OLEFIN EPOXIDATION AND ALKANE HYDROXYLATION CATALYZED BY ROBUST SULFONATED MANGANESE AND IRON PORPHYRINS SUPPORTED ON CATIONIC ION-EXCHANGE RESINS

Robust sulfonated manganese and iron porphyrin supported on poly(vinylpyridinium) polymers have been used as catalysts in olefin epoxidation and alkane hydroxylation by iodosylbenzene. The metalloporphyrins are attached to protonated or methylated poly(vinylpyridine) polymers by the coordination of one pyridine unit, thus providing a proximal effect, and by additional interactions of the porphyrin sulfonato groups with the polymer pyridinium units. The best catalysts are the complexes containing halogen atoms at the pyrrole beta-positions. In all these oxygenation reactions manganese porphyrins are better catalysts than the corresponding iron complexes. From comparative studies with another ion-exchange resin without a potential axial ligand, it can be noted that the concept of the proximal effect is a key factor in metalloporphyrin-catalyzed reactions, not only for soluble complexes but also for supported catalysts.