Enhancement of catalytic performance in asymmetric transfer hydrogenation by microenvironment engineering of the nanocage
Cooperative Activation Effect in the Hydrolytic Kinetic Resolution of
Epoxides on [Co(salen)] Catalysts Confined in Nanocages
Reactions on Chiral Catalysts Entrapped within the Mesoporous Cage
The enantioselective cyanosilylation of aldehydes on a
chiral VO(Salen) complex encapsulated in SBA-16
4. Enhancement of Catalytic Performance in Asymmetric Transfer Hydrogenation by Microenvironment Engineering of the Nanocage
Shiyang Bai, Hengquan Yang, Peng Wang, Jinsuo Gao, Bo Li, Qihua Yang* and Can Li*
Chem. Commun.,2010, DOI: 10.1039/c0cc01401j. http://10.1039/c0cc01401j
Our group ever reported a general method for encapsulation of different transition metal complexes in the nanocage of SBA-16 for asymmetric catalysis. Since there are no covalent linkage and other strong interactions between the complex and the surface of the nanocage, the metal complexes encapsulated in the nanocage keep their catalytic properties as much as possible. Several high performance solid catalysts for asymmetric catalysis were successfully obtained by encapsulating transition metal complex such as Ru-TsDPEN, Co(Salen) and VO(Salen) in the nanocage of SBA-16.
Recently, different silylation reagents were used not only for reducing the pore entrance size but alos for tailoring the microenvironment of the resulted catalyst. Ru-TsDPEN confined in the nanocage with amphiphilic microenvironment can be ten times more active than that with hydrophobic one in the transfer hydrogenation of acetophenone in HCOONa-H2O, which is mainly due to the enhanced diffusion rates of reactants during the catalytic process.
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