ABSTRACT
The chiral sources employed include circularly polarized light, chiral sensitizers, chiral solvents, chiral substituents, chiral host-guest assemblies, and chiral crystalline environments. A more frequently employed source of chiral induction has been the use of a chiral substituent appended to a prochiral substrate as a chiral auxiliary. The strategy of employing a chirally modified zeolite as a reaction medium requires the inclusion of two different molecules, C and R within the interior spaces of an achiral zeolite. The ability to restrict the reduction reaction only to the cages containing both the reactant and the chiral inductor allowed us to examine, for the first time, chiral induction within a zeolite without any interference from reactions that occurred in cages lacking the chiral inductors. The dependence of chiral induction on the nature of cations suggests a crucial role of the cation present in the supercages in the chiral induction process.
