NEW SCHIFF-BASES DERIVED FROM TRANS-PYRAZOLYLCYCLOHEXANOL - SYNTHESIS, COORDINATION CHEMISTRY AND STRUCTURAL FEATURES

Transformation of the OH function of trans-2-(pyrazol-1-yl)cyclohexan- 1-ol into an amino group was achieved by various methods with inversio n of the reaction centre and provided access to new polydentate Schiff bases bearing phenol, pyridine and furan donors. The co-ordination ch emistry of these bases was investigated for Pd-II, Re-I and Re-V. It w as shown by means of NMR spectroscopy that the special stereochemical situation of the 1,2-cis-configurated cyclohexane backbone allows a fl exible adaptation to different co-ordination conditions. On the other hand, the rigid-asymmetrically substituted cyclohexane ring is respons ible for an asymmetric arrangement of the donor fragments at the metal centre, which is required for applications of these compounds in enan tioselective catalysis.