In the catalytic cycle of Cytochrome P450, the generation of [(porphyrin)^+•Fe^IV(O)] from [(porphyrin)Fe^III(OOH)] involves

Concept:​

• The cytochrome P450 monooxygenases (P450s) are thiolate heme proteins that can, often under physiological conditions, catalyze many oxidative transformations of a wide variety of molecules. This heme protein is known as the porphyrin ring.  
• Most CYPs require a protein partner to deliver one or more electrons to reduce the iron (and eventually molecular oxygen).

Explanation:

• The catalytic cycle cytochrome of P450-reductase (CPR) and cytochrome b5 is as follows:

• The binding of substrate R-H with Cytochrome P450 (CYPs) (1) causes a decrease in the redox potential, which allows the first electron transfer from cytochrome P450-reductase (CPR) (2).
• The reduction of Fe³⁺ to Fe²⁺ makes suitable O₂ binding (3), which now can accept a second electron from either CPR or cytochrome b₅ (cyt b₅) (4), to form a hydroperoxyl intermediate:

• The O₂⁻² complex reacts with surrounding protons to form the highly reactive oxyferryl intermediate(5) involves the heterolytic O-O cleavage of hydroperoxyl intermediate. The Fe-ligated O atom (6) is transferred to the substrate forming a hydroxylated form of the substrate (7).

Conclusion:

Hence, in the catalytic cycle of Cytochrome P450, the generation of [(porphyrin)+•FeIV(O)] from [(porphyrin)FeIII(OOH)] involves Heterolytic O-O cleavage of [(porphyrin)FeIII(OOH)].