Our investigations were focused on the transhydrogenation of carbonyl groups using Co(II)-salen complexes entrapped in zeolites. The Co-salen 1 complex was occluded in the zeolite as a "ship-in-the-bottle" (SIB) catalyst, as could be demonstrated by means of DRIFT-IR spectra, DTG, nitrogen adsorption isothermes and soxhlet extraction. The results of the test reactions show that an immobilization of the Co-salen 1 complex in the zeolite as a "SIB" complex results in an enantiomeric excess as high as in the homogeneous case. The Co-salen 1 USY SIB catalyst shows its best ee-value at higher temperature (25 degrees C) than the homogeneous one (-10 degrees C). The reason could be the steric constraints of the Co-salen complex in the zeolite framework.