P. Piaggio et al., Catalytic asymmetric epoxidation of stilbene using a chiral salen complex immobilized in Mn-exchanged Al-MCM-41, J CHEM S P2, (1), 2000, pp. 143-148
Citations number
35
Categorie Soggetti
Physical Chemistry/Chemical Physics
Journal title
JOURNAL OF THE CHEMICAL SOCIETY-PERKIN TRANSACTIONS 2
Manganese-exchanged Al-MCM-41 modified by the chiral salen ligand [(R,R)-(-
)-N,N'-bis(3,5-di-tert-butylsalicylidene)cyclohexane-1,2-diamine] can be us
ed 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 f
or the oxidation of (Z)-stilbene to the (E)-epoxide using homogeneous (77.5
% ee) or heterogeneous (70% ee) catalysts. The effect of temperature, solve
nts and donor ligands on the yield and enantioselection are discussed.