Manganese complex catalyst for valencene oxidation: The first use of metalloporphyrins for the selective production of nootkatone

•Oxidation of valencene by O2 catalyzed by manganese porphyrins in a green solvent.•A new methodology was developed for valencene oxidation by O2 with Mn-porphyrins.•Yields of nootkatone and valencene epoxide up to 48% in 4 h.•Imidazole improves product yield in the valencene oxidation by O2.