"release and catch" catalysis by tungstate species for the oxidative cleavage of olefins

Article abstract of DOI:10.1039/c7cy00062f

The oxidative cleavage of olefins produces valuable carbonyl compounds, and thus, the development of green catalytic methods using H₂O₂ as an oxidant is highly desired. In this work, we have successfully developed an efficient catalytic system for the oxidative cleavage of olefins and related compounds using H₂O₂. In the presence of tungstate species supported on zinc-modified tin dioxide (W/Zn-SnO₂), the oxidative cleavage of 1-methyl-1-cyclohexene proceeds efficiently through multistep reaction pathways involving oxygenation, hydrolysis, perhydrolysis, and isomerization reactions. In this reaction system, active peroxotungstate species, generated by the reaction of the supported tungstate species with H₂O₂, are released into the solution during the course of the reaction. At the end of the reaction (after the complete consumption of H₂O₂), the released tungstate species are re-captured by the support. The W/Zn-SnO₂ catalyst can be reused at least nine times for the oxidative cleavage of 1-methyl-1-cyclohexene without loss of catalytic performance and can be applied to the oxidation of various other substrate molecules.

Full text of DOI:10.1039/c7cy00062f

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Submitted to Catalysis Science & Technology as an article (revised)
“Release and catch” catalysis by tungstate species for the oxidative cleavage of
olefins
†
Yu Yoshimura, Yoshiyuki Ogasawara,* Kosuke Suzuki, Kazuya Yamaguchi* and Noritaka Mizuno*
Department of Applied Chemistry, School of Engineering, The University of Tokyo,
7ꢀ3ꢀ1 Hongo, Bunkyoꢀku, Tokyo 113ꢀ8656, Japan.
Eꢀmail: tmizuno@mail.ecc.uꢀtokyo.ac.jp, kyama@appchem.t.uꢀtokyo.ac.jp, ogasawara@appchem.t.uꢀtokyo.ac.jp.
Abstract
The oxidative cleavage of olefins produces valuable carbonyl compounds, and thus, the development of green
catalytic methods using H2O2 in the role of oxidant is highly desired. In this work, we have successfully developed
an efficient catalytic system for the oxidative cleavage of olefins and related compounds using H2O2. In the
presence of tungstate species supported on zincꢀmodified tin dioxide (W/Zn–SnO2), the oxidative cleavage of
1ꢀmethylꢀ1ꢀcyclohexene proceeds efficiently through multistep reaction pathways involving oxygenation,
hydrolysis, perhydrolysis, and isomerization reactions. In this reaction system, active peroxotungstate species,
generated by the reaction of the supported tungstate species with H2O2, are released into solution during the course
of the reaction. At the end of the reaction (after the complete consumption of H2O2), the released tungstate species
are reꢀcaptured by the support. The W/Zn–SnO2 catalyst can be reused at least nine times for the oxidative cleavage
of 1ꢀmethylꢀ1ꢀcyclohexene without loss in catalytic performance and can be applied to the oxidation of various
other substrate molecules.
† Electronic Supplementary Information (ESI) available: Data of products, Figs. S1–S10 and Tables S1–S7. See
DOI: 10.1039/x0xx00000x
1

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Introduction
The oxidation reactions of simple organic compounds into functionalized products, such as alcohols, phenols,
epoxides, and carbonyl compounds, are of significant importance because these oxyꢀfunctionalized products are
very useful in the production of commodity and specialty chemicals.1 The oxidative cleavage of olefins generates
valuable carbonyl compounds, such as ketones, aldehydes, and carboxylic acids.2 One typical method for olefin
cleavage is ozonolysis, which is a conventional industrial process that uses ozone in the role of oxidant.3 Other
typical methods include processes that use transition metalꢀbased stoichiometric oxidants (e.g., potassium
permanganate and chromyl chloride) or transition metal catalysts (e.g., osmium tetroxide and ruthenium chloride)
with suitable coꢀoxidants (e.g., sodium periodate and oxone).4 However, these dated methods have several
drawbacks, including the use of hazardous and expensive reagents and the formation of byꢀproducts derived from
these oxidants. Therefore, the development of new and efficient catalytic methods using greener oxidants is highly
desired.
In recent years, various liquidꢀphase oxidations using H2O2 as the terminal oxidant have attracted significant
attention because H2O2 is considered to be a green oxidant since it is much safer and less expensive than peroxides
and peracids, it has a high content of active oxygen species (47 wt%), and it theoretically generates water as the
sole byꢀproduct.5 To date, catalytic systems for the H2O2ꢀbased oxidative cleavage of olefins using various
transitionꢀmetal catalysts, including W, Mo, V, Ti, Ru, Re, Cr, and Fe, have been reported.6−8 Among them,
tungstenꢀbased catalytic systems have been widely developed.6,7 For example, Noyori and coꢀworkers
demonstrated the oxidative cleavage of various cyclic olefins in the presence of a catalytic amount of
Na2WO4⋅2H2O and a quaternary ammonium salt.6a Furthermore, H2WO4,6b,c polyoxotungstate species,6d−g and
peroxotungstate species6h−k have also been reported as efficient homogeneous catalysts for the oxidative cleavage of
olefins. The use of heterogeneous catalysts for liquidꢀphase reactions is more desirable owing to their facile
separation and reusability.9 Although several tungstenꢀbased “heterogeneous” catalytic systems for oxidative olefin
cleavage have been reported,7 most of these systems experience leaching of the active tungstate species and/or their
severe deactivation in repeat catalyst reuse experiments. In addition, in most cases, no reliable experimental
evidence is presented as to whether the observed catalysis was truly heterogeneous and based on the supported
tungstate species or originated from leached tungstate species.
Herein, we report an efficient catalytic system for the oxidative cleavage of olefins and related compounds
using H2O2 as the oxidant and tungstate species supported on zincꢀmodified tin dioxide (W/Zn–SnO2) as the
catalyst. On the basis of the evidences from several control experiments, we discovered that the active
peroxotungstate species formed by the reaction of the supported tungstate species with H2O2 were released into
solution during the course of the reaction and were reꢀcaptured onto the support at the end of the reaction (after the
complete consumption of H2O2). The W/Zn–SnO2 catalyst could be reused at least nine times without any
appreciable loss in performance and could be used to oxidize various substrate molecules. This “release and catch”
catalytic system combines the advantages of both homogeneous and heterogeneous catalyses.
2

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Results and discussion
Detailed investigation into the WO3-catalyzed oxidative olefin cleavage
Initially, we investigated the WO3ꢀcatalyzed oxidative cleavage of olefins using H2O2 as the oxidant since WO3 is
easily available and frequently utilized as the heterogeneous catalyst for various oxidation reactions.7b−d,10 The
results for the WO3ꢀcatalyzed oxidative cleavage of 1ꢀmethylꢀ1ꢀcyclohexene (1a) with 30% aqueous H2O2 (5
equivalents with respect to 1a) are summarized in Table 1. The reaction using WO3 under the present conditions
effectively produced the desired cleavage product 6ꢀoxoheptanoic acid (2a) in 92% yield after 24 h (Table 1,
entry 2), and the H2O2 oxidant was completely consumed in the course of the reaction. The reaction did not proceed
at all in the absence of either WO3 or H2O2 (Table 1, entries 4 and 5). For the WO3ꢀcatalyzed reaction, the insoluble
species were removed by hot filtration after 4 h (33% yield of 2a; Table 1, entry 1), and the reaction was conducted
with the filtrate under the same conditions. In this case, the reaction did not stop, and 2a was produced in 90% yield
after a total time of 24 h (Table 1, entry 3). In addition, it was confirmed by inductively coupled plasma atomic
emission spectroscopy (ICPꢀAES) analysis that 24% of the tungsten species had leached into the reaction solution
after 4 h. Therefore, it is possible that the soluble tungstate species that are generated during the reaction act as the
truly active "homogeneous" catalytic species in the oxidative olefin cleavage under the present conditions.
In order to clarify the nature of the active species, the following control experiments were conducted. WO3
was reacted with H2O2 (without 1a) under the conditions described in Table 1 (Fig. 1a). After 1 h, the unreacted
insoluble WO3 was removed by hot filtration, yielding a colorless transparent filtrate (Fig. 1b). Coldꢀspray
ionization (CSI) mass analysis (negativeꢀion mode) of the filtrate indicated signals assignable to various
peroxotungstate species, such as [HWO2(O2)2]− (m/z = 280.9), [H3WO4(O2)]− (m/z = 282.9), [HWO(O2)3]− (m/z =
296.9), [H3WO3(O2)2]− (m/z = 298.9), [H5WO5(O2)]− (m/z = 300.9), [HW2O3(O2)4]− (m/z = 544.9),
[W2O2(O2)4OtBu]− (m/z = 600.9), [HW3O4(O2)6]− (m/z = 808.8), and [HW4O5(O2)8]− (m/z = 1072.7) (Figs. 2 and S1,
ESI†). The addition of 1a to the peroxotungstateꢀcontaining filtrate, followed by stirring of the resultant solution at
80 °C for 24 h, produced 2a in 86% yield. At this point, the solution was transparent and still contained some H2O2.
After 72 h, the H2O2 was completely consumed, and a white precipitate appeared as shown in Fig. 1c. The
precipitate was collected by filtration and analyzed by ICPꢀAES and Raman spectroscopy. The tungsten content in
the precipitate was approximately 72 wt%. The Raman spectrum of the precipitate exhibited characteristic bands at
962 cm−1 and 815 cm−1 assignable to the (W–O–W) vibrations, respectively (Fig. S2, ESI†).11 These
ν(W=O) and ν
results suggest that the precipitate contained polytungstate species.
On the basis of the aboveꢀmentioned experimental results, it is most likely that dissolved peroxotungstate
species are the catalytically active species in this reaction. During the catalytic reaction, a significant amount of
tungstate species leached into the solution, specifically 24% of the tungsten species had leached into the reaction
solution after 4 h. (Table 1, entry 1). Once the H2O2 had been consumed, the amount of the leached tungsten
species decreased significantly; however, a nonꢀnegligible amount of tungstate species (7%) remained in the
solution (Table 1, entry 2). The CSIꢀmass spectrum of the filtrate of the solution after the reaction for entry 2
presented a signal assignable to hexatungstate, [HW6O19]− (m/z = 1408.6) (Fig. S3, ESI†); thus the remained
species are relatively small anionic polytungstate species.
We propose that the WO3ꢀcatalyzed oxidative cleavage of 1a proceeds through the following mechanism
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(Fig. 3). Initially, various peroxotungstate species are formed by the reaction of WO3 with H2O2 and leached into
solution (Step 1: Release). The reaction of 1a with the leached peroxotungstate species yields the corresponding
cleavage product and tungstate species (Step 2: Reaction). The tungstate species are reacted with H2O2 to
regenerate the active peroxotungstate species (Step 3: Regeneration). After the H2O2 is consumed, majority of the
dissolved tungstate species become insoluble polytungstate species (Step 4: Catch). Such a system is known as a
“release and catch” (or “boomerang”) catalytic system.12 In “release and catch” systems, the high reusability of a
catalyst can be achieved through the reꢀimmobilization of most of the released active species onto suitable supports
at the end of the reaction. In the case of WO3ꢀcatalyzed oxidative cleavage of 1a with H2O2, a nonꢀnegligible
amount of soluble tungsten species still remained in the reaction solution even after the complete consumption of
H2O2. In addition, a significant decrease in the product yield was observed when WO3 was reused.13
Use of supported tungstate catalysts
We prepared two kinds of supported tungstate catalysts using SnO2 and SiO2 and the impregnation method (referred
to as W/support, see the Experimental section).14 The XRD pattern of W/SnO2 had the same signals as that of the
parent SnO2 (Figs. S4a and b, ESI†). The XRD pattern of W/SiO2 exhibited weak and broad signals assignable to
monoclinic WO3 in addition to the SiO2 signals (Figs. S4c and d, ESI†). Raman spectra of the catalysts indicated
bands assignable to the tungstate species in addition to those of the supports; the broad bands at 960–980 cm−1 are
assignable to the ν
(W=O) vibrations of polytungstate species, and the bands around 807 cm−1, 710 cm−1, and
272 cm−1 are characteristic of WO3 vibrations (Fig. S5, ESI†).11 These results indicate that nonꢀcrystalline
polytungstate species and small crystals of WO3 are probably supported on the surface of these catalysts.
Next, these two catalysts were utilized in the oxidative cleavage of 1a with H2O2 (Table 2). We confirmed
that the desired 2a was not produced in the presence of just SnO2 or SiO2 under the current conditions (Table 2,
entries 3 and 4). After 24 h, W/SnO2 and W/SiO2 produced 2a in 64% and 63% yields, respectively (Table 2,
entries 1 and 2). In the case of W/SiO2, most of the leached tungsten species remained dissolved in the reaction
solution even at the end of the reaction (Table 2, entry 2). On the other hand, when W/SnO2 was used, the amount
of leached tungsten species significantly decreased, and most of the dissolved tungsten species were
reꢀimmobilized onto the surface of the support at the end of the reaction (Table 2, entry 1). This discrepancy likely
arises from the difference in the point of zero charge (pzc) values of SnO2 and SiO2, which are reported to be 6–7
and approximately 2, respectively.15 Thus, the surface of SiO2 is more negatively charged than the SnO2 surface.
The negatively charged dissolved tungstate species are less repelled by the SnO2 surface compared with the SiO2
surface, thereby facilitating reꢀimmobilization onto the SnO2 surface.
Oxidative olefin cleavage using W/Zn–SnO2
To further improve the catalytic performance of the supported tungstate catalyst, we focused on our previous report
that indicated that the catalytic performance of a supported polyoxotungstate catalyst for various kinds of
H2O2ꢀbased oxidation reactions, such as epoxidation, sulfoxidation, and Nꢀoxidation, was improved by
modification of the SnO2 support with zinc species.16 Therefore, we prepared a tungstate catalyst supported on
zincꢀmodified tin dioxide (W/Zn–SnO2, see the Experimental section).16 The XRD pattern of the W/Zn–SnO2
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catalyst showed the same signals as SnO2 (Fig. S6, ESI†). A Raman spectrum of the W/Zn–SnO2 catalyst presented
bands assignable to tungstate species and to SnO2; the broad bands at 960–980 cm−1 are assignable to the
(W=O)
ν
vibrations of polytungstate species, and the bands at 807 cm−1, 710 cm−1, and 272 cm−1 are characteristic of WO3
vibrations (Fig. S7, ESI†).11 These results indicate that nonꢀcrystalline polytungstate species and small crystals of
WO3 are supported on the surface.
Fig. 4a shows the reaction profile for the W/Zn–SnO2ꢀcatalyzed oxidative cleavage of 1a under the same
reaction conditions described in Table 2.17 The yield of 2a after 24 h was 92%, which was higher than that obtained
when W/SnO2 was used (64%, Table 2, entry 1). The amount of released tungsten species increased soon after the
reaction began, reaching a maximum value (14% of total tungsten species) after 2 h, and then decreased as the
reaction progressed, becoming negligible (<1%) at the reaction time of 24 h (after the complete consumption of
H2O2). The leaching of other metal species (Zn and Sn) was negligible throughout the course of the reaction. In
order to confirm the reaction mechanism, W/Zn–SnO2 was stirred under the reaction conditions described in Fig. 4
(without 1a) for 1 h and removed by hot filtration, in a manner identical to the experiment performed with WO3.
The CSIꢀmass analysis of the filtrate indicated the presence in the reaction solution of virtually the same
peroxotungstate species as those formed by the reaction of WO3 with H2O2 (Fig. S1, ESI†). The addition of 1a to
the filtrate, followed by stirring of the resultant solution at 80 °C for 24 h, produced 2a in 89% yield. These results
clearly indicate that the W/Zn–SnO2ꢀcatalyzed oxidative cleavage of 1a using H2O2 also proceeds through a
“release and catch” catalytic mechanism and that most of the leached tungstate species are reꢀimmobilized on the
surface of the catalyst at the end of the reaction.
Next, we examined the reusability and the durability of W/Zn–SnO2 for the oxidative cleavage of 1a. After
the reaction, the W/Zn–SnO2 catalyst was recovered by hot filtration, washed with acetone, dried in open air, and
reused in a subsequent reaction. In this manner, W/Zn–SnO2 could be reused at least nine times without a
significant decrease in catalytic performance (Fig. 5a, 89–93% yields of 2a).13 The XRD and the Raman spectra of
the nineꢀtimes reused W/Zn–SnO2 were in good agreement with the spectra of the freshly prepared W/Zn–SnO2
catalyst (Figs. 5b and c). These results indicated no significant structural changes in W/Zn–SnO2 even after the nine
reuses.
It has been reported that the oxidative cleavage of olefins using H2O2 proceeds through several multistep
reaction pathways, which include various types of oxidation and hydrolysis reactions.6a,7a In order to determine the
reaction pathways active in the present W/Zn–SnO2 catalytic system, the time course of the intermediates was
traced as well as 1a and 2a. Fig. 4b presents the yields of the observed intermediates by GC analysis,
1ꢀmethylꢀ1,2ꢀepoxycyclohexane (3a), 1ꢀmethylꢀ1,2ꢀcyclohexanediol (4a), 6ꢀoxoheptanal (5a), and
2ꢀmethylcyclohexanone (6a), which were produced in the oxidative cleavage of 1a; the major intermediates were
4a and 5a. When the oxidation of 3a was carried out, almost the same reaction profile as described in Fig. 4 was
observed (Fig. S8, ESI†), indicating that 3a is the initial intermediate in this reaction system and converted into
subsequent intermediates immediately. The most widely accepted reaction pathway for the H2O2ꢀbased oxidative
cleavage of olefins proposed by Noyori and coꢀworkers6a includes epoxidation, epoxide hydrolysis to 1,2ꢀdiols, and
oxidation of 1,2ꢀdiols, followed by Baeyer–Villiger oxidation (Path A in Fig 6). In the present W/Zn–SnO2 catalytic
system, the corresponding 1,2ꢀdiol 4a was one of the major intermediates. When the reaction of 4a was conducted,
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2a was selectively produced in 91% yield after 24 h (Fig. S9, ESI†). Therefore, we consider that the present
oxidative cleavage possibly proceeds through Path A in Fig. 6 although the intermediates produced through this
reaction pathway were hardly detected. In addition, 5a was not detected in the oxidation of 4a (Fig. S9, ESI†).
Venturello and coꢀworkers proposed another reaction pathway, namely perhydrolytic pathway (Path B in Fig 6).6i In
Path B, the perhydrolysis of epoxides produces βꢀhydroperoxy alcohols, which are converted into the desired
cleavage products through decomposition to carbonyl compounds (like 5a) and/or oxidation to αꢀoxo
hydroperoxides.6i In the present W/Zn–SnO2ꢀcatalyzed oxidative cleavage of 1a, 5a was also the major
intermediate. Thus, Path B should also be considered. In addition to the intermediates in Path A (4a) and Path B
(5a), a small amount of 6a was also observed in the oxidation reactions of 1a and 3a (Figs. 4b and S8, ESI†). On
the basis of the Lewis acid or Brønsted acidꢀcatalyzed isomerization of epoxides into ketones,18 we attribute the
formation of 6a to the isomerization of 3a. The oxidation of 6a proceeded to produce 2a in 35% yield after 24 h,
and 7ꢀmethylꢀ2ꢀoxepanone (7a) was also detected at the initial stage of the reaction (Fig. S10, ESI†). Thus. the
oxidation of 6a into 2a most likely proceeded through Path C as described in Fig. 6, which comprises Baeyer–
Villiger oxidation, hydrolysis, and alcohol oxidation, as has been reported elsewhere.19 On the basis of the
aforementioned experimental results, we propose that the present W/Zn–SnO2ꢀcatalyzed oxidative cleavage of 1a
using H2O2 as the oxidant proceeds through three parallel pathways described in Fig. 6; the initial intermediate is
the epoxide 3a, which is subsequently converted into the 1,2ꢀdiol 4a through hydrolysis, the βꢀhydroperoxy
alcohols through perhydrolysis, and the ketone 6a through isomerization. Many steps in Fig. 6 are facilitated by the
acidic reaction conditions, and the acidic natures of the dissolved peroxotungstate species, which were detected by
CSIꢀmass spectroscopy (Fig. S1, ESI†), and the Zn–SnO2 support are likely critical to the reaction.20
Finally, we turn our attention to the examination of the substrate scope for the current W/Zn–SnO2ꢀcatalyzed
oxidative cleavage reaction. The oxidative cleavage of different substrate molecules was conducted under the
optimized reaction conditions in the presence of W/Zn–SnO2, and the results are summarized in Fig. 7. A variety of
cyclic and linear olefins (1a–1f) were cleaved to give their corresponding carbonyl compounds (2a–2f) in moderate
to high yields (Fig. 7, entries 1–6). In addition to olefins, the reaction of phenylacetylene (1g) produced benzoic
acid (2c) in a moderate yield (Fig. 7, entry 7). Acenes, such as naphthalene (1h) and anthracene (1i), were
converted into phthalic acid (2h) and 2,3ꢀnaphthalenedicarboxylic acid (2i), respectively, and quinones were also
produced in these cases (Fig. 7, entries 8 and 9). In most cases, however, the total yields of the observed products
were somewhat lower than the substrate conversions likely owing to several intermediates and/or byꢀproducts that
could not be detected by GC and/or HPLC analyses.
Conclusion
We began the current work with a detailed investigation of the WO3ꢀcatalyzed oxidative cleavage of 1a using H2O2
as the oxidant. The detailed CSIꢀmass analysis revealed that various kinds of peroxotungstate species formed by the
reaction of WO3 with H2O2 leached into solution during reaction and became insoluble at the end of the reaction.
Thus, it was determined that the present catalytic system can be categorized as “release and catch.” On the basis of
our results, we developed a supported tungstate catalyst, W/Zn–SnO2, that efficiently catalyzed the oxidative
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cleavage of olefins using H2O2 through a “release and catch” catalytic mechanism. This W/Zn–SnO2 catalyst could
be reused at least nine times without an appreciable decline in catalytic performance and was successfully applied
to the oxidation of various substrate molecules. Thus, we developed W/Zn–SnO2 and applied it as a highly
promising (pseudo)heterogeneous catalyst for the oxidative cleavage of olefins and related compounds using H2O2.
Experimental Section
Materials
Solvents and substrates were obtained from Kanto Chemical or TCI and purified prior to use if necessary.21 H2O2
(30% aqueous solution, Kanto Chemical), WO3 (Junsei Chemical), (NH4)6H2W12O40⋅nH2O (Wako),
Zn(NO3)2⋅6H2O (Wako), CDCl3 (Acros Organics), and Ce(NH4)4(SO4)4⋅2H2O (Wako) were used as received. SnO2
(Guaranteed Reagent, >98%, Kanto Chemical, BET surface area: 45 m2 g−1), SiO2 (CARiACT Qꢀ10, Fuji Silysia
Chemical, BET surface area: 274 m2 g−1), γꢀAl2O3 (KHSꢀ24, Sumitomo Chemical, BET surface area: 160 m2 g−1),
TiO2 (STꢀ01, Ishihara Sangyo, BET surface area: 308 m2 g−1), ZrO2 (RCꢀ100, Daiichi Kigenso Kagaku Kogyo,
BET surface area: 89 m2 g−1), ZnO (Wako, BET surface are: 37 m2 g−1), and MgO (NOꢀ0012ꢀHP, Ionic Liquids
Technologies, BET surface area: 36 m2 g−1) were commercially available. These oxides were pretreated by
calcination in air at 400 °C for 3 h.
Instruments
GC measurements were performed on a Shimadzu GCꢀ2014 gas chromatograph equipped with a flame ionization
detector (FID) and an InertCap FFAP capillary column (internal diameter = 0.25 mm and length = 30 m) or an
InertCap 5 capillary column (internal diameter = 0.25 mm and length = 30 m). GCꢀMS spectra were recorded on a
Shimadzu GCMSꢀQP2010 equipped with an InertCap 5 capillary column at an ionization voltage of 70 eV. HPLC
analyses were performed on a Shimadzu Prominence system using a UV detector (Shimadzu SPDꢀ20A, 254 nm)
equipped with an Inertsil ODSꢀ3 column (internal diameter = 4.6 mm and length = 250 mm) using a mixed solvent
of MeOH/H2O (9/1 v/v) as an eluent. ICPꢀAES analyses were performed on a Shimadzu ICPSꢀ8100 spectrometer.
Raman spectra were measured on a JASCO NRSꢀ5100 spectrometer using a 532 nm laser. XRD patterns were
recorded using a Rigaku SmartLab instrument under Cu Kα radiation (λ = 1.5418 Å, 45 kV, 200 mA). CSI mass
spectra (in CH3CN) were recorded on a JEOL JMSꢀT100CS spectrometer. Typical measurement conditions were as
follows: orifice voltage of −10 V for negative ions, sample flow of 0.1 mL min−1, spray temperature of −10 °C, and
ion source at room temperature. Liquidꢀstate 1H and 13C NMR spectra were recorded on a JEOL JNMꢀECA 500. 1H
and 13C NMR spectra were measured at 500 MHz and 125 MHz, respectively, using tetramethylsilane as an internal
standard (δ = 0 ppm). BET surface areas were measured by N2 adsorption at −196 °C using a Micromeritics ASAP
2010 instrument.
Preparation of tungstate supported catalysts
W/Zn–SnO2 catalyst was prepared according to the following procedure.16 An aqueous solution (50 mL) of
Zn(NO3)2⋅6H2O (120.8 mg) containing SnO2 (2.5 g) was stirred vigorously for 1 h at room temperature. The
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solution was evaporated to dryness, and the resulting solid was calcined in air for 2 h at 300 °C, yielding Zn–SnO2
(Zn: 1.0 wt%). Next, an aqueous solution (30 mL) of (NH4)6H2W12O40⋅nH2O (143.0 mg) containing Zn–SnO2
(1.0 g) was stirred vigorously for 1 h at room temperature. The solution was evaporated to dryness, and the
resulting solid was calcined for 3 h at 400 °C to give W/Zn–SnO2. The tungsten and zinc contents were 9.1 wt%
and 0.9 wt%, respectively. The other supported tungstate catalysts on SnO2 (W/SnO2) and SiO2 (W/SiO2) were
prepared in the same manner. The tungsten content was 9.1 wt% in both W/SnO2 and W/SiO2.
Catalytic reaction
A typical procedure for the oxidative cleavage of olefins proceeded as follows: 1 (0.5 mmol), W/Zn–SnO2 (100 mg,
t
W: 10 mol% with respect to 1), and BuOH or CH3CN (1.5 mL) were charged to a glass reactor with a
Teflonꢀcoated magnetic stir bar. The reaction was initiated by the addition of 30% aqueous H2O2 (2.5 mmol),
followed by stirring at 80 °C for 24 h. The conversions and product yields were determined by GC or HPLC
analysis using oꢀdichlorobenzene, naphthalene, or biphenyl as an internal standard. The products were identified by
the comparison of their GC or HPLC retention times and/or GCꢀMS spectra with those of pure samples (ESI†). The
complete consumption of H2O2 was confirmed using a test paper for H2O2 detection (QUANTOFIX Peroxide 100,
MachereyꢀNagel). After the reaction, the used catalyst was retrieved by hot filtration, washed with acetone, and
dried under open air at room temperature. The recovered catalyst was reused, and the quantity of leached metal
species in the filtrate was determined by ICPꢀAES analysis. As for the isolation of 2a, the filtrate was concentrated
by evaporation, and the crude product was subjected to column chromatography on silica gel using
acetone/chloroform as an eluent to give pure 2a in 82% isolated yield. The purity of 2a was confirmed by 1H and
13C NMR analysis (ESI†).
Acknowledgement
This work was supported in part by JSPS KAKENHI Grant No. 15H05797 in Precisely Designed Catalysts with
Customized Scaffolding.
References and Notes
1
(a) Modern Oxidation Methods, ed. J.ꢀE. Bäckvall, WileyꢀVCH, Wheinheim, 2004; (b) F. Cavani and J. H.
Teles, ChemSusChem, 2009, 2, 508; (c) T. Punniyamurthy, S. Velusamy and J. Iqbal, Chem. Rev., 2005, 105,
2329; (d) J. A. Labinger and J. E. Bercaw, Nature, 2002, 417, 507.
2
(a) F. E. Kuehn, R. W. Fischer, W. A. Herrmann and T. Weskamp, in Transition Metals for Organic Synthesis
2nd ed., Vol. 2, ed. M. Beller and C. Bolm, WileyꢀVCH, Weinheim, 2004, pp. 427−436; (b) P. Spannring, P. C.
A. Bruijnincx, B. M. Weckhuysen and R. J. M. K. Gebbink, Catal. Sci. Technol., 2014, 4, 2182; (c) A.
Rajagopalan, M. Lara and W. Kroutil, Adv. Synth. Catal., 2013, 355, 3321.
3
(a) S. G. V. Ornum, R. M. Champeau and R. Pariza, Chem. Rev., 2006, 106, 2990; (b) R. Criegee, Angew.
Chem., Int. Ed., 1975, 14, 745; (c) P. S. Bailey, Chem. Rev., 1958, 58, 925.
8

Page 9 of 17
Catalysis Science & Technology
View Article Online
DOI: 10.1039/C7CY00062F
4
5
6
(a) R. Pappo, D. S. Allen, R. U. Lemieux and W. S. Johnson, J. Org. Chem., 1956, 21, 478; (b) B. R. Travis, R.
S. Narayan and B. Borhan, J. Am. Chem. Soc., 2002, 124, 3824; (c) E. C. Ashby and A. B. Goel, J. Org. Chem.,
1981, 46, 3936; (d) K. B. Wiberg and K. A. Saegebarth, J. Am. Chem. Soc., 1957, 79, 2822; (e) P. Viski, Z.
Szeverényi and L. I. Simándi, J. Org. Chem., 1986, 51, 3213; (f) K. B. Wiberg and R. D. Geer, J. Am. Chem.
Soc., 1966, 88, 5827; (g) F. Freeman and N. J. Yamachika, J. Am. Chem. Soc., 1970, 92, 3730.
(a) R. Noyori, M. Aoki and K. Sato, Chem. Commun., 2003, 1977; (b) W. R. Sanderson, Pure Appl. Chem.,
2000, 72, 1289; (c) B. S. Lane and K. Burgess, Chem. Rev., 2003, 103, 2457; (d) G. Grigoropoulou, J. H. Clark
and J. A. Elings, Green Chem., 2003, 5, 1; (e) M. Uyanik and K. Ishihara, ACS Catal., 2013, 3, 513; (f) G. De
Faveri, G. Ilyashenko and M. Watkinson, Chem. Soc. Rev., 2011, 40, 1722; (g) G.ꢀJ. ten Brink, I. W. C. E.
Arends and R. A. Sheldon, Chem. Rev., 2004, 104, 4105.
(a) K. Sato, M. Aoki and R. Noyori, Science, 1998, 281, 1646; (b) T. Oguchi, T. Ura, Y. Ishii and M. Ogawa,
Chem. Lett., 1989, 857; (c) Y. Wen, X. Wang, H. Wei, B. Li, P. Jin and L. Li, Green Chem., 2012, 14, 2868; (d)
K. Fujitani, T. Mizutani, T. Oida and T. Kawase, J. Oleo Sci., 2009, 58, 37; (e) S. Ren, Z. Xie, L. Cao, X. Xie,
G. Qin and J. Wang, Catal. Commun., 2009, 10, 464; (f) J. AlcañizꢀMonge, G. Trautwein and A. GarciaꢀGarcia,
J. Mol. Catal. A: Chem., 2014, 394, 211; (g) Y. Ishii, K. Yamawaki, T. Ura, H. Yamada, T. Yoshida and M.
Ogawa, J. Org. Chem., 1988, 53, 3587; (h) W. Zhu, H. Li, X. He, H. Shu and Y. Yan, J. Chem. Res., 2006, 774;
(i) E. Antonelli, R. D’Aloisio, M. Gambaro, T. Fiorani and C. Venturello, J. Org. Chem., 1998, 63, 7190; (j) Y.
Deng, Z. M. Kun and W. J. Chen, Green Chem., 1999, 275; (k) A. Haimov, H. Cohen and R. Neumann, J. Am.
Chem. Soc., 2004, 126, 11762.
7
(a) C. D. Brooks, L.ꢀC. Huang, M. McCarron and R. A. W. Johnstone, Chem. Commun., 1999, 37; (b) Z.
Bohström, I. RicoꢀLattes and K. Holmberg, Green Chem., 2010, 12, 1861; (c) S. Ghosh, S. S. Acharyya, S.
Adak, L. N. S. Konathala, T. Sasaki and R. Bal, Green Chem., 2014, 16, 2826; (d) H. Noureddini and M.
Kanabur, J. Am. Oil Chem. Soc., 1999, 76, 305. (e) L. Meng, S. Zhai, Z. Sun, F. Zhang, Z. Xiao and Q. An,
Microporous Mesoporous Mater., 2015, 204, 123; (f) M. Vafaeezadeh, M. M. Hashemi and M. ShakourianꢀFard,
Catal. Commun., 2012, 26, 54; (g) C.ꢀY. Cheng, K.ꢀJ. Lin, M. R. Prasad, S.ꢀJ. Fu, S.ꢀY. Chang, S.ꢀG. Shyu,
H.ꢀS. Sheu, C.ꢀH. Chen, C.ꢀH. Chuang and M.ꢀT. Lin, Catal. Commun., 2007, 8, 1060; (h) M. Vafaeezadeh and
M. M. Hashemi, Catal. Commun., 2014, 43, 169.
8
(a) Z. Saedi, S. Tangestaninejad, M. Moghadam, V. Mirkhanim and I. MohammadpoorꢀBaltork, Catal.
Commun., 2012, 17, 18; (b) S.ꢀO. Lee, R. Raja, K. D. M. Harris, J. M. Thomas, B. F. G. Johnson and G. Sankar,
Angew. Chem., Int. Ed., 2003, 42, 1520; (c) W. A. Herrmann, T. Weskamp, J. P. Zoller and R. W. Fisches, J.
Mol. Catal. A: Chem., 2000, 153, 49; (d) H. Mimoun, L. Saussine, E. Daire, M. Postel, J. Fischer and R. Weiss,
J. Am. Chem. Soc., 1983, 105, 3101; (e) F. Shi, M. K. Tse, M.ꢀM. Pohl, A. Brückner, S. Zhang and M. Beller,
Angew. Chem., Int. Ed., 2007, 46, 8866; (f) N. Ma, Y. Yue, W. Hua and Z. Gao, Appl. Catal. A: General, 2003,
251, 39; (g) V. Kogan, M. M. Quintal and R. Neumann, Org. Lett., 2005, 7, 5039; (h) A. Dhakshinamoorthy
and K. Pitchumani, Tetrahedron, 2006, 62, 9911; (i) W. Adam, A. Corma, A. Martínez and M. Renz, Chem.
Ber., 1996, 129, 1453; (j) A. Behr, N. Tenhumberg and A. Wintzer, RSC Adv., 2013, 3, 172; (k) C.ꢀM. Che, W.ꢀP.
Yip and W.ꢀY. Yu, Chem. Asian J., 2006, 1, 453.
9
(a) Fine Chemicals through Heterogeneous Catalysis, ed. R. A. Sheldon and H. van Bekkum, WileyꢀVCH,
9

Catalysis Science & Technology
Page 10 of 17
View Article Online
DOI: 10.1039/C7CY00062F
Weinheim, 2001; (b) R. A. Sheldon and R. S. Downing, Appl. Catal. A: General, 1999, 189, 163.
10 (a) R. Jin, H. Li and J.ꢀF. Deng, J. Catal., 2001, 203, 75; (b) X.ꢀL. Yang, W.ꢀL. Dai, C. Guo, H. Chen, Y. Cao,
H. Li, H. He and K. Fan, J. Catal., 2005, 234, 438; (c) P. R. Makgwane and S. S. Ray, Catal. Commun., 2014,
54, 118; (d) M. Ammi, B. Pourbadiei, T. P. A. Ruberu and L. K. Woo, New J. Chem., 2014, 38, 1250.
11 (a) M. M. Ostromecki, L. J. Burcham and I. E. Wachs, J. Mol. Catal. A: Chem., 1998, 132, 59; (b) E. I.
RossꢀMedgaarden and I. E. Wachs, J. Phys. Chem. C, 2007, 111, 15089; (c) M. M. Ostromecki, L. J. Burcham,
I. E. Wachs, N. Ramani and J. G. Ekerdt, J. Mol. Catal. A: Chem., 1998, 132, 43; (d) E. L. Lee and I. E. Wachs,
J. Phys. Chem. C, 2008, 112, 6487; (e) D. S. Kim, M. Ostromecki and I. E. Wachs, Chem. Lett., 1995, 33, 209;
(f) M. A. Vuurman and I. E. Wachs, J. Phys. Chem., 1991, 95, 9928; (g) L. Macalik, J. Hanuza and A. A.
Kaminskii, J. Mol. Struct., 2000, 555, 289; (h) D. Kasprowicz, A. Majchrowski and E. Michalski, J. Alloys
Compd., 2011, 509, 6354.
12 (a) M. Gruttadauria, F. Giacalone and R. Noto, Green Chem., 2013, 15, 2608; (b) A. Ohtaka, T. Okagaki, G.
Hamasaka, Y. Uozumi, T. Shinagawa, O. Shimomura and R. Nomura, Catalysts, 2015, 5, 106; (c) A. Ohtaka, T.
Yamaguchi, R. Nishikiori, O. Shimomura and R. Nomura, Asian J. Org. Chem., 2013, 2, 399; (d) A. Ohtaka, E.
Sakaguchi, T. Yamaguchi, G. Hamasaka, Y. Uozumi, O. Shimomura and R. Nomura, ChemCatChem, 2013, 5,
2167; (e) L. Xing, J.ꢀH. Xie, Y.ꢀS. Chen, L.ꢀX. Wang and Q.ꢀL. Zhou, Adv. Synth. Catal., 2008, 350, 1013; (f) C.
Pavia, F. Giacalone, L. A. Bivona, A. M. P. Salvo, C. Petrucci, G. Strappaveccia, L. Vaccaro, C. Aprile and M.
Gruttadauria, J. Mol. Catal. A: Chem., 2014, 387, 57; (g) F. Tinnis, O. Verho, K. P. J. Gustafson, C.ꢀW. Tai, J.ꢀE.
Bäckvall and H. Adolfsson, Chem. –Eur. J., 2014, 20, 5885; (h) H. A. Beejapur, V. Campisciano, F. Giacalone
and M. Gruttadauria, Adv. Synth. Catal., 2015, 357, 51; (i) S. VásquezꢀCéspedes, K. M. Chepiga, N. Möller, A.
H. Schäfer and F. Glorius, ACS Catal., 2016, 6, 5954; (j) F. Giacalone, V. Campisciano, C. Calabrese, V. L.
Parola, Z. Syrgiannis, M. Prato and M. Gruttadauria, ACS Nano, 2016, 10, 4627; (k) W. Dong, P. Chen, W. Xia,
P. Weide, H. Ruland, A. Kostka, K. Köhler and M. Muhler, ChemCatChem, 2016, 8, 1269; (l) X.ꢀL. Shi, H. Lin,
P. Li and W. Zhang, ChemCatChem, 2014, 6, 2947.
13 Under the conditions described in Table 1, the WO3ꢀcatalyzed oxidative cleavage of 1a produced 2a in 92%
yield after 24 h (Table 1, entry 2). When WO3 was reused under the same reaction conditions, the yield of 2a
decreased to 63%. In the previously reported WO3ꢀcatalyzed oxidative cleavage of cyclohexene, a deactivation
of WO3 is also observed.7b
14 To use supported catalysts along with H2O2, the nonꢀproductive decomposition of H2O2 induced by supports
should be avoided. The decomposition of H2O2 in the presence of various supports, such as SnO2, SiO2, Al2O3,
ZrO2, TiO2, ZnO, and MgO, was examined (Table S1, ESI†). While the decomposition was significantly
promoted by Al2O3, ZrO2, TiO2, ZnO, and MgO under the current conditions, the reaction barely proceeded
when SnO2 and SiO2 were used, indicating that these two supports are suitable for the oxidation with H2O2.
15 (a) M. Kosmulski, J. Colloid Interface Sci., 2006, 298, 730; (b) R. H. Yoon, T. Salman and G. Donnay, J.
Colloid Interface Sci., 1979, 70, 483.
16 (a) K. Kamata, K. Yonehara, Y. Sumida, K. Hirata, S. Nojima and N. Mizuno, Angew. Chem., Int. Ed., 2011, 50,
12062; (b) S. Nojima, K. Kamata, K. Suzuki, K. Yamaguchi and N. Mizuno, ChemCatChem, 2015, 7, 1097.
17 The reaction conditions and the loading amounts of tungsten and zinc species were optimized from the
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perspective of the yield of 2a and the amount of tungsten leaching (Tables S2–S6, ESI†).
18 (a) B. Rickborn, in Comprehensive Organic Synthesis, Vol. 3, ed. B. M. Trost, Pergamon, Oxford, 1991, pp.
733−775; (b) E. Jürgens, B. Wucher, F. Rominger, K. W. Törnroos and D. Kunz, Chem. Commun., 2015, 51,
1897; (c) V. Gudla and R. Balamurugan, Tetrahedron Lett., 2012, 53, 5243; (d) R. Hrdina, C. E. Müller, R. C.
Wende, K. M. Lippert, M. Benassi, B. Spengler and P. R. Schreiner, J. Am. Chem. Soc., 2011, 133, 7624; (e)
X.ꢀM. Deng, X.ꢀL. Sun and Y. Tang, J. Org. Chem., 2005, 70, 6537; (f) K. Suda, S. Nakajima, Y. Satoh and T.
Takanami, Chem. Commun., 2009, 1255; (g) K. Suda, T. Kikkawa, S. Nakajima and T. Takanami, J. Am. Chem.
Soc., 2004, 126, 9554; (h) Y. Kita, S. Matsuda, R. Inoguchi, J. K. Ganesh and H. Fujioka, J. Org. Chem., 2006,
71, 5191; (i) K. Suda, K. Baba, S. Nakajima and T. Takanami, Chem. Commun., 2002, 2570; (j) S.
Kulasegaram and R. J. Kulawiec, J. Org. Chem., 1994, 59, 7195; (k) B. C. Ranu and U. Jana, J. Org. Chem.,
1998, 63, 8212; (l) M. W. C. Robinson, K. S. Pillinger, I. Mabbett, D. A. Timms and A. E. Graham,
Tetrahedron, 2010, 66, 8377.
19 (a) A. Dutta, M. Pramanik, A. K. Patra, M. Nandi, H. Uyamab and A. Bhaumik, Chem. Commun., 2012, 48,
6738; (b) A. K. Patra, A. Dutta and A. Bhaumik, Chem. –Eur. J., 2013, 19, 12388; (c) Y. Usui and K. Sato,
Green Chem., 2003, 5, 373.
20 The amounts of 6a formation during the W/SnO2ꢀcatalyzed reaction of 1a were larger than those during the
W/Zn–SnO2ꢀcatalyzed reaction (Table S7, ESI†). The formation of 6a is undesirable because the conversion of
6a into 2a (Path C) is somewhat slower than Path A and Path B (Fig. S10, ESI†). One possible role of
zincꢀmodification is to reduce the formation of 6a. During the W/SnO2ꢀcatalyzed reaction of 1a, significant
amounts of tertꢀbutyl hydroperoxide (TBHP) were formed by the reaction of tertꢀbutyl alcohol (solvent) and
H2O2. We confirmed that the oxidation of 1a, 3a, and 4a into 2a did not proceed at all when using TBHP
instead of H2O2. Thus, the TBHP formation is a nonꢀproductive reaction in the present system, which lowers
the efficiency of H2O2 utilization. Notably, the TBHP formation was much suppressed by utilizing the
zincꢀmodified SuO2 support (Table S7, ESI†). This is also an important role of the zincꢀmodification.
21 Purification of Laboratory Chemicals 5th ed., ed. W. L. F. Armarego and C. L. L. Chai,
ButterworthꢀHeinemann, Oxford, 2003.
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a
Table 1 Oxidative cleavage of 1a into 2a using WO3 and H2O2
O
WO3, H2O2
tBuOH, 80 °C
COOH
1a
2a
Time
(h)
Yield
(%)
33
Tungsten leaching
Entry
(%)
24
7
1
4
2
24
92
3b
4c
5d
4 + 20
24
90
−
nd
nd
24
nd
−
t
a Reaction conditions: 1a (0.5 mmol), WO3 (10 mol% with respect to 1a), 30% aqueous H2O2 (2.5 mmol), BuOH
(1.5 mL), 80 °C. Yields were determined by GC analysis using oꢀdichlorobenzene as an internal standard. Tungsten
leaching was determined by ICPꢀAES analysis. b The insoluble species were removed from the reaction mixture by
hot filtration after 4 h, and the reaction was carried out with the filtrate for further 20 h (a total time of 24 h).
c Without H2O2. d Without WO3. nd = not detected.
Table 2 Oxidative cleavage of 1a into 2a using supported tungstate catalystsa
O
Cat., H2O2
tBuOH, 80 °C
COOH
1a
2a
Yield
(%)
64
Tungsten leaching
Entry
Cat.
(%)
<1
53
−
1
2
3
4
W/SnO2
W/SiO2
SnO2
63
<1
SiO2
<1
−
t
a Reaction conditions: 1a (0.5 mmol), catalyst (100 mg), 30% aqueous H2O2 (2.5 mmol), BuOH (1.5 mL), 80 °C,
24 h. Yields were determined by GC analysis using oꢀdichlorobenzene as an internal standard. Tungsten leaching
was determined by ICPꢀAES analysis.
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t
Fig. 1 Pictures of (a) the suspension containing BuOH (1.5 mL), WO3 (50 µmol), and 30% aqueous H2O2
(2.5 mmol), (b) the filtrate after the removal of insoluble species by hot filtration, and (c) the suspension obtained
after the reaction of 1a at 80 °C for 72 h.
600.9
296.9
298.9
300.9
808.8
800
544.9
280.9
282.9
1072.7
200
400
600
1000
1200
m/z
Fig. 2 CSIꢀmass spectrum (negativeꢀion mode) of the filtrate shown in Fig. 1b. The signals at m/z 280.9, 282.9,
296.9, 298.9, 300.9, 544.9, 600.9, 808.8, and 1072.7 were assignable to [HWO2(O2)2]−, [H3WO4(O2)]−,
[HWO(O2)3]−, [H3WO3(O2)2]−, [H5WO5(O2)]−, [HW2O3(O2)4]−, [W2O2(O2)4OtBu]−, [HW3O4(O2)6]−, and
[HW4O5(O2)8]−, respectively. The magnified views are shown in Fig. S1, ESI†.
Fig. 3 Possible reaction mechanism for the WO3ꢀcatalyzed oxidative cleavage of 1a.
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OH
O
O
W/Zn−SnO2, H2O2
tBuOH, 80 °C
O
COOH
CHO
OH
O
1a
2a
3a
4a
5a
6a
(a)
(b)
◆: Conversion ▲: Tungsten leaching
■: Yield of 2a
◆: Yield of 3a ▲: Yield of 5a
■: Yield of 4a ✕: Yield of 6a
30
25
20
15
10
5
100
80
60
40
20
0
20
16
12
8
4
0
0
0
4
8
12
16
20
24
0
4
8
12
16
20
24
Time (h)
Time (h)
Fig. 4 Reaction profile for the W/Zn–SnO2ꢀcatalyzed oxidative cleavage of 1a into 2a using H2O2 as the oxidant.
(a) Conversion, yield of 2a, and tungsten leaching. (b) Yields of 3a, 4a, 5a, and 6a. Reaction conditions: 1a
t
(0.5 mmol), W/Zn–SnO2 (100 mg, W: 10 mol% with respect to 1a), 30% aqueous H2O2 (2.5 mmol), BuOH
(1.5 mL), and 80 °C. Conversions and yields were determined by GC analysis using oꢀdichlorobenzene as an
internal standard. Tungsten leaching was determined by ICPꢀAES analysis.
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(a)
100
80
60
40
20
0
93
92
92
92
91
91
91
91
90
89
1
2
3
4
5
6
7
8
9
10
Reaction cycles
(b)
as-prepared
after 9th reuse
10
20
30
40
50
60
70
80
90
2θ (degee)
(c)
as-prepared
after 9th reuse
1100 1000
800
600
400
200
Raman Shift (cm−1
)
Fig. 5 Reuse of W/Zn–SnO2 for the oxidative cleavage of 1a using H2O2 as the oxidant. (a) Yield of 2a in the reuse
test. (b) XRD patterns and (c) Raman spectra of asꢀprepared W/Zn–SnO2 and W/Zn–SnO2 recovered after ten
cycles of oxidative cleavage of 1a.
Path A
OH
OH
OH
OH
O
HO OH
[O]
[O]
H2O
O
COOH
COOH
4a
O
H2O
−H2O
Path B
OOH
O
O
H2O2
[O]
[O]
O
CHO
OH
1a
3a
2a
5a
Path C
[O]
OH
[O]
H2O
O
COOH
O
6a
7a
O
Fig. 6 Possible reaction pathways for the W/Zn–SnO2ꢀcatalyzed oxidative cleavage of 1a into 2a using H2O2 as the
oxidant.
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Entry 1
Entry 6a
OH
O
n-C5H11COOH n-C5H11CHO
n-C5H11
2f
1f
COOH
COOH
OH
1a
2a
92%
Conv.: 98%
3%
58%
4%
Conv.: >99%
Entry 2a
Entry 7
COOH
HOOC
COOH
1b
2b
Conv.: >99%
77%
1g
2c
OH
Conv.: 66%
44%
10%
Entry 3a
COOH
CHO
OH
O
O
Entry 8
1c
2c
COOH
Conv.: >99%
63%
12%
2%
Entry 4
COOH
1h
2h
O
CHO
Conv.: 33%b
31%b
2%b
1d
2d
Conv.: >99%
46%
16%
O
Entry 9
Entry 5a
COOH
COOH
n-C6H13COOH n-C6H13CHO
n-C6H13
1i
2i
11%b
1e
2e
33%
O
Conv.: >99%
3%
Conv.: 71%b
22%
Fig. 7 W/Zn–SnO2ꢀcatalyzed oxidative cleavage of different substrate molecules using H2O2 as the oxidant.
Reaction conditions: 1 (0.5 mmol), W/Zn–SnO2 (100 mg, W: 10 mol% with respect to substrates), 30% aqueous
H2O2 (2.5 mmol), tBuOH (1.5 mL), 80 °C, and 24 h. Yields were determined by GC analysis using
oꢀdichlorobenzene as an internal standard. a CH3CN (1.5 mL) was used instead of tBuOH. b Conversions and yields
were determined by HPLC analysis using biphenyl and naphthalene as internal standards for entry 8 and 9,
respectively.
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In the presence of tungstate species supported on zinc-modified tin dioxide (W/Zn–SnO2), oxidative cleavage of
olefins and related compounds using H2O2 efficiently proceeds through a “release and catch” catalytic mechanism.
1