Jacobsen’s complexes are famous for their capability in the epoxidation of unfunctionalized olefins with high enantioselectivities. However, the applicability of this catalytic system has been severely limited by several practical problems such as deactivation and separation after reaction. Grafting of Jacobsen-type complexes on solid supports are attractive to overcome these problems but led to a decrease in selectivity. Herein a combined theoretical and experimental approach is used to unravel the detailed factors governing the selectivity. Advanced molecular modeling techniques on the full catalytic systems are used to find the mechanism behind the selectivity. The importance of the C3 and C5 substituents was determined by analyzing transition states for various approaches during the oxygen transfer. An analysis of the asymmetric complex, that is often used in a grafting approach, has shown an inherent tendency to a decreased selectivity due to the lack of specific bulky groups. Experimentally an immobilized Jacobsen catalyst on a metal organic framework (MIL101) was synthesized which confirms the computational tendencies but the decrease in selectivity is limited, indicating that the MIL-101(Cr) is a suitable carrier for this complex.