A NOVEL CATALYTIC-SYSTEM FOR OXYGENATION WITH MOLECULAR-OXYGEN INDUCED BY TRANSITION-METAL COMPLEXES WITH A MULTIDENTATE N-HETEROCYCLIC PODAND LIGAND

An efficient system for the catalytic epoxidation reaction of olefins with molecular oxygen was achieved by the utilization of FeCl2 and the N-heterocyclic podand ligand, s{2-(4-imidazolyl)ethyl}-2,6-pyridinedi carboxamide (BIPA), without the need for a co-reductant. The pyridyl-s ubstituted N-heterocyclic podand ligand, -bis{2-(2-pyridyl)ethyl}-2,6- pyridinedicarboxamide (2-BPEPA) was useful in the Co(OAc)(2)-catalyzed selective oxygenation of phenols to the corresponding p- or o-quinone s with molecular oxygen. Efficiency of the oxygenation catalysts large ly depends on the coordination interaction with the heterocyclic moiet ies of the podand ligands.