Reactions of propargyl compounds containing a cyclobutyl group induced by a ruthenium complex

Article abstract of DOI:10.1002/asia.201200589

Reactions of [Ru]Cl ([Ru]={Cp(PPh₃)₂Ru}; Cp=cyclopentadienyl) with three alkynyl compounds, 1, 5, and 8, each containing a cyclobutyl group, are explored. For 1, the reaction gives the vinylidene complex 2, with a cyclobutylidene group, through dehydration at C _δH and C_γOH. With an additional methylene group, compound 5 reacts with [Ru]Cl to afford the cyclic oxacarbene complex 6. The reaction proceeds via a vinylidene intermediate followed by an intramolecular cyclization reaction through nucleophilic addition of the hydroxy group onto C_α of the vinylidene ligand. Deprotonation of 2 with NaOMe produces the acetylide complex 3 and alkylations of 3 by allyl iodide, methyl iodide, and ethyl iodoacetate generate 4 a-c, respectively, each with a stable cyclobutyl group. Dehydration of 1 is catalyzed by the cationic ruthenium acetonitrile complex at 70 °C to form the 1,3-enyne 7. The epoxidation reaction of the double bond of 7 yields oxirane 8. Ring expansion of the cyclobutyl group of 8 is readily induced by the acidic salt NH ₄PF₆ to afford the 2-ethynyl-substituted cyclopentanone 9. The same ring expansion is also seen in the reaction of [Ru]Cl with 8 in CH₂Cl₂, affording the vinylidene complex 10, which can also be obtained from 9 and [Ru]Cl. However, in MeOH, the same reaction of [Ru]Cl with 8 affords the bicyclic oxacarbene complex 12 a through an additional cyclization reaction. Transformation of 10 into 12 a is readily achieved in MeOH/HBF₄, but, in MeOH alone, acetylide complex 11 is produced from 10. In the absence of MeOH, cyclization of 10, induced by HBF₄, is followed by fluorination to afford complex 13. Crystal structures of 6 and 12 a' were determined by single-crystal diffraction analysis. Copyright

Full text of DOI:10.1002/asia.201200589

DOI: 10.1002/asia.201200589
Reactions of Propargyl Compounds Containing a Cyclobutyl Group Induced
by a Ruthenium Complex
Yung-Ching Wang, Ying-Chih Lin,* and Yi-Hung Liu[a]
Abstract: Reactions of [Ru]Cl ([Ru]=
{Cp(PPh3)2Ru}; Cp=cyclopentadienyl)
allyl iodide, methyl iodide, and ethyl
iodoacetate generate 4a–c, respectively,
each with a stable cyclobutyl group.
Dehydration of 1 is catalyzed by the
cationic ruthenium acetonitrile com-
plex at 708C to form the 1,3-enyne 7.
The epoxidation reaction of the double
bond of 7 yields oxirane 8. Ring expan-
sion of the cyclobutyl group of 8 is
readily induced by the acidic salt
NH4PF6 to afford the 2-ethynyl-substi-
tuted cyclopentanone 9. The same ring
expansion is also seen in the reaction
of [Ru]Cl with 8 in CH2Cl2, affording
the vinylidene complex 10, which can
also be obtained from 9 and [Ru]Cl.
However, in MeOH, the same reaction
of [Ru]Cl with 8 affords the bicyclic
oxacarbene complex 12a through an
additional cyclization reaction. Trans-
formation of 10 into 12a is readily ach-
ieved in MeOH/HBF4, but, in MeOH
alone, acetylide complex 11 is pro-
duced from 10. In the absence of
MeOH, cyclization of 10, induced by
HBF4, is followed by fluorination to
afford complex 13. Crystal structures of
6 and 12a’ were determined by single-
crystal diffraction analysis.
ACHTUNGTRENNUNG
with three alkynyl compounds, 1, 5,
and 8, each containing a cyclobutyl
group, are explored. For 1, the reaction
gives the vinylidene complex 2, with
a cyclobutylidene group, through dehy-
dration at CdH and CgOH. With an ad-
ditional methylene group, compound 5
reacts with [Ru]Cl to afford the cyclic
oxacarbene complex 6. The reaction
proceeds via a vinylidene intermediate
followed by an intramolecular cycliza-
tion reaction through nucleophilic ad-
dition of the hydroxy group onto Ca of
the vinylidene ligand. Deprotonation
of 2 with NaOMe produces the acety-
lide complex 3 and alkylations of 3 by
Keywords: cyclization
·
cyclobu-
tanes · fluorine · ring expansion ·
ruthenium
Introduction
tion of a g-hydroxyvinylidene intermediate. However, if Cd
of such an intermediate has one hydrogen atom, subsequent
dehydration may proceed to give a vinylvinylidene com-
plex.[7] In our previous study on the reaction of a ruthenium
complex with propargyl alcohol containing a cyclopropyl
ring, even with CdH, an allenylidene complex with a three-
membered ring was isolated. Ring expansion of this allenyli-
dene complex was found to be mildly induced by a halide
anion and other reagents. The development of ring expan-
sion of various cycloalkyl groups is an important methodolo-
gy for organic synthesis.[8] Reactions of functional groups
with three-membered rings, such as cyclopropanes,[9a] vinyl-
cyclopropanes,[9b] cyclopropenes,[9a] and methylenecyclopro-
panes (MCPs),[9c] have been developed. Particularly, owing
to high ring strain and the electron-rich double bond, MCPs
display a rich range of reactivities, including [3+2] cycload-
dition,[10a] rearrangement,[10b] and substitution reactions.[10c]
Methylenecyclobutane was first discovered by Gustavson.[11]
Because of the presence of the cyclobutyl ring and olefinic
double bond, the chemistry and applications of this com-
pound have been exploited,[12] for example, cycloaddition,[13]
ring-opening reactions,[14] and polymerization.[15] To further
enhance the chemical reactivity, the olefinic functional
group bonded to cycloalkyl has been modified by epoxida-
tion or aziridination. For example, ring-opening reactions of
highly strained oxiranes easily proceed under both acidic
and basic conditions. Propargyl heterocyclopropanes, when
During the past decade, the chemistry of transition-metal vi-
nylidene, acetylide, and allenylidene complexes has attracted
a great deal of attention. Reactions, such as alkylation,[1] cat-
[2]
À
alytic C C bond formation, and ring opening, using these
complexes have been extensively explored.[3] The first metal
vinylidene complex was reported in 1972.[4] It is now known
that activation of a terminal alkyne by a metal center and
alkylation of a metal acetylide complex are two major meth-
ods for the preparation of metal vinylidene complexes. The
formation of the first allenylidene complex was reported by
Selegue in 1982 through the reaction of propargyl alcohol
and an appropriate precursor complex in the presence of
[5]
NH4PF6. The majority of transition-metal allenylidene
complexes are based on ruthenium. However, other metals,
such as osmium,[6a] molybdenum,[6b] and tungsten,[6c] have
also been reported to give similar complexes. The formation
of the allenylidene complex generally proceeds by dehydra-
[a] Y.-C. Wang, Prof. Dr. Y.-C. Lin, Y.-H. Liu
Department of Chemistry
National Taiwan University
Taipei, 106 (Taiwan)
Fax : (+886)223636359
E-mail: yclin@ntu.edu.tw
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/asia.201200589.
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FULL PAPER
treated with transition-metal complexes, undergo cascade
cyclization.[16] Namely, a catalytic amount of silver or gold
complexes converts alkynyl oxiranes or aziridines into
furans or pyrroles in the presence of external nucleophi-
les.[16b]
Herein, we report reactions of [Ru]Cl ([Ru]={Cp-
ACHTUNGTRENNUNG(PPh3)2Ru}; Cp=cyclopentadienyl) with alkynyl compounds
containing a cyclobutyl group. Ring expansion of the cyclo-
butyl group is achieved when epoxidation is introduced near
the four-membered ring. Furthermore, participation of the
triple bond results in the formation of bicyclic oxacarbene
complex, the structure of which was confirmed by single-
crystal diffraction analysis. A fluorine derivative of this bicy-
clic oxacarbene complex was also prepared.
Results and Discussion
Catalytic Dehydration of 1
Scheme 1. Reactions of [Ru]Cl with propargyl alcohol 1 with a cyclobutyl
ring. mCPBA=m-chloroperbenzoic acid.
Propargyl alcohol 1 with a cyclobutyl ring was prepared in
high yield from the reaction of cyclobutylphenyl ketone
with ethynylmagnesium bromide in tetrahydrofuran (THF).
Treatment of [Ru]Cl with 1 in the presence of KPF6 in
MeOH at room temperature afforded the vinylidene com-
plex 2 containing a cyclobutylidene group. Presumably the
reaction proceeds through the formation of vinylidene inter-
mediate A shown in Scheme 1. The dehydration of A then
takes place between CdH and CgOH to afford 2.[7] No alle-
nylidene complex was observed. Previously, we reported the
reaction of the cyclopropyl analogue of 1 with [Ru]Cl, af-
fording a allenylidene complex containing the cyclopropyl
group. However, in the reaction of 1, the dehydration pro-
cess of the intermediate A to form 2 is favored. Theoretical
calculations on a simple model with no cycloalkyl group
show that the vinylidene complex is 2.1 kcalmolÀ1 more
stable than the allenylidene complex.[17] Thus, the presence
of the cyclopropyl group may affect the relative stability,
whereas the four-membered ring has a less influential role.
The 31P NMR spectrum of 2 displays a singlet resonance at
signed to the cyclobutyl group, revealing the structure of 2.
2
The triplet 13C resonance at d=357.76 ppm with J
(C,P)=
16.3 Hz is assigned to Ca bound to ruthenium. This chemical
shift is within the range of Ca resonances of many other
ruthenium vinylidene complexes.[18]
Treatment of 2 with NaOMe in MeOH afforded the light
yellow acetylide complex 3, the structure of which was de-
1
termined by NMR spectroscopy. The H resonance of CbH
1
at d=4.90 ppm of 2 disappeared in the H NMR spectrum
of 3. Treatment of 3 with allyl iodide, methyl iodide, and
ethyl iodoacetate separately in the presence of KPF6 afford-
ed the corresponding cationic vinylidene complexes 4a, 4b,
1
and 4c.[1] In the H NMR spectrum of 4c, the singlet reso-
nance at d=2.87 ppm is assigned to CgH2. The Ca resonance
in the 13C NMR spectrum appears as a triplet at d=
2
350.77 ppm with J
N
appears at d=172.33 ppm. Previously, we reported the de-
protonation reaction of an ester-containing vinylidene com-
plex by nBu4NOH at CgH, followed by a cyclization reaction
to afford a cyclopropenyl complex as well as a furyl com-
plex.[19] Unfortunately, treatment of 4c with nBu4NOH
failed to yield the expected product and 4c decomposed.
The vinylidene complexes 4a–4c are relatively stable. At-
tempts at ring expansion of the cyclobutylidene group of
4a–4c by using various transition-metal complexes failed.
The reaction of 2 with a small amount of acetonitrile in
CHCl3 at reflux afforded the 1,3-enyne 7 containing the cy-
clobutylidene group and [Ru]NCMe+ (Scheme 1). Transfor-
mation of 2 to 7 proceeds via a p-coordinated alkyne species
followed by substitution with acetonitrile.[20] However, the
yield of 7 from 1 by this indirect route is low. Interestingly,
direct treatment of 1 with 30 mol% of [Ru]NCMe+ in
MeOH at 708C affords 7 in 90% yield, as determined by
NMR spectroscopy. In this reaction, a small amount of 2,
less than 10% yield, is also produced. Furthermore, treat-
1
d=41.26 ppm. In the H NMR spectrum, no coupling is ob-
served between the broad signal at d=4.90 ppm, assigned to
CbH, and resonances in the range of d=2.77–1.99 ppm, as-
Abstract in Chinese:
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Reactions of Propargyl Compounds
ment of 1 with 30 mol% of [Ru]Cl and MeCN/NH4PF6 in
MeOH at 708C also produced 7 after a slightly longer reac-
tion time. If the solvent is changed from MeOH to MeOD,
the terminal alkynyl hydrogen of 7 is replaced by deuterium.
Deuteration should occur during the formation of vinylidene
intermediate A. The dehydration of 1 when using P4O10
(from 08C to RT) also produced 7, but only in 45% yield
with impurities. Catalytic dehydration of analogous com-
pounds, leading to the formation of cyclobutylidene deriva-
tives, has been induced by FeCl3 in toluene, but, the cyclo-
butylidene compound was formed as a minor product in
38% yield.[21]
Figure 1. An ORTEP drawing of the cationic complex 6. For clarity,
phenyl groups of the triphenylphosphine ligands on ruthenium, except
the ipso carbon atoms, and PF6À are omitted (thermal ellipsoids are set at
the 30% probability level). Selected bond lengths [ꢁ] and angles [8]:
Formation of the Cyclic Carbene Complex
À
À
À
À
Ru1 P1 2.3262(5), Ru1 P2 2.3631(5), Ru1 C1 1.9430(18), O2 C1
Alkynyl alcohol 5, also with a cyclobutyl group, was pre-
pared in high yield from the reaction of cyclobutylphenyl
ketone with prop-2-ynylmagnesium bromide. Treatment of
[Ru]Cl with 5 in the presence of NH4PF6 in CH2Cl2 at room
temperature afforded the yellow cyclic oxacarbene complex
6 containing a cyclobutyl group. (Scheme 2)
À
À
À
À
1.318(2), O2 C4 1.512(2), C4 C5 1.519(3), C5 C6 1.549(3), C6 C7
À
À
1.545(3), C7 C8 1.542(4), C5 C8 1.540(3); O2-C1-Ru1 127.10(13), C1-
O2-C4 113.96(13), C4-C5-C8 118.09(19), C8-C7-C6 88.20(18), C8-C5-C6
88.13(17), C5-C6-C7 87.40(18), C5-C8-C7 87.81(19).
example, the ring expansion of alkylidene epoxide cyclobu-
tane was reported to give cyclopentanone.[22a–c] To achieve
ring expansion of the cyclobutyl group in 7, a new epoxide
group was introduced. Compound 7 was treated with
mCPBA to afford cyclobutyloxirane 8. Two olefinic 13C reso-
nances of 7 at d=154.98 and 114.61 ppm disappeared in the
13C NMR spectrum of 8. The reaction of 8 with [Ru]Cl in
CH2Cl2/NH4PF6 produced the vinylidene complex 10 con-
taining a cyclopentanone ring (Scheme 3). Ring expansion
Scheme 2. Reaction of alkynyl alcohol 5 containing a cyclobutyl ring with
[Ru]Cl.
As expected, no dehydration was observed. The reaction
presumably proceeds through formation of B, followed by
an intramolecular cyclization reaction by nucleophilic addi-
tion of the hydroxy group to Ca=Cb of the vinylidene ligand
of B to afford 6. The structure of 6 was determined by
NMR spectroscopy. The 31P NMR spectrum of 6 displays
2
two doublet resonances at d=46.29 and 43.60 ppm with J-
ACHTUNGTRENNUNG
(P,P)=30.7 Hz, owing to the stereogenic sp3 carbon. Two
multiplet resonances in the 1H NMR spectrum at d=3.78
and 3.37 ppm were assigned to the diastereotopic CbH2
group. The HMBC spectrum shows correlation of one reso-
nance of CbH2 with the triplet 13C resonance at d=
2
299.82 ppm with J
N
Single crystals of 6 were obtained from a solution of 6 in
CH2Cl2 layered with diethyl ether. The structure of 6 was
confirmed by
a single-crystal X-ray diffraction study
(Figure 1). Complex 6 has distorted three-legged piano-stool
coordination geometry around the ruthenium center, which
bonds to a Cp, two PPh3, and the cyclic carbene ligand. The
Scheme 3. Proposed mechanism for the formation of 12a and 13.
À
bond length of Ru1 C1 of 1.943(2) ꢁ shows a typical ruthe-
nium–carbene bond. The twisted four-membered ring is
bonded to the tetrahydrofuryl ring.
of 8 to generate cyclopentanone compound 9, induced by
the acidic salt NH4PF6, was also achieved in the absence of
[Ru]Cl.
The reaction of 9 with [Ru]Cl/NH4PF6 also yielded 10.
Deprotonation of 10 by NaOMe in MeOH afforded the ace-
tylide complex 11. The structures of complexes 10 and 11
were determined by various spectroscopic methods. In the
Ring Expansion Using Epoxides
The ring opening of the methylenecycloalkyl group by epox-
idation has been previously reported in the literature.[22] For
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Ying-Chih Lin et al.
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2D HMBC NMR spectrum of 10, the resonance at d=
216.33 ppm, assigned to the carbonyl carbon, correlates with
resonances of all methylene hydrogen atoms in the five-
membered ring because of 2J
(C,H) and 3J
ACHUTGTNRENNUG ACHUTNTGREN(NUGN C,H) coupling;
this revealed the cyclic structure.
Additional cyclization takes place for 10 in MeOH/HBF4,
thereby yielding bicyclic oxacarbene complex 12a, the struc-
ture of which was determined by NMR spectroscopy. In the
2D HSQC NMR spectrum of 12a, three 13C resonances at
d=39.89, 32.98, and 21.71 ppm each correlate with the cor-
responding hydrogen atoms of three methylene groups of
the cyclopentyl ring. The 13C resonance at d=56.25 ppm is
assigned to the bridgehead carbon with the phenyl group.
The resonance of the bridgehead acetal carbon of 12a is ex-
pected to appear within the range of d=130–140 ppm. In
the 2D HMBC NMR spectrum, the 13C resonance at d=
137.00 ppm correlates with all methylene hydrogen atoms of
the two rings and is assigned to the bridgehead acetal
Figure 2. An ORTEP drawing of the cationic complex 12a’. For clarity,
phenyl groups of the dppe ligands on ruthenium, except the ipso carbon
À
atoms, and PF6 are omitted (thermal ellipsoids are set at the 30% prob-
À
ability level). Selected bond lengths [ꢁ] and angles [8]: Ru1 P1
À
À
À
À
2.2796(8), Ru1 P2 2.2823(9), Ru1 C1 1.949(3), C1 C2 1.5025, C1 O1
À
À
À
À
1.320(4), C2 C3 1.508(5), O1 C4 1.509(5), C3 C4 1.520(6), C4 C5
À
À
1.492(7), C3 C7 1.592(7), C6 C7 1.505(9); C1-O1-C4 113.8(3), C4-C3-C7
100.1(4), O1-C1-Ru1 128.1(2).
1
carbon of 12a. In the H NMR spectrum, the two doublet
2
resonances at d=4.36 and 4.26 ppm with J
N
of 12a’ were obtained from a solution of 12a’ in CH2Cl2 lay-
ered with diethyl ether. The structure of 12a’ was deter-
mined by a single-crystal X-ray diffraction study (Figure 2).
Complex 12a’ has a distorted three-legged piano-stool coor-
dination geometry around the ruthenium center, which
bonds to Cp, dppe, and the bicyclic oxacarbene ligand. The
are assigned to two hydrogen atoms of CbH2 because of the
nearby stereogenic sp3 carbon. In the 31P NMR spectrum,
two doublets appear at d=45.86 and 44.41 ppm with 2J-
ACHTUNGTRENNUNG
(P,P)=30.8 Hz.[23] However, in the absence of MeOH, the
reaction of 10 with HBF4 in CH2Cl2 affords the fluorine-sub-
stituted bicyclic oxacarbene complex 13. Namely, fluorine is
À
bond length of Ru1 C1 in 12a’ of 1.949(3) ꢁ shows a typical
added to the carbocationic site to yield 13. In the 13C NMR
ruthenium–carbene bond. The bond length of C3 C7 in
À
1
À
spectrum of 13, a doublet at d=137.62 ppm with J
N
12a’ of 1.592(7) ꢁ attests to C C bond formation. Two dihe-
248.8 Hz is assigned to the CF group. All other 13C resonan-
ces of the five-membered cyclopentyl ring in the 13C NMR
spectrum display doublet signals owing to coupling with the
dral angles, C2-C3-C4-C5 and O1-C4-C3-C7, of 123.08 and
89.348, respectively, indicate twisting of the all-carbon five-
membered ring.
1
2
fluorine atom. All coupling constants, including J
N
Oxabicycles are fundamental structural fragments of
many natural products.[25] For example, hexahydro-2H-cyclo-
penta[b]furans are important heterobicycles because they
are a component of HIV-1 protease inhibitors.[26] The forma-
tion of oxabicycles has been previously introduced by the
oxy-Favorskii rearrangement of a-halolactones.[25] However,
the structure of a-halolactones substrates and steric hin-
drance between the incoming nucleophiles and the sub-
strates can greatly affect the oxy-Favorskii rearrangement
process. Herein, we present an efficient way to synthesize
hexahydro-2H-cyclopenta[b]furans. Organofluorides are
widely used as pharmaceuticals[27] and agrochemicals.[28]
Compounds containing fluorine can increase lipophilicity to
enhance bioavailability[29] or increase metabolic stability.[29b]
Consequently, synthetic methodologies for carbon–fluorine
bond formation have been significantly investigated.[30] Fluo-
rinations including electrophilic[31a] and nucleophilic fluori-
nation,[31b] the use of fluorinated synthons,[31c] and electro-
chemical methods[31d] have been reported. For example,
ring-opening hydrofluorination of substituted aryl epoxides
with HBF4 afforded fluorohydrins.[32] Herein, we describe an
easy method to prepare a fluorooxabicyclic product.
G
ACHTUNGTRENNUNG
data.[24] Other main features of the 2D NMR spectra are
similar to those of 12a. Remarkably, the direct reaction of 8
with [Ru]Cl in the presence of KPF6 in MeOH at room tem-
perature also affords 12a. This ring-expansion/cyclization re-
action occurs only in alcohols, that is, no reaction was ob-
served in CHCl3. However, the reactions in ethanol and n-
propanol, producing the corresponding products 12b and
12c (Table 1), require longer reaction times.
Moreover, treatment of
8 with [Ru’]Cl ([Ru’]=Cp-
ACHTUNGTRENNUNG(dppe)Ru; dppe=1,2-bis(diphenylphosphino)ethane))
causes similar ring expansion and cyclization to afford the
analogous bicyclic oxacarbene complex 12a’. Single crystals
Table 1. Cascade cyclization and ring expansion of 8 on [Ru]Cl in differ-
ent solvents.
Entry
Solvent
t [h]
Product (Yield [%])
1
2
3
4
5
6
CH2Cl2
CHCl3
MeOH
EtOH
PrOH
NH3/MeOH
12
12
12
16
30
12
10 (95)
–
12a (90)
12b (85)
12c (82)
12a (88)
[a]
The proposed mechanism for the formation of 12a and 13
is illustrated in Scheme 3. Ring expansion of 8, induced by
the acidic salt NH4PF6, generates compound 9. Then, the
terminal alkyne of 9 reacts with [Ru]Cl to give 10. In
[a] No formation of ruthenium complex.
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Reactions of Propargyl Compounds
trometry, elemental analysis, and X-ray diffraction studies were carried
out at the Regional Center of Analytical Instrument located at the Na-
tional Taiwan University. Complex [Ru]Cl[33] was prepared from
RuCl3·xH2O, which was purchased from Steam Chemicals, according to
a literature method. Complex [Ru’]Cl[34] was prepared from [Ru]Cl, ac-
cording to a procedure reported in the literature.
MeOH/HBF4, intramolecular nucleophilic attack of oxygen
of the carbonyl group of 10 takes place in the presence of
an acidic proton to afford intermediate G with a tertiary car-
bocation. The role of the acid is believed to prevent depro-
tonation, thus making the nucleophilic addition of carbonyl
oxygen to the cationic vinylidene Ca feasible. Finally, addi-
tion of a methoxide from MeOH to G forms 12a. However,
in the absence of MeOH, the addition of a fluorine atom
from HBF4 to G forms complex 13. Our attempts to prepare
12a from 10 in MeOH in the presence of KPF6 resulted in
the formation of 11. Deprotonation of 10 readily occurs,
even in mostly neutral or weakly basic conditions. No cycli-
zation was observed for 11 possibly as a result of a lack of
cationic charge to induce nucleophilic addition. Therefore,
speculatively, as shown in the lower left part of Scheme 3,
direct reaction of 8 with [Ru]Cl may proceed alternatively
by cyclization of the vinylidene intermediate D, giving E, in-
stead of 10, followed by ring expansion to yield G.
Synthesis of 1
Ethynylmagnesium bromide (0.50m, 75.1 mL, 38 mmol) was added to
a
solution of cyclobutyl phenyl ketone (3.01 g, 18.8 mmol) in THF
(40 mL) under nitrogen. The mixture was stirred at 408C for 24 h. Then
the reaction was quenched with a saturated aqueous solution of NH4Cl
(30 mL), and diethyl ether (3ꢂ20 mL) was used to extract the crude
product. The combined organic layers were dried under vacuum and the
residue was purified by column chromatography using ethyl acetate
(EA)/hexane (1:7) as the eluent to give
1
(2.91 g, 83%). 1H NMR
(CDCl3): d=7.62–7.28 (m, 5H; Ph), 2.82–2.75 (m, 1H; CH), 2.73 (s, 1H;
ꢀ
CH), 2.38 (s, 1H; OH), 2.29–2.19 (m, 1H; CH2), 2.14–2.03 (m, 1H;
CH2), 1.94–1.75 ppm (m, 6H; CH2); 13C NMR (CDCl3): d=142.82,
ꢀ
ꢀ
128.06, 127.66, 125.32 (Ph), 85.07 (C ), 74.91 ( CH), 74.48 (C), 46.80
(CH), 23.68 (CH2), 22.95 (CH2) 16.53 ppm (CH2); MS: m/z: 186.10 [M+];
elemental analysis calcd (%) for C13H14O: C 83.83, H 7.58; found: C
83.79, H 7.51.
Previously, a cascade cyclization/ring-expansion process
for 2-alkynyl-1-azaspiroACTHNURGTNE[NUG 2,3]hexanes catalyzed by 10 mol%
Synthesis of Complex 2
of PtCl2 in dioxane/H2O (2:1) at 1008C was reported to
yield cyclopenta[b]pyrroles.[16a] In our case, similar cascade
cyclization/ring expansion of 8 is induced by [Ru]Cl at room
temperature. The cyclized product remains bonded to the
metal as a carbene ligand.
MeOH (20 mL) was added to a Schlenk flask charged with [Ru]Cl
(62 mg, 0.085 mmol), 1 (20 mg, 0.10 mmol), and KPF6 (50 mg, 0.27 mmol)
under nitrogen. The resulting solution was stirred at room temperature
overnight. Then the solution was filtered through a bed of Celite to
remove the insoluble salts and the solvent of the filtrate was removed
under vacuum. The solid residue was extracted with a small volume of
CH2Cl2 followed by re-precipitation through the addition of diethyl ether
(50 mL) with stirring. Precipitates thus formed were collected in a glass
frit, washed with diethyl ether/hexanes (1:1), and dried under vacuum.
Compound 2 was obtained as a yellow powder (0.078 g, 90%). 1H NMR
(CDCl3): d=7.52–6.75 (m, 50H; Ph), 5.06 (s, 5H; Cp), 4.90 (s, 1H; =
Conclusion
Dehydration of propargyl alcohol 1, containing a cyclobutyl
group, was catalyzed by the cationic complex [Ru]
N
CH), 2.77 (t, 3J
(H,H)=8.0 Hz, 2H; CH2), 2.61 (t, 3J
ACHUTGTNRENNUG ACHUTNTGREN(NUGN H,H)=8.0 Hz, 2H;
CH2), 1.99 ppm (m, 2H; CH2); 13C NMR (CDCl3): d=357.76 (t, 2J-
, generating 1,3-enyne 7, which contained a cyclobutylidene
group. Treatment of [Ru]Cl with 1 in MeOH in the presence
of KPF6 afforded vinylidene complex 2, also with a cyclobu-
tylidene group. With an additional methylene group, prop-
argyl compound 5 reacted with [Ru]Cl to give cyclic oxacar-
bene complex 6. Epoxidation of 7 yielded cyclobutyl oxirane
8, which underwent cascade cyclization/ring expansion with
[Ru]Cl in alcohols at room temperature to afford bicyclic
oxacarbene complex 12. Alternatively, the ring-expansion
reaction of 8 in CH2Cl2 induced by [Ru]Cl/NH4PF6, afforded
vinylidene complex 10, containing a cyclopentanone group.
Cyclization of 10, induced by HBF4 in CH2Cl2, was followed
by fluorination in the absence of MeOH, thus generating
the monofluorinated bicyclic oxacarbene complex 13.
ACHUTNGERNUN(G C,P)=16.3 Hz, Ca), 139.54–116.08 (Cb, Ph, =CPh, =CACHTUNTGREN(NUGN CH2)2), 94.69 (Cp),
31.14 (CH2), 30.94 (CH2), 16.86 ppm (CH2); 31P NMR (CDCl3): d=
41.26 ppm (s, PPh3); MS: m/z: 859.22 [M+]; elemental analysis calcd (%)
for C54H47F6P3Ru: C 64.60, H 4.72; found: C 64.42, H 4.58.
Synthesis of Complex 3
A mixture of 2 (0.16 g, 0.16 mmol) and NaOMe (8.6 mg, 0.16 mmol) in
MeOH (30 mL) was stirred for 3 min at room temperature. Then the sol-
vent was removed under vacuum and diethyl ether (20 mL) was added.
The mixture was stirred by using an ultrasonic cleaner. The solution was
filtered through neutral Al2O3 to remove insoluble salts, then the solvent
was removed under vacuum. Compound 3 was obtained as a yellow
powder (0.081 g, 95%). 1H NMR (CDCl3): d=7.64–700 (m, 42H; Ph),
4.31 (s, 5H; Cp), 3.01 (m, 2H; CH2), 2.91 (m, 2H; CH2), 1.95 ppm (m,
2H; CH2); 13C NMR (CDCl3): d=114.34 (t, 2J
142.12–111.42 (Ph, Cb, =CPh, =C
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
(CH2), 17.59 ppm (CH2); 31P NMR (CDCl3): d=50.49 ppm (s, PPh3); MS:
m/z: 859.22 [M+]; elemental analysis calcd (%) for C54H46P2Ru: C 75.60,
H 5.40; found: C 75.52, H 5.35.
Experimental Section
Synthesis of Complex 4a
General Procedures
Allyl iodide (0.10 g, 0.58 mmol) was added to a solution of 3 (0.13 g,
0.15 mmol), KPF6 (0.02 g, 0.3 mmol), and CH2Cl2 (20 mL) in a Schlenk
flask under nitrogen. The solution was stirred for 8 h at 408C. Then the
solution was filtered through Celite to remove insoluble salts and the sol-
vent was removed under vacuum, the solid residue was extracted with
a small volume of CH2Cl2, followed by reprecipitation with diethyl ether
(50 mL). Precipitates thus formed were collected in a glass frit, washed
with diethyl ether/hexanes (1:1) and dried under vacuum. Compound 4a
was obtained as a yellow powder (0.11 g, 90%). 1H NMR (CDCl3): d=
The manipulations were performed under an atmosphere of dry nitrogen
by using vacuum-line and standard Schlenk techniques, unless mentioned
otherwise. Solvents were dried by standard methods and distilled under
nitrogen before use. All reagents were obtained from commercial suppli-
ers and were used without further purification. NMR spectra were re-
corded on Bruker AC-300, DPX-400, and AVIII-400 FT-NMR spectrom-
eters at room temperature and are reported in units of d with residual
protons in the solvents as a standard. Electrospray ionization mass spec-
Chem. Asian J. 2012, 00, 0 – 0
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemasianj.org
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Ying-Chih Lin et al.
FULL PAPER
7.42–6.94 (m, 46H; Ph), 5.84–5.82 (m, 1H; =C(C)H), 5.13 (d, 3J
(H,H)=
emental analysis calcd (%) for C55H51OP3F6Ru: C 63.76, H 4.96; found:
C 63.60, H 4.90.
10.9 Hz, 1H; =CH), 5.03 (d, 3J
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
Synthesis of 7
G
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
[Ru]NCMePF6 (30 mol%, 0.28 g, 0.32 mmol) in MeOH (20 mL) was
added to a Schlenk flask charged with 1 (0.20 g, 1.07 mmol) under nitro-
gen. The resulting solution was stirred at 608C overnight. Then the solu-
tion was filtered through Celite to remove insoluble salts and the solvent
was removed under vacuum, the solid residue was extracted with a small
volume of CH2Cl2, followed by reprecipitation with diethyl ether
(50 mL). After filtration, the precipitate was dried under vacuum and the
residue was purified by column chromatography using hexanes as the
eluent to give 7 (0.13 g, 70%).
ACHTUNGTRENNUNG(CH2)2, =CH2, =CH), 93.74 (Cp), 34.05 (CH2), 32.81
(CH2), 29.62 (CH2), 17.74 ppm (CH2); 31P NMR (CDCl3): d=42.63 ppm
(s, PPh3); MS: m/z: 899.25 [M+]; elemental analysis calcd (%) for
C57H51F6P3Ru: C 65.58, H 4.92; found: C 65.49, H 4.89.
Synthesis of Complex 4b
Complex 4b (0.11 g, 92%) was similarly prepared from
3 (0.10 g,
0.12 mmol), KPF6 (0.02 g, 0.30 mmol), and methyl iodide (0.08 g,
0.58 mmol). 1H NMR (CDCl3): d=7.40–6.92 (m, 37H; Ph), 4.92 (s, 5H;
Dehydration was also induced by P4O10. MeOH (20 mL) was added to
a Schlenk flask charged with 1 (0.20 g, 1.07 mmol) and P4O10 (0.30 g,
1.07 mmol). The solution was stirred at 08C and over 4 h the temperature
Cp), 2.90 (t, 3J(H,H)=8.1 Hz, 2H; CH2), 2.68 (t, 3J
ACHTUNGTRENNUNG ACHTUNGTRENNUNG
CH2), 2.02 (s, 3H; CH3), 2.02 ppm (m, 3J
13C NMR (CDCl3): d=352.62 (t, 2J
(Cb, Ph, =CPh, =CACHTUNGTRENNUNG(CH2)2), 93.51 (Cp), 33.84 (CH2), 32.33 (CH2), 17.65
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
was raised to room temperature under nitrogen to yield 7 (0.08 g 45%).
1
ꢀ
H NMR (CDCl3): d=7.55–7.25 (m, 5H; Ph), 3.24 (s, 1H; CH), 3.14–
(CH2), 12.71 ppm (CH3); 31P NMR (CDCl3): d=42.80 ppm (s, PPh3); MS:
m/z: 873.23 [M+]; elemental analysis calcd (%) for C55H49F6P3Ru: C
64.89, H 4.85; found: C 64.53, H 4.79.
3.06 (m, 4H; 2 CH2), 2.16 ppm (m, 2H; CH2). 13C NMR (CDCl3): d=
ꢀ
154.98 (=C), 136.41, 128.10, 126.64, (Ph), 114.61, (=C), 81.05 (C ), 80.47
+
ꢀ
( CH), 33.29 (CH2), 33.03 (CH2), 17.27 ppm (CH2); MS: m/z: 168.09 [M
]; elemental analysis calcd (%) for C13H12: C 92.81, H 7.19; found: C
92.70, H 7.15.
Synthesis of Complex 4c
Complex 4c (0.23 g, 85%) was similarly prepared from
3 (0.20 g,
Synthesis of 8
0.24 mmol), KPF6 (0.02 g, 0.3 mmol), and ethyl iodoacetate (0.08 g,
0.37 mmol). 1H NMR (CDCl3): d=7.40–6.89 (m, 39H; Ph), 5.13 (s, 5H;
mCPBA (47 mg, 0.27 mol) dissolved in CH2Cl2 (2 mL) was added to a so-
lution of 7 (23 mg, 0.14 mmol) in CH2Cl2 (10 mL) under nitrogen at 08C.
The mixture was stirred at room temperature for 24 h. Then the reaction
was quenched with a saturated aqueous solution of NH4Cl (20 mL), and
diethyl ether (3ꢂ10 mL) was used to extract the crude product. The com-
bined organic layers were dried under vacuum and the residue was puri-
fied by column chromatography using EA/hexanes (1:8) as the eluent to
Cp), 4.19 (q, 3J(H,H)=7.2 Hz, 2H; CH2), 2.92 (t, 3J
ACHTUNGTRENNUNG ACHTUNTGREN(NUGN H,H)=7.3 Hz, 2H;
3
3
CH2), 2.87 (s, 2H; CH2), 2.80 (t, J
(H,H)=7.3 Hz, 2H; CH2), 1.27 ppm (t, 3J
13C NMR (CDCl3): d=350.77 (t, 2J
(C,P)=15.1 Hz, Ca), 172.33 (C=O),
145.87–120.34 (Cb, Ph, =CPh, =C(CH2)2,), 94.53 (Cp), 61.50 (CH2), 33.73
ACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
(CH2), 32.57 (CH2), 31.02 (CH2), 17.47 (CH2), 14.27 ppm (CH3);
31P NMR (CDCl3): d=41.62 ppm (s; PPh3); MS: m/z: 945.26 [M+]; ele-
mental analysis calcd (%) for C58H53O2F6P3Ru: C 63.91, H 4.90; found: C
63.80, H 4.87.
1
give 8 (17 mg, 80%). H NMR (CDCl3): d=7.40–7.24 (m, 5H; Ph), 2.63–
ꢀ
2.54 (m, 2H; CH2), 2.57 (s, 1H; CH), 2.48–2.39 (m, 1H; CH2), 1.91–1.80
(m, 2H; CH2), 1.74–1.64 ppm (m, 1H; CH2); 13C NMR (CDCl3): d=
ꢀ
ꢀ
135.32, 127.99, 126.18, (Ph), 80.78 (C ), 74.00 ( CH), 72.06 (C), 58.71
(C), 30.17 (CH2), 28.41 (CH2), 11.86 ppm (CH2); MS: m/z: 184.09 [M+];
elemental analysis calcd (%) for C13H12O: C 84.75, H 6.57; found: C
84.68, H 6.52.
Synthesis of 5
Prop-2-yn-1-ylmagnesium bromide in THF (0.50m, 73.8 mL, 37 mmol)
was added to a solution of cyclobutyl phenyl ketone (2.78 g, 17.3 mmol)
in THF (40 mL) under nitrogen. The mixture was stirred at 408C for
24 h. Then the reaction was quenched with a saturated aqueous solution
of NH4Cl (35 mL), and diethyl ether (3ꢂ25 mL) was used to extract the
crude product. The combined organic layers were dried under vacuum
and the residue was purified by column chromatography by using EA/
hexanes (1:5) to give 5 (3.10 g, 88%). 1H NMR (CDCl3): d=7.47–7.27
(m, 5H; Ph), 2.90–2.81 (m, 1H; CH), 2.76–2.66 (m, 2H; CH2), 2.46 (s,
Synthesis of Complex 9
NH4PF6 (20 mg, 0.13 mol) was added to
a solution of 8 (23 mg,
0.13 mmol) in CH2Cl2 (10 mL) under nitrogen at room temperature. The
mixture was stirred for 24 h. Then the reaction was quenched with a satu-
rated aqueous solution of NH4Cl (20 mL) and diethyl ether (3ꢂ10 mL)
was used to extract the crude product. The combined organic layers were
dried under vacuum and the residue was purified by column chromatog-
1H; CH), 2.22–1.57 ppm (m, 7H; OH, 3 CH2); 13C NMR (CDCl3): d=
ꢀ
raphy using EA/hexanes (1:8) as the eluent to give 9 (21.8 mg, 95%).
ꢀ
ꢀ
144.00, 127.97, 126.87, 125.37 (Ph), 80.27 (C ), 75.33 ( CH), 71.59 (C),
44.91 (CH), 30.30 (CH2), 22.55 (CH2), 22.48 (CH2), 16.86 ppm (CH2);
MS: m/z: 200.12 [M+]; elemental analysis calcd (%) for C14H16O: C
83.96, H 8.05; found: C 83.85, H 8.03.
1
ꢀ
H NMR (CD2Cl2): d=7.48–7.31 (m, 5H; Ph), 2.56 (s, 1H; C ), 2.63–
2.07 ppm (m, 6H; 3 CH2); 13C NMR (CD2Cl2): d=212.52 (C=O), 139.00,
ꢀ
ꢀ
128.44, 127.40, 127.10 (Ph), 83.13, 73.53 (C , HC ), 40.07, 37.06,
19.42 ppm (3CH2); MS: m/z: 184.09 (M+); elemental analysis calcd (%)
for C13H12O: C 84.75, H 6.57; found: C 84.57, H 6.47.
Synthesis of Complex 6
The reaction of 5 (0.07 g, 0.35 mmol) and [Ru]Cl (0.20 g, 0.27 mmol) was
carried out in the presence of NH4PF6 (45 mg, 0.27 mmol) in CH2Cl2
(20 mL) at room temperature for 1 day. The solution was filtered through
Celite to remove insoluble salts, then the solvent was removed under
vacuum, and the solid residue was extracted with a small volume of
CH2Cl2 followed by reprecipitation with diethyl ether (50 mL). Precipi-
tates thus formed were collected in a glass frit, washed with diethyl
ether/hexanes (1:1), and dried under vacuum. Compound 6 was obtained
as a yellow carbene complex (0.24 g 85%). 1H NMR (CD2Cl2): d=7.41–
6.80 (m, 37H; Ph), 4.81 (s, 5H; Cp), 3.79–3.77 (m, 1H; CH2), 3.38–3.36
(m, 1H; CH2), 2.31–2.13 (m, 3H; CH2, CH), 1.80–1.12 ppm (m, 6H; 3
Synthesis of Complex 10
CH2Cl2 (20 mL) was added to a Schlenk flask charged with [Ru]Cl
(82 mg, 0.11 mmol),
8 (26 mg, 0.14 mmol), and NH4PF6 (46 mg,
0.28 mmol) under nitrogen. The resulting solution was stirred at room
temperature overnight. Then the solution was filtered through Celite to
remove insoluble salts, the solvent was removed under vacuum, and the
solid residue was extracted with a small volume of CH2Cl2, followed by
reprecipitation with diethyl ether (20 mL). Precipitates thus formed were
collected in a glass frit, washed with diethyl ether/hexanes (1:1), and
dried under vacuum. Compound 10 was obtained as a light orange
powder (0.11 g, 92%).
CH2); 13C NMR (CD2Cl2): d=299.82 (t, 2J
ACTHNUGTRENNG(U C,P)=13.3 Hz, Ca), 138.96–
126.02 (Ph), 110.27 (C(O)Ph), 90.62 (Cp), 62.32 (CH2), 44.23 (CH), 28.86
Complex 10 can also be prepared from [Ru]Cl and 9. CH2Cl2 (20 mL)
was added to a Schlenk flask charged with [Ru]Cl (82 mg, 0.11 mmol), 9
(26 mg, 0.14 mmol), and NH4PF6 (46 mg, 0.28 mmol). Product 10 was
(CH2), 25.07 (CH2), 24.79 (CH2), 17.01 ppm (CH2); 31P NMR (CD2Cl2):
2
d=46.29, 43.60 ppm (2d, J
N
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www.chemasianj.org
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Asian J. 0000, 00, 0 – 0
ÝÝ These are not the final page numbers!

Reactions of Propargyl Compounds
similarly isolated in 90% yield. 1H NMR (CDCl3): d=7.55–6.88 (m,
46H; Ph), 5.06 (s, 5H; Cp), 4.42 (br, 1H; =CH), 2.48–1.77 ppm (m, 6H;
(CDCl3, 160 MHz): d=46.59, 44.80 ppm (2d, 2J
ACTHNGUTERN(NUG P,P)=30.3 Hz, 2 PPh3);
MS: m/z: 921.26 [M+]; elemental analysis calcd (%) for C56H53O2P3F6Ru:
3 CH2); 13C NMR (CDCl3): d=348.88 (t, 2J
(C,P)=15.5 Hz, Ca), 216.33
C 63.10, H 5.01; found: C 62.89, H 4.89.
(C=O), 140.65–126.95 (Ph, PPh3), 118.91 (Cb), 94.52 (Cp), 55.45 (CPh),
Synthesis of Complex 12c
38.17 (CH2), 36.32 (CH2), 18.94 ppm (CH2); 31P NMR (CDCl3): d=41.18,
2
40.79 ppm (2d, J
N
Complex 12c (0.23 g, 82%) was similarly prepared from
8 (78 mg,
tal analysis calcd (%) for C54H47F6OP3Ru: C 63.59, H 4.64; found: C
63.33, H 4.57.
0.42 mmol), [Ru]Cl (0.28 g, 0.38 mmol), and KPF6 (0.07 g, 0.4 mmol) in
propanol. 1H NMR (CDCl3): d=7.90–6.76 (m, 42H; Ph), 4.87 (s, 5H;
Cp), 4.48, 4.23 (2d, 2J
ACHTUNGTRENNUNG
Synthesis of Complex 11
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
A mixture of 10 (0.18 g, 0.18 mmol) and NaOMe (11 mg, 0.21 mmol) in
MeOH (30 mL) was stirred at room temperature. Then the solvent was
removed under vacuum and then diethyl ether (20 mL) was added. The
mixture was stirred in an ultrasonic cleaner. The solution was filtered
through neutral Al2O3 to remove insoluble salts, then the solvent was re-
moved under vacuum. The final product can be obtained as a yellow
powder identified as 11 (0.16 g, 98%). Also, a solution of 10 (0.18 g,
0.18 mmol) in MeOH (30 mL) in the presence of KPF6 was stirred at
room temperature to yield 11 in 90% yield. 1H NMR (CDCl3): d=7.68–
7.08 (m, 37H; Ph), 4.29 (s, 5H; Cp), 2.24–0.86 ppm (m, 6H; 3 CH2);
13C NMR (CDCl3): d=213.78 (C=O), 142.12–106.55 (Ph, Cb), 105.43 (Ca)
85.30 (Cp), 57.94 (CPh), 42.28 (CH2), 37.20 (CH2), 19.48 ppm (CH2);
AHCTUNGTRENNUNG
(CH3); 31P NMR (CDCl3): d=46.25, 44.63 ppm (2d, 2J
ACHTNUTRGNE(NUG P,P)=30.3 Hz,
2PPh3); MS: m/z: 935.27 [M+]; elemental analysis calcd (%) for
C57H55O2P3F6Ru: C 63.39, H 5.31; found: C 63.11, H 5.27.
Synthesis of Complex 13
HBF4 (0.1 mL) and CH2Cl2 (20 mL) were added to a Schlenk flask
charged with 10 (0.12 g, 0.12 mmol) under nitrogen. The resulting solu-
tion was stirred at room temperature for 1 h. The color of solution
changed from deep red to light yellow. Then the solution was filtered
through Celite to remove insoluble salts, the solvent was removed under
vacuum, and the solid residue was extracted with a small volume of
CH2Cl2, followed by reprecipitation with diethyl ether (40 mL). Precipi-
tates thus formed were collected in a glass frit, washed with diethyl
ether/hexanes (1:1), and dried under vacuum. Compound 13 was ob-
tained as a light yellow powder (0.12 g, 96%). 1H NMR (CDCl3): d=
31P NMR (CDCl3): d=51.18, 50.88 ppm (2d, 2J
ACTHNUTRGNE(UNG P,P)=37.8 Hz, 2 PPh3);
MS: m/z: 875.21 [M+]; elemental analysis calcd (%) for C54H46OP2Ru: C
74.21, H 5.31; found: C 74.11, H 5.30.
Synthesis of Complex 12a
MeOH (20 mL) was added to a Schlenk flask charged with [Ru]Cl
(0.12 g, 0.16 mmol), 8 (36 mg, 0.20 mmol), and KPF6 (50 mg, 0.27 mmol)
under nitrogen. The resulting solution was stirred at room temperature
overnight. Then the solution was filtered through Celite to remove in-
soluble salts, the solvent was removed under vacuum, and the solid resi-
due was extracted with a small volume of CH2Cl2, followed by reprecipi-
tation with diethyl ether (30 mL). Precipitates thus formed were collected
in a glass frit, washed with diethyl ether/hexanes (1:2), and dried under
vacuum. Compound 12a was obtained as a light yellow powder (0.16 g,
90%). The reaction of 10 in HBF4/MeOH for 30 min also yielded 12a.
1H NMR (CH2Cl2): d=7.69–6.86 (m, 42H; Ph), 4.92 (s, 5H; Cp), 4.36,
7.41–6.88 (m, 42H; Ph), 5.04 (s, 5H; Cp), 4.60, 4.16 (2d, 2J
2H; CH2), 2.29–1.17 ppm (m, 6H; 3CH2); 13C NMR (CDCl3): d=300.79
(t, 2J
(C,P)=13.2 Hz, Ca), 139.65–126.96 (Ph, 2 PPh3), 137.62 (d, J(C,F)=
248.8 Hz, CF), 92.33 (Cp), 74.00 (CH2), 56.07 (d, J(C,F)=16.7 Hz, CPh),
(C,F)=25.6 Hz, CH2),
(C,F)=6.6 Hz CH2); 31P NMR (CDCl3): d=46.06,
ACHTUNGTREN(NUNG H,H)=20.34,
G
ACHTUNGTRENNUNG
2
AHCTUNGTRENNUNG
38.97 (d, 3J(C,F)=3.0 Hz, CH2), 34.62 (d, 2J
ACTHNUGTRENNUGN ACHTUNGTRENNNUG
21.02 ppm (d, 3J
42.78 ppm (2d, J
A
(P,P)=30.5 Hz, 2 PPh3); MS: m/z: 895.22 [M+]; elemen-
tal analysis calcd (%) for C54H48OP3F7Ru: C 62.37, H 4.65; found: C
62.03, H 4.58.
2
Single-Crystal X-ray Diffraction Analyses
4.26 (2d, 2H; 2J
ACHTUNGTRENNUNG(H,H)=19.3 Hz, CH2), 3.20 (s, 3H; OCH3), 2.21–
1.18 ppm (m, 6H; 3CH2); 13C NMR (CH2Cl2): d=297.61 (br, Ca), 140.05–
Single crystals of complexes 6 and 12a’ suitable for X-ray diffraction
were grown as mentioned above. A single crystal of 6 and 12a’ was glued
to a glass fiber and mounted on a SMART CCD diffractometer. The dif-
fraction data were both collected by using 3 kW sealed-tube MoKa radia-
tion (T=150 K). The exposure time was 5 s per frame. SADABS[35] (Sie-
mens area detector absorption) absorption correction was applied and
decay was negligible. Data were processed and the structure was solved
and refined by the SHELXTL[36] program. Brief crystal data and related
parameters of complexes 6 and 12a’ are listed below:
126.98 (Ph, CACHTUNGTRENNUNG(OCH3)), 91.10 (Cp), 76.35 (CH2), 56.25 (CPh), 54.40
(OCH3), 39.89 (CH2), 32.98 (CH2), 21.71 ppm (CH2); 31P NMR (CH2Cl2):
2
d=45.86, 44.41 ppm (2d, J
N
]; elemental analysis calcd (%) for C55H51O2P3F6Ru: C 62.80, H 4.89;
found: C 62.69, H 4.82.
Synthesis of Complex 12a’
Complex 12a’ (0.14 g, 92%) was similarly prepared from 8 (33 mg,
0.18 mmol), [Ru’]Cl (0.11 g, 0.17 mmol), and KPF6 (0.02 g, 0.3 mmol).
Crystal data for 6·CH2Cl2: C56H53Cl2F6OP3Ru; Mr =1120.86; 0.25ꢂ0.20ꢂ
0.15 mm; orthorhombic space group Pbca; a=22.2228(2), b=17.9118(2),
1H NMR (CDCl3): d=7.82–6.49 (m, 46H; Ph), 5.21 (s, 5H; Cp), 3.68,
c=24.9796(2) ꢁ; a=90, b=90, g=908; V=9943.14(16) ꢁ3; Z=8; 1calcd
=
2
3.54 (2d, 2H; J
G
1.498 mgmÀ3; m=0.583 mmÀ1; F
wR2 =0.0828; 11402 independent reflections.
ACHTUNGTNER(NNUG 000)=4592; T=150(2) K; R1 =0.0376;
(s, 3H; OCH3), 1.79–0.36 ppm (m, 6H; 3CH2); 13C NMR (CDCl3): d=
292.73 (t, 2J
A
Crystal data for 12a’: C45H45F6O2P3Ru; Mr =925.79; 0.20ꢂ0.15ꢂ0.10 mm;
monoclinic space group P21/n; a=13.7867(3), b=15.0755(2), c=
19.6565(4) ꢁ; a=90, b=98.804(2), g=908; V=4037.30(13) ꢁ3; Z=4;
(Cp), 74.42 (CH2), 55.21 (CPh), 53.04 (OCH3), 39.41 (CH2), 32.99 (CH2),
27.39 (m, CH2CH2), 20.68 ppm (CH2); 31P NMR (CDCl3): d=89.89,
2
89.06 ppm (2d, J
N
1calcd =1.523 mgmÀ3; m =0.574 mmÀ1; F
ACTHNUTRGEN(UNG 000)=1896; T=150(2) K; R1 =
tal analysis calcd (%) for C45H45O2P3F6Ru: C 58.38, H 4.90; found: C
58.20, H 4.85.
0.0455; wR2 =0.1156; 9194 independent reflections.
CCDC 892285 (6) and 892286 (12a’) contain the supplementary crystallo-
graphic data for this paper. These data can be obtained free of charge
from The Cambridge Crystallographic Data Centre via www.ccdc.cam.a-
c.uk/data_request/cif.
Synthesis of Complex 12b
Complex 12b (0.24 g, 85%) was similarly prepared from
8 (61 mg,
0.33 mmol), [Ru]Cl (0.22 g, 0.30 mmol), and KPF6 (0.07 g, 0.4 mmol) in
EtOH. 1H NMR (CDCl3): d=7.96–6.81 (m, 42H; Ph), 4.94 (s, 5H; Cp),
4.49, 4.32 (2d, 2J
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
AHCTUNGTRENNUNG
ACHTUNGTRENNUNG
Chem. Asian J. 2012, 00, 0 – 0
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Ying-Chih Lin et al.
FULL PAPER
M. Al-Amin, Y. Hirai, K. Shishido, Tetrahedron 2011, 67, 3194–
3200.
Acknowledgements
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Received: July 2, 2012
Published online: && &&, 0000
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ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Asian J. 0000, 00, 0 – 0
ÝÝ These are not the final page numbers!

FULL PAPER
Complex matters: Ring expansion of
cyclobutyloxirane 1, induced by [Ru]Cl
in CH2Cl2, affords the vinylidene com-
plex 2 with a substituted cyclopenta-
none. In MeOH, the same reaction
gives the bicyclic oxacarbene complex
3 through an additional cyclization
reaction. In the absence of MeOH,
cyclization of 2, induced by HBF4, is
followed by a fluorination to afford
complex 4.
Cyclization
Yung-Ching Wang, Ying-Chih Lin,*
Yi-Hung Liu
&&&& — &&&&
Reactions of Propargyl Compounds
Containing a Cyclobutyl Group
Induced by a Ruthenium Complex
Chem. Asian J. 2012, 00, 0 – 0
ꢀ 2012 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemasianj.org
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