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, N,N'-bis{2-(4-imidazolyl)ethyl}-2,6-pyridinedicarboxamide (BIPA), without the need for a co-reductant. The pyridyl-substituted N-heterocyclic podand ligand, N,N'-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-quinones with molecular oxygen. Efficiency of the oxygenation catalysts largely depends on the coordination interaction with the heterocyclic moieties of the podand ligands.