Catalytic autoxidations using tris-diimine iron(II) coordination complexes

The hydrocarbon-soluble coordination complex [Fe(4,7-diphenyl-1,10-phenanthroline)3](SO3CF3)2 (1) is an active catalyst for the autoxidation of cumene and cyclohexane. The activity of 1 in the autoxidation of cumene at 60 °C is comparable to that of tetra(pentafluorophenyl)porphyrin iron(III) chloride (2), a halogenated iron porphyrin with high autoxidation activity. The kinetic data have been fit by a mechanism in which the iron catalyst is activated by reaction with peroxide and the resulting active complex acts as a peroxide decomposition catalyst producing chain-carrying radicals. The activity of 1 is also comparable to that of 2 in the autoxidation of cyclohexane at 135 °C. The utility of catalyst 1 is enhanced by its solubility in pure hydrocarbon substrates.

Graphical abstractThe hydrocarbon-soluble coordination complex [Fe(4,7-diphenyl-1,10-phenanthroline)3](SO3CF3)2 (1) is an active catalyst for the autoxidation of cumene and cyclohexane. The activity of 1 in the autoxidation of cumene at 60 °C is comparable to that of tetra(pentafluorophenyl)porphyrin iron(III) chloride (2), a halogenated iron porphyrin with high autoxidation activity. The kinetic data have been fit by a mechanism in which the iron catalyst is activated by reaction with peroxide and the resulting active complex acts as a peroxide decomposition catalyst producing chain-carrying radicals. The activity of 1 is also comparable to that of 2 in the autoxidation of cyclohexane at 135 °C. The utility of catalyst 1 is enhanced by its solubility in pure hydrocarbon substrates.Figure optionsDownload full-size imageDownload as PowerPoint slide