S.-Y. Chen et al. / Journal of Catalysis 270 (2010) 196–205
205
catalyst, and the results are also listed in Table 2. The pinacol con-
version and pinacolone selectivity over Reg-Zr–SBA-15 were 80%
and 82%, respectively, similar to those of the first run. These results
imply that the Zr–SBA-15 materials can be easily regenerated by
washing and calcination and the catalytic activity is well retained
in pinacol rearrangement.
ated by washing and calcination, and the high activities in pinacol
rearrangement were retained. Moreover, the large mesopores of
Zr–SBA-15 materials also facilitated the pinacol-type rearrange-
ment of bulky (1S, 2S, 3R, 5S)-(+)-2,3-pinanediol. The major prod-
uct over Zr–SBA-15 was camphor, a product of H-migration.
Acknowledgments
3.2.5. Catalytic rearrangement of (1S, 2S, 3R, 5S)-(+)-2,3-pinanediol
The pinacol-type rearrangement of bulky (1S, 2S, 3R, 5S)-(+)-
2,3-pinanediol was also examined by various catalysts used in
the present study. Table 4 summarizes the results of the reaction
at 110 °C for 1.5 h. Among the catalysts studied, only Zr–SBA-15
and HY-zeolite showed catalytic activities in this reaction. More-
over, Zr–SBA-15 materials with Zr/Si ratio greater than 0.03 gave
much higher conversions than HY-zeolite. The pinanediol conver-
sion was proportional to the Zr loading in the Zr–SBA-15 materials.
The pinanediol conversion reached 82% in 1.5 h over 0.1Zr–SBA-15
catalyst. The main products were camphor (a product of H-migra-
tion), p-cymene (a product in combination of alkyl- and H-migra-
tion) and campholenic aldehyde (a product of alkyl-migration). In
The financial supports from the National Science Council and
the Ministry of Education, Taiwan, are gratefully acknowledged.
Acknowledgments are also extended to Chih-Yuan Tang and
Ching-Yen Lin of Instrumentation Center, National Taiwan Univer-
sity, Taiwan, for TEM and SEM experiments, and Chin-Nan Ke of
National Tsing-Hua University, Taiwan, for the ICP-AES
experiment.
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