Chiral Metal Transition Complexes in Zeolites: Enantioselective Hydrogenation of Dehydrophenylalanine Derivatives

Rhodium and nickel complexes with N–based chiral ligands were introduced into a modified Y zeolite which contains supermicropores, and mesopores, and used as catalysts in the hydrogenation of N–acyldehydrophenylalanine derivatives. The zeolite shows a cooperative effect on the reaction rate and on enantioselectivity of the reaction, increasing the enantiomeric excess (ee%) up to 99%. It also allows to recycle the catalyst without loss of reactivity and selectivity. Thus, the metal transition complexes into zeolite represents a truly heterogeneous counterpart of the homogeneous organometallic catalysts.