Reactivity and mechanisms of metalloporphyrin-catalyzed oxidations

Abstract

<jats:p> Effective systems for the catalytic oxygenation of hydrocarbons have been developed based on metalloporphyrins containing iron, manganese and ruthenium. These metalloporphyrin catalysts were inspired by studies of the mechanism of the heme oxygenase cytochrome P450 and related enzymes. Oxometalloporphyrins, which have now been spectroscopically characterized, have very high reactivity as oxygen transfer agents. A combination of experimental and computational methods has begun to provide an understanding of the structure and reactivity of these oxometalloporphyrin complexes and the mechanisms of oxygen transfer reactions they catalyze. </jats:p>

Understanding the Reactivity of Mn-Oxo Porphyrins for Substrate Hydroxylation: Theoretical Predictions and Experimental Evidence Reconciled

“…Generally, for metalloporphyrin-catalyzed oxidation of substrates, the so-called Groves rebound mechanism is widely accepted. 24 , 25 , 26 A recent investigation on the Mn(V)OP + system performed by Pierloot et al 28 with correlated ab initio methods (CASPT2, RASPT2) provided an accurate description for the spin state energetics, the oxyl character of the complex and for their role in oxygen transfer reactions. Analogously, the Mn(V)OP + singlet ground state was proven to lack the oxyl character and to be kinetically inert.…”

Understanding the Reactivity of Mn-Oxo Porphyrins for Substrate Hydroxylation: Theoretical Predictions and Experimental Evidence Reconciled

“…Generally, for metalloporphyrin-catalyzed oxidation of substrates, the so-called Groves rebound mechanism is widely accepted. 24 , 25 , 26 A recent investigation on the Mn(V)OP + system performed by Pierloot et al 28 with correlated ab initio methods (CASPT2, RASPT2) provided an accurate description for the spin state energetics, the oxyl character of the complex and for their role in oxygen transfer reactions. Analogously, the Mn(V)OP + singlet ground state was proven to lack the oxyl character and to be kinetically inert.…”

Control of the axial coordination of a surface-confined manganese(III) porphyrin complex

“…13 Complexes of manganese porphyrins are known to catalyse the halogenation of aliphatic substrates, 14 and have shown high reactivity toward alkene epoxidation. 15 Recently, STM imaging of individual manganese porphyrin catalysts at a liquid-solid interface was reported, wherein, the formation of an oxomanganese porphyrin intermediate was visualized prior to the chemical transformation of alkenes into epoxides. 16 Concerning the Cl-MnTPP molecule, the metal-bound Cl ligand maintains the central manganese ion in the stable +3 oxidation state.…”

“…The rich coordination chemistry of manganese porphyrins makes them ideal candidates for a wide range of chemically responsive applications [13]. Complexes of manganese porphyrins are known to catalyse the halogenation of aliphatic substrates [14], and have shown high reactivity towards alkene epoxidation [15]. Recently, STM imaging of individual manganese porphyrin catalysts at a liquid-solid interface was reported, wherein, the formation of an oxomanganese porphyrin intermediate was visualized prior to the chemical transformation of alkenes into epoxides [16].…”

Coupling and uncoupling mechanisms in the methoxythreonine mutant of cytochrome P450cam: a quantum mechanical/molecular mechanical study

“…These processes are of vital importance in biosystems, where the enzyme participates in detoxification and in biosyntheses [1]. Since the activation of inert C–H bonds is one of the holy grails of chemistry [9], the facility to carry out this process makes the P450 enzyme superfamily a model for creative mimetic chemistry [10] designed to generate novel catalysts that can perform C–H activation.…”

Understanding the Reactivity of Mn-Oxo Porphyrins for Substrate Hydroxylation: Theoretical Predictions and Experimental Evidence Reconciled

“…Generally, for metalloporphyrin-catalyzed oxidation of substrates, the so-called Groves rebound mechanism is widely accepted. 24 , 25 , 26 A recent investigation on the Mn(V)OP + system performed by Pierloot et al 28 with correlated ab initio methods (CASPT2, RASPT2) provided an accurate description for the spin state energetics, the oxyl character of the complex and for their role in oxygen transfer reactions. Analogously, the Mn(V)OP + singlet ground state was proven to lack the oxyl character and to be kinetically inert.…”

Control of the axial coordination of a surface-confined manganese(III) porphyrin complex

“…13 Complexes of manganese porphyrins are known to catalyse the halogenation of aliphatic substrates, 14 and have shown high reactivity toward alkene epoxidation. 15 Recently, STM imaging of individual manganese porphyrin catalysts at a liquid-solid interface was reported, wherein, the formation of an oxomanganese porphyrin intermediate was visualized prior to the chemical transformation of alkenes into epoxides. 16 Concerning the Cl-MnTPP molecule, the metal-bound Cl ligand maintains the central manganese ion in the stable +3 oxidation state.…”

“…The rich coordination chemistry of manganese porphyrins makes them ideal candidates for a wide range of chemically responsive applications [13]. Complexes of manganese porphyrins are known to catalyse the halogenation of aliphatic substrates [14], and have shown high reactivity towards alkene epoxidation [15]. Recently, STM imaging of individual manganese porphyrin catalysts at a liquid-solid interface was reported, wherein, the formation of an oxomanganese porphyrin intermediate was visualized prior to the chemical transformation of alkenes into epoxides [16].…”

Coupling and uncoupling mechanisms in the methoxythreonine mutant of cytochrome P450cam: a quantum mechanical/molecular mechanical study

“…These processes are of vital importance in biosystems, where the enzyme participates in detoxification and in biosyntheses [1]. Since the activation of inert C–H bonds is one of the holy grails of chemistry [9], the facility to carry out this process makes the P450 enzyme superfamily a model for creative mimetic chemistry [10] designed to generate novel catalysts that can perform C–H activation.…”

Understanding the Reactivity of Mn-Oxo Porphyrins for Substrate Hydroxylation: Theoretical Predictions and Experimental Evidence Reconciled

“…Generally, for metalloporphyrin-catalyzed oxidation of substrates, the so-called Groves rebound mechanism is widely accepted. 24 , 25 , 26 A recent investigation on the Mn(V)OP + system performed by Pierloot et al 28 with correlated ab initio methods (CASPT2, RASPT2) provided an accurate description for the spin state energetics, the oxyl character of the complex and for their role in oxygen transfer reactions. Analogously, the Mn(V)OP + singlet ground state was proven to lack the oxyl character and to be kinetically inert.…”

Control of the axial coordination of a surface-confined manganese(III) porphyrin complex

“…13 Complexes of manganese porphyrins are known to catalyse the halogenation of aliphatic substrates, 14 and have shown high reactivity toward alkene epoxidation. 15 Recently, STM imaging of individual manganese porphyrin catalysts at a liquid-solid interface was reported, wherein, the formation of an oxomanganese porphyrin intermediate was visualized prior to the chemical transformation of alkenes into epoxides. 16 Concerning the Cl-MnTPP molecule, the metal-bound Cl ligand maintains the central manganese ion in the stable +3 oxidation state.…”

“…The rich coordination chemistry of manganese porphyrins makes them ideal candidates for a wide range of chemically responsive applications [13]. Complexes of manganese porphyrins are known to catalyse the halogenation of aliphatic substrates [14], and have shown high reactivity towards alkene epoxidation [15]. Recently, STM imaging of individual manganese porphyrin catalysts at a liquid-solid interface was reported, wherein, the formation of an oxomanganese porphyrin intermediate was visualized prior to the chemical transformation of alkenes into epoxides [16].…”

Coupling and uncoupling mechanisms in the methoxythreonine mutant of cytochrome P450cam: a quantum mechanical/molecular mechanical study

“…These processes are of vital importance in biosystems, where the enzyme participates in detoxification and in biosyntheses [1]. Since the activation of inert C–H bonds is one of the holy grails of chemistry [9], the facility to carry out this process makes the P450 enzyme superfamily a model for creative mimetic chemistry [10] designed to generate novel catalysts that can perform C–H activation.…”