involves the coordination of a
stable, free silylene to a transition metal fragment (Scheme 2a).7
However, the reactivity of complexes synthesized via this method
often results in displacement of the silylene ligand7b or the
generation of tetravalent silicon.7c A widely employed procedure
is based on abstraction of an anionic substituent, such as a
halogen or triflate, from the silicon atom (Scheme 2b).3,4,8
Recently, this chemistry has been extended to include abstraction
of hydride from silicon.4 Importantly, anion abstraction inher-
ently yields cationic silylene species. Another effective approach
has been termed “silylene extrustion”, which involves two sequential
Received: August 24, 2011
Published: September 22, 2011
r
2011 American Chemical Society
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Scheme 2
SiꢀH activations (e.g., Scheme 2c).9 In an example of this
process, a silane reacts with a metal alkyl complex to undergo
oxidative addition, followed by a CꢀH reductive elimination.
Finally, an α-hydride migration occurs to produce the silylene
ligand. This methodology can result in cationic9a or neutral
complexes.9f
way, removal of Me3SiCl, the volatile product of the reaction
(bp 56 °C), forced the reaction to completion. Subsequent
drying under vacuum gave 1 as a purple solid in high isolated
yield (89%).
Transition metal silylene complexes are extremely oxygen and
moisture sensitive, and a number of examples are thermally
unstable. This inherent instability has been assuaged by the use of
bulky substituents on the metal fragment and the silicon atom.10
Additionally, the use of electron-donating substituents on the
silyl ligand allowed for the first base-free examples of silylenes.11
Because the substituents at silicon play a strong role in determin-
ing stability and reactivity for a silylene complex, it is important to
establish versatile synthetic methods that allow access to a wide
range of new silylene complexes.
Herein we describe the synthesis and reactivity of
Cp*(PiPr3)RuOTf (1), a new metal complex that activates a
number of primary and secondary silanes. Several of the resulting
metal silyl species have proven to be useful precursors to new
ruthenium silylene complexes.
The 1H NMR spectrum of 1 reveals a single peak for the Cp*
methyl groups, a septet for the methine protons of the isopropyl
groups, and a doublet of doublets for the methyl protons of the
isopropyl groups, indicative of a highly symmetric molecule. The
31P{1H} NMR spectrum displays a single peak at 48.0 ppm that is
downfield from that of free PiPr3 (19.0 ppm). A single resonance
at ꢀ76.7 ppm is observed by 19F NMR spectroscopy. The
multiple NMR active nuclei of 1 make for convenient NMR
spectroscopic handles for exploring reactivity.
X-ray quality crystals were obtained as purple blocks from a
solution of 1 in (Me3Si)2O at ꢀ30 °C (Figure 1). The triflate
ligand binds to the Ru center through one oxygen atom, with a
RuꢀO bond length of 2.136(2) Å. Although complex 1 formally
possesses a 16 electron count, no additional inter- or intramo-
lecular contacts are observed between the Ru center and the
triflate ligand.
To verify that the bulky phosphine ligand would not preclude
the formation of a complex containing more ligands, complex 1
in CH2Cl2 was exposed to 1 atm of CO gas (eq 2). At room
temperature, the dark purple solution quickly faded to a dark
yellow color. The presence of a CO ligand was observed in the
infrared spectrum, as a ν(CO) stretch at 1945 cmꢀ1, indicating
that there is less back-bonding to the CO of 2 than in Cp*-
(PiPr3)RuCl(CO) (1910 cmꢀ1).12 Additionally, an X-ray struc-
ture of 2 confirms the proposed structure.13
’ RESULTS AND DISCUSSION
Synthesis, Characterization, and Reactivity of Cp*(PiPr3)-
RuOTf (1). The complex Cp*(PiPr3)RuCl has been shown to
activate phenylsilane, and the resulting product, Cp*(PiPr3)-
RuHCl(SiH2Ph), undergoes chloride abstraction to give a base-
stabilized silylene complex that exhibits unusually high anti-
Markovnikov regioselectivity as a catalyst for alkene hydrosilyla-
tions.3 Attempts to extend this methodology to additional
catalysts of the type [Cp*(PiPr3)Ru(H)2(dSiHR)]+ have pro-
ven difficult, especially given the limited reactivity of Cp*(PiPr3)-
RuCl toward more sterically demanding primary silanes. Because
the anion abstraction method to afford cationic silylene com-
plexes has been successful for both SiꢀCl and SiꢀOTf deriva-
tives, Cp*(PiPr3)RuOTf was targeted as a potential starting
material for access to new cationic silylene complexes.
Initial attempts to synthesize Cp*(PiPr3)RuOTf from the
reaction of Cp*(PiPr3)RuCl with Me3SiOTf at room tempera-
ture in diethyl ether for 24 h resulted in an inseparable mixture of
starting material and product. Slow removal of volatile materials
was somewhat successful in driving the reaction toward comple-
tion, but paramagnetic side products and inconsistent yields were
problematic. The use of a high boiling ether solvent such as Bu2O
(bp 143 °C) allowed for access to pure Cp*(PiPr3)RuOTf (1)
(eq 1). After stirring Cp*(PiPr3)RuCl with 1.1 equiv of Me3-
SiOTf (bp 140 °C) at room temperature for 1 h, the volatile
materials were slowly removed under vacuum over 6 h. In this
Complex 1 readily decomposes in the presence of many arenes
to form complexes of the type [Cp*Ru(arene)][OTf].14 These
complexes precipitate from solution as white solids and can easily
be differentiated from dark purple 1. It is therefore important to
avoid the use of arene solvents such as benzene and toluene
during manipulations of 1.
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large JSiH coupling constant of 215.4 Hz. The two hydride ligands
(ꢀ11.81 and ꢀ12.86 ppm) are diastereotopic due to the chiral Si
center and are associated with small JSiH coupling constants
(JSiH = 11.4 Hz), indicating that there is not a strong interaction
between the hydrides and the silicon center. The 29Si NMR
spectrum displays a single resonance at 62.4 ppm, in the region
typical for a silyl ligand (SiR3) bound to a transition metal.16 The
31P{1H} NMR spectrum exhibits a resonance at 78.2 ppm that is
downfield of that observed for 1 (48.0 ppm). Additionally, 19F
NMR spectroscopy confirms the presence of the triflate anion
with a peak at ꢀ76.3 ppm. The NMR data for 3ꢀ12 follow
similar trends and are tabulated in Table 1. Most noteworthy are
the small JSiH coupling constants observed for all complexes
(JSiH e 20 Hz), indicating very weak secondary interactions
between the hydrides and the silicon. The range of 29Si NMR
resonances from 44.3 ppm for 5 to 118.9 ppm for 11 is typical of
silyl ligands with a variety of substituents.
Similar complexes containing a (triflate)silyl ligand have pre-
viously been synthesized, of the type Cp*(PMe3)2MSiR2OTf
(M = Ru, Os).8b,17 For the complex M = Os and R = iPr, the
triflate anion reversibly dissocates to provide access to the
transient silylene complex, [Cp*(PMe3)2OsSi(iPr)2][OTf].
The degree of dissociation was found to depend on the polarity
of the solvent; the 29Si NMR resonance for this compound in
C6D6 (100 ppm) is at much higher field than that observed with
CD2Cl2 solvent (223 ppm). This behavior is not observed for
3ꢀ12, as NMR spectra for samples in C6D6 and CD2Cl2 are very
similar. For example, complex 9 displays a 29Si resonance at 84.1
ppm in C6D6 and at 87.4 ppm in CD2Cl2. Therefore, a transient
silylene species does not appear to significantly contribute to the
29Si NMR shifts of 3ꢀ12.
Figure 1. Molecular structure of 1 displaying thermal ellipsoids at the
50% probability level. H atoms have been omitted for clarity. Selected
bond lengths (Å): Ru(1)ꢀO(1) = 2.136(2), Ru(1)ꢀP(1) = 2.4088(9),
S(1)ꢀO(1) = 1.474(2), S(1)ꢀO(2) = 1.431(2), S(1)ꢀO(3) =
1.434(2).
Synthesis and Characterization of Cp*(PiPr3)Ru(H)2(SiRR0OTf)
Complexes. Complex 1 was found to react cleanly with 1 equiv of
H3SiPh at room temperature in ether in 30 min to give Cp*(PiPr3)-
Ru(H)2(SiHPhOTf) (3) as a light tan solid in very good yield (eq 3).
Whereas the reaction of Cp*(PiPr3)RuCl with PhSiH3 gives the
simple oxidative addition product Cp*(PiPr3)RuHCl(SiH2Ph),15 the
Ru(IV) complex 3 is the result of two SiꢀH bond cleavages and
migration of the triflate anion to the Si center.
Crystals of 8 suitable for X-ray crystallography were grown
from a pentane solution at ꢀ30 °C. Two independent molecules
per asymmetric unit are present, and all hydride ligands were
located (Figure 2). The silicon center is close to tetrahedral (sum
of angles around Si = 343.4°) and displays a bonding interaction
with the triflate anion. Additionally, the RuꢀSi distance of
2.3138(17) Å is in the range expected for RuꢀSi single bonds.16
The RuꢀH Si distances are all greater than 2 Å, indicating
3 3 3
that full oxidative addition has occurred. However, the hydride
ligands are somewhat canted toward the silyl ligands and away
from the phosphine, as indicated by the average PꢀRuꢀH angle
of 77.7°, which is greater than the average SiꢀRuꢀH angle of
63.7°. The short SiꢀO(1) bond length (1.815(3) Å) further
suggests that this complex possesses little silylene character. The
solid-state structure of 12 varies little from that of 8 (Figure 3).
Additionally, the solid-state structures of 8 and 12 are remarkably
similar to that of Cp*(PiPr3)Ru(H)2(SiHMesCl), indicating that
the anionic substituent (Clꢀ or OTfꢀ) on silicon does not
significantly influence the solid-state molecular geometry.18
Synthesis and Characterization of Ruthenium Silylene
Complexes [Cp*(PiPr3)Ru(H)2(dSiRR0)][B(C6F5)4]. A number
of cationic silylene complexes have been synthesized via an anion
or hydride abstraction, and the triflate complexes 3ꢀ12 seemed
potentially suitable for this purpose. Initial attempts to replace
the triflate anion with a more weakly coordinating counterion
focused on use of the Li(Et2O)2[B(C6F5)4] salt. Addition of
1 equiv of Li(Et2O)2[B(C6F5)4] to 8 in C6D5Br produced a bright
orange solution, and 1H NMR spectroscopy revealed quantitative
conversion to a new species. However, the 29Si resonance at 127.8
ppm indicated the likely formation of a base-stabilized silylene
Filtration of the reaction solution through a Celite plug and
removal of solvent in vacuo resulted in analytically pure 3. In an
analogous manner, reactions of 1 with H3SiMes, H3Si(C6F5),
H3SiSiPh3, H3SiSi(SiMe3)3, H2SiPh2, H2SiPhMe, H2SiEt2,
H2SiiPr2, and 9-silafluorene gave complexes 4ꢀ12, respectively.
A number of these organosilanes do not react cleanly with
Cp*(PiPr3)RuCl to afford similar complexes, and thus 1 allows
for the synthesis of a number of silylene precursor complexes that
were not previously accessible.
Due to the multiple NMR-active nuclei present in 3ꢀ12, a
large amount of structural information can be obtained for these
complexes to support the structures proposed in eq 3. For
1
example, the H NMR spectrum for 4 reveals an SiꢀH group
that gives rise to a resonance at 7.02 ppm, with a characteristically
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Table 1. NMR Data for Complexes 3ꢀ12
complex
δ 1H (SiH) (2JSiH
)
δ 1H (RuH) (2JSiH
)
δ
29Si (RuSi)
Cp*(PiPr3)RuH2(SiHPhOTf) (3)
Cp*(PiPr3)RuH2(SiHMesOTf) (4)
Cp*(PiPr3)RuH2(SiH(C6F5)OTf) (5)
Cp*(PiPr3)RuH2(SiH(SiPh3)OTf) (6)
Cp*(PiPr3)RuH2(SiH(Si(SiMe3)3OTf) (7)
Cp*(PiPr3)RuH2(SiPh2OTf) (8)
Cp*(PiPr3)RuH2(SiPhMeOTf) (9)
Cp*(PiPr3)RuH2(SiEt2OTf) (10)
Cp*(PiPr3)RuH2(Si(iPr)2OTf) (11)
Cp*(PiPr3)RuH2(SiFluOTf) (12)
6.76 (211.5)
7.02 (215.4)
6.75 (227.9)
6.86 (188.6)
6.97 (192.5)
ꢀ11.51, ꢀ12.49 (18.8)
ꢀ11.81, ꢀ12.86 (10.4)
ꢀ11.57, ꢀ12.26 (<7)
ꢀ10.96, ꢀ12.09 (21.8)
ꢀ10.98, ꢀ13.01 (11.4)
ꢀ11.56 (12.3)
65.1
62.4
44.3
63.3
69.3
83.4
84.1
106.5
118.9
77.9
ꢀ11.66, ꢀ13.52 (9.8)
ꢀ12.14 (12.5)
ꢀ11.82 (12.3)
ꢀ11.17 (12.2)
downfield relative to that of the silyl complex 4 (7.02 ppm) and in
a region typical for H-substituted silylene complexes.4,9b,9c,10 The
two hydride ligands of 13 (ꢀ11.47 ppm) are equivalent and
exhibit a strong coupling to the silicon atom (2JSiH = 58.2 Hz).
The downfield 29Si NMR resonance at 228.9 ppm is character-
istic of a silylene ligand. The 19F NMR spectrum reveals three
resonances at ꢀ132.2, ꢀ162.7, and ꢀ166.5 ppm that are char-
acteristic of the [B(C6F5)4]ꢀ counterion, and a peak associated
with triflate (ꢀ76.0 ppm for 4) is absent.
Complex 13 displays very limited solubility in noncoordinat-
ing solvents, which necessitated the use of polar solvents. To
reduce the possibility of reaction with the solvent, C6H5F and
C6D5Br were used exclusively for synthesis and characterization.
In solution, 13 decomposes within 24 h to multiple unidentified
species, and the characteristic bright orange color fades to pale
brown. However, as a solid, 13 can be stored at ꢀ30 °C for one to
two weeks without decomposition.
Several previously reported silylene complexes have been
found to have observable secondary interactions between
MꢀH and the silylene ligand, as indicated by a JSiH greater than
20 Hz.9b,c,20 For example, the family of neutral silylene com-
plexes Cp*(dmpe)Mo(H)(dSiRR0) exhibit JSiH values of 30ꢀ
Figure 2. Molecular structure of 8 displaying thermal ellipsoids at the
50% probability level. One molecule and selected H atoms have been
omitted for clarity. Selected bond lengths (Å): Ru(1)ꢀSi(1) =
2.3138(17), Ru(1)ꢀP(1) = 2.3338(14), Ru(1)ꢀH(1) = 1.41(4), Ru-
(1)ꢀH(2) = 1.51(5), Si(1)ꢀO(1) = 1.815(3).
48 Hz, and an H Si interaction is confirmed by a neutron
3 3 3
structure.9b The degree of H Si interaction for the cationic
3 3 3
complex, with diethyl ether acting as the base. Subsequent exposure
to vacuum was not successful in removing the ether.
silylyne hydride complex [Cp*(dmpe)(H)MotSiMes][B(C6F5)4]
is somewhat ambiguous on the basis of NMR data (JSiH = 15 Hz)
and X-ray crystallography, but appears to be rather weak.20
Another group 6 neutral silylene complex synthesized by Tobita
and co-workers, [Cp*(CO)2(H)WdSi(H){C(SiMe3)3}], also
has a high JSiH of 28.6 Hz.9c Interestingly, the analogous
ruthenium complex [Cp*(CO)(H)RudSi(H){C(SiMe3)3}] does
not display such an interaction.10 The JSiH value for 13 is signi-
ficantly higher than that observed for other complexes, indicative
To avoid the introduction of coordinating solvents during the
synthesis of silylene complexes, an ether-free [B(C6F5)4]ꢀ reagent
capable of removing triflate was required. Thus, the ability of
[Et3Si toluene][B(C6F5)4]19 to afford the desired solvate-free
3
silylenes was explored with 3ꢀ12. The compound [Et3Si toluene]-
3
[B(C6F5)4] is an interesting reagent because it can act as either
an anion abstraction reagent (with loss of Et3SiX) or a hydride
abstraction reagent (with loss of Et3SiH). Both anion and hydride
abstraction have proven to be effective strategies for generation of
silylene complexes.6
of a stronger H
Si interaction. This type of interaction
3 3 3
was predicted on the basis of theoretical calculations by
Beddie and Hall with a simplified system, [Cp(PH3)RuH2-
(dSiH2)]+, but is not observable for the previously synthe-
sized, ether-stabilized silylene complex [Cp*(PiPr3)Ru(H)2-
The reactivity of [Et3Si toluene][B(C6F5)4] was first examined
3
with 4, which possesses an SiꢀH and an SiꢀOTf group that could
(dSiHPh Et2O)][B(C6F5)4].3,6b
potentially be susceptible to abstraction. A solution of 1 equiv of
3
[Et3Si toluene][B(C6F5)4] in C6H5F was added to a solution of
Anion abstraction was utilized for synthesis of the disubstitut-
3
4 in C6H5F, resulting in an immediate color change from pale
yellow to bright orange (eq 4). Complex 13, [Cp*(PiPr3)Ru(H)2-
(dSiHMes)][B(C6F5)4], was isolated as an orange solid.
ed silylene complex [Cp*(PiPr3)Ru(H)2(dSiPh2)][B(C6F5)4]
(15). Complex 8 was treated with 1 equiv of [Et3Si toluene]-
3
[B(C6F5)4] in C6H5F, and the product (15) precipitated from
1
Multinuclear NMR spectroscopy confirms the identity of 13 as
pentane at ꢀ30 °C as a bright yellow solid. The H NMR
1
a hydrogen-substituted ruthenium silylene complex. H NMR
spectrum for 15 differs very little from that of 8. Most notably, the
resonance for the hydride ligands of 15 is further downfield
spectroscopy reveals an SiꢀH resonance at 7.99 ppm, shifted
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1
at ꢀ9.11 ppm (relative to ꢀ11.56 ppm for 8). The presence of the
silylene ligand was confirmed with 29Si NMR spectroscopy by a
resonance at 339.0 ppm. No silicon satellites were detected for the
ruthenium hydride resonance via a 29Si-filtered 1H NMR experiment
optimized for a variety of JSiH values, suggesting the absence of a
significant interaction between the hydride ligand and the silicon
and several unidentified Cp*-containing species (by H, 31P,
and 29Si NMR spectroscopy). All attempts to isolate or observe
[Cp*(PiPr3)Ru(H)2(dSiHPh)][B(C6F5)4] resulted only in
observation of 15. The transformation of Cp*(PiPr3)RuH2-
SiHPhOTf to [Cp*(PiPr3)RuH2(dSiPh2)]+ upon reaction with
[Et3Si][B(C6F5)4] would appear to involve a silylene-mediated
redistribution at silicon. This might occur via a bimolecular
exchange of groups between silyl and silylene complexes of
2
center. As determined by structural investigations of Cp*-
(dmpe)MoH(dERR0) (E = Si, Ge) complexes, such H Si
3 3 3
interactions can be quite sensitive to steric influences, and in particular
by rotation about the MꢀSi bond.21 The [B(C6F5)4]ꢀ anion displays
three characteristic resonances in the 19F NMR spectrum (ꢀ132.6,
ꢀ163.1, and ꢀ166.8 ppm), and full conversion from the triflate was
further supported by the absence of the downfield triflate peak (at
ꢀ75.7 ppm for 8). Complexes 14, 16, and 17 display similar
spectroscopic properties, which are tabulated in Table 2.
Reactions to access silylene complexes were also attempted
with 3, 5, 6, 10, and 11. For example, 1 equiv of Li(Et2O)2-
[B(C6F5)4] was added to 5 in C6D5Br at room temperature to
give an orange solution. Immediate characterization by multinuclear
NMR spectroscopy revealed multiple hydride-containing species and
ruthenium, as has been previously characterized for the related
Cp*(PMe3)Ru fragment.22
several silicon species. Analogous attempts with [Et3Si toluene]-
3
[B(C6F5)4] resulted in similar mixtures of products. Attempted
purification of the reaction mixtures by crystallization yielded
impure oils. Interestingly, the reaction of 3 with 1 equiv of
[Et3Si][B(C6F5)4] yielded the diphenyl silylene 15 (45% yield)
’ CONCLUSION
Cp*(PiPr3)RuOTf (1) represents a new electrophilic ruthe-
nium complex that readily activates primary and secondary
organosilanes. More generally, it should prove to be a useful
starting material for investigations of bond activations at ruthe-
nium. As compared to the similar complex Cp*(PiPr3)RuCl,
1 tolerates silanes with a significantly wider variety of substi-
tution patterns to give silyl triflate complexes. The reagent
[Et3Si][B(C6F5)4] selectively acts as a triflate abstraction reagent
even in the presence of SiꢀH bonds to yield new ruthenium
silylene complexes. The complex [Cp*(PiPr3)Ru(H)2(dSiHMes)]+
(13) displays significant interactions between the ruthenium
hydride ligands and the silicon center by NMR spectroscopy. Signi-
ficantly, related interactions were previously predicted by Hall and co-
workers but had not been experimentally observed.5b Interestingly,
secondary silylenes such as complex [Cp*(PiPr3)Ru(H)2(dSiPh2)]+
(22) do not appear to have such significant RuꢀH Si inter-
3 3 3
actions, but this is probably the result of unfavorable HꢀRuꢀ
SiꢀC torsion angles. Stoichiometric and catalytic reactivity
studies of silylene complexes 13ꢀ17 are currently underway,
as well as further EꢀH bond activiation studies with 1.
’ EXPERIMENTAL SECTION
General Considerations. All experiments were carried out under
a nitrogen atmosphere using standard Schlenk techniques or an inert
atmosphere (N2) glovebox. Olefin impurities were removed from
pentane by treatment with concentrated H2SO4, 0.5 N KMnO4 in
3 M H2SO4, and then NaHCO3. Pentane was then dried over MgSO4,
stored over activated 4 Å molecular sieves, and dried over alumina.
Figure 3. Molecular structure of 12 displaying thermal ellipsoids at the
50% probability level. Selected H atoms have been omitted for clarity.
Selected bond lengths (Å): Ru(1)ꢀSi(1) = 2.2986(9), Ru(1)ꢀP(1) =
2.3369(8), Ru(1)ꢀH(1) = 1.56(3), Ru(1)ꢀH(2) = 1.54(3), Si(1)ꢀO-
(1) = 1.8108(16).
Table 2. NMR Data for Complexes 13ꢀ17
complex
δ 1H (SiH) (2JSiH
)
δ 1H (RuH) (2JSiH
)
δ
29Si (RuSi)
[Cp*(PiPr3)RuH2(dSiHMes)][B(C6F)4] (13)
Cp*(PiPr3)RuH2(dSiH(Si(SiMe3)3)][B(C6F)4] (14)
[Cp*(PiPr3)RuH2(dSiPh2)][B(C6F)4] (15)
[Cp*(PiPr3)RuH2(dSiPhMe)][B(C6F)4] (16)
[Cp*(PiPr3)RuH2(dSiFlu)][B(C6F)4] (17)
7.99 (226.5)
7.42 (214.9)
ꢀ11.46 (58.2)
ꢀ7.08 (37.1)
ꢀ9.11 (not observed)
ꢀ9.88 (not observed)
ꢀ8.69 (not observed)
228.9
241.0
339.0
275.9
328.8
5528
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Organometallics
ARTICLE
Thiophene impurities were removed from benzene and toluene by
treatment with H2SO4 and saturated NaHCO3. Benzene and toluene
were then dried over CaCl2 and further dried over alumina. Tetrahy-
drofuran, diethyl ether, dichloromethane, and hexanes were dried over
alumina. Fluorobenzene was dried over P2O5, degassed, and distilled
under N2. Methylene chloride-d2 was dried by vacuum distillation from
CaH2. Benzene-d6 was dried by vacuum distillation from Na/K alloy.
Bromobenzene-d5 was refluxed over CaH2 for 20 h and then distilled
under nitrogen. Cp*(PiPr3)RuCl15 and [Et3Si][B(C6F5)4]18 were pre-
pared according to literature methods. All other chemicals were pur-
chased from commercial sources and used without further purification.
NMR spectra were recorded using Bruker AVB 400, AV-500, or AV-
600 spectrometers equipped with a 5 mm BB probe. Spectra were
recorded at room temperature and referenced to the residual protonated
solvent for 1H. 31P{1H} NMR spectra were referenced relative to 85%
H3PO4 external standard (δ = 0). 19F{1H} spectra were referenced
relative to a C6F6 external standard. 13C{1H} NMR spectra were
calibrated internally with the resonance for the solvent relative to
tetramethylsilane. For 13C{1H} NMR spectra, resonances obscured by
the solvent signal are omitted. 29Si NMR spectra were referenced relative
(ArC), 128.6 (ArC), 127.9 (ArC), 95.9 (C5Me5), 26.7 (CH(CH3)2, d,
1JPC = 26.8 Hz), 19.0 (CH(CH3)2), 18.8 (CH(CH3)2), 10.8 (C5Me5).
31P{1H} NMR (C6D6, 163.0 MHz): δ 79.4. 29Si NMR (C6D6, 99.4 MHz):
δ 65.1. 19F{1H} NMR (C6D6, 376.5 MHz): δ ꢀ78.0. Anal. Calcd for
C24H44F3O3PRuSSi: C, 47.76; H, 6.78. Found: C, 48.08; H, 7.00.
Cp*(PiPr3)Ru(H)2(SiHMesOTf) (4). By a procedure analogous
to that for 3, complex 4 was obtained as a light tan solid in 90% yield
(0.115 g). 1H NMR (C6D6, 600MHz):δ 7.02 (1H, m, JH = 7.2Hz, 1JSiH
=
215.4 Hz, SiH), 6.70 (2H, s, ArH), 2.67 (6H, s, ArCH3), 2.11 (3H, s,
ArCH3), 1.72 (15H, s, C5Me5), 1.59 (3H, septet, J = 7.2 Hz, CH-
(CH3)2), 0.90 (9H, dd, J = 7.1 Hz, JPH = 13.5 Hz, CH(CH3)2), 0.68 (9H,
dd, J = 7.1 Hz, JPH = 13.0 Hz, CH(CH3)2), ꢀ11.81 (1H, d, 2JPH = 26.1 Hz,
2JSiH = 10.4 Hz, JH = 7.2 Hz, RuH), ꢀ12.86 (1H, d, 2JPH = 24.9 Hz, 2JSiH
= 10.4 Hz, JH = 7.2 Hz, RuH). 13C{1H} NMR (C6D6, 150.9 MHz): δ
143.1 (ArC), 138.5 (ArC), 136.4 (ArC), 129.1 (ArC), 96.5 (C5Me5),
27.3 (CH(CH3)2, d, 1JPC = 25.7 Hz), 22.8 (ArMe), 21.1 (ArMe), 19.9
(CH(CH3)2), 18.6 (CH(CH3)2), 11.2 (C5Me5). 31P{1H} NMR (C6D6,
163.0 MHz): δ 78.2. 29Si NMR (C6D6, 99.4 MHz): δ 62.4. 19F{1H}
NMR (C6D6, 376.5 MHz): δ ꢀ76.3. Anal. Calcd for C29H50F3O3PRuS-
Si: C, 50.05; H, 7.24. Found: C, 50.38; H, 7.51.
1
to a tetramethylsilane standard and obtained via 2D H 29Si HMBC
Cp*(PiPr3)Ru(H)2(SiH(C6F5)OTf) (5). By a procedure analogous
to that for 3, complex 5 was obtained as a light orange solid in 22% yield
(0.030 g). 1H NMR (C6D6, 600 MHz): δ 6.75 (1H, s, 1JSiH = 227.9 Hz,
SiH), 1.79 (3H, septet, J = 7.4 Hz, CH(CH3)2), 1.55 (15H, s, C5Me5),
unless specified otherwise. The following abbreviations have been used
to describe peak multiplicities in the reported NMR spectroscopic data:
“m” for complex multiplet and “br” for broadened resonances. Elemental
analyses were performed by the College of Chemistry Microanalytical
Laboratory at the University of California, Berkeley.
Cp*(PiPr3)RuOTf (1). To a stirred solution of Cp*(PiPr3)RuCl
(3.12 g, 7.24 mmol) in Bu2O was added Me3SiOTf (1.44 mL, 7.96 mmol)
dropwise over a period of 5 min. The purple solution was allowed to stir
for 4 h and then placed under vacuum for 12 h. After the reaction mixture
was stripped to dryness, the purple solid was collected to give 1 in 89%
yield (3.50 g). 1H NMR (CD2Cl2, 600 MHz): δ 1.92 (3H, septet, J =
6.9 Hz, CH(CH3)2), 1.35 (15H, s, C5Me5), 0.95 (18H, dd, J = 6.9 Hz,
JPH = 13.1 Hz, CH(CH3)2). 13C{1H} NMR (CD2Cl2, 150.9 MHz): δ
75.2 (C5Me5), 25.3 (CH(CH3)2, d, 1JPC = 19.8 Hz), 19.5 (CH(CH3)2),
12.8 (C5Me5). 31P{1H} NMR (CD2Cl2, 163.0 MHz): δ 48.0. 19F{1H}
NMR (CD2Cl2, 376.5 MHz): δ ꢀ76.7. Anal. Calcd for C20H36F3O3-
PRuS: C, 44.03; H, 6.65. Found: C, 44.12; H, 6.76.
2
2
0.92 (18H, m, CH(CH3)2), ꢀ11.57 (1H, d, JPH = 25.1 Hz, JSiH
=
<7 Hz, RuH), ꢀ12.26 (1H, d, 2JPH = 28.2 Hz, 2JSiH = <7, RuH). 13C{1H}
NMR (C6D6, 150.9 MHz): δ 137.9 (ArC), 136.2 (ArC), 120.3 (ArC),
118.2 (ArC), 96.8 (C5Me5), 26.3 (CH(CH3)2, d, 1JPC = 26.0 Hz), 18.8
(CH(CH3)2), 18.7 (CH(CH3)2), 10.5 (C5Me5). 31P{1H} NMR (C6D6,
163.0 MHz): δ 77.0. 29Si NMR (C6D6, 99.4 MHz): δ 44.3. 19F{1H} NMR
(C6D6, 376.5 MHz): δ ꢀ78.3, ꢀ129.9, ꢀ154.0, ꢀ163.0. Anal. Calcd for
C26H39F8O3PRuSSi: C, 41.99; H, 5.29. Found: C, 42.36; H, 5.66.
Cp*(PiPr3)Ru(H)2(SiH(SiPh3)OTf) (6). By a procedure analogous
to that for 3, complex 6 was obtained as a light orange solid in 40% yield
(0.061 g). 1H NMR (C6D6, 600 MHz): δ 7.97 (6H, d, J = 6.9 Hz, PhH),
7.26 (6H, t, J = 6.9 Hz, PhH), 7.20 (3H, t, J = 6.9 Hz, PhH), 6.86 (1H, br
s, 1JSiH = 188.6 Hz, SiH), 1.85 (3H, septet, J = 7.9 Hz, CH(CH3)2), 1.67
(15H, s, C5Me5), 0.97 (9H, dd, J = 7.9 Hz, JPH = 13.9 Hz, CH(CH3)2),
0.74 (9H, dd, J = 7.9 Hz, JPH = 13.4 Hz, CH(CH3)2), ꢀ10.96 (1H, d,
2JPH = 27.6 Hz, 2JSiH = 21.8 Hz, RuH), ꢀ12.09 (1H, d, 2JPH = 27.6 Hz,
2JSiH = 21.8 Hz, RuH). 13C{1H} NMR (C6D6, 150.9 MHz): 137.0
(ArC), 135.9 (ArC), 129.7 (ArC), 129.2 (ArC), 97.0 (C5Me5), 26.6
(CH(CH3)2, d, 1JPC = 24.8 Hz), 19.0 (CH(CH3)2), 18.8 (CH(CH3)2),
11.3 (C5Me5). 31P{1H} NMR (C6D6, 163.0 MHz): δ 77.8. 29Si NMR
(C6D6, 99.4 MHz): δ 63.3, ꢀ24.9. 19F{1H} NMR (C6D6, 376.5 MHz):
Cp*(PiPr3)Ru(CO)OTf (2). A 1:1 pentane/ether solution of 1
(0.42 g, 0.77 mmol) was degassed and cooled to 0 °C. The solution
was exposed to 1 atm of CO and stirred for 1 h to give an orange-yellow
solution. The reaction mixture was filtered through Celite and then
cooled to ꢀ30 °C to give 2 as orange crystals in 51% yield (0.23 g).
1H NMR (CD2Cl2, 600 MHz): δ 2.78 (3H, septet, J = 7.3 Hz,
CH(CH3)2), 2.04 (15H, s, C5Me5), 1.47 (18H, dd, J = 7.3 Hz, JPH
=
17.6 Hz, CH(CH3)2). 13C{1H} NMR (CD2Cl2, 150.9 MHz): 208.5
(CO, d, JPC = 20.1 Hz), 94.9 (C5Me5), 25.6 (CH(CH3)2, d, 1JPC = 22.6 Hz),
19.6 (CH(CH3)2), 10.2 (C5Me5). 31P{1H} NMR (CD2Cl2, 163.0 MHz):
δ 57.3. 19F{1H} NMR (CD2Cl2, 376.5 MHz): δ ꢀ75.9. IR (cmꢀ1):
ν(CO) 1945. Anal. Calcd for C21H36F3O4PRuS: C, 43.97; H, 6.33. Found:
C, 43.96; H, 6.20.
δ ꢀ78.0. Anal. Calcd for C38H54F3O3PRuSSi2 1/2(C6H5F): C, 55.70;
3
H, 6.44. Found: C, 55.64; H, 6.50.
Cp*(PiPr3)Ru(H)2(SiH(Si(SiMe3)3)OTf) (7). By a procedure ana-
logous to that for 3, complex 7 was obtained as a light pink solid in 22%
yield (0.030 g). 1HNMR(C6D6, 600 MHz): δ6.97 (1H, s, 1JSiH = 192.5 Hz,
SiH), 1.89 (3H, septet, J = 7.3 Hz, CH(CH3)2), 1.81 (15H, s, C5Me5),
1.03 (9H, dd, J = 7.3 Hz, JPH = 13.6 Hz, CH(CH3)2), 0.96 (9H, dd, J =
7.3 Hz, JPH = 13.7 Hz, CH(CH3)2), 0.49 (27H, s, SiMe3), ꢀ10.98 (1H,
d, 2JPH = 28.5 Hz, 2JSiH = 11.4 Hz, RuH), ꢀ13.01 (1H, d, 2JPH = 26.5 Hz,
2JSiH = 11.4, RuH). 13C{1H} NMR (C6D6, 150.9 MHz): δ 96.3
Cp*(PiPr3)Ru(H)2(SiHPhOTf) (3). A solution of PhSiH3 (0.020 g,
0.18 mmol) in 1 mL of diethyl ether was added to a solution of
Cp*(PiPr3)RuOTf (0.10 g, 0.18 mmol) in 2 mL of diethyl ether. The
reaction solution was stirred for 20 min before being filtered through a
Celite plug. The resulting solution was stripped to dryness to give a light
yellow solid (0.095 g, 79% yield). 1H NMR (C6D6, 600 MHz): δ 8.07
(2H, d, J = 7.5 Hz, PhH), 7.33 (2H, t, J = 7.5 Hz, PhH), 7.19 (1H, t, J =
7.5 Hz, PhH), 6.76 (1H, t, JH = 4.7 Hz, 1JSiH = 211.5 Hz, SiH), 1.84 (3H,
septet, J = 7.4 Hz, CH(CH3)2), 1.57 (15H, s, C5Me5), 1.01 (9H, dd, J =
1
(C5Me5), 26.7 (CH(CH3)2, d, JPC = 22.5 Hz), 19.5 (CH(CH3)2),
19.0 (CH(CH3)2), 11.5 (C5Me5), 3.3 (SiMe3). 31P{1H} NMR (C6D6,
163.0 MHz): δ 77.8. 29Si NMR (C6D6, 99.4 MHz): δ 69.3, ꢀ9.2,
ꢀ118.4. 19F{1H} NMR (C6D6, 376.5 MHz): δ ꢀ77.3. Anal. Calcd for
C29H66F3O3PRuSSi5: C, 42.25; H, 8.07. Found: C, 42.54; H, 7.88.
Cp*(PiPr3)Ru(H)2(SiPh2OTf) (8). By a procedure analogous to
that for 3, complex 8 was obtained as a light brown solid in 59% yield
(0.079 g). 1H NMR (C6D6, 600 MHz): δ 8.15 (4H, d, J = 7.2 Hz, PhH),
7.26 (4H, t, J = 7.2 Hz, PhH), 7.14 (2H, t, J = 7.2 Hz, PhH), 1.57 (18H, s,
7.4 Hz, JPH = 13.4 Hz, CH(CH3)2), 0.94 (9H, dd, J = 7.4 Hz, JPH
=
13.5 Hz, CH(CH3)2), ꢀ11.51 (1H, d, 2JPH = 27.3 Hz, 2JSiH = 18.8 Hz,
JH = 4.7 Hz, RuH), ꢀ12.49 (1H, d, 2JPH = 26.6 Hz, 2JSiH = 18.8 Hz, JH =
4.7 Hz, RuH). 13C{1H} NMR (C6D6, 150.9 MHz): δ 141.1 (ArC), 133.4
5529
dx.doi.org/10.1021/om200795x |Organometallics 2011, 30, 5524–5531

Organometallics
ARTICLE
C5Me5 + CH(CH3)2), 0.94 (18H, dd, J = 7.2 Hz, JPH = 13.4 Hz,
the ꢀ30 °C freezer. After 1 h, an orange oil settled to the bottom of the
vial. The solution was carefully decanted, and the resulting orange oil was
dried under vacuum for 1 h to afford 13 as an orange solid in 53% yield
2
1
CH(CH3)2), ꢀ11.56 (2H, d, JPH = 26.5 Hz, JSiH = 12.3 Hz, RuH).
13C{1H} NMR (C6D6, 150.9 MHz): δ 142.8 (PhC), 135.3 (PhC), 128.7
(PhC), 127.0 (PhC), 99.2 (C5Me5), 27.1 (CH(CH3)2, d, 1JPC = 22.6 Hz),
19.2 (CH(CH3)2), 10.7 (C5Me5). 31P{1H} NMR (C6D6, 163.0 MHz):
δ 77.5. 29Si NMR (C6D6, 99.4 MHz): δ 83.4. 19F{1H} NMR (C6D6,
376.5 MHz): δ ꢀ75.7. Anal. Calcd for C32H48F3O3PRuSSi: C, 52.66; H,
6.63. Found: C, 52.45; H, 6.40.
1
1
(0.048 g). H NMR (C6D5Br, 600 MHz): δ 7.99 (1H, br s, JSiH
=
226.5 Hz, SiH), 6.93 (2H, s, ArH), 2.42 (6H, s, ArCH3), 2.38 (3H, s,
ArCH3), 2.06 (3H, septet, J = 7.1 Hz, CH(CH3)2), 1.58 (15H, s,
C5Me5), 1.09 (18H, dd, J = 7.1 Hz, JPH = 13.8 Hz, CH(CH3)2), ꢀ11.47
(2H, d, 2JPH = 14.1 Hz, 2JSiH = 58.2 Hz, RuH). 13C{1H} NMR (C6D5Br,
150.9 MHz): δ 149.6 (B(C6F)4), 148.2 (B(C6F)4), 142.9 (ArC), 140.0
(ArC), 137.7 (B(C6F)4), 135.9 (B(C6F)4), 129.0 (ArC), 97.4 (C5Me5),
26.1 (CH(CH3)2, d, 1JPC = 19.6 Hz), 21.9 (ArMe), 21.5 (ArMe), 19.1
(CH(CH3)2), 10.6 (C5Me5). 31P{1H} NMR (C6D5Br, 163.0 MHz): δ
66.2. 29Si NMR (C6D5Br, 99.4 MHz): δ 228.9. 19F{1H} NMR (C6D5Br,
376.5 MHz): δ ꢀ132.2, ꢀ162.7, ꢀ166.5. Anal. Calcd for C52H50BF20PRu-
Si: C, 50.95; H, 4.11. Found: C, 50.66; H, 4.50.
[Cp*(PiPr3)Ru(H)2(dSiH(Si(SiMe3)3)][B(C6F)4] (14). By a pro-
cedure analogous to that for 13, complex 14 was obtained as a bright red
solid in 63% yield (0.031 g). 1H NMR (C6D6, 600 MHz): δ 7.42 (1H, s,
1JSiH = 214.9 Hz, SiH), 1.88 (15H, s, C5Me5), 1.64 (3H, m, CH(CH3)2),
1.12 (18H, dd, J = 7.2 Hz, JPH = 14.8 Hz, CH(CH3)2), 0.47 (27H, s,
SiMe3), ꢀ7.08 (2H, d, 2JPH = 24.9 Hz, 2JSiH = 37.1 Hz, RuH). 13C{1H}
NMR (C6D6, 150.9 MHz): δ 149.6 (B(C6F)4), 148.0 (B(C6F)4), 137.6
(B(C6F)4), 136.0 (B(C6F)4), 97.8 (C5Me5), 30.4 (CH(CH3)2), 19.7
(CH(CH3)2), 19.0 (CH(CH3)2), 11.6 (C5Me5), 3.1 (SiMe3), 2.3
(SiMe3). 31P{1H} NMR (C6D6, 163.0 MHz): δ 83.8. 29Si NMR
(C6D6, 99.4 MHz): δ 241.0, ꢀ7.1, ꢀ46.4. 19F{1H} NMR (C6D6,
376.5 MHz): δ ꢀ132.2, ꢀ162.5, ꢀ166.4. Anal. Calcd for C29H66BF20PRu-
Si5: C, 46.12; H, 4.91. Found: C, 46.45; H, 4.54.
Cp*(PiPr3)Ru(H)2(SiPhMeOTf) (9). By a procedure analogous to
that for 3, complex 9 was obtained as a light peach solid in 81% yield
(0.099 g). 1H NMR (C6D6, 600 MHz): δ 8.03 (2H, d, J = 7.3 Hz, PhH),
7.35 (2H, t, J = 7.3 Hz, PhH), 7.21 (1H, t, J = 7.3 Hz, PhH), 1.81 (3H,
septet, J = 7.4 Hz, CH(CH3)2), 1.54 (15H, s, C5Me5), 1.02 (18H, m,
CH(CH3)2), 0.89 (3H, s, CH3), ꢀ11.66 (1H, d, 2JPH = 26.8 Hz, 1JSiH
=
2
1
9.8 Hz, RuH), ꢀ13.52 (1H, d, JPH = 26.4 Hz, JSiH = 9.8 Hz, RuH).
13C{1H} NMR (C6D6, 150.9 MHz): δ 145.1 (PhC), 132.8 (PhC), 128.0
1
(PhC), 127.0 (PhC), 95.9 (C5Me5), 27.8 (CH(CH3)2, d, JPC = 26.9
Hz), 19.4 (CH(CH3)2), 18.7 (CH(CH3)2), 13.7 (SiMe), 10.5 (C5Me5).
31P{1H} NMR (C6D6, 163.0 MHz): δ 79.8. 29Si NMR (C6D6, 99.4
MHz): δ 84.1. 19F{1H} NMR (C6D6, 376.5 MHz): δ ꢀ76.4. Anal.
Calcd for C27H46F3O3PRuSSi: C, 48.56; H, 6.94. Found: C, 48.94;
H, 7.04.
Cp*(PiPr3)Ru(H)2(SiEt2OTf) (10). By a procedure analogous to
that for 3, complex 10 was obtained as a light pink-brown solid in 56%
yield (0.065 g). 1H NMR (C6D6, 600 MHz): δ 1.81 (3H, septet, J = 7.2
Hz, CH(CH3)2), 1.61 (15H, s, C5Me5), 1.34 (6H, m, CH2CH3), 1.13
(4H, m, CH2CH3), 1.00 (18H, dd, J = 7.2 Hz, JPH = 13.1 Hz,
PCH(CH3)2), ꢀ12.14 (2H, d, 2JPH = 26.8 Hz, 1JSiH = 12.5 Hz, RuH).
13C{1H} NMR (C6D6, 150.9 MHz): δ 95.4 (C5Me5), 27.6 (CH(CH3)2,
d, 1JPC = 23.3 Hz), 19.1 (CH(CH3)2), 16.4 (CH2CH3), 10.7 (C5Me5),
8.3 (CH2CH3). 31P{1H} NMR (C6D6, 163.0 MHz): δ 79.3. 29Si NMR
(C6D6, 99.4 MHz): δ 106.5. 19F{1H} NMR (C6D6, 376.5 MHz): δ
ꢀ76.6. Anal. Calcd for C24H48F3O3PRuSSi: C, 45.48; H, 7.63. Found:
C, 45.63; H, 7.70.
[Cp*(PiPr3)Ru(H)2(dSiPh2)][B(C6F)4] (15). By a procedure
analogous to that for 13, complex 15 was obtained as a bright yellow
solid in 57% yield (0.048 g). 1H NMR (C6D5Br, 600 MHz): δ 7.88 (4H,
d, J = 7.3 Hz, PhH), 7.63 (2H, t, J = 7.3 Hz, PhH), 7.58 (4H, t, J = 7.3 Hz,
PhH), 1.77 (15H, s, C5Me5), 1.69 (3H, septet, J = 7.0 Hz, CH(CH3)2),
0.98 (18H, dd, J = 7.0 Hz, JPH = 14.5 Hz, CH(CH3)2), ꢀ9.11 (2H, d,
2JPH = 25.5 Hz, RuH). 13C{1H} NMR (C6D5Br, 150.9 MHz): δ 149.3
(B(C6F)4), 147.7 (B(C6F)4), 141.8 (ArC), 139.1 (ArC), 137.4 (B(C6F)4),
135.9 (ArC), 135.6 (B(C6F)4), 133.6 (ArC), 199.1 (C5Me5), 27.4
Cp*(PiPr3)Ru(H)2(SiiPr2OTf) (11). By a procedure analogous to
that for 3, complex 11 was obtained as a light pink solid in 53% yield
(0.064 g). 1H NMR (C6D6, 600 MHz): δ 1.87 (3H, septet, J = 7.1 Hz,
PCH(CH3)2), 1.70 (2H, septet, J = 7.4 Hz, SiCH(CH3)2), 1.58 (15H, s,
C5Me5), 1.54 (6H, d, J = 7.4 Hz, SiCH(CH3)2), 1.40 (6H, dd, J = 7.4 Hz,
SiCH(CH3)2), 1.06 (18H, dd, J = 7.1 Hz, JPH = 13.2 Hz, PCH(CH3)2),
ꢀ11.82 (2H, d, 2JPH = 27.0 Hz, 1JSiH = 12.3 Hz, RuH). 13C{1H} NMR
(C6D6, 150.9 MHz): δ 95.6 (C5Me5), 27.9 (PCH(CH3)2, d, 1JPC = 22.8
Hz), 23.6 (SiCH(CH3)2), 19.7 (SiCH(CH3)2), 19.6 (SiCH(CH3)2),
19.4 (PCH(CH3)2), 11.3 (C5Me5). 31P{1H} NMR (C6D6, 163.0 MHz):
δ 77.8. 29Si NMR (C6D6, 99.4 MHz): δ 118.9. 19F{1H} NMR (C6D6,
376.5 MHz): δ ꢀ75.0. Anal. Calcd for C26H52F3O3PRuSSi: C, 47.18; H,
7.92. Found: C, 47.47; H, 8.19.
1
(CH(CH3)2, d, JPC = 24.8 Hz), 19.2 (CH(CH3)2), 11.0 (C5Me5).
31P{1H} NMR (C6D5Br, 163.0 MHz): δ 81.0. 29Si NMR (C6D5Br, 99.4
MHz): δ 339.0. 19F{1H} NMR (C6D5Br, 376.5 MHz): δ ꢀ132.6,
ꢀ163.1, ꢀ166.8. Anal. Calcd for C55H48BF20PRuSi: C, 52.43; H, 3.84.
Found: C, 52.06; H, 3.89.
[Cp*(PiPr3)Ru(H)2(dSiPhMe)][B(C6F)4] (16). By a procedure
analogous to that for 13, complex 16 was obtained as a light brown solid
1
in 52% yield (0.033 g). H NMR (C6D6, 600 MHz): δ 7.95 (2H, m,
PhH), 7.58 (2H, m, PhH), 7.41 (1H, m, PhH), 1.78 (15H, s, C5Me5),
1.71 (3H, septet, J = 7.0 Hz, CH(CH3)2), 1.52 (3H, s, CH3), 0.99 (18H,
dd, J = 7.0 Hz, JPH = 14.3 Hz, CH(CH3)2), ꢀ9.88 (2H, d, 2JPH = 25.3 Hz,
RuH). 13C{1H} NMR (C6D6, 150.9 MHz): δ 149.7 (B(C6F)4), 148.1
(B(C6F)4), 139.5 (ArC), 137.6 (B(C6F)4), 135.9 (B(C6F)4), 134.1
(ArC), 128.3 (ArC), 124.3 (ArC), 97.2 (C5Me5), 27.9 (CH(CH3)2, d,
1JPC = 22.0 Hz), 19.6 (CH(CH3)2), 11.3 (C5Me5), 10.8 (SiMe). 31P{1H}
NMR (C6D6, 163.0 MHz): δ 81.2. 29Si NMR (C6D6, 99.4 MHz): δ
275.9. 19F{1H} NMR (C6D6, 376.5 MHz): δ ꢀ132.2, ꢀ162.8, ꢀ166.6.
Anal. Calcd for C50H46BF20PRuSi: C, 50.14; H, 3.87. Found: C, 50.02;
H, 4.25.
[Cp*(PiPr3)Ru(H)2(dSiFlu)][B(C6F)4] (17). By a procedure ana-
logous to that for 13, complex 17 was obtained as a bright yellow solid in
69% yield (0.036 g). 1H NMR (C6D6, 600 MHz): δ 7.93 (2H, d, ArH),
7.55 (4H, m, ArH), 7.46 (2H, m, ArH), 1.84 (15H, s, C5Me5), 1.67 (3H,
septet, J = 7.0 Hz, CH(CH3)2), 0.97 (18H, dd, J = 7.0 Hz, JPH = 14.6 Hz,
CH(CH3)2), ꢀ8.69 (2H, br s). 13C{1H} NMR (C6D6, 150.9 MHz): δ
149.7 (B(C6F)4), 148.1 (B(C6F)4), 139.4 (ArC), 137.6 (B(C6F)4),
136.5 (ArC), 135.9 (B(C6F)4), 135.7 (ArC), 134.7 (ArC), 121.3
Cp*(PiPr3)Ru(H)2(SiFluOTf) (12). By a procedure analogous to
that for 3, complex 12 was obtained as a colorless solid in 42% yield
(0.056 g). 1H NMR (C6D6, 600 MHz): δ 7.96 (2H, m, ArH), 7.69 (2H,
m, ArH), 7.30 (4H, m, ArH), 2.05 (3H, septet, J = 7.1 Hz, CH(CH3)2),
1.29 (15H, s, C5Me5), 1.16 (18H, dd, J = 7.1 Hz, JPH = 13.0 Hz, CH-
2
1
(CH3)2), ꢀ11.17 (2H, d, JPH = 25.9 Hz, JSiH = 12.2 Hz, RuH).
13C{1H} NMR (C6D6, 150.9 MHz): δ 146.6 (ArC), 140.4 (ArC), 132.9
(ArC), 130.4 (ArC), 120.2 (ArC), 95.4 (C5Me5), 27.4 (CH(CH3)2, d,
1JPC = 22.7 Hz), 19.2 (CH(CH3)2), 10.2 (C5Me5). 31P{1H} NMR
(C6D6, 163.0 MHz): δ 79.1. 29Si NMR (C6D6, 99.4 MHz): δ 77.9.
19F{1H} NMR (C6D6, 376.5 MHz): δ ꢀ76.4. Anal. Calcd for C32H46-
F3O3PRuSSi: C, 52.80; H, 6.37. Found: C, 52.70; H, 6.17.
[Cp*(PiPr3)Ru(H)2(dSiHMes)][B(C6F)4] (13). A solution of
[Et3Si toluene][B(C6F5)4] (0.055 g, 0.07 mmol) in 0.5 mL of C6H5F
3
was added to a solution of 4 (0.050 g, 0.07 mmol) in 1 mL of C6H5F.
After stirring for 5 min at room temperature, 15 mL of pentane was
added to the bright orange solution, and the reaction vessel was placed in
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Organometallics
ARTICLE
1
(ArC), 99.7 (C5Me5), 27.9 (CH(CH3)2, d, JPC = 25.2 Hz), 19.6
(CH(CH3)2), 11.7 (C5Me5). 31P{1H} NMR (C6D6, 163.0 MHz): δ
84.6. 29Si NMR (C6D6, 99.4 MHz): δ 328.8. 19F{1H} NMR (C6D6,
376.5 MHz): δ ꢀ132.3, 162.8, 166.6. Anal. Calcd for C55H46BF20PRuSi:
C, 52.52; H, 3.69. Found: C, 52.28; H, 4.03.
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X-ray Crystallography. The single-crystal X-ray analysis of com-
pounds 1, 8, and 12 were carried out at the UC Berkeley CHEXRAY
crystallographic facility. Measurements were made on a Bruker APEX
CCD area detector with graphite-monochromated Mo Kα radiation
(λ = 0.71069 Å). Data were integrated and analyzed for agreement using
Bruker APEX2 v. 2009.1.23 Empirical absorption corrections were made
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SHELX program package.25
’ ASSOCIATED CONTENT
S
Supporting Information. This material is available free
of charge via the Internet at http://pubs.acs.org.
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’ AUTHOR INFORMATION
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Present Addresses
†General Electric Global Research, Niskayuna, NY 12309.
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’ ACKNOWLEDGMENT
This work was supported by the National Science Foundation
under Grant No. CHE-0957106 and an NSF Graduate Fellowship
to M.E.F.
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