Tandem cyclization of enynes containing a thioether or ether linkage via ruthenium allenylidene and vinylidene complexes

Article abstract of DOI:10.1021/om400742x

The two aromatic S-enynes HCi - CCH(OH)(C₆H ₄)SCH₂C(R)=CH₂ (1a, R = Me; 1b, R = H) containing olefinic groups with and without an internal methyl substitutent and the O-enyne HCi - CCH(OH)CMe₂CH₂OCH ₂C(Me)=CH₂ (1c) also with an internal methyl substituent on the olefinic group but with no aromatic group have been prepared. In the [Ru]Cl-induced ([Ru] = Cp(PPh)₃Ru) reactions of 1a,c, the presence of the methyl group promotes cyclization reactions and their tandem cyclizations are further induced by MeOH. The reaction of 1a in CH₂Cl₂ gives the three products 2a-4a. Complex 2a, with a seven-membered thio ring bonded at C_β of the vinylidene ligand, is formed via a C-C bond formation between two unsaturated groups in moderate yield. Complex 3a is formed via migration of PPh₃ from the metal onto the terminal carbon of the alkynyl group followed by coordination of the S atom. The carbene complex 4a is formed by S addition to the internal carbon of the alkynyl group accompanied by migration of the allylic group from sulfur to the newly formed thiophene ring. Tandem cyclization of 1a in MeOH generates the organic product 8a via 2a. In the reaction, the vinylidene complex 7a, a formal methanol addition product of 2a, is also formed as a side product. Deprotonation of 7a gives the acetylide complex 9a. The reaction of 1c affords the vinylidene complex 2c in CH ₂Cl₂ via a similar cyclization process with no other side product. Deprotonation of 2c followed by allylation gave the disubstituted vinylidene complex 10c. Tandem cyclization of 1c in MeOH also gives the organic product 8c. In the reaction of [Ru]Cl with 1b containing no methyl group in the olefinic part, no C-C bond formation was observed. The reactions of [Ru]NCCH₃⁺ with 1a,b each gave only 4a,b, respectively, with no side product. All of these reaction products are characterized by spectroscopic methods as well as elemental analysis. In addition, the structures of three complexes 5a, 9a, and 10c have been confirmed by X-ray diffraction analysis.

Full text of DOI:10.1021/om400742x

Article
pubs.acs.org/Organometallics
Tandem Cyclization of Enynes Containing a Thioether or Ether
Linkage via Ruthenium Allenylidene and Vinylidene Complexes
Yi-Jhen Feng, Ji-Xian Lo, Ying-Chih Lin,* Shou-Ling Huang, Yu Wang, and Yi-Hung Liu
Department of Chemistry, National Taiwan University, Taipei, Taiwan 106, Republic of China
S
* Supporting Information
ABSTRACT: The two aromatic S-enynes HCCCH(OH)(C6H4)SCH2C(R)CH2 (1a,
R = Me; 1b, R = H) containing olefinic groups with and without an internal methyl
substitutent and the O-enyne HCCCH(OH)CMe2CH2OCH2C(Me)CH2 (1c) also
with an internal methyl substituent on the olefinic group but with no aromatic group have
been prepared. In the [Ru]Cl-induced ([Ru] = Cp(PPh)3Ru) reactions of 1a,c, the presence
of the methyl group promotes cyclization reactions and their tandem cyclizations are further
induced by MeOH. The reaction of 1a in CH2Cl2 gives the three products 2a−4a. Complex
2a, with a seven-membered thio ring bonded at Cβ of the vinylidene ligand, is formed via a
C−C bond formation between two unsaturated groups in moderate yield. Complex 3a is
formed via migration of PPh3 from the metal onto the terminal carbon of the alkynyl group
followed by coordination of the S atom. The carbene complex 4a is formed by S addition to
the internal carbon of the alkynyl group accompanied by migration of the allylic group from
sulfur to the newly formed thiophene ring. Tandem cyclization of 1a in MeOH generates the organic product 8a via 2a. In the
reaction, the vinylidene complex 7a, a formal methanol addition product of 2a, is also formed as a side product. Deprotonation of
7a gives the acetylide complex 9a. The reaction of 1c affords the vinylidene complex 2c in CH2Cl2 via a similar cyclization
process with no other side product. Deprotonation of 2c followed by allylation gave the disubstituted vinylidene complex 10c.
Tandem cyclization of 1c in MeOH also gives the organic product 8c. In the reaction of [Ru]Cl with 1b containing no methyl
group in the olefinic part, no C−C bond formation was observed. The reactions of [Ru]NCCH3+ with 1a,b each gave only 4a,b,
respectively, with no side product. All of these reaction products are characterized by spectroscopic methods as well as elemental
analysis. In addition, the structures of three complexes 5a, 9a, and 10c have been confirmed by X-ray diffraction analysis.
product in MeOH.7 The methyl substituent on the internal
INTRODUCTION
■
carbon of the olefinic part of enynes promotes cyclization
Sulfur- and oxygen-containing heterocyclic compounds are
widely found in natural products, and many of them display
reactions.5g,7 We now extend our study to explore the
cyclization of S- and O-containing 1,8-enynes, also with a
biological activity.1 In addition, compounds of this type also
methyl substituent on the internal carbon of the olefinic group,
serve as valuable building blocks in organic synthesis and are
using ruthenium complexes. Vinylidene complexes retaining an
now considered as important structural units in materials
olefinic group are obtained after the first cyclization, which
development. Therefore, many new synthetic approaches to
progress to further cyclization in different solvents to give a
tricyclic product. In addition, for S-enynes, we observed the
exclusive formation of substituted benzothiophene and its
subsequent oxidation to yield the corresponding aldehyde, both
these heterocyclic compounds have been reported.2 Transition-
metal-catalyzed cycloisomerization and olefin metathesis are
now regularly employed for preparations of these hetero-
cycles.3,4 It is now well-known that the ruthenium-catalyzed or
in high yield, when the reaction conditions are properly
induced intra- and intermolecular carbon−carbon bond
modified. Cyclizations of a similar enyne system with two
forming reactions between propargylic alcohols and alkenes5
readily proceed via an allenylidene intermediate under mild
terminal methyl substituents, instead of one internal methyl
substituent, at the olefinic groups was also investigated. The
conditions. Enynes with no hydroxyl group undergo
ruthenium-induced cyclizations most likely via vinylidene
intermediates.6 These allenylidene and vinylidene complexes
play crucial roles in inducing intramolecular enyne coupling,
leading to cyclized products. Previously, we described the
ruthenium-mediated cycloisomerizations of 1,n-enynes (n = 6−
8), each with a methyl substituent at the internal carbon of the
terminal olefinic group, producing a vinylidene complex with a
newly formed five- to seven-membered ring containing an
olefinic group.5g,7 Such a vinylidene complex can undergo
further cyclization using the olefinic group to give a tricyclic
presence of two methyl substituents along with their location
significantly alters the cyclization reactivity. These results will
be reported separately.7b
RESULTS AND DISCUSSION
■
First Cyclization. Treatment of the aromatic S-enyne 1a,
containing one methyl group on the internal carbon of the
Received: July 26, 2013
Published: November 1, 2013
© 2013 American Chemical Society
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olefinic group, with [Ru]Cl ([Ru] = Cp(PPh3)2Ru) in the
presence of NH4PF6 in CH2Cl2 at room temperature afforded
the vinylidene complex 2a, the metallacyclic complex 3a, and
the carbene complex 4a, in a ratio of 25:67:8, as determined by
NMR in a 93% total yield (see Scheme 1). Deprotonation of 2a
attests to the C−C bond formation, and the separation C(11)−
C(13) = 1.315(5) Å corresponds to a double bond.
As shown in Scheme 2, the cyclization reaction is proposed
to proceed via the allenylidene complex A, acting as enophile.
Scheme 2. Formation of 2a−4a from 1a
Scheme 1. Reaction of 1a with [Ru]Cl in CH2Cl2
took place when the mixture was passed through an Al2O3
column, yielding the acetylide complex 5a as the first yellow
band. The second band contained a mixture of 3a and 4a.
Protonation of 5a with HBF4 at 0 °C quantitatively yielded 2a.
The structures of 2a and 5a, each with a newly formed seven-
membered ring, have been determined by 2D-NMR data and
5a have been further characterized by single-crystal X-ray
diffraction analysis. In the 2D-HMBC NMR spectrum of 2a,
the triplet peak at δ 344.77 with 2JCP = 15.7 Hz assigned to Cα
Addition of the tethering olefinic group5d,f to the electrophilic
Cγ causes C−C bond formation, giving B bearing a cationic
charge at the methyl-substituted tertiary carbon. The stability of
the tertiary carbocationic intermediate assists this cyclization. A
concerted allenylidene−ene5a,c process, not shown in the
scheme, could be an alternative pathway. For a similar
ruthenium allenylidene complex with no methyl group on the
olefinic part, no cyclization reaction was observed.5g,7
1
Interestingly, at slightly higher temperature, the C−C bond
formation leading to 2a is hindered in CH2Cl2. The reaction
yields 3a as the major product at 40 °C. The relatively upfield
shows correlation with the multiplet H resonance at δ 4.44
assigned to CγH, which shows correlations with two 1H
multiplet resonances at δ 2.65 and 2.37, assigned to the
neighboring CH2 group in the COSY NMR spectrum. The 2D
NMR spectra of 5a also display similar correlations. Single
crystals of 5a are obtained from an ether/n-pentane solution at
0 °C. An ORTEP type view of 5a is shown in Figure 1, with
1
shifted 31P resonance at δ −5.52 along with the doublet H
2
peak at δ 5.65 with JHP = 34.0 Hz in the NMR spectra of 3a
1
reveal the presence of a phosphonium group. The singlet H
resonance at δ 3.38, which disappears upon addition of D2O, is
assigned to OH. These data clearly reveal migration of a PPh3
from metal to Cα and the presence of a hydroxyl group.
Therefore, formation of 3a should proceed via π coordination
of the triple bond to the metal center to give C,8 as shown in
Scheme 2, instead of via the allenylidene intermediate A. Then
migration of PPh3 to Cα provides a vacant site for subsequent
sulfur coordination to afford 3a.
Thermolysis of 2a in CH3CN at 50 °C affords the enyne
product 6a and [Ru]NCCH3 (see Scheme 1).9 Previously,
+
+
[Ru]NCCH3 -catalyzed cyclization reactions of aromatic all-
carbon enynes containing propargyl alcohol with one methyl
group on the internal carbon of the olefinic group bound to the
ortho position of the aromatic ring was reported7 to afford
organic products with newly formed six-membered rings.
Figure 1. ORTEP drawing of 5a. For clarity, aryl groups of the PPh3
ligands, except the ipso carbons on Ru, are omitted (thermal ellipsoids
are set at the 50% probability level). Selected bond distances (Å) and
angles (deg): Ru(1)−C(1), 2.021(3); C(1)−C(2), 1.207(4); C(2)−
C(3), 1.481(4); C(3)−C(4), 1.518(4); S(1)−C(9), 1.768(3); S(1)−
C(10), 1.826(4); C(11)−C(12), 1.518(4); C(11)−C(13), 1.315(5);
C(3)−C(12), 1.549(4); C(2)−C(1)−Ru(1), 172.4(2); C(1)−C(2)−
C(3), 178.0(3); C(9)−C(4)−C(3), 118.6(3); C(9)−S(1)−C(10),
104.66(16); C(10)−C(11)−C(12), 116.3(3); C(13)−C(11)−C(12),
122.0(4); C(13)−C(11)−C(10), 121.6(4).
+
However, when 1a was directly treated with [Ru]NCCH3 in
CH2Cl2, conversion of 1a to 6a was not observed; instead, the
reaction produced 4a as the only product. A series of 2D NMR
studies and mass spectroscopy established the structure of 4a.
In the 1H NMR spectrum of 4a, the relatively downfield triplet
resonance at δ 14.92 is assigned to CαH. As shown in Scheme
2, the cyclization yielding 4a is believed to proceed by π
coordination of the triple bond to the metal center to give C.
Then nucleophilic addition of S atom to Cβ of the activated
triple bond gives intermediate E. Dehydroxylation is followed
by a migration of the methyl-substituted allylic group to give
4a. Migration of the allylic group to Cγ could proceed either via
a direct 1,3-allyl shift10 or by a Cope rearrangement.11
selected bond distances and angles. Obviously, a new C−C
bond formed between Cγ and the terminal carbon of the
olefinic group. The acetylide ligand is nearly linear (C(2)−
C(1)−Ru(1) = 172.4(2)°), showing the bond lengths Ru(1)−
C(1) = 2.021(3) Å, C(1)−C(2) = 1.207(4) Å, and C(2)−C(3)
= 1.481(4) Å. The bond length of C(3)−C(12), 1.549(4) Å,
Oxidation of 4a to Aldehyde. A recent study by our
group revealed that a metal carbene complex with a highly
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conjugated ring system may be readily oxidized in the presence
of tertiary amines under an oxygen atmosphere to yield the
corresponding aldehyde.12 Also having a highly conjugated ring
system, 4a was thus reacted with O2 in the presence of excess
NEt3 in CH3CN at ambient temperature to afford 2-
benzothiophenecarbaldehyde (11a) in 83% yield. In the
absence of NEt3, no aldehyde was obtained even under an
oxygen atmosphere. Compound 11a has been used as a
precursor for the synthesis of dihydrofuro[3,4-c]pyridinones,
showing inhibition of the cytolytic effects of the lymphocyte
toxin perforin.13
methoxide addition to B shown in Scheme 2. For 7a, with no
olefinic group, no further cyclization is observed. However,
deprotonation of 7a yields the acetylide complex 9a.
The structures of 7a−9a have also been established by a
series of 2D NMR studies and mass spectra, and complex 9a
was characterized by single-crystal X-ray diffraction analysis.
Diastereoisomers are observed for both 7a and 9a in an
approximate ratio of 1:0.5 due to the presence of two
stereogenic centers. Spectroscopic data clearly reveal additions
of OMe groups to the newly formed seven-membered ring in
7a and 9a. For 8a, the two multipet peaks at δ 5.82 and 5.65 are
1
The proposed pathway for the oxygenation is shown in
assigned to two olefinic hydrogens in the H NMR spectrum.
Scheme 3.12 Activation of O2 by coordination to the metal
In the HMBC spectra of 8a, the 13C resonance at δ 41.16
1
assigned to SCH2 shows correlation with the H resonances at
Scheme 3. Mild Oxidation of 4a To Give Aldehyde
δ 2.46, 2.24, and 2.09 assigned to two other methylene groups.
These correlations support the proposed structure of 8a. The
cascade cyclization of 1a is proposed to proceed via 2a, as
shown in Scheme 4. Then the second C−C bond formation
between the olefinic moiety and Cα yields the cationic species
G. Addition of methoxide at the cationic carbon followed by
protonation gives 8a and [Ru]Cl. Single crystals of 9a were
obtained from a solution of ether/acetone at 0 °C. An ORTEP
type view of 9a is shown in Figure 2, with selected bond
distances and angles.
center is initiated by dissociation of a PPh3 ligand.14 Then, NEt3
is reacted with the activated oxygen to yield ONEt3 and an
unobserved metal oxo carbene complex.15 Coupling of the oxo
and carbene ligands is promoted by recoordination of PPh3,
leading to the intermediate M,16 which readily generates 11a in
good yield.
Tandem Cyclization of 1a. Previously the Ru-catalyzed
cyclization of the aromatic enynes HCCCH(OH)(C6H4)-
(CH2)nCMeCH2 (n = 1, 2) with a methyl group on the
olefinic unit in CH2Cl2 was reported to afford the vinylidene
complexes, each with an olefinic group which would undergo
further cyclization in MeOH.7 While the first cyclization
product 6a from 1a is also an enyne, more cyclization is thus
expected. Indeed, the reaction of 1a with [Ru]Cl in MeOH
yields the tandem cyclization product 8a together with 2a, 3a,
and the vinylidene complex 7a, in a ratio of 15:45:29:11 in a
95% total yield at room temperature (see Scheme 4). The yield
of 8a is improved to 40% at 50 °C. In EtOH, thermal treatment
of 1a with [Ru]Cl also affords 3a and 8a′, with an ethoxy
group. The formation of 7a is reasonably explained by the
Figure 2. ORTEP drawing of 9a. For clarity, aryl groups of the PPh3
ligands on Ru, except the ipso carbons, are omitted (thermal ellipsoids
are set at the 50% probability level). Selected bond distances (Å) and
angles (deg): Ru(1)−P(1), 2.2917(11); Ru(1)−P(2), 2.2901(9);
Ru(1)−C(1), 2.041(4); C(1)−C(2), 1.198(6); C(2)−C(3), 1.499(6);
C(3)−C(4), 1.509(7); C(3)−C(12), 1.571(7); S(1)−C(9), 1.756(6);
S(1)−C(10), 1.795(7); C(10)−C(11), 1.545(9); C(11)−C(12),
1.501(8); C(11)−C(13), 1.531(9); O(1)−C(11), 1.417(8); O(1)−
C(14), 1.341(9); C(11)−C(13), 1.531(9); C(2)−C(1)−Ru(1),
178.6(4); C(1)−C(2)−C(3), 173.6(5); C(9)−S(1)−C(10),
102.2(3); C(12)−C(11)−C(10), 115.3(5); C(11)−C(12)−C(3),
117.2(5).
Scheme 4. Tandem Cyclization of 1a in MeOH
Tandem Cyclization of 1c. The aliphatic enyne 1c, also
containing a methyl substituent in the olefinic group but with
an ether linkage instead of the thio ether linkage of 1a,
underwent similar [Ru]Cl-induced cyclization to give simpler
cyclization products. Treatment of 1c with [Ru]Cl in the
presence of NH4PF6 in CH2Cl2 afforded the vinylidene
complex 2c with a newly formed seven-membered oxepane
derivative.
Deprotonation of 2c at the vinylidene ligand with NaOMe/
MeOH gave the acetylide complex 5c as a light yellow powder,
which regenerated 2c in HBF4. Complex 5c, with a relatively
remote stereogenic center at Cγ, displays a somewhat broad 31
P
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resonance at δ 51.94 for 5c. The doublet resonance at δ 4.57
distances and angles, confirming the presence of the seven-
membered oxepane ring in the vinylidene ligand. The bond
lengths Ru(1)−C(1) = 1.864(3) Å and C(1)−C(2) = 1.308(5)
Å show a typical vinylidene bond skeleton. The bond length
C(3)−C(4) = 1.539(6) Å attests to the C−C bond formation
and C(5)−C(9) = 1.367(9) Å is a double bond.
1
assigned to CβH in the H NMR spectrum of 2c disappears in
1
the H NMR spectrum of 5c. Heating 2c in CH3CN to reflux
for 1 day affords the organic enyne 6c, as shown in Scheme 5.
Scheme 5. Tandem Cyclization Reactions of 1c
The promotional effect of MeOH for tandem cyclization is
also observed in this system. Thermolysis of 2c and [Ru]Cl in
CHCl3/MeOH at 50 °C generated the fused cyclic organic
product 8c in 90% yield. In addition, thermolysis of 6c with 30
+
mol % of [Ru]NCCH3 in CHCl3/MeOH at 50 °C also
afforded 8c in high yield. Compound 8c was also directly
obtained from the reaction of 1c with 30 mol % of
+
[Ru]NCCH3 in CHCl3/MeOH at 50 °C, in 70% yield. In
+
EtOH and i-PrOH, treatment of 1c with [Ru]NCCH3
afforded 8c′ and 8c″, respectively. As the steric bulk of the
alcohol increases, the yield of 8c″ decreases to about 30% yield.
The structure of 8c has been determined by spectroscopic
+
methods. When 1c is treated with [Ru]NCCH3 in CDCl3/
CD3OD, both olefinic protons of 8c-D are deuterated.
Therefore, the cascade cyclization of 1c should first give 2c,
undergoing a fast H/D exchange process between the
vinylidene hydrogen and solvent. Then, addition of the olefinic
moiety to Cα of the vinylidene ligand in 2c yields the cationic
species J. Addition of alkoxide at the cationic site, followed by
Alternatively, direct conversion of 1c to 6c is catalyzed by 30
mol % of [Ru]NCCH3+ in CHCl3 at 60 °C in 78% yield. In the
1H NMR spectrum of 6c, the characteristic doublet acetylenic
resonance appears at δ 2.10 with 4JHH = 2.5 Hz. Two multiplet
resonances at δ 4.92 and 4.83 are assigned to the olefinic
methylene group on the oxepane ring. The cyclization reaction
is believed to proceed via formation of the allenylidene
intermediate H (see Scheme 5) followed by an intramolecular
attack of the alkene group onto Cγ of the allenylidene ligand,
giving the alkynyl complex I with a cationic charge at the
methyl-substituted tertiary carbon. A subsequent 1,5-hydrogen
shift then yields 2c. The vinylidene ligand is readily replaced by
CH3CN to produce 6c.
Treatment of 5c with allyl bromide and methyl iodide
afforded the vinylidene complexes 10c and 10c′, respectively
(see Scheme 5), which are stable under thermolytic conditions
and display similar characteristic NMR data. Single crystals of
10c, with an allylic group at Cβ, were obtained in diethyl ether/
CH2Cl2 solution, and the structure was determined by a single-
crystal X-ray diffraction study. An ORTEP type view of the
cationic complex 10c is shown in Figure 3 with selected bond
+
protonation or deuteration, gives 8c and [Ru]NCCH3 (see
Scheme 5).
Enynes with No Methyl Group. To study the effect of the
methyl substituent in the olefinic group on the cyclization
reaction, we prepared the similar aromatic propargylic alcohol
1b, containing an analogous ortho-substituted olefinic chain but
no methyl group. Treatment of 1b with [Ru]Cl in CH2Cl2 at
ambient temperature afforded a mixture of the metallacyclic
complex 3b, the phosphonium acetylide complex 12b, and the
allenylidene complex 13b, in a ratio of 52:14:34 in a 93% total
yield (see Scheme 6). The same reaction at 40 °C yields 3b as
Scheme 6. Reactions of 1b
the major product along with the allyltriphenylphosphonium
product.17 For the reaction of 1b with [Ru]Cl in the presence
of excess PPh3, a 95% yield of 12b is obtained.18 Unlike 1a,
which shows reactivity for cyclization, compound 1b in CH2Cl2
displays no cyclization involving C−C bond formation. The
stability of the tertiary carbocation originating from the
presence of the methyl group in 1a should play a key role in
promoting the cyclization reaction. The reaction of 1b in
MeOH yields no cyclization product.
Figure 3. ORTEP drawing of 10c. For clarity, phenyl groups of the
PPh3 ligands on Ru, except the ipso carbons, and PF6 , are omitted
−
(thermal ellipsoids are set at the 25% probability level). Selected bond
distances (Å) and angles (deg): Ru(1)−C(1), 1.864(3); C(1)−C(2),
1.308(5); C(2)−C(12), 1.536(5); C(3)−C(4), 1.539(6); C(5)−C(9),
1.367(9); C(13)−C(14), 1.241(7); Ru(1)−C(1)−C(2), 168.0(3);
C(4)−C(3)−C(8), 115.4(3); C(6)−C(5)−C(4), 117.0(6); C(6)−
O(1)−C(7), 115.5(6).
+
Interestingly, when 1b was treated with [Ru]NCCH3 in
CH2Cl2, the carbene complex 4b, analogous to 4a, was isolated
as the only product. Sulfur attack at Cβ indicates the
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6.8 Hz, 1H, OH), 1.85 (s, 3H, Me), 0.18 (s, 9H, TMS). 13C NMR
(CDCl3, 100.6 MHz): δ 141.73 (CH), 140.67 (Ph), 134.31 (Ph),
132.88 (Ph), 128.74 (Ph), 127.62 (Ph), 127.46 (Ph), 114.44 (CH2),
104.93 (C), 91.75 (C), 63.15 (CH), 43.30 (CH2), 21.22 (Me),
−0.17 (Me3Si). To a solution of S1 (3.0 g, 10 mmol) in 10 mL of
THF at room temperature was added Bu4NF (20.7 mL, 21 mmol).
After 4 h the reaction mixture was extracted with diethyl ether. The
organic layers were washed with brine, dried over MgSO4, and
subjected to flash column chromatography over silica gel (SiO2) with a
9/1 hexane/EA mixture as eluent to give the light yellow oil 1a (2.14
g, 98% yield). Spectroscopic data of 1a are as follows. 1H NMR
(CDCl3, 400.1 MHz): δ 7.72 (m, 1H, Ph), 7.44 (m, 1H, Ph), 7.29 (m,
intermediacy of the π-coordinated alkynyl ligand. Allylic
migration also takes place. The reaction of 4b with oxygen in
the presence of excess NEt3 was also carried out in CH3CN at
ambient temperature for 1 day to afford aldehyde 11b in 88%
yield (Scheme 6). Isomerization of the double bond is caused
by a more stable conjugation with the ring system.
CONCLUSION
■
The [Ru]Cl-induced cyclization reactions of S- and O-enynes
1a,c involving C−C bond formation are promoted by the
presence of a methyl substituent in the olefinic part via
formation of a carbocationic intermediate. Because of the
higher coordinating ability of S, the reaction of S-enyne 1a
produces the cyclized product along with several side products.
On the other hand, the reaction of O-enyne 1c gives the
cyclized product with no side products. Furthermore, tandem
cyclizations of both 1a,c are induced in MeOH, yielding benzo-
fused cyclic thioether 8a and fused cyclic ether 8c, respectively,
while in CH2Cl2 only one cyclization is observed. For the S-
enyne 1b with no methyl substituent, a similar cyclization is not
observed. However, for 1a,b, cyclization involving C−S bond
3
4
2H, Ph), 5.96 (dd, JHH = 6.1 Hz, JHH = 2.3 Hz, 1H, CH), 4.80 (t,
3JHH = 1.5 Hz, 1H, CH2), 4.74 (d, 3JHH = 0.7 Hz, 1H, CH2), 3.52 (s,
3
2H, CH2), 2.74 (m, 1H, CCH), 2.66 (d, JHH = 2.3 Hz, 1H, OH),
1.86 (s, 3H, Me). 13C NMR (CDCl3, 100.6 MHz): δ 141.28 (CH),
140.59 (Ph), 134.31 (Ph), 132.72 (Ph), 128.94 (Ph), 127.63 (Ph),
127.47 (Ph), 114.43 (CH2), 83.37 (C), 74.94 (CH), 62.52
(CH), 43.35 (CH2), 21.20 (Me). MS ESI: m/z 219.0844 [M + H]+.
Anal. Calcd for C13H14OS: C, 71.52; H, 6.46. Found: C, 71.47; H,
6.49.
Synthesis of 1b. Compound S2 (2.83 g, 93% yield) was similarly
prepared from Me3SiCCH (3.5 mL, 25 mmol), n-BuLi (7.2 mL, 18
mmol), and 2-(allylthio)benzaldehyde21b (2.0 g, 11 mmol). Spectro-
scopic data of S2 are as follows. 1H NMR (CDCl3, 400.1 MHz): δ 7.69
(m, 1H, Ph), 7.43 (m, 1H, Ph), 7.28 (m, 2H, Ph), 5.92 (d, 3JHH = 6.1
Hz, 1H, CH), 5.85 (m, 2H, CH), 5.05 (d, 3JHH = 8.6 Hz, 1H, cis 
CH2), 5.04 (d, 3JHH = 17.3 Hz, 1H, trans CH2), 3.54 (d, 3JHH = 7.0
Hz, 2H, CH2), 2.90 (d, 3JHH = 6.1 Hz, 1H, OH), 0.18 (s, 9H, Me3Si).
13C NMR (CDCl3, 100.6 MHz): δ 141.81 (Ph), 133.72 (CH),
133.39, 132.88, 128.73, 127.67, 127.66 (Ph), 118.01 (CH2), 104.94
(C), 91.72 (C), 63.12 (CH), 38.62 (CH2), −0.17 (Me3Si). Then
compound 1b (1.41 g, 96% yield) was similarly prepared from Bu4NF
(14.5 mL, 14.5 mmol) and S2 (3.0 g, 9.9 mmol). Spectroscopic data of
1b are as follows. 1H NMR (CDCl3, 400.1 MHz): δ 7.72 (m, 1H, Ph),
+
formation is achieved by the use of [Ru]NCCH3 . The
cyclization is accompanied by allylic migration to give
exclusively the carbene complexes 4a,b, respectively. Triethyl-
amine is found to promote oxidation of the carbene ligand of 4
in the presence of oxygen to give aldehyde in high yield. Even
though many products are obtainable from S-enynes 1a,b
induced by [Ru]Cl, product selectivity is achieved by careful
control of the reaction conditions.
EXPERIMENTAL SECTION
■
3
4
General Procedures. The manipulations were performed under
an atmosphere of dry nitrogen using vacuum-line and standard
Schlenk techniques. Solvents were dried by standard methods and
distilled under nitrogen before use. The ruthenium complex
Cp(PPh3)2RuCl19 and 1c20 were prepared by following the methods
reported in the literature. The C and H analyses and X-ray diffraction
studies were carried out at the Regional Center of Analytical
Instrument at the National Taiwan University. Mass spectra were
recorded using a LCQ Advantage (ESI) and Finnigan MAT 95S (EI)
mass spectrometers. NMR spectra were recorded on Bruker Avance III
400 and 500 FT-NMR spectrometers at room temperature (unless
7.44 (m, 1H, Ph), 7.29 (m, 2H, Ph), 5.95 (dd, JHH = 6.1 Hz, JHH =
2.2 Hz, 1H, CH), 5.86 (m, 1H, CH), 5.06 (m, 2H, CH2), 3.55 (d,
3
3JHH = 7.1 Hz, 2H, CH2), 2.92 (d, JHH = 2.3 Hz, 1H, CCH), 2.66
(d, 3JHH = 2.3 Hz, 1H, OH). 13C NMR (CDCl3, 100.6 MHz): δ 141.31
(Ph), 133.69 (CH), 133.27, 132.63, 128.93, 127.66, 127.52 (Ph);
118.14 (CH2), 83.40 (C), 75.01 (CH), 62.46 (CH), 38.60
(CH2). MS ESI: m/z 205.0687 [M + H]+. Anal. Calcd for C12H12OS:
C, 70.55; H, 5.92. Found: C, 70.50; H, 5.94.
Synthesis of 2a and 5a. A mixture of [Ru]Cl (300 mg, 0.41
mmol), 1a (143 mg, 0.62 mmol), and NH4PF6 (166 mg, 1.02 mmol)
in CH2Cl2 (40 mL) was stirred at ambient temperature for 1 day. The
solvent was removed under vacuum, CH2Cl2 was used to extract the
product, and the crude mixture was filtered through Celite to remove
the insoluble precipitates. The filtrate was concentrated to ca. 5 mL
and was added to stirred diethyl ether (60 mL) to produce an olive
precipitate. The powder was collected, washed with diethyl ether, and
dried under vacuum to give a mixture of 2a, 3a, and 4a. The mixture
was dissolved in CH2Cl2 and was passed through an acidic Al2O3
column with hexane/ether/CH2Cl2 as eluent. Collecting the yellow
band followed by drying under vacuum resulted in the yellow powder
5a (278 mg, 79% yield), mp 127−129 °C. Spectroscopic data of 5a are
1
stated otherwise). H NMR and 13C NMR spectra were obtained at
ambient temperature, and chemical shifts are expressed in parts per
million (δ, ppm). Proton chemical shifts are referenced to δ 7.26
(CDCl3), 5.32 (CD2Cl2), 7.15 (C6D6), and 2.05 (acetone-d6). Carbon
chemical shifts are referenced to δ 77.1 (CDCl3), 53.92 (CD2Cl2),
127.69 (C6D6), and 205.36 and 28.99 (acetone-d6). The 31P NMR
spectra were measured relative to external 85% phosphoric acid. Both
13C and 31P spectra were proton-decoupled spectra. Melting points
were measured in open capillaries on a MPA100 melting point
apparatus and are uncorrected.
1
Synthesis of 1a. To a solution of Me3SiCCH (4.1 mL, 28.6
mmol) in 10 mL of THF at −78 °C, under nitrogen, was added n-BuLi
(8.3 mL, 21 mmol). After 20 min, 2-(2-methylallylthio)-
benzaldehyde21a (2.5 g, 13 mmol) in 10 mL of dry diethyl ether
was added. The mixture was kept at −78 °C for 30 min and was
warmed to room temperature. The mixture was quenched with
saturated aqueous NH4Cl solution and extracted with diethyl ether (3
× 10 mL). The combined organic layers were washed with brine, dried
over MgSO4, and evaporated to give the crude product, which was
purified by flash chromatography on a silica gel column (hexane/EA,
9/1) to give S1 (3.28 g, 87% yield). Spectroscopic data of S1 are as
follows. 1H NMR (CDCl3, 400.1 MHz): δ 7.69 (m, 1H, Ph), 7.40 (m,
as follows. H NMR (C6D6, 400.1 MHz): δ 8.55−6.886.90 (m, Ph),
5.11 (d, 3JHH = 9.1 Hz, 1H, CγH), 4.73 (s, 1H, CH), 4.64 (s, 1H, 
CH), 4.45 (s. 5H, Cp), 3.21−3.15 (m, 3H, SCH2 and CHCH2), 2.52
(m, 1H, CHCH2). 13C NMR (C6D6, 100.6 MHz): δ 148.86−126.01
2
(Ph, C), 114.02 (CH2), 112.39 (Cβ), 96.40 (t, JCP = 24.9 Hz,
Cα), 85.12 (Cp), 47.40 (CH2), 40.33 (C), 38.50 (SCH2). 31P NMR
2
(C6D6, 162.0 MHz): δ 51.22, 50.71 (2 d, Jpp = 37.4 Hz, PPh3). MS
ESI: m/z 891.19 [M + 1]+. Anal. Calcd for C54H46P2RuS: C, 72.81; H,
5.21. Found: C, 73.11; H, 5.34. Single crystals of 5a were obtained
from a hexane/acetone solution at 5 °C.
A solution of HBF4·Et2O (48%, 0.02 mL, 0.11 mmol) in diethyl
ether (20 mL) was added dropwise at 0 °C to a stirred solution of 5a
(300 mg, 0.33 mmol) in 10 mL of ether. Immediately, insoluble solid
precipitated but the addition was continued until no further solid was
3
1H, Ph), 7.26 (m, 2H, Ph), 5.93 (s, 1H, CH), 4.78 (t, JHH = 1.5 Hz,
1H, CH2), 4.72 (s, 1H, CH2), 3.50 (s, 2H, CH2), 2.97 (t, 3JHH
=
6383
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Organometallics
Article
formed. The solution was then decanted, and the pink solid was
washed with diethyl ether and dried in vacuo to give the pink powder
2a (225 mg, 75% yield), mp 137−139 °C. Spectroscopic data of 2a are
as follows. 1H NMR (CD2Cl2, 400.1 MHz): δ 7.58−7.03 (m, Ph), 5.65
(d, 2JHH = 10.0 Hz, 1H, CβH), 5.09 (s, 5H, Cp), 4.96 (s, 1H, CH2),
The powder was collected, washed with diethyl ether, and dried under
vacuum. The mixture was then dissolved in CH2Cl2 and was passed
through an Al2O3 column with hexane/ether/CH2Cl2 as eluent.
Collecting the yellow band followed by drying under vacuum resulted
in a mixture of 5a and 9a as a yellow powder from deprotonation of 2a
and 7a, respectively (388.37 mg; the ratio of 5a and 9a is about 0.3:1.6
and the ratio of major and minor diastereomers of 9a is ca. 1:0.6 from
the NMR spectrum). Spectroscopic data of 9a are as follows for the
2
4.89 (s, 1H, CH2), 4.44 (m, 1H, CH), 3.35, 3.21 (2 d, JHH = 12.4
Hz, 2H, SCH2), 2.65 (m, 1H, CH2), 2.37 (m, 1H, CH2). 13C NMR
2
(CD2Cl2, 100.6 MHz): δ 344.77 (t, JCP = 15.7 Hz, Cα), 146.89−
1
127.20 (Ph, C), 115.96 (CH2), 115.67 (Cβ), 94.40 (Cp), 45.11
major diastereomer. H NMR (C6D6, 400.1 MHz): δ 8.75−7.24 (m,
(CH2), 39.40 (SCH2), 38.83 (Cγ). 31P NMR (CD2Cl2, 162.0 MHz): δ
Ph), 4.83 (d, 3JHH = 9.8 Hz, 1H, CγH), 4.44 (s, 5H, Cp), 2.93 (s, 3H,
OMe), 2.69−2.57 (m, 3H, SCH2 and CHCH2), 1.95 (m, 1H, CH2),
1.63 (s, 3H, Me). 13C NMR (C6D6, 100.6 MHz): δ 151.79−125.58
2
44.07, 42.73 (2 d, Jpp = 26.6 Hz, PPh3). MS ESI: m/z 891.19 [M]+.
Anal. Calcd for C54H47BF4P2RuS: C, 66.33; H, 4.84. Found: C, 66.91;
H, 5.08.
2
(Ph), 113.63 (Cβ), 95.33 (t, JCP = 25.1 Hz, Cα), 85.08 (Cp), 76.58
(C(OMe)(Me)), 48.36 (OMe), 47.90 (CH2), 42.28 (SCH2), 36.51
(Cγ), 21.49 (Me). 31P NMR (C6D6, 162.0 MHz): δ 51.58, 50.18 (2 d,
2Jpp = 37.4 Hz, PPh3). Spectroscopic data are as follows for the minor
distereomer. 1H NMR (C6D6, 400.1 MHz): δ 8.75−7.24 (m, Ph), 5.50
Synthesis of 3a. A mixture of [Ru]Cl (200 mg, 0.27 mmol), 1a
(88 mg, 0.41 mmol), and NH4PF6 (111 mg, 0.69 mmol) in CH2Cl2
(40 mL) was stirred at 40 °C for 1 day. The solvent was removed
under vacuum, CH2Cl2 was used to extract the crude product, and the
mixture was filtered through Celite to remove the insoluble
precipitates. The filtrate was concentrated to ca. 5 mL and added to
stirred diethyl ether (60 mL) to produce a green-yellow precipitate,
which was collected, washed with diethyl ether, and dried under
vacuum to give a green-yellow powder containing mostly 3a and a
trace amount of unidentified product (less than 5% of the mixture
from NMR) (total weight 236 mg, yield of 3a ca. 80%). Spectroscopic
data of 3a are as follows. 1H NMR (CDCl3, 500.2 MHz): δ 7.75−6.87
3
(d, JHH = 9.3 Hz, 1H, CγH), 4.44 (s, 5H, Cp), 3.15 (s, 3H, OMe),
2.77 (m, 1H, SCH2), 2.69 (m, 1H, CH2), 2.33 (d, 3JHH = 14.5 Hz, 1H,
SCH2), 1.54 (m, 1H, CH2), 0.84 (s, 3H, Me). 13C NMR (C6D6, 100.6
2
MHz): δ 151.79−125.58 (Ph), 114.21 (Cβ), 93.42 (t, JCP = 24.8 Hz,
Cα), 85.08 (Cp), 73.47 (C(OMe)(Me)), 49.95 (COMe), 46.31
(CH2), 42.62 (SCH2), 34.19 (Cγ), 25.26 (Me). 31P NMR (C6D6,
2
162.0 MHz): δ 51.53, 50.26 (2 d, Jpp = 37.6 Hz, PPh3). MS: m/z:
923.22 [M + 1]+. Single crystals of 9a are obtained from a solution of
ether/acetone at 0 °C. Anal. Calcd for C55H50OP2RuS: C, 71.64; H,
5.47. Found: C, 71.31; H, 5.40.
2
(m, Ph), 5.87 (d, JHP = 36.2 Hz, 1H, CHPPh3), 4.81 (s, 1H, 
CH), 4.63 (s, 5H, Cp), 4.53 (s, 1H, CH), 3.79 (d, 2JHH = 12.5 Hz, 1H,
2
CH2), 3.47 (d, JHH = 12.6 Hz, 1H, CH2), 3.40 (s, 1H, OH), 1.71 (s,
A solution of HBF4·Et2O (48%, 0.02 mL, 0.11 mmol) in diethyl
ether (20 mL) was added dropwise at 0 °C to a stirred solution of the
mixture of 5a and 9a (300 mg) in 10 mL of ether. Immediately, an
insoluble solid precipitated but the addition was continued until no
further solid was formed. The solution was then decanted, and the
pink solid was washed with diethyl ether and dried under vacuum to
yield a mixture of 2a and 7a as a pink powder (the ratio of 2a and 7a is
about 0.3:1.3 and the ratio of major and minor diastereomers of 7a is
ca. 1:0.3. from the 1H NMR spectrum). Spectroscopic data of 7a are as
follows for the major diastereomer. 1H NMR (CD2Cl2, 400.1 MHz): δ
7.43−7.00 (m, Ph), 5.41−5.25 (m, 2H, CβH and CγH), 5.19 (s, 5H,
3H, Me). 13C NMR (CDCl3, 100.6 MHz): δ 233.50 (t, 2JCP = 16.4 Hz,
1
Cα), 145.55−120.50 (Ph, C), 117.08 (CH), 100.75 (d, JCP
=
64.8 Hz), 81.68 (Cp), 78.23 (CH), 56.87 (CH2), 21.29 (Me). 31P
NMR (CDCl3, 202.5 MHz): δ 55.73 (br, PPh3), −5.67 (br, PPh3). MS
ESI: m/z 909.20 [M]+. Anal. Calcd for C54H49F6OP3RuS: C, 61.53; H,
4.69. Pure complex 3a was not obtained.
+
Synthesis of 4a. A mixture of [Ru]NCCH3 (300 mg, 0.34
mmol), 1a (112 mg, 0.51 mmol), and NH4PF6 (166 mg, 1.02 mmol)
in CH2Cl2 (40 mL) was stirred at ambient temperature for 1 day. A
procedure similar to that used to obtain the crude mixture of 3a
yielded a filtrate, which was concentrated to ca. 5 mL and added to
stirred diethyl ether (60 mL) to produce an olive precipitate. The
powder was collected, washed with diethyl ether, and dried under
vacuum to give the olive powder 4a (186 mg, 83% yield), mp 184−
2
Cp), 3.43 (s, 3H, OMe), 3.03 (d, JHH = 15.0 Hz, 1H, SCH2), 2.49−
2.39 (m, 2H, SCH2 and CH2), 1.65 (m, 1H, CH2), 1.23 (s, 3H, Me).
2
13C NMR (CD2Cl2, 100.6 MHz): δ 346.64 (t, JCP = 15.6 Hz, Cα),
149.56−125.01 (Ph), 119.21 (Cβ), 94.49 (Cp), 73.96 (C(OMe)-
(Me)), 49.34 (OMe), 48.46 (CH2), 40.57 (SCH2), 31.48 (Cγ), 25.30
(Me). 31P NMR (CD2Cl2, 162.0 MHz): δ 44.16, 43.64 (2 d, 2Jpp = 27.0
Hz, PPh3). Spectroscopic data are as follows for the minor
1
185 °C. Spectroscopic data of 4a are as follows. H NMR (CDCl3,
3
400.1 MHz): δ 14.92 (t, JPH = 11.3 Hz, 1H, CαH), 8.05−6.95 (m,
Ph), 5.15 (s, 5H, Cp), 4.41 (s, 1H, CH2), 3.76 (s, 1H, CH2), 2.67
(s, 2H, CH2), 1.66 (s, 3H, Me). 13C NMR (CDCl3, 100.6 MHz): δ
280.26 (t, 2JCP = 12.2 Hz, Cα), 162.58−123.65 (Ph, C), 112.69 (
CH2), 94.78 (Cp), 35.45 (CH2), 23.70 (Me). 31P NMR (CDCl3, 162.0
MHz): δ 45.23 (s, PPh3). MS ESI: m/z 891.19 [M]+. Anal. Calcd for
C54H47F6P3RuS: C, 62.60; H, 4.57. Found: C, 62.35; H, 4.46.
1
distereomer. H NMR (CD2Cl2, 400.1 MHz): δ 7.43−7.00 (m, Ph),
5.25 (s, 5H, Cp), 5.00 (m, 1H, CβH), 3.79 (m, 1H, CγH), 3.37 (s, 3H,
OMe), 2.68 (m, 2H, SCH2), 2.21 (m, 1H, CH2), 1.76 (m, 1H, CH2),
1.31 (s, 3H, Me). 13C NMR (CD2Cl2, 100.6 MHz): δ 346.54 (t, 2JCP
=
15.3 Hz, Cα), 149.56−125.01 (Ph), 118.00 (Cβ), 94.81 (Cp), 81.53
(C(OMe)(Me)), 49.04 (OMe), 45.14 (SCH2), 43.44 (CH2), 32.00
(Cγ), 25.54 (Me). 31P NMR (CD2Cl2, 162.0 MHz): δ 43.84, 43.28 (2
d, 2Jpp = 26.2 Hz, PPh3). MS: m/z 923.22 (M)+. Pure complex 7a was
not obtained.
Synthesis of 8a. A mixture of [Ru]Cl (200 mg, 0.27 mmol), 1a
(88 mg, 0.41 mmol), and KPF6 (126 mg, 0.69 mmol) in MeOH (40
mL) was heated to 50 °C for 1 day. A crude mixture was similarly
obtained using the same procedure as for 3a. The mixture in CH2Cl2
(5 mL) was added to stirred hexane (60 mL) to produce an olive
precipitate and yellow filtrate. The yellow solution was purified by flash
chromatography on a silica gel column (hexane/ether, 9/1) to give the
light yellow oil 8a (22.6 mg, 40% yield). Spectroscopic data of 8a are
Synthesis of 6a. A solution of 2a (200 mg, 0.20 mmol) in CH3CN
(10 mL) was stirred at 50 °C for 1 day. The crude mixture was
concentrated to ca. 3 mL and added to a stirred diethyl ether (20 mL)
to produce a precipitate and a yellow filtrate. The yellow filtrate was
collected and subjected to flash column chromatography over silica gel
(SiO2) with hexane as eluent to give the light yellow oil 6a (37.3 mg,
91% yield). Spectroscopic data of 6a are as follows. 1H NMR (CD2Cl2,
400.1 MHz): δ 7.76 (m, 1H, Ph), 7.51 (m, 1H, Ph), 7.33 (m, 1H, Ph),
7.18 (m, 1H, Ph), 4.82 (m, 2H, CH2), 4.50 (m, 1H, CH), 3.35 (q,
3
3JHH = 12.2 Hz, 2H, SCH2), 2.93 (m, 1H, CH2), 2.43 (d, JHH = 2.5
Hz, 1H, CH), 2.36 (m, 1H, CH2). 13C NMR (CDCl3, 100.6 MHz):
δ 143.35 (C), 143.01, 134.33, 133.27, 128.33, 127.32, 127.07 (Ph),
116.00 (CH2), 85.06 (C), 72.02 (CH), 44.25 (CH2), 38.62
(SCH2), 35.77 (CH). MS ESI: m/z 223.0549 [M + Na]+. Anal. Calcd
for C13H12S: C, 77.95; H, 6.04. Found: C, 77.75; H, 6.11.
1
2
as follows. H NMR (CDCl3, 400.1 MHz): δ 7.36 (d, JHH = 7.5 Hz,
1H, Ph), 7.22−7.06 (m, 3H, Ph), 5.82 (m, 1H, CH), 5.65 (m, 1H,
CH), 3.75 (br, 1H, CH), 3.30 (s, 3H, OMe), 3.06, 2.83 (2 d, 2JHH
=
Synthesis of 7a and 9a. A mixture of [Ru]Cl (300 mg, 0.41
mmol), 1a (134 mg, 0.62 mmol), and KPF6 (189 mg, 1.04 mmol) in
MeOH (40 mL) was stirred at ambient temperature for 1 day. The
crude product containing a mixture of 2a, 3a, and 7a from the reaction
was obtained using the same procedure as that described for 2a−4a.
14.4 Hz, 2H, SCH2), 2.47 (m, 2H, CHCH2, CHCH2), 2.24 (m, 1H,
CHCH2), 2.09 (m, 1H, CHCH2). 13C NMR (CDCl3, 100.6 MHz):
δ 142.51, 136.58, 132.25, 130.99 (Ph), 128.01 (C), 127.03 (Ph),
126.32 (C), 126.16 (Ph), 74.45 (MeOC), 48.87 (OMe), 43.51
(CH), 41.16 (SCH2), 34.71 (CHCH2), 34.47 (CHCH2). MS ESI:
6384
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Organometallics
Article
m/z 255.0812 [M + Na]+. Anal. Calcd for C14H16OS: C, 72.37; H,
6.94. Found: C, 72.13; H, 7.03.
1H, CH), 2.10 (d, 4JHH = 2.50 Hz, 1H, CH), 1.03 (s, 3H, Me), 0.94
(s, 3H, Me). 13C NMR (CDCl3, 100.6 MHz): δ 147.49 (C), 112.67
(CH2), 85.72 (C), 77.28 (CH2), 74.59 (CH2), 36.23 (CH2),
70.97 (CH), 34.21 (C), 37.74 (C), 25.31 (Me), 20.92 (Me). MS
ESI: m/z 165.1217 [M + H]+. Anal. Calcd for C11H16O: C, 80.44; H,
9.82. Found: C, 80.19; H, 9.93.
Synthesis of 8a′. Compound 8a′ (30 mg, 42% yield) was similarly
prepared from [Ru]Cl (200 mg, 0.27 mmol), 1a (88 mg, 0.41 mmol),
and KPF6 (126 mg, 0.69 mmol) in EtOH (40 mL) at 50 °C.
1
Spectroscopic data of 8a′ are as follows. H NMR (CDCl3, 400.1
MHz): δ 7.35 (d, 2JHH = 8.3 Hz, 1H, Ph), 7.21−7.05 (m, 3H, Ph), 5.82
(m, 1H, CH), 5.63 (m, 1H, CH), 3.75 (br, 1H, CH), 3.53 (m,
2H, OCH2), 3.05, 2.84 (2 d, 2JHH = 14.5 Hz, 2H, SCH2), 2.46 (m, 2H,
CHCH2, CHCH2), 2.26 (m, 1H, CHCH2), 2.10 (m, 1H,
CHCH2), 1.21 (t, 3JHH = 7.03 Hz, 3H, Me). 13C NMR (CDCl3, 100.6
MHz): δ 142.50, 136.70, 132.34, 131.06 (Ph), 127.95 (C), 127.09
(Ph), 126.60 (C), 126.23 (Ph), 74.45 (CH2OC), 56.36 (OCH2),
43.65 (CH), 41.86 (SCH2), 35.54 (CHCH2), 35.08 (CHCH2),
16.30 (Me). MS ESI: m/z 269.0967 [M + Na]+. Anal. Calcd for
C15H18OS: C, 73.13; H, 7.36. Found: C, 72.79; H, 7.48.
Synthesis of 10c. Complex 5c (110 mg, 0.13 mmol) and KPF6
(26 mg, 0.14 mmol) were placed in a Schlenk flask, and CH2Cl2 (20
mL) was added under nitrogen. After allyl bromide (17 mg, 0.14
mmol) was added, the resulting solution was stirred for 8 h. A crude
mixture was obtained using the same procedure as for 3a. The mixture
was extracted with a small volume of CH2Cl2 followed by
reprecipitation with 50 mL of diethyl ether. The precipitate thus
formed was collected on a glass frit, washed with 1/1 ethyl ether/
hexane, and dried under vacuum to give the pink powder 10c (100 mg,
90% yield), mp 180−181 °C. Spectroscopic data of 10c are as follows.
1H NMR (CDCl3, 400.1 MHz): δ 7.74−6.79 (m, 49H, Ph), 5.89 (m,
1H, C(C)H), 5.11 (s, 5H, Cp), 5.11 (m, 2H, CH2), 4.63 (s, 1H,
Synthesis of 2c. A mixture of [Ru]Cl (250 mg, 0.34 mmol), 1c
(61 mg, 0.34 mmol), and NH4PF6 (81 mg, 0.50 mmol) in CH2Cl2 (20
mL) was stirred at ambient temperature for 1 day. A crude mixture was
obtained using the same procedure as for 3a. The mixture was
extracted with a small volume of CH2Cl2 followed by reprecipitation
by addition to 50 mL of diethyl ether. The precipitate thus formed was
collected in a glass frit, washed with 1/1 diethyl ether/hexane, and
dried under vacuum to give the deep yellow product 2c. Purification
by deprotonation of 2c with NaOMe/MeOH described below gave 5c,
which regenerated pink powder 2c in HBF4 (210 mg, 70% yields), mp:
156−158 °C. Spectroscopic data of 2c are as follows. 1H NMR
(CDCl3, 400.1 MHz): δ 6.94−7.66 (m, 34H, Ph), 5.13 (s, 5H, Cp),
2
CH2), 4.55 (s, 1H, CH2), 4.16, 3.75 (2 d, JHH = 14.25 Hz, 2H,
2
OCH2), 3.26, 2.72 (2 d, 2JHH = 12.21 Hz, 2H, OCH2), 3.13 (dd, JHH
= 16.79 Hz, 3JHH = 6.11 Hz, 1H, CH2), 2.77−2.65 (m, 2H, CH2), 2.25
3
(m, 1H, CH2), 2.22 (d, JHH = 6.11 Hz, 1H, CH), 1.04 (s, 3H, Me),
0.83 (s, 3H, Me). 13C NMR (CDCl3, 100.6 MHz): δ 349.67 (t, 3JCP
=
14.04 Hz, Cα), 148.16−111.99 (Cβ, Ph, C(CH2)2, CH2), 94.02
(Cp), 81.98 (OCH2), 74.50 (OCH2), 4.77 (CH), 39.97 (CH2), 38.33
(C), 27.56 (CH2), 26.46 (Me), 21.00 (Me). 31P NMR (CDCl3, 162.0
2
MHz): δ 41.38, 40.68 (2 d, JPP = 27.68 Hz, PPh3). MS ESI: m/z
895.28 [M]+. Anal. Calcd for C55H55F6OP3Ru: C, 63.52; H, 5.33.
Found: C, 63.19; H, 5.55. Single crystals of 10c were obtained from an
ether/CH2Cl2 solution at 0 °C.
3
4.57 (d, JHH = 10.47 Hz, 1H, CβH), 4.76 (s, H, CH2), 4.54 (s, H,
3
2
CH2), 4.12 (t, JHH = 15.11 Hz, 2H, CH2), 3.30, 3.16 (2 d, JHH
=
12.71 Hz, 2H, CH2), 2.35 (m, 1H, CH2), 2.15 (m, 1H, CH2), 0.99 (s,
Synthesis of 10c′. Complex 10c′ (120 mg, 93% yield) was
similarly prepared from 5c (130 mg, 0.15 mmol), KPF6 (31 mg, 0.18
mmol), and methyl iodide (26 mg, 0.18 mmol), mp 174−176 °C.
3H, Me), 0.97 (s, 3H, Me). 13C NMR (CDCl3, 100.6 MHz): δ 343.94
3
(t, JCP = 15.21 Hz, Cα), 147.04 (C), 128.21−134.61 (Ph), 115.64
1
(Cβ), 112.92 (CH2), 94.32 (Cp), 76.80 (CH2), 74.43(CH2), 38.69
(CH2), 44.23 (CH), 38.16(Me), 26.09 (Me), 21.90 (Me). 31P NMR
(CDCl3, 162.0 MHz): δ 43.24, 43.02 (2 d, 2JPP = 26.35 Hz, PPh3). MS
ESI: m/z 855.25 [M]+. Anal. Calcd for C52H51BF4OP2Ru: C, 66.32; H,
5.46. Found: C, 66.68; H, 5.71.
Spectroscopic data of 10c′ are as follows. H NMR (CDCl3, 400.1
MHz): δ 7.77−6.93 (m, 42H, Ph), 5.14 (s, 5H, Cp), 4.63 (s, 1H, 
2
CH2), 4.41 (s, 1H, CH2), 4.18, 3.87 (2 d, JHH = 14.18 Hz, 2H,
OCH2), 3.34, 2.92 (2 d, 2JHH = 12.02 Hz, 2H, OCH2), 2.49 (t, 3JHH
=
12.91 Hz, 1H, CH), 2.20, 1.86 (2 d, 2JHH = 11.57 Hz, 2H, CH2), 1.76
(s, 3H, Me), 1.04 (s, 3H, Me), 0.93 (s, 3H, Me). 13C NMR (CDCl3,
100.6 MHz): δ 350.81 (t, 3JCP = 15.19 Hz, Cα), 148.22 (C(CH2)2),
135.23−128.42 (Cβ, Ph), 112.23 (CH2), 93.93 (Cp), 81.00
(OCH2), 74.59 (OCH2), 43.85 (CH2), 40.15 (CH2), 36.34 (C),
27.12 (Me), 21.65 (Me), 7.98 (Me). 31P NMR (CDCl3, 162.0 MHz):
δ 42.43, 41.44 (2 d, 2JPP = 26.42 Hz, PPh3). MS ESI: m/z 869.26 [M]+.
Anal. Calcd for C53H53F6OP3Ru: C, 62.78; H, 5.27. Found: C, 63.01;
H, 5.13.
Synthesis of 5c. A mixture of 2c (85 mg, 0.099 mmol) and
NaOMe (6.0 mg, 0.11 mmol) in MeOH (30 mL) was stirred for 5 min
at room temperature. Then, the solvent was removed under vacuum
and the residue was extracted with diethyl ether (20 mL). The yellow
filtrate was passed through a neutral Al2O3 column to remove the
insoluble salts. Collecting the yellow band followed by drying under
vacuum resulted in THE yellow powder 5c (77 mg, 90% yield), mp
179−181 °C. Spectroscopic data of 5c are as follows. 1H NMR (C6D6,
500.2 MHz): δ 7.69−7.73 (m, 12H, Ph), 6.92−6.98 (m, 18H, Ph),
5.00 (s, 1H, CH2), 4.79 (s, 1H, CH2), 4.39 (s, 5H, Cp), 4.59, 4.26
Synthesis of 8c. A solution of 1c (65 mg, 0.36 mmol) and
+
[Ru]NCCH3 (78 mg, 0.11 mmol) in 2/1 CHCl3/MeOH cosolvent
2
2
(2 d, JHH = 14.17 Hz, 2H, OCH2), 3.90, 3.33 (2 d, JHH = 11.81 Hz,
2H, OCH2), 2.86 (m, 2H, CH2), 2.76 (m, 1H, CγH), 1.51 (s, 3H, Me),
1.22 (s, 3H, Me). 13C NMR (C6D6, 125.8 MHz): δ 127.39−140.12
(Ph), 113.45 (Cβ), 92.69 (t, 2JCP = 24.43 Hz, Cα), 85.44 (Cp), 110.72
(CH2), 151.45 (C), 78.96 (CH2), 75.42 (CH2), 39.64 (CH2),
26.63 (Me), 21.74 (Me), 39.59 (C). 31P NMR (C6D6, 162.0 MHz): δ
51.94 (s, PPh3). MS ESI: m/z 855.25 [M + 1]+. Anal. Calcd for
C52H50OP2Ru: C, 73.14; H, 5.90. Found: C, 72.85; H, 5.73.
was heated to 50 °C for 1 day. A crude mixture was similarly obtained
using the same procedure as for 6c. Then the mixture was added to
diethyl ether (10 mL) to produce a pale orange precipitate and filtrate.
The precipitate was collected, washed with diethyl ether, and dried
+
under vacuum to give [Ru]NCCH3 . The filtrate was dried under
vacuum and the crude product purified by flash chromatography (silica
gel, hexanes/EtOAc 10/1) to afford the light yellow oil 8c (55 mg,
1
77%). Spectroscopic data for 8c are as follows. H NMR (CDCl3,
Synthesis of 6c. A solution of 2c (150 mg, 0.17 mmol) in CDCl3
(1.5 mL) and CH3CN (0.15 mL) in a tube was heated to 60 °C for 1
day. The solvent was removed under vacuum, CH2Cl2 (1.0 mL) was
used to extract the product, and the mixture was filtered through
Celite to remove the insoluble precipitate. Then the filtrate was added
to diethyl ether (6 mL) to produce a pale orange precipitate, which
was collected by filtration, washed with diethyl ether, and dried under
400.1 MHz): δ 5.81 (m, 1H, C(C)H), 5.70 (m, 1H, C(C)H),
2
2
4.12, 3.19 (2 d, JHH = 14.07 Hz, 2H, OCH2), 3.44, 3.11 (2 d, JHH
=
12.27 Hz, 2H, OCH2), 3.28 (s, 3H, OMe), 2.62 (2 d, 2JHH = 12.82 Hz,
1H, CH2), 2.12 (m, 1H, CH23), 1.92 (m, 1H, CH2), 2.05 (br, 1H, CH),
2
1.43 (dd, JHH = 12.82 Hz, JHH = 7.31 Hz, 1H, CH2), 1.14 (s, 3H,
Me), 0.81 (s, 3H, Me). 13C NMR (CDCl3, 100.6 MHz): δ 128.96 (
C), 126.25 (C), 83.09 (OCH2), 81.60 (OCH2), 78.42 (C), 49.29
(OMe), 44.46 (CH), 38.01 (C), 36.57 (CH2), 28.91 (CH2), 26.67
(Me), 23.75 (Me). MS ESI: m/z 197.8102 [M + H]+. Anal. Calcd for
C12H20O2: C, 73.43; H, 10.27. Found: C, 73.28; H, 10.33.
+
vacuum to give [Ru]NCCH3 . The filtrate was dried under vacuum
and the crude product purified by flash chromatography (silica gel,
hexanes/EtOAc 10/1) to afford the light yellow oil 6c (26 mg, 92%).
1
Spectroscopic data for 6c are as follows. H NMR (CDCl3, 400.1
Synthesis of 8c′. Compound 8c′ (49 mg, 70% yield) was similarly
prepared from 1c (61 mg, 0.33 mmol) and [Ru]NCCH3+ (73 mg, 0.10
mmol) in 2/1 CHCl3/EtOH cosolvent, and the solution was heated to
MHz): δ 4.92 (s, 1H, CH2), 4.83 (s, 1H, CH2), 4.23, 4.13 (2 d,
2
2JHH = 14.51 Hz, 2H, OCH2), 3.35, 3.13 (2 d, JHH = 12.51 Hz, 2H,
OCH2), 2.48 (m, 2H, CH2), 2.23 (dt, 3JHH = 9.54 Hz, 4JHH = 2.50 Hz,
50 °C for 1 day. Spectroscopic data of 8c′ are as follows. H NMR
1
6385
dx.doi.org/10.1021/om400742x | Organometallics 2013, 32, 6379−6387

Organometallics
Article
(CDCl3, 400.1 MHz): δ 5.80 (m, 1H, C(C)H), 5.70 (m, 1H, 
C(C)H), 4.11, 3.22 (2 d, 2JHH = 13.96 Hz, 2H, OCH2), 3.53 (m, 2H,
MHz): δ 49.62, 48.50 (dd, 2Jpp = 36.5 Hz, 5JPP = 5.1 Hz, PPh3), 15.85
(t, 5Jpp = 5.1 Hz, CPPh3). MS ESI: m/z 1139.27 [M]+. Anal. Calcd for
C71H60F6P4RuS: C, 66.40; H, 4.71. Found: C, 66.21; H, 4.59.
OCH2), 3.43, 3.11 (2 d, 2JHH = 12.16 Hz, 2H, OCH2), 2.61 (d, 2JHH
=
1
12.77 Hz, 1H, CH2), 2.14 (m, 1H, CH2), 1.93 (m, 1H, CH2), 2.04 (br,
Spectroscopic data of 13b are as follows. H NMR (CDCl3, 400.1
1H, CH), 1.47 (dd, 2JHH = 13.30 Hz, 3JHH = 7.48 Hz, 1H, CH2), 1.15
MHz): δ 9.67 (s, 1H, CγH), 7.70−6.99 (m, 34H, Ph), 5.92 (m, 1H, 
(t, JHH = 7.06 Hz, 3H, Me), 1.13 (s, 3H, Me), 0.81 (s, 3H, Me). 13C
3
CH), 5.18 (s, 1H, CH2), 5.14 (s, 5H, Cp), 5.10 (s, 1H, CH2),
3
3.67 (d, JHH = 6.0 Hz, 2H, CH2). 31P NMR (CDCl3, 162.0 MHz): δ
NMR (CDCl3, 100.6 MHz): δ 128.94 (C), 126.34 (C), 83.08
(OCH2), 81.60 (OCH2), 78.42 (C), 49.29 (OMe), 44.46 (CH), 38.01
(C), 36.57 (CH2), 28.91 (CH2), 26.67 (Me), 23.75 (Me). MS ESI: m/
z 211.8102 [M + H]+. Anal. Calcd for C13H22O2: C, 74.24; H, 10.54.
Found: C, 73.94; H, 10.41.
46.55 (s, PPh3). MS ESI: m/z 877.18 [M]+. Anal. Calcd for
C53H45F6P3RuS: C, 62.29; H, 4.44. Pure complex 13b was not
obtained.
Synthesis of 3b. A mixture of [Ru]Cl (200 mg, 0.27 mmol), 1b
(83 mg, 0.41 mmol), and NH4PF6 (111.7 mg, 1.03 mmol) in CH2Cl2
(40 mL) was stirred at 40 °C for 1 day. The crude mixture was
obtained using the same procedure as for 3a. The powder was
collected, washed with diethyl ether, and dried under vacuum to give
an olive powder (188 mg) containing mostly 3b (ca. 78% yield).
Attempts to purify 3b failed. Spectroscopic data of 3b are as follows.
Synthesis of 8c″. Compound 8c″ (30 mg, 43% yield) was
similarly prepared from 1c (57 mg, 0.31 mmol) and [Ru]NCCH3+ (68
mg, 0.093 mmol) in 2/1 CHCl3/i-PrOH cosolvent, and the solution
was heated to 50 °C for 1 day. Spectroscopic data of 8c″ are as follows.
1H NMR (CDCl3, 400.1 MHz): δ 5.78 (m, 1H, C(C)H), 5.68 (m,
2
1H, C(C)H), 4.11, 3.23 (2 d, JHH = 13.95 Hz, 2H, OCH2), 3.94
3
2
1H NMR (CDCl3, 400.1 MHz): δ 7.77−6.86 (m, Ph), 5.83 (d, 2JHP
=
(septet, JHH = 6.18 Hz, 1H, CH), 3.44, 3.12 (2 d, JHH = 12.12 Hz,
2H, OCH2), 2.58 (d, 2JHH = 12.68 Hz, 1H, CH2), 2.12 (m, 1H, CH2),
1.91 (m, 1H, CH2), 2.03 (br, 1H, CH), 1.51 (dd, JHH = 12.51 Hz,
36.2 Hz, 1H, CHPPh3), 5.72 (m, 1H, CH), 5.01 (s, 1H, CH2),
4.95 (s, 1H, CH2), 4.89 (s, 1H, CH), 4.64 (s, 5H, Cp), 3.76 (m, 1H,
CH2), 3.58 (m, 1H, CH2), 3.29 (br, 1H, OH). 13C NMR (CDCl3,
100.6 MHz): δ 233.47 (br, Cα), 160.36−127.49 (Ph, CH), 120.81
(CH2), 100.95 (br, CHPPh3), 81.64 (Cp), 78.15 (CH), 53.72
(CH2). 31P NMR (CDCl3, 162.0 MHz): δ 56.26 (br, PPh3), −5.50 (br,
PPh3). MS ESI: m/z 895.02 [M]+. Anal. Calcd for C53H47F6OP3RuS:
C, 61.21; H, 4.56. Pure complex 3b was not obtained.
2
3JHH = 7.33 Hz, 1H, CH2), 1.14 (s, 3H, Me), 0.81 (s, 3H, Me), 1.13 (s,
6H, 2 Me). 13C NMR (CDCl3, 100.6 MHz): δ 128.86 (C), 126.38
(C), 83.16 (OCH2), 83.07 (OCH2), 79.03 (C), 64.23 (OCH),
44.53 (CH), 37.98 (C), 37.64 (CH2), 31.07 (CH2), 26.70 (Me), 25.54
(Me), 25.33 (Me), 23.76 (Me). MS ESI: m/z 247.1661 [M + Na]+.
Anal. Calcd for C14H24O2: C, 74.95; H, 10.78. Found: C, 74.74; H,
10.86.
Synthesis of 4b. Complex 4b (239 mg, 80% yield) was prepared
+
Synthesis of 11a. In a flask containing 4a (300 mg, 0.29 mmol)
were added NEt3 (5 mL) and CH3CN (10 mL) in air. The mixture
was stirred at room temperature for 1 day. The originally brown
solution turned dark brown. Then the solvent was removed under
vacuum. The residue was purified by flash chromatography (silica gel,
hexane/ether 4/1) to afford the light yellow oil 11a (52.0 mg, 83%).
from [Ru]NCCH3 (300 mg, 0.34 mmol), 1b (104 mg, 0.51 mmol),
and NH4PF6 (166 mg, 1.02 mmol) in CH2Cl2 (40 mL), mp 184−186
°C, using a procedure similar to that for 4a. Spectroscopic data of 4b
are as follows. 1H NMR (CDCl3, 400.2 MHz): δ 15.03 (t, 3JPH = 10.51
Hz, 1H, CαH), 8.05−6.96 (m, Ph), 5.54 (m, 1H, CH), 5.15 (s, 5H,
Cp), 4.72 (d, 3JHH = 9.4 Hz, 1H, CH2), 4.46 (d, 3JHH = 17.2 Hz, 1H,
CH2), 2.90 (s, 2H, CH2). 13C NMR (CDCl3, 100.6 MHz): δ 280.19
1
Spectroscopic data for 11a are as follows. H NMR (CDCl3, 400.1
2
MHz): δ 10.30 (s, 1H, CHO), 7.88 (m, 2H, Ph), 7.49 (m, 1H, Ph),
7.41 (m, 1H, Ph), 4.88 (s, 1H, CH2), 4.67 (s, 1H, CH2), 3.95 (s,
2H, CH2), 1.81 (s, 3H, Me). 13C NMR (CDCl3, 100.6 MHz): δ
184.08 (CHO), 144.27, 142.86, 142.24, 139.71, 138.65, 128.25,
124.84, 142.38, 123.32 (Ph and C), 113.14 (CH2), 34.58 (CH2),
22.74 (Me). MS ESI: m/z 217.0687 [M + H]+. Anal. Calcd for
C13H12OS: C, 72.19; H, 5.59. Found: C, 71.97; H, 5.68.
(t, JCP = 12.3 Hz, Cα), 162.12−123.75 (Ph, C), 117.31 (CH2),
94.64 (Cp), 31.66 (CH2). 31P NMR (CDCl3, 162.0 MHz): δ 45.33 (s,
PPh3). MS ESI: m/z 877.18 [M]+. Anal. Calcd for C53H45F6P3RuS: C,
62.29; H, 4.44. Found: C, 62.57; H, 4.53.
Synthesis of 11b. Compound 11b (36 mg, 88% yield), similar to
the preparation of 11a from 4a, was prepared from 4b (200 mg, 0.20
mmol), NEt3 (5 mL), and CH3CN (10 mL) in air. Spectroscopic data
for 11a are as follows. 1H NMR (CDCl3, 400.2 MHz): δ 10.21 (s, 1H,
Synthesis of 12b and 13b. A mixture of [Ru]Cl (300 mg, 0.41
mmol), 1b (109 mg, 0.53 mmol), KPF6 (189 mg, 1.03 mmol), and
PPh3 (323 mg, 1.23 mmol) in MeOH (40 mL) was stirred at ambient
temperature for 1 day. The crude mixture was obtained using the same
procedure as for 3a. The crude mixture in 5 mL of CH2Cl2 was added
to diethyl ether to produce a yellow precipitate, which was filtered and
dried under vacuum to give the yellow powder 12b (491 mg, 95%
yield), mp 148−150 °C. Compound 12b (250 mg, 0.20 mmol) was
treated with excess K2CO3 (81 mg, 0.58 mmol) in 20 mL of MeOH at
room temperature for 15 min under nitrogen. Then dimethyl
acetylenedicarboxylate (DMAD; 28 mg, 0.19 mmol) was added, and
the mixture was stirred for 10 min. The resulting yellow solution was
reduced to ca. 5 mL under vacuum to produce a precipitate. The
precipitate thus formed was collected on a glass frit, and hexane was
used to wash the precipitate to yield a yellow solution, which was dried
and redissolved in diethyl ether. Then a solution of HBF4·Et2O (48%,
0.02 mL, 0.11 mmol) in diethyl ether (20 mL) was added dropwise at
0 °C to this yellow solution. Immediately, insoluble solid precipitated
but the addition was continued until no further solid was formed. The
solution was then decanted, and the red solid was washed with diethyl
ether and dried in vacuo to yield the red powder 13b (127 mg, 78%).
3
3
CHO), 7.96 (d, JHH = 8.1 Hz, 1H, Ph), 7.86 (d, JHH = 8.1 Hz, 1H,
3
3
Ph), 7.50 (t, JHH = 7.1 Hz, 1H, Ph), 7.43 (t, JHH = 7.4 Hz, 1H, Ph),
6.87 (m, 1H, CH), 6.29 (m, 1H, CH), 2.06 (m, 3H, Me). 13C
NMR (CDCl3, 100.6 MHz): δ 185.07 (CHO), 144.58, 141.88,
138.72, 138.07 (Ph), 137.34 (CH), 128.28, 124.94, 124.64, 123.27
(Ph), 121.42 (CH), 19.30 (Me). MS ESI: m/z 203.0503 [M + H]+.
Anal. Calcd for C12H10OS: C, 71.25; H, 4.98. Found: C, 71.07; H,
5.05.
Single-Crystal X-ray Diffraction Analyses. Single crystals of
complexes 5a, 9a, and 10c suitable for X-ray diffraction study were
grown as mentioned above. Single crystals were glued to a glass fiber
and mounted on a SMART CCD diffractometer. The diffraction data
were collected by using 3 kW sealed-tube Mo Kα radiation (T = 295
K). The exposure time was 5 s per frame (Siemens area detector
absorption). SADABS22 absorption correction was applied, and decay
was negligible. Data were processed, and the structure was solved and
refined by the SHELXTL23 program. Hydrogen atoms were placed
geometrically by using a riding model with thermal parameters set to
1.2 times that for the atoms to which they are attached and 1.5 times
for the methyl hydrogen atoms.
1
Spectroscopic data of 12b are as follows. H NMR (d-acetone, 400.1
MHz): δ 7.92−7.06 (m, 49H, Ph), 6.78 (d, 3JHH = 17.9 Hz, 1H, CγH),
5.63 (m, 1H, CH), 5.00 (d, 3JHH = 17.2 Hz, 1H, trans CH2), 4.93
ASSOCIATED CONTENT
■
3
(d, JHH = 10.2 Hz, 1H, cis CH2), 4.31 (s, 5H, Cp), 3.40 (m, 1H,
S
* Supporting Information
CH2), 3.16 (m, 1H, CH2). 13C NMR (d-acetone, 100.6 MHz): δ
138.75−133.66 (Ph), 133.04 (CH), 132.81−127.39 (Ph), 118.68
(Cβ), 117.95 (CH2), 97.96 (d, 2JCP = 9.4 Hz, Cα), 84.97 (Cp), 38.29
CIF files, tables, and figures giving crystallographic data for 5a,
9a, and 10c and NMR spectra of new complexes. This material
is available free of charge via the Internet at http://pubs.acs.org.
1
(d, JCP = 46.9 Hz, Cγ), 37.48 (CH2). 31P NMR (d-acetone, 162.0
6386
dx.doi.org/10.1021/om400742x | Organometallics 2013, 32, 6379−6387

Organometallics
Article
(7) (a) Ma, H. W.; Lin, Y. C.; Huang, S. L. Org. Lett. 2012, 14, 3846−
3849. (b) Feng, Y. J.; Lai, Y. H.; Lin, Y. C.; Huang, S. L.; Liu, Y. H.
Chem. Asian J. 2013, DOI: 10.1002/asia.201301264.
(8) (a) Cadierno, V.; Gamasa, M. P.; Gimeno, J.; Borge, J.; García-
Granda, S. Organometallics 1997, 16, 3178−3187. (b) Cadierno, V.;
́
Gamasa, M. P.; Gimeno, J.; Gonzalez-Bernardo, C. Organometallics
2001, 20, 5177−5188. (c) Arikawa, Y.; Asayama, T.; Tanaka, C.;
Tashita, S. Y.; Tsuji, M.; Ikeda, K.; Umakoashi, K.; Onishi, M.
Organometallics 2008, 27, 1227−1233. (d) Nishimura, Y.; Arikawa, Y.;
Inoue, T.; Onishi, M. Dalton Trans. 2005, 930−937. (e) Hansen, H.
D.; Nelson, J. H. Organometallics 2000, 19, 4740−4755.
AUTHOR INFORMATION
Corresponding Author
*Y.C.L.: e-mail, yclin@ntu.edu.tw; fax, (+886) 233668670.
Notes
■
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We thank the National Science Council of Taiwan for financial
support.
(9) (a) Bassetti, M.; Cadierno, V.; Gimeno, J.; Pasquini, C.
Organometallics 2008, 27, 5009−5016. (b) Cadierno, V.; Gamasa, M.
P.; Gimeno, J. Organometallics 1999, 18, 2821−2832. (c) Cadierno, V.;
Gamasa, M. P.; Gimeno, J. Eur. J. Inorg. Chem. 2001, 571−579.
(10) (a) Villemin, D.; Hachemi, M. Synth. Commun. 1995, 25, 2311−
2318. (b) Majumdar, K. C.; Ghosh, M.; Jana, M. Synthesis 2002, 669−
673. (c) Kobbelgaard, S.; Brandes, S.; Jorgensen, K. A. Chem. Eur. J.
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