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. (C) 2003 Elsevier Science (USA). All rights reserved.