Chiral catalysts confined in porous hosts: 2. Catalysis

The catalytic activities of the dirhodium carboxamide catalysts immobilised in the pores of MCM-41 and on the surface of Aerosil 200 (see preceeding paper) have been investigated. The catalysts were tested in the SiH insertion reaction of dimethylphenylsilane with methyl phenyl diazoacetate and in the cyclopropanation reaction of styrene with ethyl and tert-butyl diazoacetate. Significant improvements in enantioselectivity (SiH insertion) and in regioselectivity (cyclopropanation) were induced due to the spatial confinement by the carrier.