Res. Chem. Intermed.
, Vol. 34, Nos 5–7, pp. 507–517 (2008)
Koninklijke Brill NV, Leiden, 2008.
Also available online - www.brill.nl/rci
Lewis-type catalytic activity of direct incorporated Zr- and
NANZHE JIANG, JEONG-BOON KOO, SANG-CHEOL HAN and
Laboratory of Nano-Green Catalysis and Nano Center for Fine Chemicals Fusion Technology,
Department of Chemistry, Inha University, Incheon 402-751, South Korea
Received 5 November 2006; accepted 23 January 2007
Abstract—Metal incorporation into nanoporous materials could give Lewis acid sites through the
framework substitution of silica matrix, which are supposed to be in tetrahedral substitution of silica.
In this work, Zr- and Sn-incorporated SBA-16 were directly synthesized by the microwave synthesis
method. These microwave synthesized Zr- and Sn-SBA-16 mesoporous silica materials were proven
to have tetrahedral-positioned Zr and Sn species. Zr- and Sn-incorporated mesoporous silica materials
were applied in activation of ketones by Lewis acid sites to catalyze Meerwein–Ponndorf–Verly
reduction of cyclohexanone and Baeyer–Villiger oxidation of adamantanone, respectively. Optimum
incorporated Zr- and Sn-species gave almost 100% selectivity with high activity onto corresponding
alcohol and lactone, respectively.
Keywords: Microwave; incorporation; Sn-SBA-16; Zr-SBA-16; Lewis acid.
Metal incorporation into nanoporous silica materials could give Lewis acid sites
through the framework substitution of silica matrix which were supposed to be in
tetrahedral substitution of silicon. The supported Lewis acid sites could offer several
advantages over various heterogeneous catalytic applications, such as Lewis-acid-
catalyzed Meerwein–Ponndorf–Verley (MPV) reduction [1, 2], Baeyer–Villiger
(B–V) oxidation [3, 4], Friedel–Crafts reaction , etc.
The MPV reduction of carbonyl compounds using secondary alcohols as hydro-
gen donor is a highly selective reaction (Scheme 1) that is widely used in the syn-
thesis of natural materials and drugs . Usually, the process is conducted in the
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