M. Riahi Farsani et al.
Table 4. Catalytic performance of various Keggin and Wells–Dawson sandwich-type POMs in oxidation of cyclohexene at different temperaturesa
25 °C 85 °C
Selectivity (%)c
Selectivity (%)
Conversion
(%)b
Conversion
(%)
Entry
Catalyst
A
B
C
A
B
C
1
2
3
4
5
6
7
8
9
10
TBA10[Ni4(PW9O34)2]
TBA10[Co4(PW9O34)2]
TBA6[Fe4(PW9O34)2]
23
9
45
62
81
82
93
45
52
78
74
86
4
7
8
7
1
5
8
5
6
0
51
31
11
11
6
25
11
64
19
75
15
8
31
48
64
66
75
30
29
31
27
71
5
64
44
27
27
21
62
61
61
66
29
8
9
61
16
72
12
6
TBA10[Mn4(PW9O34)2]
TBA10[Zn4(PW9O34)2]
TBA16[Ni4(P2W15O56)2]
TBA16[Co4(P2W15O56)2]
TBA12[Fe4(P2W15O56)2]
TBA16[Mn4(P2W15O56)2]
TBA16[Zn4(P2W15O56)2]
7
4
50
40
17
20
14
8
10
8
50
15
53
53
17
58
7
0
aReaction conditions: cyclohexene: 1 mmol; catalyst: 0.01 mmol; CH3CN: 3 ml; H2O2: 2 mmol; time: 6 h.
bConversions and yields refer to GC yields.
cSelectivities are with respect to epoxide (A), enol (B) and enone (C) products and obtained as moles of the indicated product to the sum of moles of all
products.
Table 5. Catalyst recycling in the oxidation of cyclooctenea
Acknowledgements
Conversion (%)b
Support for this research by the University of Isfahan is acknowledged.
Entry
Catalyst
Run 1 Run 2 Run 3 Run 4
1
2
3
4
TBA6[Fe4(PW9O34)2]
TBA10[Zn4(PW9O34)2]
TBA12[Fe4(P2W15O56)2]
TBA16[Zn4(P2W15O56)2]
75
85
60
65
74
84
60
64
72
82
58
62
68
79
55
58
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