TY - JOUR
T1 - Catalytic asymmetric epoxidation of stilbene using a chiral salen complex immobilized in Mn-exchanged Al-MCM-41
AU - Piaggio, Paola
AU - Langham, Christopher
AU - McMorn, Paul
AU - Bethell, Donald
AU - Bulman Page, Philip C.
AU - Hancock, Frederick E.
AU - Sly, Chris
AU - Hutchings, Graham J.
PY - 2000
Y1 - 2000
N2 - Manganese-exchanged Al-MCM-41 modified by the chiral salen ligand [(R,R)-(-)-N,N'-bis(3,5-di-tert-butylsalicylidene)cyclohexane-1,2-diamin e] can be used as an enantioselective heterogeneous epoxidation catalyst using iodosyl benzene as oxygen donor. Epoxidation of (Z)- and (E)-stilbene is studied in detail and experiments are described that demonstrate that the reaction is wholly catalysed heterogeneously. Similar enantioselectivity is observed for the oxidation of (Z)-stilbene to the (E)-epoxide using homogeneous (77.5% ee) or heterogeneous (70% ee) catalysts. The effect of temperature, solvents and donor ligands on the yield and enantioselection are discussed.
AB - Manganese-exchanged Al-MCM-41 modified by the chiral salen ligand [(R,R)-(-)-N,N'-bis(3,5-di-tert-butylsalicylidene)cyclohexane-1,2-diamin e] can be used as an enantioselective heterogeneous epoxidation catalyst using iodosyl benzene as oxygen donor. Epoxidation of (Z)- and (E)-stilbene is studied in detail and experiments are described that demonstrate that the reaction is wholly catalysed heterogeneously. Similar enantioselectivity is observed for the oxidation of (Z)-stilbene to the (E)-epoxide using homogeneous (77.5% ee) or heterogeneous (70% ee) catalysts. The effect of temperature, solvents and donor ligands on the yield and enantioselection are discussed.
KW - DESIGN
KW - HYDROGENATION
KW - MCM-41
KW - ENANTIOSELECTIVE EPOXIDATION
KW - UNFUNCTIONALIZED OLEFINS
KW - OXIDATIONS
U2 - 10.1039/A904900B
DO - 10.1039/A904900B
M3 - Article
VL - 1
SP - 143
EP - 148
JO - Journal of the Chemical Society-Perkin Transactions 2
JF - Journal of the Chemical Society-Perkin Transactions 2
SN - 0300-9580
ER -