ORGANIC
LETTERS
2
005
Vol. 7, No. 6
077-1079
Palladium Nanoparticles Entrapped in
Aluminum Hydroxide: Dual Catalyst for
Alkene Hydrogenation and Aerobic
Alcohol Oxidation
1
†
†
†
‡
Min Serk Kwon, Namdu Kim, Cheon Min Park, Jae Sung Lee,
‡
,†
Kyung Yeon Kang, and Jaiwook Park*
DiVision of Molecular and Life Science and Department of Chemical Engineering,
Pohang UniVersity of Science and Technology, San 31 Hyojadong, Pohang, Kyeongbuk
790-784, Republic of Korea
Received December 31, 2004
ABSTRACT
A new aluminum hydroxide-supported palladium catalyst (1) made by a one-pot synthesis through nanoparticle generation and gelation shows
a dual catalytic activity for olefinic hydrogenation and aerobic alcohol oxidation.
We report a new palladium catalyst that is highly active in
both alkene hydrogenation and aerobic alcohol oxidation.
To the best of our knowledge, this is the first report of such
a catalyst that consecutively performs the two reactions in
one pot. Furthermore, the catalyst is recyclable and am-
phiphilic, active in both water and common organic solvents.
Palladium nanoparticles have proved to be attractive
Nanoparticles have been immobilized on inorganic solid
5
6
7
supports or embedded in organic polymers, dendrimers,
8
multilayer polyelectrolyte films, and ionic liquids for
9
separation and reuse. However, the immobilization often
suffers from problems such as low reactivity, degradation,
palladium leaching, and difficult synthetic procedures.
Very recently, we reported a simple one-pot method of
making recyclable palladium catalysts through generation of
1
catalysts in many useful transformations, including the
2
hydrogenation of alkenes and alkynes, the oxidation of
palladium nanoparticles from Pd(PPh and tetra(ethylene
)
3 4
3
4
alcohols, and carbon-carbon coupling reactions.
glycol) dissolved in (MeO) Si or (i-PrO) Ti and subsequent
4
4
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gelation by treatment with water. The resulting gels showed
†
Division of Molecular and Life Science.
Department of Chemical Engineering.
‡
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(
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(
1
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0.1021/ol047381w CCC: $30.25
© 2005 American Chemical Society
Published on Web 02/25/2005