Reactions of furylruthenium complexes with oxygen and trimethylsilyl azide

Article abstract of DOI:10.1002/ejic.200500621

The reaction of the (α-alkoxyfuryl)ruthenium complexes 4 with oxygen opens the five-membered furyl ring to give the addition product [Ru]O ₂CCR=CHCO₂CH₃, (5, [Ru] = Cp(PPh ₃)₂Ru). Further reactions of

Full text of DOI:10.1002/ejic.200500621

FULL PAPER
DOI: 10.1002/ejic.200500621
Reactions of Furylruthenium Complexes with Oxygen and Trimethylsilyl Azide
Ku-Hsien Chang,[a] Hui-Ling Sung,[a] and Ying-Chih Lin*[a]
Keywords: Ruthenium / Furyl ligand / Oxygen
The reaction of the (α-alkoxyfuryl)ruthenium complexes 4
with oxygen opens the five-membered furyl ring to give the
thenium complex 11b containing a methyl crotonate group
with TMSN3 affords the five-membered-ring triazole and
[Ru]–CN. In this reaction cleavage of the C=C double bond
addition product [Ru]O2CCR=CHCO2CH3, (5, [Ru]
=
Cp(PPh3)2Ru). Further reactions of 5 with CH3I and with or- of the three-membered ring could be caused by consecutive
ganic acid gave CH3O2CCR=CHCO2CH3, (6), and
HO2CCR=CHCO2CH3, (7), respectively. The reaction of 4
with TMSN3 [TMS = (CH3)3Si] gives the ruthenium azide
[Ru]–N3 and α-alkoxyfuran, which is readily hydrolyzed to
additions of TMSN3 to olefinic carbon atoms of intermediates
formed during the reaction.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
lactone in acidic medium. Treatment of the cyclopropenylru- Germany, 2006)
complex was also observed as a kinetic product. It is known
Introduction
that organic cyclopropenyl ketones in the presence of metal
halides could be converted to furans.[9] DЈyakonov and his
co-workers also reported that the reaction of ethyl diazo-
acetate with 1-phenylpropyne give cyclopropene ester and
2-ethoxyfuran.[10] The former compound underwent pho-
tolysis to give the latter one, which yielded diethyl ester
upon air oxidation.[11] Synthesis and reactions of a few
transition-metal furyl complexes have been reported. Iri-
dium hydride complex containing σ-furyl ligand can be ob-
tained by the reaction of metal cyclooctadienyl complex
with furan.[12] The metal furyl complex reacted with tert-
butylacetylene by insertion of the alkyne into the Ir–C bond
to form an vinyl iridium hydride complex.[13] Furyl tungsten
complexes are obtained by the reaction of propargyl tung-
sten complexes with aldehydes. This furyl ligand is easily
dissociated from the metal fragment and further reacts with
Grignard reagent.[14]
Trimethylsilyl azide and sodium azide were used widely
in organic or organometallic reactions.[15] Organic azides
react with alkenes or alkynes giving triazoline or triazole
compounds through a [3+2] cycloaddition.[16] However, for
efficient [3+2] cycloaddition to give triazoles, the presence
of an electron-withdrawing group is needed either at the
alkyne or at the azide part. Coupling reaction between az-
ide, such as TMSN3, with simple alkyne and allyl carbon-
ates catalyzed by Pd0/CuI was reported by Yamamoto and
his co-workers[17] as an efficient method for the synthesis of
triazoles. The azide reagent is also commonly used in the
synthesis of metal complexes with N-heterocyclic ligand. A
number of N-coordinated Fe tetrazole derivatives were ob-
tained by the reaction of sodium azide with the coordinated
CN of the N-coordinated iron nitrile complex. The mecha-
nism probably involves nucleophilic attack of the azide
Chemistry of organometallic ruthenium complexes plays
important role in many catalytic reactions, such as asym-
metric hydrogenation,[1] olefin metathesis[2] and polymeriza-
tion.[3] Metal-mediated processes in many instances make
possible certain reactions, which are not feasible without
the involvement of metal ions. It is therefore important to
better understand how an organic moiety attached on the
metal undergoes chemical transformation. We previously
reported the synthesis of cyclopropenyl complexes of ruthe-
nium through a deprotonation reaction of vinylidene com-
plexes.[4] The same approach could also be used for the syn-
thesis of metal-coordinated azirinyl complexes from metal
isocyanide complexes.[5] Highly strained organic cyclopro-
pene and azirine compounds are synthetically useful.[6] Par-
ticipation of d orbital of Ru metal may stabilize this highly
strained organic moiety consisting of a three-membered
ring thus making these complexes readily accessible for fur-
ther exploitation for the preparation of organic molecules.
For example, reactions of various cyclopropenylruthenium
complexes with TMSN3 gave a number of tetrazole and tri-
azole compounds depending on the substituents on the
three-membered ring.[7] And the reactions of azirinylru-
thenium complexes with aldehyde or acetone gave oxazol-
inyl complexes.[6] The previously reported regiochemistry of
the carbon–carbon bond formation in the photoreaction of
organic azirine with carbonyl group is reversed.[8]
Interestingly, upon deprotonation of vinylidene com-
plexes containing an ester group at Cγ of the vinylidene
ligand, we observed formation of furyl complexes as
thermodynamic products. The corresponding cyclopropenyl
[a] Department of Chemistry, National Taiwan University,
Taipei, Taiwan 106, Republic of China
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K.-H. Chang, H.-L. Sung, Y.-C. Lin
FULL PAPER
anion to the carbon atom of the coordinated nitrile fol- quantitative yield. The reaction is faster in solution but is
lowed by cyclization.[18] The reaction of furyl metal com- accompanied with extensive decomposition. Under the
plexes with TMSN3 was not investigated before. Herein we same reaction condition, exposure of complex 4b also yields
report reactions of the furylruthenium complex with oxygen the analogous oxygen addition product 5b (Scheme 2).
and TMSN3 and the reaction of the cyclopropenylruthe-
nium complex containing a crotonate group with TMSN3
is also reported.
Results and Discussion
Preparation of Furyl Complexes: The reaction of the vi-
nylidene complex 2a containing a 1-cyclohexenyl group at
Cβ and an ester group at Cγ with nBu4NOH in acetone
yields the furyl complex 4a as the thermodynamic product
(Scheme 1). The reaction proceeds through protonation at
Cγ followed by an intramolecular cyclization first giving the
three-membered cyclopropenyl complex 3a as the kinetic
product with a small amount of 4a within 0.5 h. Conversion
of 3a to 4a is completed within 3 h. The 31P NMR spectrum
of 4a displays a singlet resonance at δ = 50.6 ppm, however,
the 31P NMR spectrum of the kinetic product 3a displays
a two-doublet pattern at δ = 52.5, 48.5 ppm with JP–P
=
36.4 Hz indicating the presence of a stereogenic carbon cen-
ter at the cyclopropenyl ligand. As shown in Scheme 1, the
furylruthenium complex 4b was also prepared by deproton-
ation of the vinylidene complex 2b containing a phenyl sub-
stituent.[4b] Deprotonation reaction of dinuclear vinyl-
ideneruthenium complexes containing an ester substituent
at Cγ gave the dinuclear bisfuryl complexes.[4e] Organic fu-
ran adds to [Ir(COD)(PMe3)3]Cl to yield a furyl iridium
hydride complex.[12]
Scheme 2.
1
In the H NMR spectrum of 5a two singlet resonances
at δ = 5.53 and 4.79 ppm are assigned to the olefinic proton
and the Cp group, respectively. The 31P NMR spectrum of
5a in CDCl3 displays a singlet resonance at δ = 39.5 ppm.
In the 13C NMR spectrum the resonance at δ = 174.2 ppm
is assigned to the O-coordinated CO2 group and the reso-
nance at δ = 166.9 ppm is assigned to the CO2 group of the
terminal ester.
Furan is known to react with singlet oxygen.[19] It has
been reported by Scarpati and her co-workers that photo-
sensitized oxidation of various substituted furans under
strictly anhydrous conditions at about –15 °C generated in
quantitative yields the endo-peroxides, which decomposed
at room temperature in the absence of solvent and moisture.
However, at 4 °C the endo-peroxide in nitromethane was
converted into the oxiranes.[20] These endo-peroxides could
also react with diethyl sulfide at 0 °C yielding diones, which
further react with tert-butyl hydroperoxide in the presence
of triethylamine to give oxiranes. On the basis of these re-
ports, we propose that the reaction of the furylruthenium
complex with O2 could proceed through the formation of
the endo-peroxide intermediate with subsequent ruthenium
migration to oxygen accompanied with cleavage of both C–
O and O–O bonds affording complex 5a (Scheme 2). The
reaction could occur in both solid and liquid state without
prior formation of singlet oxygen.[19] The endo-peroxide in-
termediate was not observed in our system. This facile reac-
tion could possibly be assisted by the participation of the d
orbital of the ruthenium metal and/or the presence of the
Scheme 1.
Reaction of 4 with Oxygen: Exposure of complex 4a as a neighboring methoxy group.[11]
solid in air for two weeks generates the oxygen addition
Further reaction of 5a with CH3I generates metal iodide
product [Ru]O2CC(C6H9)=CHCO2CH3, (5a) in almost [Ru]–I and the diester 6a containing a 1-cyclohexenyl sub-
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Reactions of Furyl-Ru Complexes with Oxygen and Trimethylsilyl Azide
FULL PAPER
stituent[21] by cleavage of the Ru–O bond (Scheme 2). The indicating some degree of back-bonding from the metal
reaction was carried out at 50 °C and the organic product moiety. In contrast, furan compounds have less ring strain.
6a was extracted with diethyl ether and was identified by It thus requires less or even no back-bonding of the metal
1
NMR spectroscopy. In the H NMR spectrum of 6a, two d electron for the coordination of the relatively more stable
singlet resonances at δ = 3.88 and 3.71 ppm with the ratio furyl group. Thus, unlike the M–C bond in cyclopropenyl
1:1 are assigned to two OCH3 groups. Analogous, the dies- complex, the M–C bond in furyl metal complexes is rela-
ter compound 6b can also be obtained from the reaction of tively weak and cleavage of the bond was observed in the
5b with CH3I. Compound 6b was previously obtained from reaction with TMSN3.
the reaction of phenylacetylene with alcohol at room tem-
Synthesis and Reactions of Vinylidene Complex Contain-
perature under atmospheric pressure of carbon monoxide ing Crotonate Group: Because the five-membered ring furyl
in the presence of Pd catalyst.[22] The reaction of 5 with complex was readily prepared from the vinylidene complex
protic acid breaks the Ru–O bond and yields compound containing a terminal ester group, it would be interesting to
7, which was identified by NMR and high-resolution mass carry out deprotonation reaction of the vinylidene complex
spectroscopy.
containing a crotonate group, which als possess a terminal
Reactions of TMSN3 with Furylruthenium Complexes: Re- ester group. A seven-membered ring ligand is expected to
actions of TMSN3 with furylruthenium complexes 4a and be obtained. We prepared the cationic vinylidene complex
4b give the metal-free α-alkoxyfuran 8, (8a, R = C6H9; 8b, {[Ru]=C=C(R)CH2CH=CH–CO2CH3][Br]} (R = C6H9,
R = Ph), respectively, and the ruthenium azide complex 10a; R = Ph, 10b) containing a terminal methyl crotonate
[7a]
1
[Ru]–N3 in high yield (Scheme 3). In the H NMR spec- group at Cβ in high yield by the treatment of [Ru]–CϵC–R
4
trum of 8a, the doublet resonance at δ = 5.25 with JH,H
=
([Ru] = Cp(PPh3)2Ru, R = C6H9, 1a; R = Ph, 1b) with
1.2 Hz is assigned to the olefinic hydrogen. In the 2D-NMR BrCH2CH=CHCO2CH3. These cationic pink vinylideneru-
COSY spectrum, this resonance is found to correlate with thenium complexes are stable in air and soluble in polar
the resonance at δ = 6.78 ppm (overlapped with those of solvent but insoluble in ether and hexane. Spectroscopic
phenyl hydrogen) assignable to the other olefinic proton on data of 10a displays of a deshielded Cα resonance as a trip-
the furyl ring. Hydrolysis of α-alkoxyfuran 8b in acidic con- let at δ = 351.8 ppm with JP–C = 15.4 Hz in the 13C NMR
dition gave organic the lactone 4-phenyl-2(5H)-furanone spectrum and a singlet 31P NMR resonance at δ = 42.3 ppm
(9b) in quantitative yield. The 1H NMR spectrum of 9b in CDCl3 at room temperature. Complex 10b was isolated
displays a triplet resonance at δ = 6.36 ppm and a doublet in 88% yield. In the 13C NMR spectrum of 10b, resonances
4
resonance at δ = 5.22 ppm with a ratio of 1:2 with JH,H at δ = 153.9 and 144.7 are assigned to the olefinic carbon
= 1.8 Hz. Hydrolysis of alkoxyfuran to lactone has been atoms of the crotonate group and the corresponding 1H
reported.[23] Comparison of spectroscopic data with those NMR resonances appear at δ = 6.71 and 5.62 ppm, as-
of the authentic sample[24] confirms the structure of 9b.
signed from the 2D HMQC spectrum.
However, in the deprotonation of the vinylidene complex
containing a crotonate group only the cyclopropenyl com-
plex was obtained. The reaction of 10b with nBu4NOH
gives the three-membered ring cyclopropenyl complex 11b,
(Scheme 4). The 31P NMR spectrum of 11b displays two-
doublet resonances at δ = 52.2 and 48.9 ppm with JP–P
=
36.1 Hz due to the presence of a stereogenic carbon center
1
at the three-membered ring. In the H NMR spectrum of
11b the doublet resonance at δ = 2.62 with JH,H = 9.62 Hz
Scheme 3.
is assigned to the CH group of the three-membered ring
The reaction of TMSN3 with the cyclopropenylruthe- indicating the presence of a CH group of the adjacent
nium complex[7] caused opening of the three-membered double bond. However, deprotonation of the vinylidene
ring, but the reaction of 4 with TMSN3 brought about complex 10a containing a 1-cyclohexenyl group gave several
cleavage of the M–C bond. This could be explained as fol- unidentifiable decomposition products, no cyclopropenyl
lows: Organic cyclopropene is highly strained with the esti- complex was observed. Conjugate double bond of the cy-
mated strain energy well over 50 kcal/mol.[25] However, the clopropenyl and 1-cyclohexenyl groups could possibly lower
cyclopropenyl ligand can be stabilized by coordination to a the degree of back donation from the metal, thus destabiliz-
transition metal through back-bonding from the metal d ing the compound.
orbital to Cα. We previously reported solid-state structure
The reaction of the cyclopropenylruthenium complex 11b
of several cyclopropenylruthenium complexes.[4] From sin- containing a methyl crotonate substituent with excess of
gle-crystal X-ray diffraction studies, Ru–C bond lengths are TMSN3 resulted in formation of a five-membered triazolate
in the range of 2.0345–2.0482 Å for these complexes, which ring organic product 12 (Scheme 4) and [Ru]–CN.[27] The
are consistently shorter than that of a typical Ru–C(sp2) organic product 12 was collected by extraction of the reac-
single bond [bond length 2.0637–2.09012 Å].[26] This might tion mixture with hexane and was identified by H NMR
1
indicate that the Ru–C bond in cyclopropenyl-Ru complex spectrum and high-resolution mass spectrum. In the 1H
could be slightly stronger than a regular Ru–C single bond NMR spectrum of compound 12, the resonance at δ = 3.31
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Concluding Remarks
The reactions of furyl and cyclopropenylruthenium com-
plexes with O2 and TMSN3 are investigated. While the cy-
clopropenyl complex with an ester substituent undergoes
tautomerization to give the furyl complex, the methyl cro-
tonate cyclopropenyl complex is inert toward such a trans-
formation. The reaction of furyl metal complex with oxygen
through endo-peroxide requires no assistance of photo-irra-
diation. Cleavage of the Ru–C bond was observed in the
reaction of TMSN3 with the furylruthenium complex. Re-
action of TMSN3 with the cyclopropenylruthenium com-
plex containing a methyl crotonate substituent yielded ru-
thenium cyanide and organic triazole. The reaction causes
cleavage of the C=C double bond of the three-membered
ring.
Experimental Section
General Procedures: All manipulations were performed under nitro-
gen using vacuum-line, dry box, and standard Schlenk techniques.
CH3CN and CH2Cl2 were distilled from CaH2 and diethyl ether
and THF from Na/ketyl. All other solvents and reagents were of
reagent grade and were used without further purification. NMR
spectra were recorded with Bruker DMX-500, AM-300 and AC-
200 (FT-NMR spectrometers at room temperature unless states
otherwise) and were reported in units of δ with residual protons in
the solvent as a standard (CDCl3, δ = 7.24 ppm; C6D6, δ = 7.15
ppm; C2D6CO, δ = 2.04 ppm). FAB mass spectra were recorded
Scheme 4.
ppm is assigned to the OCH3 group, and two triplet reso-
nances at δ = 3.07 and 2.71 ppm with JH,H = 7.39 Hz are
3
with
a JEOL SX-102A spectrometer. Vinylidene complexes
assigned to two neighboring CH2 groups. Tautomerism of ([Ru]=C=C(R)CH2CO2CH, R = C6H9, 2a; R = Ph, 2b) and furyl
complexes 4 (R = C6H9, 4a; R = Ph, 4b) were prepared following
the method reported in the literature.[4b] Elemental analyses were
carried out at the Regional Center of Analytical Instrument located
at the National Taiwan University.
the triazole compound 12 might occur to yield two possible
structures shown in Scheme 4.
The reaction of 11b with TMSN3 results in cleavage of
the C=C double bond of the cyclopropenyl ring yielding
[Ru]–CN and 12. A possible reaction sequence is depicted
in Scheme 4. The reaction may start with an addition of a
TMS group to the double bond of the methyl crotonate
group. This is accompanied with opening of the three-mem-
bered ring resulting in the formation of a cationic vinylidene
intermediate followed by hydrolysis of TMS to afford A
(Scheme 4). Then addition of the azide anion at Cα ac-
companied with addition of the second TMS group at Cδ
followed by hydrolysis of the TMS group gave B. The sin-
Synthesis of Vinylidene Complexes with Ester Group
[Ru]=C=C(C6H9)CH2CO2CH3][Br] (2a): To a CH2Cl2 (20.0 mL)
[4b]
solution of [Ru]CϵCC6H9
(200 mg, 0.25 mmol) (1b),
BrCH2CO2CH3 (0.12 mL, 1.25 mmol) was added under nitrogen.
The resulting solution was stirred at room temperature for 18 h,
then, the solvent was concentrated to about 5 mL. This mixture
was slowly added to 60 mL of vigorously stirred diethyl ether. The
light-orange precipitate thus formed was filtered off and washed
with diethyl ether and hexane and dried under vacuum to give the
product 2a (172 mg, 79% yield). Spectroscopic data for 2a are as
1
gle-bond character of the Cα–Cβ in B may facilitate its follows: H NMR (300 MHz, CDCl3, 25 °C): δ = 7.42–6.95 (m, 30
H, Ph), 5.77 (br., 1 H, CH of C6H9), 5.22 (s, 5 H, Cp), 3.69 (s, 3
H, OCH3), 2.69 (s, 2 H, CH2), 2.14, 1.88, 1.68, 1.49 (br., 8 H, 4
CH2 of C6H9) ppm. 31P{1H} NMR (121.6 MHz, CDCl3, 25 °C): δ
= 42.1 (s) ppm. 13C NMR (75.4 MHz, CDCl3, 25 °C): δ = 351.5
(Cα, JC,P = 15.0 Hz), 171.8 (CO2), 134–128.4 (Ph), 125.6 (Cβ), 94.5
(Cp), 52.2 (OCH3), 28.8 (CH2), 27.5, 26.0, 22.7, 21.6 (CH2 of
C6H9) ppm. MS FAB: m/z = 869.0 [M+ – Br], 606.9 [M+ – Br,
cleavage. Loss of N2 and a [3+2] cycloaddition of the Cβ–
Cγ double bond with N3– give the triazole 12 and [Ru]–CN.
This result is the same as that observed for the reaction
of TMSN3 with cyclopropenyl complex containing a vinyl
group.[7]
Recently, synthesis of organic tetrazolates complexes
using transition-metal complexes as catalysts has received
much attention.[28] The three-component coupling reaction
using organic cyano compounds, allyl methyl carbonate,
and trimethylsilyl azide catalyzed by a palladium complex
gave various 2-allyltetrazoles in good yields. Tetrazolate
complexes of palladium have also been prepared by nucleo-
philic attack of azide anion at the carbon atom of the coor-
dinated nitrile followed by cycloaddition reaction.[17]
PPh3], 428.8 [M+ – Br, PPh3, C2(C6H9)CH2CO2CH3], 345.1 [M+
–
Br, 2PPh3]. C52H49BrO2P2Ru (948.88): calcd. C 65.82 H, 5.20;
found C 66.17, H 5.36.
Synthesis of 4a: To a solution of 2a (100 mg, 0.11 mmol) in 5 mL
of acetone was added a solution of nBu4NOH (0.2 mL, 0.2 mmol)
under nitrogen. The mixture was stirred at room temperature for
4 h yielding a light yellow microcrystalline precipitate. The product
was filtered off and washed with 2×5 mL of acetone, 2×5 mL of
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FULL PAPER
CH3CN, then dried under vacuum and was identified as 4a (74 mg,
74% yield). Spectroscopic data for 4a are as follows: 1H NMR
(300 MHz, C6D6, 25 °C): δ = 7.43–6.96 (m, 30 H, Ph), 5.99 (br., 1
H, CH of C6H9), 5.12 (s, 1 H, CH), 4.50 (s, 5 H, Cp), 2.97 (s, 3 H,
OCH3), 2.46, 2.29, 1.86, 1.78 (br., 8 H, 4 CH2 of C6H9) ppm.
ether. The solvent and CH3I were removed under vacuum. The
organic product is identified as 6a (21 mg, 85% yield). The organo-
metallic product was identified as [Ru]–I[29] (82 mg, 92% yield). 6a:
1H NMR (300 MHz, CDCl3, 25 °C): δ = 5.08 (br., 1 H, CH of
C6H9), 5.77 (s, 1 H, =CH), 3.88 (s, 3 H, OCH3), 3.71 (s, 3 H,
31P{1H} NMR (121.6 MHz, C6D6, 25 °C): δ = 50.6 (s) ppm. 13C OCH3), 2.21–1.59 (br., 8 H, 4 CH2 of C6H9) ppm. MS (EI): m/z =
NMR (75.4 MHz, C6D6, 25 °C): δ = 164.9 (CO), 141.4 (t, JC,P
=
224 [M+]. High-resolution MS for C12H16O4: calcd. 224.2567;
found 224.2563. The same procedure was used for the reaction of
18.8 Hz, Cα), 139.7–127.8 (Ph), 124.5 (=CH), 85.5 (Cγ), 84.9 (Cp),
57.9 (OCH3), 32.2, 26.3, 24.5, 23.4 (CH2 of C6H9) ppm. MS FAB: 5b (100 mg, 0.11 mmol) with CH3I (36 μL, 0.58 mmol), and the
m/z = 869.4 [M+ + 1]. C52H48O2P2Ru (867.97): calcd. C 71.96, H product extracted with diethyl ether was identified as 6b in 89%
5.57; found C 71.83, H 5.48.
yield (21 mg). The organometallic product was identified as [Ru]–I
(84 mg, 94% yield). 6b: 1H NMR (300 MHz, CDCl3, 25 °C): δ =
7.25–7.18 (m, 5 H, Ph), 6.29 (s, 1 H, CH), 3.92 (s, 3 H, CH3), 3.76
(s, 3 H, CH3) ppm. 13C NMR (75.4 MHz, CDCl3, 25 °C): δ =
168.3, 165.4 (two COCH3), 149.0 (CPh), 133.1–126.8 (Ph), 117.0
(CH), 52.7, 52.0 (two CH3) ppm. High-resolution MS for
C12H12O4: calcd. 220.0736; found 220.0732.
Observation of 3a: To a solution of 2a (100 mg, 0.12 mmol) in 5 mL
of acetone was added a solution of nBu4NOH (0.3 mL, 0.3 mmol,
1 m in CH3OH) under nitrogen at room temperature. H2O was
added to the mixture immediately and yielded the light yellow
microcrystalline precipitate. The product was filtered off and
washed with 2×5 mL of CH3CN, then dried under vacuum and
identified as 3a (89 mg, 89% yield). Complex 3a is not stable at
room temperature. By monitoring the 31P NMR spectrum, 3a was
found as a pure product at the initial stage, spectroscopic data of
3a was obtained within 3 min. Then the product 4a was observed.
Spectroscopic data for 3a are as follows: 1H NMR (300 MHz,
C6D6, 25 °C): δ = 7.44–6.94 (m, 30 H, Ph), 5.65 (br., 1 H, CH of
C6H9), 4.65 (s, 5 H, Cp), 3.74 (s, 3 H, OCH3), 2.47 (s, 1 H, CH),
2.50–1.24 (br., 8 H, 4 CH2 of C6H9) ppm. 31P{1H} NMR
(121.6 MHz, C6D6, 25 °C): δ = 52.5, 48.5 (AX, JP–P = 36.4 Hz)
ppm.
Reaction of 5 with Protic Acid: To a solution of complex 5a
(100 mg, 0.10 mmol) in CDCl3 prepared under N2 in an NMR
tube, hydrochloric acid (50 μL of aqueous 37% HCl, 0.6 mmol)
was added. The reaction is complete within about 4 h at room tem-
perature. The solvent was removed under vacuum. The organic
product was extracted with diethyl ether and identified as 7a
(18 mg, 86% yield). The organometallic product was identified as
[Ru]–Cl (73 mg, 92% yield). The solvent and HCl were removed
under vacuum at 60 °C. 7a: 1H NMR (300 MHz, CDCl3, 25 °C): δ
= 6.82 (s, 1 H, CH), 6.30 (br., 1 H, CH of C6H9), 3.73 (s, 3 H,
OCH3), 2.22–1.58 (br., 8 H, 4 CH2 of C6H9) ppm. MS (EI): 210
[M+]. The same procedure was used for the reaction of 5b (100 mg,
0.11 mmol) with acid, and the product extracted with diethyl ether
was identified as 7b (17 mg, 90% yield). The organometallic prod-
uct was identified as [Ru]–Cl (65 mg, 90% yield). 7b: 1H NMR
(300 MHz, CDCl3, 25 °C): δ = 7.25–7.01 (m, 5 H, Ph), 6.28 (s, 1
H, CH), 3.76 (s, 3 H, CH3) ppm. 13C NMR (75.4 MHz, CDCl3,
25 °C): δ = 170.6 (CO2H), 165.5 (CO2CH3), 148.8 (CPh), 133.3–
Synthesis of [Ru]O2CC(C6H9)=CHCO2CH3 (5a): Complex 4a
(0.20 g, 0.23 mmol) was exposed to air for 5 days at room tempera-
ture, and the light yellow powder became deep yellow. The product
was identified as 5a (0.20 g, 99% yield). Spectroscopic data for 5a
are as follows: 1H NMR (300 MHz, C6D6, 25 °C): δ = 7.64–6.96
(m, 30 H, Ph), 5.79 (br., 1 H, CH of C6H9), 5.53 (s, 1 H, CH), 4.79
(s, 5 H, Cp), 3.51 (s, 3 H, OCH3), 1.99, 1.45, 1.26, 1.01 (br., 8 H,
4 CH2 of C6H9) ppm. 31P{1H} NMR (121.6 MHz, C6D6, 25 °C): δ
= 39.5 (s) ppm. 13C NMR (75.4 MHz, C6D6, 25 °C): δ = 174.2
(RuO2C), 166.9 (CO2CH3), 160.3 (CC6H9), 139.6–127.4 (Ph), 107.2
(CH), 80.2 (Cp), 50.6 (CH3), 26.7, 25.4, 23.1, 22.2 (CH2 of
C6H9) ppm. MS FAB: m/z = 901 [M+ + 1], 869 [M+ + 1 – O2],
719.2 [M+ + CO – O2CC(C6H9)=CHCO2CH3], 691.1 [M+ – O2
CC(C6H9)=CHCO2CH3], 638 [M+ + 1 – PPh3], 429.0 [M+ – PPh3,
126.8 (Ph), 116.8 (CH), 52.0 (CH3) ppm. MS (EI): m/z = 174 [M+
CH3OH]. The HCl could be replaced with trifluoroacetic acid or
–
[30]
acetic acid yielding 7 and [Ru]–OCOCF3
or [Ru]–OCOCH3,[30]
respectively. Both reactions completed in 36 h. Trifluoroacetic acid
and acetic acid could be removed under vacuum without heating.
Reaction of 4a with TMSN3: A solution of 4a (100 mg, 0.12 mmol)
in THF (10 mL) was treated with TMSN3 (0.07 mL, 0.54 mmol).
The resulting solution was stirred at room temperature for 1 h then
the solvent was removed under vacuum. The mixture was added to
a stirred diethyl ether. Orange precipitates thus formed were filtered
off and washed with diethyl ether. The organometallic product was
identified as [Ru]–N3 (79 mg, 90% yield). The organic product was
collected by extraction with ether and purified by chromatography,
then, the solvent was removed under vacuum to give 8a, (19 mg,
90% yield). 8a: 1H NMR (300 MHz, C6D6 25 °C): δ = 6.78 (d,
4JH,H = 1.2 Hz, 1 H, CH), 5.88 (br., 1 H, CH of C6H9), 5.25 (d,
4JH,H = 1.2 Hz, 1 H, CH), 3.79 (s, 3 H, OCH3), 2.16–1.58 (br., 8
H, 4 CH2 of C6H9) ppm. MS (EI): m/z = 178 [M+].
O2CC(C6H9)=CHCO2CH3]. C52H48O4P2Ru (899.97): calcd.
69.40, H 5.38; found C 69.28, H 5.22.
C
Synthesis of [Ru]O2CC(Ph)=CHCO2CH3 (5b): Complex 4b (0.20 g,
0.23 mmol) was exposed to air for 10 days at room temperature,
and the orange powder became yellow. The 31P NMR was used to
confirm complete transformation. The yellow product was iden-
tified as 5b, and the yield is almost quantitative (0.21 g, 99% yield).
Spectroscopic data of 5b are as follows: 1H NMR (300 MHz,
CDCl3, 25 °C): δ = 7.40–6.93 (m, 35 H, Ph), 5.76 (s, 1 H, CH), 4.44
(s, 5 H, Cp), 3.63 (s, 3 H, OCH3) ppm. 31P{1H} NMR (121.6 MHz,
CDCl3, 25 °C): δ = 40.85 (s) ppm. 13C NMR (75.4 MHz, CDCl3,
25 °C): δ = 174.0 (RuO2C), 166.0 (CO2CH3), 157.3 (CPh), 138.2–
25.2 (Ph), 111.9 (CH), 78.6 (Cp), 51.1 (CH3) ppm. MS FAB: m/z
= 896.1 [M+], 719.2 [M+ + CO, O2CC(Ph)=CHCO2CH3], 691.2
[M+ – O2CC(Ph)=CHCO2CH3], 634.1 [M+ – PPh3]. C52H44O4P2Ru
(895.93): calcd. C 69.70, H 4.95; found C 69.56, H 4.82.
Reaction of 4b with TMSN3: To a flask containing compound 4b
(0.20 g, 0.23 mmol) in THF (10 mL), TMSN3 (0.20 mL,
1.49 mmol) was added. The solution was stirred at room tempera-
ture for 2 h, then the solvent was removed under vacuum. The yel-
low solid was washed with hexane and identified as [Ru]–N3
(0.16 g, 95% yield). The organic product was extracted with hexane
and was found to contain some triphenylphosphane oxide. The
pure organic product was obtained by eluting the mixture with di-
ethyl ether on a silica gel column and solvent was removed on a
Reaction of 5 with CH3I: To a solution of complex 5a (100 mg,
0.11 mmol) in CDCl3 prepared under N2 in a NMR tube, 36 μL
(0.58 mmol) of CH3I was added. The reaction was carried out at
50 °C for 3–4 h. The solvent was removed under vacuum. The or-
ganic product along with excess CH3I was extracted with diethyl
Eur. J. Inorg. Chem. 2006, 649–655
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
653

K.-H. Chang, H.-L. Sung, Y.-C. Lin
FULL PAPER
rotary evaporator. The organic product was identified as com-
uct was analytically pure and was identified as 11b in 72% yield.
pound 8b (34 mg, 91% yield). [Ru]–N3: 1H NMR (300 MHz, C6D6 (140 mg) Spectroscopic data for 11b are as follows: 1H NMR
25 °C): δ = 7.32–7.08 (m, 30 H, Ph), 4.18 (s, 5 H, Cp) ppm. 31P{1H}
NMR (121.6 MHz, CDCl3, 25 °C): δ = 41.8 (s) ppm. 8b: 1H NMR
(300 MHz, C6D6, 25 °C): δ = 7.30–7.10 (m, 5 H, Ph), 6.96 (d, 1 H,
(300 MHz, C6D6, 25 °C): δ = 7.91 (q, JH,H = 15.1, 9.62 Hz, 1 H,
CH=), 7.39–6.90 (m, 35 H, Ph), 6.67 (d, JH,H = 15.1 Hz, 1 H,
=CH), 4.56 (s, 5 H, Cp), 3.62 (s, 3 H, CH3), 2.62 (d, JH,H = 9.62 Hz,
4
4
CH, JH,H = 1.3 Hz), 5.24 (d, 1 H, CH, JH,H = 1.3 Hz), 3.23 (s, 3 1 H, CH) ppm. 31P{1H} NMR (121.6 MHz, C6D6, 25 °C): δ = 52.2,
H, CH3) ppm. High-resolution MS for C11H10O2: calcd. 174.0681;
found 174.0691. Isolation of 9b: Transformation of 8b to 9b under
acidic condition was monitored by NMR in CDCl3. Addition of
HCl (37%, 9.2 μL) to the solution of 8b (19 mg, 0.11 mmol) caused
48.9 (AX, JP–P = 36.1 Hz) ppm. 13C NMR (75.4 MHz, C6D6,
25 °C): δ = 169.1 (CH=), 168.3 (C=O), 140.2–125.8 (Ph), 112.6
(=CH), 86.4 (Cp), 50.2 (OCH3), 36.7 (CH) ppm. MS FAB: m/z =
891.4 [M+ + 1], 629.3 [M+ + 1, PPh3], 429.1 [M+ + 1 – PPh3,
the formation of 9b (16 mg, 95% yield) in about 30 min. 9b: 1H =C=C(Ph)CH2CH=CHCO2CH3]. C54H46O2P2Ru (899.97): calcd.
NMR (300 MHz, CDCl3, 25 °C): δ = 7.48 (s, 5 H, Ph), 6.36 (t, JH,H
= 1.8 Hz, 1 H, CH), 5.22 (d, JH,H = 1.8 Hz, 2 H, CH2) ppm. 13C
NMR (75.4 MHz, CDCl3, 25 °C): δ = 173.9 (OC), 163.9 (CPh),
131.8–129.6 (Ph), 113.0 (CH), 71.0 (CH2) ppm. High-resolution
MS for C10H8O2: calcd. 160.0524; found 160.0521.
C 72.88, H 5.21; found C 72.63, H 5.12.
Reaction of 11b with TMSN3: To a Schlenk flask charged with com-
plex 11b (50 mg, 0.06 mmol) was added THF (10 mL) under nitro-
gen. The resulting yellow solution was stirred and TMSN3 (0.1 mL,
0.75 mmol) was added. The mixture was stirred at room tempera-
ture for 4 h, then the solution was concentrated to about 3 mL, and
slowly added to 20 mL of a stirred hexane solution. The orange
precipitate thus formed was filtered off, and washed with diethyl
ether. The product was identified as [Ru]–CN (39 mg, 90%). The
organic product was extracted with hexane, then the extract was
filtered through silical gel. Solvent of the filtrate was removed un-
der vacuum and the product was identified as 12 (12 mg, 88%
Synthesis of Vinylidene Complexes with Methyl Crotonate: To a
Schlenk flask charged with [Ru]CϵCC6H9 (1a) (200 mg,
0.25 mmol) in CH2Cl2 (20 mL), BrCH2CH=CHCO2CH3 (0.15 mL,
1.25 mmol) was added under nitrogen. The mixture was stirred at
room temperature for 6 h, then the solution was concentrated to
about 5 mL and added dropwise to 60 mL of a vigorously stirred
diethyl ether. The pink precipitate thus formed was filtered off, and
washed with diethyl ether and hexane. The product was identified
as [Ru]=C=C(C6H9)CH2CH=CHCO2CH3][Br] (10a) (179 mg, 85%
yield). 10a: 1H NMR (300 MHz, CDCl3, 25 °C): δ = 7.41–6.99 (m,
30 H, Ph), 6.71, 6.68 (dt, JH,H = 10.0, 6.4 Hz, 1 H, CH=C), 5.73
(br., 1 H, CH of C6H9), 5.70 (d, JH,H = 10.0 Hz, 1 H, =CH), 5.11
(s, 5 H, Cp), 3.76 (s, 3 H, OCH3), 2.73 (d, JH,H = 6.4 Hz, 2 H,
CH2), 2.16, 1.71, 1.52, 1.49 (br., 8 H, 4 CH2 of C6H9) ppm. 31P{1H}
NMR (121.6 MHz, CDCl3, 25 °C): δ = 42.3 (s) ppm. 13C NMR
(75.4 MHz, CDCl3, 25 °C): δ = 351.8 (Cα, JC,P = 15.4 Hz), 166.4
(CO2), 145.8, 122.3 (C=C), 134.3–128.0 (Ph), 130.1 (CH of C6H9),
125.1 (Cβ), 94.2 (Cp), 51.5 (OCH3), 27.3, 25.8, 22.6, 21.5 (CH2 of
C6H9), 25.4 (CH2) ppm. MS FAB: m/z = 895.4 [M+ – Br], 633.2
1
yield). [Ru]–CN: H NMR (300 MHz, C6D6, 25 °C): δ = 7.81–6.96
(m, 30 H, Ph), 4.45 (s, 5 H, Cp) ppm. 31P{1H} NMR (121.6 MHz,
C6D6, 25 °C): δ = 50.38 (s) ppm. 12: 1H NMR (300 MHz, C6D6,
25 °C): δ = 7.81–6.96 (m, 5 H, Ph), 3.31 (s, 3 H, OCH3), 3.07 (t, 2
3
3
H, CH2, JH,H = 7.39 Hz), 2.71 (t, 2 H, CH2, JH,H = 7.39 Hz)
1
ppm. H NMR (300 MHz, CDCl3, 25 °C): δ = 7.67–7.06 (m, 5 H,
Ph), 3.67 (s, 3 H, OCH3), 3.19 (t, 2 H, CH2, 3JH,H = 7.39 Hz), 2.80
(t, 2 H, CH2, 3JH,H = 7.39 Hz) ppm. 13C NMR (75.4 MHz, CDCl3,
25 °C): δ = 173.9 (CO), 134.1–128.0 (Ph), 52.4 (OCH3), 33.1
(CH2O), 21.1 (CH2) ppm. MS (EI): m/z = 230 [M+]
Acknowledgments
[M+
–
Br, PPh3], 429.0 [M+
–
Br, PPh3, C2(C6H9)-
CH2CH=CHCO2CH3], 371.1 [M+ – Br, 2PPh3]. C54H51BrO2P2Ru
(974.92): calcd. C 66.53, H 5.27; found C 66.27, H 5.19. To a solu-
tion of [Ru]CϵCPh[4b] (1b) (200 mg, 0.25 mmol) in CH2Cl2
(20 mL), BrCH2CH=CHCO2CH3 (0.15 mL, 1.25 mmol) was added
under nitrogen. The mixture was stirred at room temperature for
6 h, then the volume was reduced to about 5 mL. Addition of the
mixture dropwise into 60 mL of a vigorously stirred diethyl ether
caused a pink-red solid to precipitate out. The precipitate thus
formed was filtered off and washed with diethyl ether and hexane
and dried under reduced pressure to yield the product
[Ru]=C=C(Ph)CH2CH=CHCO2CH3][Br] (10b) (197 mg, 88%
yield). 10b: 1H NMR (300 MHz, CDCl3, 25 °C): δ = 7.41–6.80 (m,
35 H, Ph), 6.71, 6.68 (dt, JH,H = 15.4, 6.58 Hz, 1 H, CH=C), 5.62
(d, JH,H = 15.4 Hz, 1 H, =CH), 5.11 (s, 5 H, Cp), 3.70 (s, 3 H,
CH3), 3.07 (d, JH,H = 6.58 Hz, 2 H, CH2) ppm. 31P{1H} NMR
We thank the National Science Council of Taiwan, R.O.C. for fin-
ancial support of this work.
[1] a) F. Pezet, J. C. Daran, I. Sasaki, H. Ait-Haddou, G. G. A.
Balavoine, Organometallics 2000, 19, 4008–4015; b) m. J. Burk,
W. Hems, D. Herzberg, C. Malan, A. Zanotti-Gerosa, Org.
Lett. 2000, 2, 4173–4176; c) D. A. Alonso, S. J. M. Nordin, P.
Roth, T. Tarnai, P. G. Andersson, M. Thommen, U. Pittelkow,
J. Org. Chem. 2000, 65, 3116–3122; d) M. Yamakawa, H. Ito,
R. Noyori, J. Am. Chem. Soc. 2000, 122, 1466–1478; e) B. M.
Trost, F. D. Toste, A. B. Pinkerton, Chem. Rev. 2001, 101,
2067–2096; f) M. Kitamura, M. Tsukamoto, Y. Bessho, M.
Yoshimura, U. Kobs, M. Widhalm, R. Noyori, J. Am. Chem.
Soc. 2002, 124, 6649–6667; g) S. N. Ringelberg, A. Meetsma,
S. I. Troyanov, B. Hessen, J. H. Teuben, Organometallics 2002,
21, 1759–1765; h) J. H. Xie, L. X. Wang, Y. Fu, S. F. Zhu, B.-
M. Fan, H. F. Duan, Q. L. Zhou, J. Am. Chem. Soc. 2003, 125,
4404–4405.
[2] a) W. D. Cotter, L. Barbour, K. L. McNamara, R. Hechter,
R. J. Lachicotte, J. Am. Chem. Soc. 1998, 120, 11016–11017; b)
M. H. Chisholm, S. T. Haubrich, J. C. Huffman, W. E. Streib,
J. Am. Chem. Soc. 1997, 119, 1634–1647; c) T. Itoh, K. Mitsu-
kura, N. Ishida, K. Uneyama, Org. Lett. 2000, 2, 1431–1434;
d) T. L. Choi, C. W. Lee, A. K. Chatterjee, R. H. Grubbs, J.
Am. Chem. Soc. 2001, 123, 10417–10418; e) L. Jafarpour, S. P.
Nolan, Organometallics 2000, 19, 2055–2057; f) Y. M. Ahn, K.
Yang, G. I. Georg, Org. Lett. 2001, 3, 1411–1413; g) M. S. San-
ford, M. Ulman, R. H. Grubbs, J. Am. Chem. Soc. 2001, 123,
749–750; h) A. E. Sutton, B. A. Seigal, D. F. Finnegan, M. L.
(121.6 MHz, CDCl3, 25 °C):
δ =
41.9 (s) ppm. 13C NMR
(75.4 MHz, CDCl3, 25 °C): δ = 347.8 (Cα, JC,P = 14.7 Hz), 166.4
(CO2), 153.9, 144.7 (C=C), 134.7–126.7 (Ph), 123.0 (Cβ), 94.4 (Cp),
51.6 (OCH3), 29.2 (CH2) ppm. MS FAB: m/z = 891.1 [M+ – Br],
629.3 [M+
– – Br, PPh3, C2(Ph)
Br, PPh3], 429.1 [M+
CH2CH=CHCO2CH3]. C54H47BrO2P2Ru (1050.79): calcd.
66.80, H 4.88; found C 66.72, H 4.82.
C
Synthesis of 11b: To a solution of 10b (200 mg, 0.22 mmol) in 5 mL
of acetone was added a 1 M solution of nBu4NOH (0.3 mL,
0.3 mmol, in CH3OH). The mixture was stirred for 1 h yielding the
light yellow microcrystalline precipitate which was filtered off and
washed with 2×5 mL of CH3CN, dried under vacuum. The prod-
654
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Eur. J. Inorg. Chem. 2006, 649–655

Reactions of Furyl-Ru Complexes with Oxygen and Trimethylsilyl Azide
FULL PAPER
Snapper, J. Am. Chem. Soc. 2002, 124, 13390–13391; i) S. Fom-
ine, S. M. Vargas, M. A. Tlenkopatchev, Organometallics 2003,
22, 93–99.
J. Org. Chem. 1975, 40, 810–811; c) S. Kamijo, T. Jin, Z. Huo,
Y. Yamamoto, Tetrahedron Lett. 2002, 43, 9707–9710; d) R.
Shintani, G. C. Fu, J. Am. Chem. Soc. 2003, 125, 10778–10779;
e) W. Carruthers, Cycloaddition Reaction in Organic Synthesis
Pergamon, Oxford, 1990, p. 269; f) C. W. Tornøe, C. Chrit-
ensen, M. Meldal, J. Org. Chem. 2002, 67, 3057–3064; g) K. V.
Gothelf, K. A. Jørgensen, Chem. Rev. 1998, 98, 863–910; h) G.
LЈabbé, Chem. Rev. 1969, 69, 345–363.
[3] a) J. E. Mcalvin, C. L. Fraser, Macromolecules 1999, 32, 6925–
6932; b) P. S. Wolfe, K. B. Wagener, Macromolecules 1999, 32,
7961–7967; c) M. Kamigaito, Y. Watanabe, T. Ando, M. Sawa-
moto, J. Am. Chem. Soc. 2002, 124, 9994–9995; d) S. Hama-
saki, M. Kamigaito, M. Sawamoto, Macromolecules 2002, 35,
2934–2940; e) L. Delaude, A. Demonceau, A. F. Noels, Macro-
molecules 2003, 36, 1446–1456; f) C. Bianchini, G. Mantovani,
A. Meli, F. Migliacci, F. Laschi, Organometallics 2003, 22,
2545–2547.
[4] a) P. C. Ting, Y. C. Lin, M. C. Cheng, Y. Wang, Organometal-
lics 1994, 13, 2150–2152; b) P. C. Ting, Y. C. Lin, G. H. Lee,
M. C. Cheng, Y. Wang, J. Am. Chem. Soc. 1996, 118, 6433–
6444; c) Y. H. Lo, Y. C. Lin, G. H. Lee, Y. Wang, Organometal-
lics 1999, 18, 982–988; d) C. W. Chang, Y. C. Lin, G. H. Lee,
Y. Wa n g , Organometallics 2000, 19, 3211–3219; e) Huang, C. C.
Lin, Y. C. Huang, S. L. Liu, Y. H. Wang, Organometallics 2003,
22, 1512–1518.
[17] a) S. Kamijo, T. Jin, Z. Huo, Y. Yamamoto, J. Am. Chem. Soc.
2003, 125, 7786–7787; b) S. Kamijo, Y. Yamamoto, Angew.
Chem. Int. Ed. 2002, 41, 3230–3233; c) S. Kamijo, T. Jin, Y.
Yamamoto, J. Am. Chem. Soc. 2001, 123, 9453–9454; d) S. Ka-
mijo, T. Jin, Y. Yamamoto, J. Org. Chem. 2002, 67, 7413–7417.
[18] A. Palazzi, S. Stagni, S. Bordoni, M. Monari, S. Selva, Organo-
metallics 2002, 21, 3774–3781.
[19] a) M. L. Graziano, M. R. Iesce, Synthesis 1984, 64–66; b)
M. L. Graziano, M. R. Iesce, R. Scarpati, Synthesis 1984, 66–
68.
[20] a) M. L. Graziano, M. R. Iesce, S. Chiosi, R. Scarpati, J.
Chem. Soc., Perkin Trans. 1. 1983, 2071–2074; b) M. L. Grazi-
ano, M. R. Iesce, B. Carli, R. Scarpati, Synthesis 1983, 125–
126; c) M. L. Graziano, M. R. Iesce, R. Scarpati, Chem. Soc.,
Perkin Trans. 1. 1982, 2007–2012; d) M. L. Graziano, M. R.
Iesce, B. Carli, R. Scarpati, Synthesis 1982, 736–738; e) M. L.
Graziano, M. R. Iesce, R. Scarpati, J. Chem. Soc., Perkin
Trans. 1. 1980, 1955–1959.
[5] J. Y. Yang, Y. H. Lo, S. L. Huang, Y. C. Lin, Organometallics
2001, 20, 3621–3623.
[6] a) M. Nakamura, N. Isobe, E. Nakamura, Chem. Rev. 2003,
103, 1295–1326; b) I. Nakamura, G. B. Bajracharya, Y. J. Yam-
amoto, Org. Chem. 2003, 68, 2297–2299; c) L. Liao, J. M. Fox,
J. Am. Chem. Soc. 2002, 124, 14322–14323; d) P. W. Jennings,
L. L. Johnson, Chem. Rev. 1994, 94, 2241–2290.
[21] K. C. Brannock, R. D. Burpitt, V. Goodlett, W. J. G. Thweatt,
J. Org. Chem. 1964, 29, 813–817.
[7] a) K. H. Chang, Y. C. Lin, Chem. Commun. 1998, 1441–1442;
b) K. H. Chang, Y. C. Lin, Y. H. Liu, Y. J. Wang, J. Chem. [22] a) B. Gabriele, G. Salerno, M. Costa, G. P. Chiusoli, J. Or-
Soc., Dalton Trans. Chem. Soc., Dalton Trans. 2001, 21, 3154–
ganomet. Chem. 1995, 503, 21–28; b) R. C. Larock, K. Naray-
anan, S. S. Hershberger, J. Org. Chem. 1983, 48, 4377–4380.
[23] B. T. Donovan-Merkert, J. Malik, L. V. Gray, J. M. O’Connor,
B. S. Fong, M. C. Chen, Organometallics 1998, 17, 1007–1009.
[24] a) N. B. Carter, R. Mabon, A. M. E. Richecoeur, J. B. Sweeney,
Tetrahedron 2002, 58, 9117–9129; b) J. Wu, Q. Zhu, L. Wang,
R. Fathi, Z. Yang, J. Org. Chem. 2003, 68, 670–673.
[25] I. R. Likhotvorik, D. W. Brown, M. Jones Jr., J. Am. Chem.
Soc. 1994, 116, 6175–6178.
3159.
[8] A. Padwa, Acc. Chem. Res. 1976, 9, 371–378.
[9] S. M. Ma, J. L. Zhang, J. Am. Chem. Soc. 2003, 125, 12386–
12387.
[10] a) I. A. DЈyakonov, M. I. Komendantov, Zh. Obshch. Khim.
1961, 31, 681–683; b) I. A. DЈyakonov, M. I. Komendantov,
Zh. Obshch. Khim. 1961, 31, 3483–3485.
[11] J. A. Pincock, A. A. Moutokapa, Can. J. Chem. 1977, 55, 979–
985.
[26] a) A. Romero, A. Santo, A. Vegas, Organometallics 1988, 7,
1988–1993; b) N. W. Alcock, A. F. Hill, R. P. Melling, Organo-
metallics 1991, 10, 3898–3903.
[12] H. E. Selnau, J. S. Merola, Organometallics 1993, 12, 1583–
1591.
[13] H. E. Selnau, J. S. Merola, Organometallics 1993, 12, 3800–
3801.
[27] W. M. Laidlaw, R. G. Denning, J. Organomet. Chem. 1993, 463,
199–204.
[14] a) K. W. Liang, W. T. Li, S. M. Peng, S. L. Wang, R. S. Liu, J.
Am. Chem. Soc. 1997, 119, 4404–4412; b) H. G. Shu, L. H.
Shiu, S. H. Wang, S. L. Wang, G. H. Lee, S. M. Peng, R. S.
Liu, J. Am. Chem. Soc. 1996, 118, 530–540.
[15] a) Z. P. Demko, K. B. Sharpless, J. Org. Chem. 2001, 66, 7945–
7950; b) E. D. Soli, P. J. DeShong, Org. Chem. 1999, 64, 9724–
9726; c) A. Dondoni, M. C. Scherrmann, A. Marra, J. L.
Delépine, J. Org. Chem. 1994, 59, 7517–7520; d) R. M. Mori-
arty, R. K. Vaid, T. E. Hopkin, B. K. Vaid, A. Tuncay, Tetrahe-
dron Lett. 1989, 30, 3019–3022; e) P. Magnus, J. Lacour, J. Am.
Chem. Soc. 1992, 114, 3993–3994; f) Y. Kita, H. Tohma, M.
Inagaki, K. Hatanaka, T. Yakura, Tetrahedron Lett. 1991, 32,
4321–4324.
[28] a) M. Alterman, A. Hallberg, J. Org. Chem. 2000, 65, 7984–
7989; b) R. A. Batey, D. A. Powell, Org. Lett. 2000, 2, 3237–
3240; c) Z. P. Demko, K. Sharpless, Org. Lett. 2001, 3, 4091–
4094; d) Z. P. Demko, K. B. Sharpless, J. Org. Chem. 2001, 66,
7945–7950; e) P. D. Zachary, K. B. Sharpless, Angew. Chem.
Int. Ed. 2002, 41, 2110–2113; f) P. D. Zachary, K. B. Sharpless,
Angew. Chem. Int. Ed. 2002, 41, 2113–2116.
[29] T. Wilczewski, B. M. Ochenska, J. F. Biernat, J. Organomet.
Chem. 1981, 215, 87–96.
[30] H. Werner, T. Braun, T. Daniel, O. Gevert, M. Schulz, J. Or-
ganomet. Chem. 1997, 541, 127–141.
Received: July 13, 2005
Published Online: November 17, 2005
[16] a) R. H. Wiley, K. F. Hussung, J. Moffat, J. Org. Chem. 1956,
21, 190–192; b) R. J. D. Pasquale, C. D. Padgett, R. W. Rosser,
Eur. J. Inorg. Chem. 2006, 649–655
© 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
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